miwaves d6.5 final cleanfinal - cordis · 2017. 11. 20. · miwaves deliverable d6.5 dissemination...

Beyond 2020 Heterogeneous Wireless Network with

Millimeter-Wave Small-Cell Access and Backhauling Grant agreement n°619563

Deliverable D6.5 mmWave Access and Backhaul Link Tests and Presentation of

Final Demonstrator

Date of Delivery: 30 April 2017 (Contractual) 17 June 2017 (Actual)

Editor: TST

Participant(s): NOKIA, NID, TST, TUD, CEA

Work package: WP6 – mmW access and backhauling proof of concept for heterogeneous

wireless networks

Dissemination: Public (PU)

Version: 1.0

Number of pages: 105

Abstract: This deliverable reports the results of MiWaveS tasks 6.3 and 6.4. It corresponds to

Deliverables D6.3 (“Beamforming tests for a single user”), D6.4 (“Access link tests with multi-

user spatial separation”) and D6.5 (“System measurements and presentation of the final joint

demonstrator”). Backhaul and access link radio components developed in work packages 3 and

4 are integrated with the base band system implemented in work package 5 and applied in

propagation situations derived from use cases defined in the project. Also, beam steering

algorithms devised in work package 2 for the access link are tested in a single and multi-user

setup in static and mobile scenarios. Deliverable D6.5 concludes the demonstration activities

as part of MiWaveS by testing the functionality of the MiWaveS PoC system and highlighting

results achieved under practical propagation conditions in nine different demonstration

campaigns.

Keywords: mm-wave, demonstrator, experiments, measurements

MiWaveS Deliverable D6.5

Dissemination level: Confidential / 105

Executive Summary

Deliverable D6.5 represents the completion of the WP6 tasks T6.3 “Access link” and T6.4 “Final

integration of backhaul and access link” by reporting the results of nine different

demonstration campaigns conducted at three different locations.

Delays involved in the development and manufacturing of demonstrator components required

to re-schedule sequential demonstration activities, originally planned to be conducted

throughout 2016, to the end of the project. To capture the results obtained in parallel

efficiently, project management proposed to report the interim results planned for

deliverables D6.3 (“Beamforming tests for a single user “) and D6.4 (“Access link tests with

multi-user spatial separation”) as well as the final results, planned for D6.5 (“System

measurements and presentation of the final joint demonstrator”) as part of one

comprehensive document.

A total of nine different demonstration and test campaigns, outdoors and indoors, have been

prepared in early 2017. These campaigns illustrate the application of MiWaveS radio and

antenna components in urban outdoor long-hop street level backhaul scenarios, indoor

backhaul scenarios, and indoor access link scenarios. Beam steering algorithms are tested in

single and multi-user settings in static and mobile access link scenarios indoors. Finally, end-to-

end application demonstrations show the operation of actual applications, such as internet

access, over the MiWaveS mmWave link.

Disclaimer: This document reflects the contribution of the participants of the research project

MiWaveS. It is provided without any warranty as to its content and the use made of for any

particular purpose.

All rights reserved: This document is proprietary of the MiWaveS consortium members. No

copying or distributing, in any form or by any means, is allowed without the prior written

consent of the MiWaveS consortium.



Authors

TST Arturo Medela [email protected]

TUD Hsiao-Lan Chiang [email protected]

TUD Tobias Kadur [email protected]

NOKIA Jyri Putkonen [email protected]

NOKIA Zhou Du [email protected]

CEA Loïc Marnat [email protected]

CEA Cédric Dehos [email protected]

CEA Sylvie Mayrargue [email protected]

NID Eckhard Ohlmer [email protected]

NID Clemens Felber [email protected]

NID Markus Ullmann [email protected]

NID Daniel Swist [email protected]



Table of Contents

List of Figures ...................................................................................................................... 7

List of Tables ..................................................................................................................... 12

List of Acronyms and Abbreviations ................................................................................... 13

1. Introduction and Background ....................................................................................... 15

1.1 MiWaveS Work Package Structure .............................................................................. 15

1.2 Use Cases, KPIs and Work Package 6 Objectives ......................................................... 15

1.3 MiWaveS Testing Process ............................................................................................ 18

1.4 Demonstration Overview ............................................................................................. 19

1.5 Demonstration System Overview ................................................................................ 22

1.5.1 Introduction ....................................................................................................... 22

1.5.2 mmWave Node Hardware Architecture ............................................................ 22

1.5.3 Base Band Hardware System ............................................................................. 24

1.5.4 Numerology ....................................................................................................... 25

1.5.5 Physical Layer .................................................................................................... 27

1.5.6 Physical Layer Control and MAC Layer .............................................................. 28

1.5.7 Closed Loop Operation ...................................................................................... 28

1.5.8 Demonstrator Graphical User Interfaces .......................................................... 29

1.5.8.1 Hardware Centric Demonstrations ......................................................... 30

1.5.8.2 Algorithm Centric Demonstrations ......................................................... 30

1.5.9 Summary of Main System Features ................................................................... 32

2. Access Link Demonstrations ......................................................................................... 34

2.1 Single-User Hardware-Centric Demonstration in Dresden.......................................... 34

2.1.1 MiWaveS V-Band Access Link Setup .................................................................. 34

2.1.2 LOS Transmission Range Test ............................................................................ 36

2.1.2.1 Introduction ............................................................................................ 36

2.1.2.2 Test conditions ........................................................................................ 36

2.1.2.3 Measurement results .............................................................................. 38

2.1.3 NLOS Transmission Test .................................................................................... 42

2.1.3.1 Introduction ............................................................................................ 42

2.1.3.2 Test conditions ........................................................................................ 42

2.1.3.3 Measurement results .............................................................................. 43

2.1.4 Summary ............................................................................................................ 44

2.2 Multi-User Hardware Centric Access Link Demonstration in Grenoble ...................... 44

2.2.1 Hardware Setup ................................................................................................. 44

2.2.2 Multi-User LOS Test ........................................................................................... 45

2.2.3 Summary ............................................................................................................ 46

2.3 Single-User Algorithm-Centric Demonstration in Dresden ......................................... 46

2.3.1 Algorithm Centric V-Band Access Link Demonstration Setup ........................... 47

2.3.2 Automatic Beam Alignment Test ....................................................................... 49

2.3.2.1 Introduction ............................................................................................ 49

2.3.2.2 Test conditions ........................................................................................ 49

2.3.2.3 Test Results ............................................................................................. 50



2.3.3 Automatic Beam Tracking Test .......................................................................... 53

2.3.3.1 Introduction ............................................................................................ 53

2.3.3.2 Test conditions ........................................................................................ 53

2.3.3.3 Test results .............................................................................................. 54

2.3.4 Summary ............................................................................................................ 56

2.4 Multi-User Algorithm-Centric Access Demonstration in Dresden ............................... 56

2.4.1 Connecting to Two Static User Devices ............................................................. 57

2.4.1.1 Introduction ............................................................................................ 57

2.4.1.2 Test conditions ........................................................................................ 57

2.4.1.3 Test Results ............................................................................................. 58

2.4.2 Maintaining the Connection to One Static and One Mobile User Device ......... 59

2.4.2.1 Introduction ............................................................................................ 59

2.4.2.2 Test conditions ........................................................................................ 59

2.4.2.3 Test Results ............................................................................................. 60

2.4.3 Two Randomly Moving User Devices ................................................................ 63

2.4.3.1 Introduction ............................................................................................ 63

2.4.3.2 Test Conditions ........................................................................................ 63

2.4.3.3 Test Results ............................................................................................. 64

2.4.4 Summary ............................................................................................................ 66

3. Backhaul Link Demonstrations ..................................................................................... 67

3.1 Hardware-Centric Backhaul Outdoor Measurements in Espoo .................................. 67

3.1.1 Outdoor Long Hop Throughput Test ................................................................. 68

3.1.2 Outdoor Easiness of Installation ........................................................................ 72

3.1.3 Outdoor Blockage: Pedestrians Walking Along the LoS Path ............................ 73

3.1.4 Outdoor Blockage: Moving Cars Passing Across the LoS Path .......................... 74

3.1.5 Indoor Coverage from Outdoors ....................................................................... 76

3.1.6 Outdoor Reflections .......................................................................................... 78

3.1.7 Conclusions ........................................................................................................ 79

3.2 Hardware-Centric Backhaul Indoor Measurements in Espoo ..................................... 79

3.2.1 Indoor Corridor .................................................................................................. 80

3.2.2 Indoor Corridor Reflections ............................................................................... 81

3.2.3 Indoor Corridor Blockage .................................................................................. 82

3.2.4 Conclusions ........................................................................................................ 84

3.3 Hardware-Centric Backhaul Demonstrations Conducted in Grenoble ........................ 84

3.3.1 Hardware Setup ................................................................................................. 85

3.3.2 Backhaul Tests ................................................................................................... 86

3.3.2.1 Standalone Transmitter Performance: .................................................... 86

3.3.2.2 Backhaul Transmission Performance ...................................................... 87

3.3.3 Summary ............................................................................................................ 88

4. End-to-End Application Demonstrations in Dresden ..................................................... 89

4.1 Hardware-Centric E-2-E Backhaul and Access Application Demonstration ................ 89

4.2 Algorithm-Centric E-2-E Access Application Demonstration ....................................... 91

4.3 Summary ...................................................................................................................... 93

5. Summary and Conclusions ........................................................................................... 94



6. References .................................................................................................................. 96

Appendix A. Details About Different mmWave Radio Setups .......................................... 98

Appendix B. Hardware-centric Single-User V-Band Access – Detailed Throughput results.

103

Appendix C. Algorithm-centric Single User V-band Access: Peak Throughput Test ......... 105



List of Figures

Figure 1—1: Structure and Work Packages of the MiWaveS project. ........................................ 15

Figure 1—2: System engineering V-model applied to MiWaveS project. ................................... 18

Figure 1—3: Testing/verification process documentation (blue) and activities (red) break-up. 19

Figure 1—4: Software layers included in hardware centric and algorithm centric

demonstrations. .......................................................................................................................... 19

Figure 1—5: mmWave node architecture showing all configuration options. ........................... 22

Figure 1—6: E-Band backhaul node (left), V-Band Access node (middle), V-band user device

node (right). ................................................................................................................................ 23

Figure 1—7: Base band hardware overview ............................................................................... 24

Figure 1—8: Radio frame structure. ............................................................................................ 25

Figure 1—9: Structuring the physical layer processing into inner and outer transceiver. ......... 27

Figure 1—10: Mapping of Algorithms to base band hardware modules .................................... 27

Figure 1—11: Physical layer driver and control layer, and MAC software architecture. ............ 28

Figure 1—12: Bi-directional closed-loop mmWave access link transmission. ............................ 29

Figure 1—13: Main front panel of AP and UD for hardware centric demonstrations ................ 30

Figure 1—14: Main AP front panel for algorithm centric demonstrations. ................................ 30

Figure 1—15: Graphical representation of the current target beam settings at AP and UD for

two users. .................................................................................................................................... 31

Figure 1—16: System Traces collected at the AP. ....................................................................... 31

Figure 1—17: Main UD front panel for algorithm centric demonstrations. ............................... 32

Figure 2—1 V-band access point and user device setup............................................................. 35

Figure 2—2. V-band access link setup ......................................................................................... 35

Figure 2—3: Test environment in a meeting room with AP and UD spaced up to 10 meters. ... 37

Figure 2—4: AP and UD prototypes set up in a meeting room. .................................................. 37

Figure 2—5: Test environment in a corridor with AP and UD spaced up to 31.4 meters........... 38

Figure 2—6: AP and UD prototypes set up in a corridor. ............................................................ 38

Figure 2—7. Base band receive power across different transmit beams. .................................. 39

Figure 2—8. Code word error rate across different beams at constant distance. ..................... 39

Figure 2—9. Code word error rate versus distance for different transmission rates. ................ 40

Figure 2—10. Throughput versus distance for different transmission rates. ............................. 40

Figure 2—11. Throughput using different beams at different distances.................................... 41

Figure 2—12: The received constellation diagram with the distance of 1, 4 and 8 meters. ...... 42



Figure 2—13: The setup to test the reflection from wall A with and without metal on the wall.

..................................................................................................................................................... 43

Figure 2—14: Access point beam switching between the User Device (top) and a spectrum

analyser with a horn antenna (down). ........................................................................................ 46

Figure 2—15: The setup of one node. ......................................................................................... 47

Figure 2—16: Flow diagram of gradient beam alignment algorithm .......................................... 48

Figure 2—17: The setup of algorithm-centric LoS SU measurement.......................................... 50

Figure 2—18: Difference of the received power between the exhaustive and gradient-based

algorithms. .................................................................................................................................. 51

Figure 2—19: Measured received power versus distance. ......................................................... 51

Figure 2—20: Geometry of the test with the rotated angle of −20 ∘. ....................................... 52

Figure 2—21: Normalized evaluation of searched beam combination versus distance. ........... 52

Figure 2—22: The setup of algorithm-centric LoS mobile SU measurement. ............................ 53

Figure 2—23: The selected beam indices by the AP over time................................................... 54

Figure 2—24: The selected beam indices by the UD over time. ................................................. 55

Figure 2—25: The achievable UD Rx throughput. ....................................................................... 55

Figure 2—26: Geometry of the NLoS path. ................................................................................. 56

Figure 2—27. Beam steering code book used during the multi-user measurements. An angular

range of +/-35° azimuth is covered by 7 beams with a half power beam width of about 23°. .. 57

Figure 2—28: The 1st setup of multi-user measurement. ........................................................... 58

Figure 2—29: The 2nd setup of multi-user measurement ........................................................... 58

Figure 2—30: The setup of the measurement. ........................................................................... 60

Figure 2—31: Receive power at the static UD0 and the mobile UD1. Left w/o AGC, right:

w/AGC. White/green: receive power at the AP (uplink), red/blue: receive power at the UDs

(downlink). .................................................................................................................................. 61

Figure 2—32: UL sum throughput using 42% of the resources for data transmission. Left w/o

AGC, right: w/AGC. ...................................................................................................................... 61

Figure 2—33: Transmit and receive beam settings at the access point. Left: static UD0, right:

mobile UD1. ................................................................................................................................. 62

Figure 2—34: Receive power at the static UD0 and the mobile UD1. Left w/o AGC, right:

w/AGC. ........................................................................................................................................ 62

Figure 2—35: Transmit and receive beam settings at the access point. Left: static UD, right:

mobile UD. ................................................................................................................................... 63

Figure 2—36: Test setup: two users moving at random ............................................................. 64

Figure 2—37: Two randomly moving user devices. View from the access point perspective. ... 64

Figure 2—38: Test run 1: connection state of both user devices and AGC settings of UD 1 ...... 65



Figure 2—39: Test run 2: connection state of both user devices and AGC settings of UD 1 ...... 65

Figure 2—40: Test run 1: selected transmit beams at AP and UD over time for UD0 and UD1. 66

Figure 3—1: Location of measurement hops in Nokia campus in Espoo, Finland. ..................... 68

Figure 3—2: E-Band non-obstructed LOS long hop measurement path. ................................... 69

Figure 3—3: Typical outdoor measurement setup. .................................................................... 69

Figure 3—4: Typical TX outdoor measurement location. ........................................................... 70

Figure 3—5: Comparison of the throughput measurement results with different MCS and hop

length. Solid line with circle marker “o” represent the outdoor measurements, and the dotted

line with start marker “*” represent the lab measurement with emulated hop length. ........... 71

Figure 3—6 Comparison of the time domain SNR measurement results with different hop

length. ......................................................................................................................................... 71

Figure 3—7: QPSK constellation diagram at the Rx for hop distances at 10 m, 20 m, 50 m, 103

m, 200 m and 400 m. .................................................................................................................. 72

Figure 3—8: A viewfinder. ........................................................................................................... 73

Figure 3—9: Indicative top and side view showing the measurement campaign. Fresnel

ellipsoid included (not to scale) .................................................................................................. 73

Figure 3—10: Measured trace of the Rx power for different Tx/Rx heights. ............................. 74

Figure 3—11: Histogram of the measured Rx power. ................................................................. 74

Figure 3—12: Car blocking and outdoor-to-indoor measurement location. .............................. 75

Figure 3—13: Indicative description of the moving car interference measurement setup (not to

scale). .......................................................................................................................................... 75

Figure 3—14: Received Rx power for different events a) , b) and c). (1), (2), (3), (4) in Fig c)

correspond respectively to the scenarios described above in the text. ..................................... 76

Figure 3—15: Measuring different window glasses in indoor-to-outdoor setup. ...................... 77

Figure 3—16: Partly obstructed LOS scenarios (snow is now shown), red x denotes the evenly

distributed lamp post. ................................................................................................................. 78

Figure 3—17: Measured reflective and partly obstructive outdoor environments. .................. 78

Figure 3—18: Channel power delay profile for various locations compared to base band and

wave-guide connected transmitter and receiver. ....................................................................... 79

Figure 3—19: Narrow indoor corridor. ....................................................................................... 81

Figure 3—20: Indoor corridor wall reflections in V-band (a) and E-band (b). ............................ 81

Figure 3—21: Pictures from indoor corridor blockage measurements. a) 70 GHz with a large

absorber, b) human body blockage at 60 GHz. ........................................................................... 82

Figure 3—22: Indoor human blockage profiles (dB full-scale) versus time in a narrow corridor.

..................................................................................................................................................... 83



Figure 3—23: Indoor human blockage profiles (dB full-scale) versus time in a wide indoor

space. .......................................................................................................................................... 83

Figure 3—24: Indoor human blockage profiles (dB full-scale) versus time in a wide indoor

space, two persons side by side. ................................................................................................. 84

Figure 3—25: V band backhaul node with the mechanical fixing plate (left) and the discrete

lens antenna (right). .................................................................................................................... 85

Figure 3—26: V band backhaul node with the mechanical fixing plate (left) and the dielectric

lens antenna (right). .................................................................................................................... 85

Figure 3—27: Characterization of standalone transmitter. Performance measured at horn

antenna : received signal constellation and spectrum for 16QAM modulation. ........................ 86

Figure 3—28: Characterization of standalone transmitter. Performance measured at horn

antenna : received signal constellation and spectrum for 64QAM modulation. ........................ 87

Figure 3—29: V band backhaul demonstration at CEA premises. .............................................. 87

Figure 4—1: Functionality added to the hardware centric software implementation to enable

uni-directional UDP traffic. ......................................................................................................... 89

Figure 4—2: E-2-E demonstration setup for streaming a video over two mmWave hops. ........ 90

Figure 4—3: Functionality added to the algorithm-centric software implementation to enable

bi-directional data connectivity. ................................................................................................. 91

Figure 4—4: E-2-E demonstration setup for providing internet connectivity over the V-Band

mmWave access link. .................................................................................................................. 92

Figure 4—5: Laboratory setup used to test the algorithm-centric E-2-E application

demonstration. ............................................................................................................................ 92

Figure 4—6: Left: access point user interface showing beam settings and scheduling

information. Right: MiWaveS project website accessed at the user device over the mmWave

link and Wireshark-based inspection of the connection. ........................................................... 93

Figure 4—7. Left: OpenVPN server status monitoring and Wireshark-based inspection of the

connection, running on the Linux PC connected to the access point. Right: OpenVPN status

monitoring on the Windows PC connected to the user device. ................................................. 93

Figure A—1: User Device, antenna and transceiver ................................................................... 98

Figure A—2: The assembled V band access point front-end ...................................................... 98

Figure A—3: Setup for using the SiBeam Phased Array Antenna. ............................................ 100

Figure A—4: Simplified transceiver block diagram explaining the beam steering architecture.

................................................................................................................................................... 101

Figure A—5: E-band backhaul radio setup in laboratory. ......................................................... 102

Figure A—6: Block diagram and frequency scheme of E-band BH radio system. ..................... 102

Figure A—7: E-band backhaul radio unit used in measurements: a) back-view, b) side-view.

Instead of fixed-beam horn antenna a steerable beam ........................................................... 102

Figure B—1: The measured throughput with respect to distance. ........................................... 104



Figure C—1. Peak throughput test using the algorithm-centric V-band access link radios. ..... 105



List of Tables

Table 1-1. MiWaveS Use Cases ................................................................................................... 16

Table 1-2. Use Case specific transmission distances. .................................................................. 16

Table 1-3. Summary of KPIs considered for the demonstrations and their presence in MiWaveS

use cases. .................................................................................................................................... 17

Table 1-4. Overview over demonstrations and corresponding radio hardware. ........................ 20

Table 1-5. System numerology. ................................................................................................... 26

Table 1-6. Modulation coding schemes and respective slot payload lengths. SNR values are

obtained from floating point simulations in an AWGN channel. ................................................ 26

Table 2-1: Required hardware for hardware-centric demo. ....................................................... 36

Table 2-2: Required laboratory equipment for hardware-centric demo. ................................... 36

Table 2-3: Measurement results. ................................................................................................ 44

Table 2-4: Required hardware for hardware-centric demo. ....................................................... 45

Table 2-5: Required laboratory equipment for hardware-centric demo. ................................... 45

Table 2-6: Required hardware for algorithm-centric demo. ....................................................... 49

Table 2-7: Required laboratory equipment for algorithm-centric demo. ................................... 49

Table 2-8: Required hardware for the algorithm-centric multi-user demonstration. ................ 56

Table 2-9: Required laboratory equipment for the algorithm-centric multi-user demonstration .

..................................................................................................................................................... 57

Table 2-10. Results for the static multi user connection test. .................................................... 59

Table 3-1: Required hardware for Espoo backhaul outdoor measurements. ............................ 68

Table 3-2: Required laboratory equipment for Espoo backhaul outdoor measurements. ........ 68

Table 3-3: Beam alignment accuracy measurements. ................................................................ 72

Table 3-4: Glass penetration losses............................................................................................. 78

Table 3-5: Required hardware for Espoo backhaul indoor measurements. ............................... 79

Table 3-6: Required laboratory equipment for Espoo backhaul indoor measurements. ........... 80

Table 3-7. Signal strengths at different AP-UE beam pair combinations with 60 GHz access

demonstrator hardware. ............................................................................................................. 80

Table 3-8. Measured wall reflection signal strengths at V-band and E-band ............................. 82

Table 3-9: Required hardware for hardware-centric demo ........................................................ 86

Table 3-10: Required laboratory equipment for hardware-centric demo .................................. 86

Table A-1: Performance figures of access point transmitter. ..................................................... 99



List of Acronyms and Abbreviations

Term Description

ADC Analog to Digital Converter

AFE Analog Front-End

AGC Adaptive Gain Control

AP Access Point

ATI Asynchronous Time Interleaving

BH Backhaul

BPSK Binary Phase-Shift Keying

DAC Digital to Analog Converter

dBFS Decibels Relative to Full Scale

DL DownLink

EC European Commission

EIRP Equivalent Isotropically Radiated Power

EMF Electro Magnetic Field

ES Exhaustive Search

EVM Error Vector Magnitude

FP7 Seventh Framework Program

FPGA Field-Programmable Gate Array

FST Fast Session Transfer

ICT Information and Communication Technologies

IF intermediate Frequency

LO Local Oscillator

LoS Light-of-Sight

MAC Media Access Control

MBH Mobile Backhaul

MIMO Multiple-Input and Multiple-Output

NLoS Non-Light-of-Sight

NRT Non Real Time

OTA Over The Air

PCB Printed circuit board

PDP Power Delay Profile



PLL Phase Locked Loop

QAM Quadrature amplitude modulation

QoS Quality of Service

QPSK Quadrature Phase-Shift Keying

RF Radio Frequency

RLC Radio Link Control

RSL Received Signal Level

RT Real Time

RX Receiver

SDU Service Data Unit

SINR Signal to Interference plus Noise Ratio

SNR Signal to Noise Ratio

TDD Time Division Duplex

TDM Time-Division Multiplexing

TX Transmitter

UD User device

UDP User Datagram Protocol

UL UpLink

WP Work Package



1. Introduction and Background

Deliverable D6.5 concludes the practical demonstration part of MiWaveS after more than

three years of work. Many scientific and engineering challenges had to be solved jointly in

order to shape the best possible version of the demonstrators initially devised.

This report summarizes the different demonstration and test outcomes and the

conclusions derived from them.

Chapter 1 provides background information about MiWaveS, use cases and KPIs as well as

the demonstration system. The remaining chapters present the different demonstrations.

1.1 MiWaveS Work Package Structure

The MiWaveS project is structured in several work-packages (WPs) covering different

aspects of mmW system definition, study of novel techniques and development of related

algorithms, as well as development of key hardware modules and prototypes, testing these

prototypes, and disseminating the results. This WP distribution is depicted in Figure 1—1 below.

Figure 1—1: Structure and Work Packages of the MiWaveS project.

MiWaveS WP 6 (WP6: mmW access and backhauling proof of concept for heterogeneous

wireless networks) addresses the demonstration of some of the use cases defined in WP1

using the transmission system prototypes designed and built in WP5 from the different

enabling technologies developed in WP2, WP3 and WP4 in the form of components or

algorithms. It will serve as a proof of concept of the anticipated improvements achieved by

using smart mmW radios in small cells and its integrations in 4G/5G mobile networks for

providing fast broad-band mobile access and backhaul.

1.2 Use Cases, KPIs and Work Package 6 Objectives

The work in MiWaveS is guided by five mmWave use cases. These have been presented in

[16] and are shown in Table 1-1 for reference.



Table 1-1. MiWaveS Use Cases

Rationale Assumptions KPIs

1. Urban Street-Level Outdoor Mobile Access and Backhaul System

City centers with a high density of

users over a large area requiring a

continuous coverage by a large

number of small cells.

High density of APs. Mesh topology.

Continuous coverage. Uniform capacity.

Outdoor environment. Stationary or low

mobility users.

End user capacity

Power/Energy

efficiency/consumption

2. Massive public events and gatherings

Massive crowds gathered for some

periods of time in small areas, e.g. for

cultural or sport events.

Reconfigurable backhauling. Non-permanent

small cells, moving cells in some cases. Low

mobility.

System Coverage

System Throughput/Capacity

Reliability (service/backhaul)

Power/Energy


3. Indoor wireless networking and coverage from outdoor

Evolution of the domestic network

toward an increase of transmission

capacity and versatility to connect to

the network.

Indoor and outdoor environments. Urban

industrial and semi-rural zones. Low mobility.

End user capacity

System throughput and capacity

Ease of installation and

configuration

4. Rural detached small-cell zones and villages

Rural or remote areas have no

conventional wired backhaul and

require high-capacity wireless

backhaul and multiple local APs.

mmW multi-hop backhaul. Remote mobile

broadband and mmW relay and end points. Rural

and sub-urban environment. Low mobility.

Backhaul range

Reliability (service/backhaul)

Power/Energy


5. Hotspot in shopping malls

Ad-hoc deployment of small cells is an

efficient solution to cope with the high

data rate traffic services in commercial

centers.

Small cell deployment. Mesh backhaul. Dense

deployment. Indoor environment. Low and high

mobility depending on traffic pattern.

Power/Energy


Spectral Efficiency

System Throughput/Capacity

The heterogeneous network architecture which has been devised to address these use

cases from various angles within the MiWaveS project, has been presented in deliverable D2.4

[19].

An analysis of these use cases, presented in deliverables in WP 1 (deliverable D1.1.1 [2])

and WP 6 (deliverable D6.1, [7]) resulted in the target transmission distances summarized in

Table 1-2.

Table 1-2. Use Case specific transmission distances.

BH

channel

BH/ AP

antenna

Link distances [meters] Capacity [Gbit/s]

AP BH AP UL/DL BH

1. Urban street-

canyon

O-LOS,

LOS

Small 25 – 50 50 – 200 2 / 5 5…10

2. Massive events O-LOS,

LOS

Large,

small

25 – 100 50 – 400 2 / 2 3…10

3. Indoor from

outdoors

Non-LOS Small,

large

10 – 20 20 – 100 (2 / 5) 5…10

4. Rural zones LOS,

O-LOS

Large 25 – 100 100 – 2000 2 / 5 2…10

5. Hotspot malls Non-LOS

O-LOS

Small 20 – 50 50 – 100 1 / 2 2…5

The peak rates in table Table 1-2 have been shown to be achievable in theory from a link

budget perspective in deliverable D1.1.1 [2]. On the E band backhaul, a peak rate of 10.5

GBit/s has been shown to be achievable by employing 2 GHz of signal bandwidth and 128 QAM



modulation. On the V band backhaul, 7.92 GBit/s have been shown to be achievable by using

1.76 GHz bandwidth and 64 QAM modulation.

From the large set of overall KPIs pursued in all work packages in MiWaveS, a relevant

subset has been derived in deliverable D6.1 [7], in order to guide the demonstration work.

These KPIs and their mapping to use cases are shown in Table 1-3.

Table 1-3. Summary of KPIs considered for the demonstrations and their presence in MiWaveS use

cases.

KPIs UCs

End User Capacity 1,2,3

Reliability (access/BH) 2,3,4

Backhaul range 4

Efficiency of installation and in operation 1,4

Access Range 2,4,5

1) End User Capacity: For measuring the end user capacity there are several metrics used in

the literature. One simple capacity metric would be to calculate the Shannon capacity

based on a measured SINR. Another more practical value would be the measured block

error rate that is computed based on the CRC check of the decoded data packets. This

approach was adopted in MiWaveS. The data rate includes pilot overhead and any guard

symbols. Therefore, the latter represents the practical throughput achievable with the

proposed system design.

2) Reliability (access / backhaul): Several effects can influence the link AP-UE, degrade its

quality, and possibly stop the service. Possible causes are:

a) Beamforming: beam unable to track the user in specific directions or with excessive

velocity;

b) Blockage of the LOS link by an obstacle;

c) Interference generated by other APs (mentioned for completeness, not relevant for

the MiWaveS tests as a single access point is available)

In particular, the experiments focus on the impact of the first two aspects in terms of

reliability.

For the BH, the experiments focus on static and mobile objects in the proximity of the LOS

BH link, i.e., the O-LOS (obstructed LOS) link.

3) Backhaul Range: The distance between an AP and a BS or, in a multi-hop configuration,

between two mmW nodes, provides information about the number of small cells needed

to cover a defined area (relatively to BH). To obtain an estimation of this KPI,

measurements of throughput can be performed verifying the limits of the relationship

power transmitted/distance present in the link budget.

4) Efficiency of Installation: The benefit of a beamsteering antenna for a simplified and faster

backhaul installation procedure has been assessed for the E-band backhaul link.

5) Access Range: Similarly to the backhaul range, this KPI provides information about the

deployment of mmW small cells and their coverage area. Single-user and multi-user

connections can be performed measuring the end user capacity and limits about the

dependence of the distance from the power transmitted will be investigated.

In addition to investigating these KPIs in practice, each test presented in the following has

been divided into smaller sub tests in order to verify the correct functionality of the system.



Finally, the work in work package 6 also addresses two main objectives on work package level

• O6.1: Test and demonstration of the components developed in WP3 and WP4 and

prototype of WP5, and

• O6.2: Proof of concept of the algorithms designed in WP2.

1.3 MiWaveS Testing Process

The general system engineering V-model in Figure 1—2 can be applied to the MiWaveS 5G

mmW access and backhaul system and demonstrator development. The process started in

WP1 by drafting system requirements and use cases as well as some system and network

element specification. More detailed specifications were developed in WP2, where also

algorithms were drafted. WPs 3 and 4 developed specifications for radio components, modules

and antennas. After and during implementation phase different hardware and software

components and modules were tested by respective work packages against their

specifications. Modules were integrated into working mmW access or BH system by WP5 that

performed integration testing as well as some system and functional testing against respective

specifications. Final system verification and demonstration of full functionality in respect to

system requirements and use cases is done by WP6.

Figure 1—2: System engineering V-model applied to MiWaveS project.

The goal of MiWaveS system verification is to show that a relevant part of requirements

(key performance indicators, objectives, use cases) set in the beginning of the project can be

met with studied and implemented technology. Due to the huge complexity of the drafted

mmW access and backhaul system, a subset of the proposed network and its functionality can

be implemented during the MiWaveS project. Figure 1—3 shows the process how the testing

and verification is split into small entities (test cases) and hardware and software setups where

these cases are run. Each of these process phases produces some essential outcome to project

documentation and deliverables. The system verification subset is a large entity of the whole

(MiWaveS) system to be planned and verified. This subset is split into test cases that define the

parameters and functions to be tested and the actual requirements to be verified. Some of the

requirements may be hard to verify directly but need an indirect approach. The system

verification subset and case plan answers the question what is tested and why.

Test setup plan defines how the testing is organised, what facilities and auxiliary

equipment and software is needed. Test results as well as environmental variables, deviations

System requirements

Use cases

System specifications

Functionality

Implementation

Component, module and

interface specificatons

System verification

Demonstration

System integration

System testing/simulation

Functional testing

Component/module testing

SW code testing

WP3, WP4

WP5

WP6WP1

WP2



from the plans and results analysis are documented test/verification report. Finally, the results

are compared to the requirements and decision is made if the (sub)system is accepted or not.

Figure 1—3: Testing/verification process documentation (blue) and activities (red) break-up.

1.4 Demonstration Overview

This section provides an overview over the different demonstrations covered in this

deliverable. The reader is referred to deliverable D5.5 [5] for detailed technical information

about the demonstrator implementation and to the following section 1.5 for a summary.

Hardware-Centric and Algorithm-Centric Demonstrations

WP6 work follows the two guiding demonstration objectives O6.1 and O6.2. In deliverable

D5.5 [5], section 2.2.3 it has been explained how demonstrations are split into hardware-

centric demonstrations targeting O6.1 and algorithm -centric demonstration targeting O6.2.

Figure 1—4: Software layers included in hardware centric and algorithm centric demonstrations.

Figure 1—4 illustrates the concept of hardware- and algorithm-centric demonstrations. In

brief, algorithm-centric demonstrations comprise layer 1, automatic layer 1 control and layer 2

MAC functionality, allowing to control the radio transceiver and beam steering antennas in real

time based on algorithms and protocols developed in MiWaveS. Algorithm-centric

demonstrations have been carried out for the access link using commercial V-band radio

hardware with beam steering antennas by Sibeam, tailored to indoor applications. Hardware-

centric demonstrations comprise the same layer 1 functionality and light layer 1 control

functionality, allowing to control radio transceivers antenna beam steering antennas manually

through a graphical user interface. Hardware-centric demonstrations have been carried out for

backhaul and access links using the radios and antennas developed in MiWaveS. The same

base band hardware is used in either case.

The split has been introduced to allow for radio components developed in MiWaveS to

arrive very late for demonstration by reducing their integration complexity and focussing on

System requirements

Use cases

System verification

subset and case planTest setup plan

Test report

and analysisTesting

Acceptance



demonstrator functionality required for O6.1. At the same time, algorithm-centric

demonstrations build on off-the-shelf radio hardware, available earlier, allowing more time for

integration and testing of beam steering algorithms and related protocol functionality.

Merged Deliverables

The original work plan included three sequential verification and demonstration steps, coupled

to three sequential deliverables and milestones as part of tasks T6.3 and T6.4: D6.3 (MS18)

(Beamforming tests and presentation of demonstrator subset 2), D6.4 (MS19) (Access link tests

and presentation of demonstrator subset 3), and D6.5 (MS20) (System measurements and

presentation of the final joint demonstrator). D6.3 and D6.4 cover basic single and multi-user

verification tests, related to beamsteering and interfaces, to ensure successful final

demonstrations reported in D6.5.

The revised work plan changed the initial sequential work over a longer period into parallel

work in a shorter period including test, verification and final demonstration. This deliverable

covers the results of D6.3, D6.4, and D6.5. It is organized into different sections summarizing

the different demonstrations which have been conducted. This includes the results of interim

test steps as well as the final demonstrations.

Summary of Demonstrations

Table 1-4 presents an overview of the different access and backhaul demonstrations which

have been conducted in Dresden, Grenoble and Espoo. Table 1-4 also provides an overview of

the radio and antenna hardware used in each demonstration as well as a mapping to

hardware- and algorithm-centric demonstrations. An overview of the demonstrator

implementation and the different radios is presented in section 1.5 and appendix A,

respectively. The reader is referred to deliverable D5.5 [5], D3.6 [12], and D4.5 [11] for details

about the components integrated into the demonstrator (the table below references the

relevant sections in these deliverables).

Table 1-4. Overview over demonstrations and corresponding radio hardware.

# Demo Name (Location) Radio Hardware D6.5

Section

Access Link

1 Single-User Hardware-Centric

V-Band Access (Dresden)

AP: ST-Fr/CEA Transceiver + VTT A1 antenna

(D5.5, 2.3.4.1; D3.6, 3.2, 4.1; D4.5, 3.2; D6.5, A1.1.2.)

UD: ST-Fr/CEA Transceiver + CEA U1 antenna

(D5.5, 2.3.4.2; D3.6, 3.2, 4.1; D4.5, 2.2; D6.5, A1.1.1)

2.1

2 Single and Multi-User

Hardware-Centric V-Band

Access (Grenoble)


(D5.5, 2.3.4.1; D3.6, 3.2, 4.1; D4.5, 3.2; D6.5, A1.1.2)


(D5.5, 2.3.4.2; D3.6, 3.2, 4.1; D4.5, 2.2; D6.5, A1.1.1)

2.2

3 Single User Algorithm-Centric


AP/UD: Sibeam transceiver + Sibeam phased array

antenna (D5.5, 2.3.4.3; D6.5, A.2)

2.3

4 Multi-User Algorithm-Centric



antenna (D5.5, 2.3.4.3; D6.5, A.2)

2.4



Backhaul Link

5 Hardware-Centric

E-Band Backhaul Outdoor

(Espoo)

Nokia/Sivers/VTT transceiver + UR1 B3s antenna

(D5.5, 3.1.1; D4.5, 4.4; D6.5, A3)

3.1

6 Hardware-Centric

E/V-Band Backhaul Indoor

(Espoo)

Nokia/Sivers/VTT transceiver + UR1 B3s antenna

(D5.5, 3.1.1; D4.5, 4.4; D6.5, A3)

Sibeam transceiver + Sibeam phased array antenna

(D5.5, 2.3.4.3; D6.5, A.2)

3.2

7 Hardware-Centric

V-Band Backhaul (Grenoble)

ST-Fr/CEA Transceiver + CEA B1a/B1Abis antenna

(D5.5, 3.1.3; D3.6, 3.2, 4.1; D4.5, 4.2, 4.3; D6.5, A1.1.)

3.3

E-2-E Application

8 Hardware-Centric E-Band

Backhaul + V Band Access

Application (Review Meeting)

Backhaul: Nokia/Sivers/VTT transceiver + UR1 B3s

antenna (D5.5, 3.1.1)


(D5.5, 2.3.4.1; D6.5, A.1.2)


(D5.5, 2.3.4.2; D6.5, A.1.1)

4.1

9 Algorithm-Centric V-Band

Access Application (Review

Meeting)


antenna (D5.5, 2.3.4.3; D6.5, A.2)

4.2

It should be highlighted that the original demonstration plan has been significantly enhanced

to tie the demonstration to use cases [2] and increase the practical relevance and visibility of

the results:

• Backhaul tests have been carried out indoors and outdoors under realistic propagation

conditions and over long distances using radio and antenna hardware designed in

MiWaveS, instead of laboratory-only tests and demonstrations.

• Final backhaul tests comprise E-band and V-band backhaul results instead of V-band

only

• The access link test includes mobility where a user device is mounted on a mobile

robot following a pre-defined route.

• E-2-E application demonstrations allows for video transmission over a combined E

band backhaul and V band access link. In addition, it allows surfing the internet over a

V band access link.

Note on Demonstration System Bandwidth and Testable Peak Rates

The base band part of the demonstration system summarized in the next section is used in

demonstrations 1, 3, 4, 5, 6, 8, 9 shown in Table 1-4. It operates at a signal bandwidth of 750

MHz, constraint by the bandwidth of ADCs and DACs available during the project time frame.

This bandwidth is by a factor of 2.7 or 2.35 smaller as compared to 2 GHz or 1.76 GHz

bandwidth assumed in link budget calculations, respectively (see Table 1-2). The peak rates

down-scale by these factors. In the future, the system could be augmented with wider-

bandwidth ADCs and DACs, and scale the parallel base band signal processing to process the

increased bandwidth in real time, using exactly the same parallel signal processing principles

used already.



In order to test also wider bandwidths (1.76 GHz) and higher peak data rates, the

demonstrations #2 and #6 in Table 1-4 use signal generator and analyzer hardware supporting

1.76 GHz of bandwidth.

1.5 Demonstration System Overview

1.5.1 Introduction

This section summarizes the implementation of the demonstration system in brief.

Detailed information about the physical layer implementation is available in deliverable D5.4

[6]. Deliverable D5.5 [5] presents the overall demonstrator implementation in detail.

Note that the hardware-centric and algorithm-centric demonstrations share the same base

band hardware, numerology and physical layer implementation as described in the following

sections. The main difference is that the hardware centric demonstrations implement a

unidirectional transmission with manual user control of transmission parameters, while the

algorithm-centric demonstrations implement a bi-directional transmission, where transmission

parameters, such as beam steering related parameters, are adjusted adaptively based on

algorithms and the MAC protocol, as outlined in section 1.4.

1.5.2 mmWave Node Hardware Architecture

The MiWaveS demonstration system comprises base station backhaul nodes, access point

nodes and user device mmWave nodes. These nodes share a common hardware architecture

and feature superset which is briefly outlined in this section. The exact configuration mainly

depends on the specific radio components and the respective interfaces offered to the base

band system.

Figure 1—5 shows an overview of the mmWave node setup including all possible

components and all possible interfaces. The exact subset, relevant for the different radios is

presented in detail in [5].

Figure 1—5: mmWave node architecture showing all configuration options.

Each mmWave node integrates three major sub systems, developed by different project

partners.



External control and monitoring sub system:

• Hosts the LabVIEW based user interface, monitoring and adjustment of MAC

parameters over Ethernet interface.

• Enables non-real time radio control through a serial control interface.

Digital base band sub system:

• Real time controller which executes the layer 2 MAC functionality, and layer 1 control

functionality.

• FPGA modules, connected to I/O and ADC/DAC modules: all wide band signal

processing is implemented in real time. Analog-to-digital conversion, digital-to-analog

conversion, FPGA-aided real time and non-real time radio control trough I/O modules

are implemented here.

mmWave radio and antenna sub system:

• Radio transceiver

• (steerable) antenna

• Interfacing control modules to condition the base band control signals to be suited to

drive the different radio components. In particular, the bias card in conjunction with

the interface card is responsible for conditioning TDD switching signals and antenna

beam selection signals. Each steerable antenna will use a dedicated interface card.

• Peripherals, such as power supplies or local oscillator reference signals.

Figure 1—6 shows three practical implementation examples for backhaul, access and user

device node, which have been used in the final demonstrations.

Figure 1—6: E-Band backhaul node (left), V-Band Access node (middle), V-band user device node

(right).

All nodes share the same common base band subsystem with radio-dependent software

configuration. The common base band subsystem is introduced in the next section. Details

about the different radios are summarized in appendix A.



1.5.3 Base Band Hardware System

Figure 1—7 shows an overview of the common base band hardware setup. Figure 1—7 also

shows the mapping of baseband signal processing functionality to different hardware modules.

Please refer do deliverable D5.4 [6] for a detailed description of the actual base band signal

processing.

Figure 1—7: Base band hardware overview

The hardware modules can be summarized as follows

1) NI PXIe 1085 chassis

18-slot chassis. The chassis connects the real-time controller and FPGA / clock modules

through a PXIe Gen2x8 backplane. Modules can communicate at up to 3.2 GB/s depending

on the module specification. In addition, it provides triggering and synchronization

functionalities.

2) NI 8135 Real Time Controller

PHY control and MAC related LabVIEW software are executed on the controller using a real

time operating system (Pharlap). The controller communicates with FPGA modules

through a high-rate PXIe Gen2x8 backplane. The specification supports a theoretical

maximum of 4 GB/s data rate between modules (single direction). For Gen2x4 rated PXIe

modules, as an example, a theoretical unidirectional data rate of 2 GB/s is supported.

Practical maximum rates are in the order of 3.2 GB/s and 1.6 GB/s respectively.

3) NI PXI-5652 Signal Generator

This component generates the sampling clock for ADC (1.5 GHz) and DAC (1.25 GHz) at

high precision.

4) NI 5771 ADC

Two-channel ADC, sampling the received single-ended I/Q base band signal at 1.5 GHz with

a resolution of 8 bit. The ADC is connected to an FPGA module which runs synchronization

and equalization receiver functionality.



5) AT 1212 DAC

Generates a differential baseband I/Q signal with a resolution of 14 bit at 1.25 GHz

sampling rate. The DAC is connected to a FPGA module which runs transmitter

modulation, signal frame generation and pulse shaping functionality.

6) NI 7975R FPGA

The FPGA modules run modulation, demodulation and coding related functions. FPGA

modules communicate with each other and with the real-time controller over the high-

rate PXIe Gen2x8 backplane.

7) NI I/O Modules (not shown)

The I/O module allows to generate or capture digital control signals in real-time on the

FPGA. This functionality is key to controlling external RF components, tightly tied to the

base band signals. Examples include on/off keying of the transmit chain or initialization

functionality.

a) NI 6581

This module comprises 2 I/O ports providing a total of 54 single ended I/O channels.

I/O voltages are {1.8, 2.5, 3.3} V. The module operates at a maximum clock rate of 100

MHz. This module is used to control the different antennas and mmW radio

components developed in MiWaveS.

b) NI 6583

This module comprises 2 I/O ports, providing a total of 35 single ended I/O and 19

LVDS channels. The module operates at a maximum clock rate of 200 MHz. This

module is required to control the Sibeam radio and antenna.

8) Octoclock-G 10 MHz reference

10 MHz reference clock with an accuracy better than 25 parts per billion. This clock

provides the 10 MHz reference signal to each NI PXIe 1085 chassis in order to minimize a-

synchronicity, in particular, in terms of sampling clocks, between different base band

transceiver nodes.

Numerology, physical layer and MAC layer which are implemented in the base band

system are summarized in the following sections.

1.5.4 Numerology

The MiWaveS system employs single carrier modulation in TDD mode. The main concept

has been initially developed in [9][8]. The signal structure is divided into radio frames, slots

and blocks as shown in Figure 1—8.

Figure 1—8: Radio frame structure.



Most importantly, a slot plays a similar role as a 3GPP LTE transmission time interval (TTI).

However, its duration is 1/10 of the LTE TTI duration (0.1024 us MiWaveS versus 1 ms in LTE).

Shortening the TTI duration by a factor of 10 is a major prerequisite to develop a low latency

communication system. Note that a slot is further divided in blocks. Each block carries a guard

interval which enables block-wise frequency domain equalization in time-dispersive channels.

Table 1-5 summarizes the system numerology.

Table 1-5. System numerology.

Property Value Comment

Symbol level

Symbol rate in MSym/s 750

Sampling rate DAC in MHz 1250

Oversampling ratio DAC 5/3

Sampling rate ADC in MHz 1500

Oversampling ratio ADC 2 integer oversampling factor enabling an

efficient receiver implementation

Block level

Block length in symbols 512

FFT Size 512 The FFT window covers one block incl. guard.

Block duration in ns 682,7

Guard length in symbols 32 guard period comprised within one block

Guard duration in ns 42,7

Data symbols per Block 480

Guard overhead 0,06

Slot level

Blocks per slot 150

Slot duration in us 102,4

Guard blocks per slot 10

Pilot blocks per slot 1-2 Depending on probing/data slot format

Data blocks per slot 138

Radio frame level

Slots per radio frame 200

Radio frame duration in ms 20,48

The system supports variable rate transmission by offering various modulation-coding

schemes as summarized in Table 1-6. On a physical layer level, the throughput can be varied per

slot, i.e., the same modulation coding scheme is employed throughout a slot. The data rate can

be varied between 147 Mbit/s up to 2318 Mbit/s, using 750 MHz signal bandwidth. Note that

3GPP-LTE compliant turbo coding is implemented.

Table 1-6. Modulation coding schemes and respective slot payload lengths. SNR values are obtained

from floating point simulations in an AWGN channel.

MCS

Idx Name

Modula

tion

Raw

Bits/

Sym

Code

Rate

Inf.

Bits/

Sym

transport

block

length in

bits

Code

word

length

in bits

Throughput

in Mbit/s

SNR dB @

CWER=0.01

AWGN

0 1/5 BPSK BPSK 1 0,23 0,23 328 1440 147 -4,60

1 1/4 QPSK QPSK 2 0,25 0,49 712 2880 320 -1,40



2 1/2 QPSK QPSK 2 0,51 1,03 1480 2880 665 2,10

3 3/4 QPSK QPSK 2 0,75 1,49 2152 2880 967 5,00

4 1/2 16 QAM 16 QAM 4 0,54 2,16 3112 5760 1398 8,00

5 3/4 16 QAM 16 QAM 4 0,76 3,05 4392 5760 1973 11,60

6 7/8 16 QAM 16 QAM 4 0,90 3,58 5160 5760 2318 14,10

1.5.5 Physical Layer

The physical layer implements real time inner and outer transceiver signal processing

distributed over multiple FPGAs. Figure 1—9 summarizes the main functionality.

Figure 1—9: Structuring the physical layer processing into inner and outer transceiver.

The mapping of signal processing functionality to FPGAs is shown in Figure 1—10. Massive

parallelism has been employed at many parts of the implementation. The turbo decoding

procedure, for instance, is implemented using 12 parallel decoder cores distributed over two

FPGA modules. The inner receiver signal processing processes 8 samples per FPGA clock cycle

in parallel to support the wide bandwidth. Functionality such as filters or FFT are purpose-built

to support this parallelism.

Figure 1—10: Mapping of Algorithms to base band hardware modules



1.5.6 Physical Layer Control and MAC Layer

The physical layer control and medium access layer software part are executed on a real

time controller. The communication with the FPGA based physical layer is handled through

FIFOs and registers. Figure 1—11 shows the layered software architecture implemented on the

real time controller.

Figure 1—11: Physical layer driver and control layer, and MAC software architecture.

The most important functions implemented on the real time controller are: Management of

system states, link setup, beam steering, multi-user scheduling, computation of radio control

parameters.

1.5.7 Closed Loop Operation

The MiWaveS PoC system implements a scheduled bi-directional closed loop mmWave

transmission system. In essence, a master node (access point in an access link setup or base

station in a backhaul link setup) orchestrates the connection with one or multiple slave nodes

(user devices in access link setup or access point in backhaul link setup). For ease of reading we

will use the access link, comprising access point (AP, master) and user devices (UD, slaves) as

an example to introduce the higher layer implementation. This setup is shown in Figure 1—12

for the example of a single user access link.

This section presents the general procedure to establish and maintain a connection.



Figure 1—12: Bi-directional closed-loop mmWave access link transmission.

1) In a first step, AP and UD, are in a disconnected state. The access point starts transmitting

pilot and control information on the downlink in order to enable the establishment of a

link. This information is broadcasted in different directions by transmitting it over multiple

beams sequentially. The UD is in receive mode in order to discover the presence of an AP.

2) Upon detecting the presence of an AP, the UD synchronizes in time and frequency to the

AP, based on the transmitted pilots.

3) Next, the UD decodes the configuration information sent over the downlink.

4) The UD measures the downlink channel quality on different receive beams as configured

by the AP and conveyed to the UD by configuration information over the downlink.

5) The AP has also configured the UD to feedback these measurements over the uplink at

predefined time instances using configuration information transmitted in the downlink.

This is done multiple times sequentially using multiple beams.

6) The AP receives during the uplink phase on multiple beams and measures the uplink

channel. The AP now possesses information about uplink and downlink channel quality

coupled to multiple transmit-beam combinations. This information is kept in a data base

for processing by the beam steering algorithm.

7) The access point and UD are now connected. The AP schedules downlink and uplink data

transmissions. This configuration information is provided to the UD over the downlink.

8) AP and UD continue measuring the channel on a reduced subset of transmit-receive beam

combinations in up- and downlink in order to track variations of the channel, in parallel to

the actual data transmission.

Note that it is the task of the beamsteering algorithm to control the beam settings used to

probe the channel (i.e., measuring the receive power using a certain transmit and receive

beam combination) and to assign a beam for the actual data transmission. This process is

continuously executed and refined in order to account for mobility of the user device.

1.5.8 Demonstrator Graphical User Interfaces

This section summarizes the main user interfaces of the mmWave nodes used in hardware-

centric and algorithm-centric centric demonstrations.



1.5.8.1 Hardware Centric Demonstrations

The main user interface used in hardware centric demonstrations is shown below in Figure

1—13. It allows low-level access to different signal quality measures, to-various FPGA algorithm

configuration options, and to radio control settings.

Figure 1—13: Main front panel of AP and UD for hardware centric demonstrations

1.5.8.2 Algorithm Centric Demonstrations

The main user interface of the access point, used in algorithm-centric demonstrations, is

shown below in Figure 1—14. The user interface provides access to scheduling settings,

selection and different beamsteering algorithms. Likewise, it allows monitoring connection

states and beamsteering related measures.

Figure 1—14: Main AP front panel for algorithm centric demonstrations.



The beam settings used to transmit data are illustrated in polar plots as shown below in

Figure 1—15.

Figure 1—15: Graphical representation of the current target beam settings at AP and UD for two

users.

Several traces are collected synchronously in radio frame intervals, such as connection

states and beam settings. These traces allow to investigate the system behaviour over time,

e.g., under the impact of mobility. Figure 1—16 illustrates an example trace showing the

connection states and the beam settings of the connection to two user devices over a duration

of 10 seconds.

Figure 1—16: System Traces collected at the AP.



The main user interface of the UD is shown in Figure 1—17. It mainly allows to monitor the

link state and beamsteering related measures.

Figure 1—17: Main UD front panel for algorithm centric demonstrations.

1.5.9 Summary of Main System Features

This section highlights the main features which are supported by the MiWaveS

demonstration platform.

1) Single carrier system operating at 750 MHz symbol rate with real time signal processing.

Supports variable rate transmission using BPSK, 4 QAM and 16 QAM modulation and

variable forward error correction code rates. Data rates can be varied between 147 Mbit/s

and 2318 Mbit/s. See [9], [8] for the general signal concept and deliverable D5.4 [6] for

details on the physical layer implementation.

2) Single configurable software architecture to configure and use five different mmWave

radio transceivers which address E-band and V-band backhauling as well as V-band access

links, with and without beam steering capability.

3) Real time and non-real time radio control. For real time radio control, radio parameters

can be re-configured once per 100us slot.

4) Bi-directional, closed-loop TDD standalone mmWave transmission.

5) Scheduled multi-user channel access in TDM mode. An access point acts as master,

aggregates information from user devices and dynamically configures their transmission

over the air.

a) Enables dynamic multi user scheduling and prevents collisions between channel

accesses of multiple users in order to ensure QoS. This is a key feature of a cellular

communication system, distinguishing it from ad hoc networks.

b) Enables dynamic assignment of resources to different users to account for different

user / data service requirements.

c) Aggregation of UL and DL channel measurements at the AP enables two-sided beam

steering (AP and UD can both simultaneously steer beams), controlled from a central

instance (AP). The protocol infrastructure allows to set arbitrary and time varying

transmit and receive beam configurations in order to test different beam steering

protocols or algorithms.



d) The system has been designed not to rely on channel reciprocity (explicit channel

feedback transmitted over the UL is available at the AP) but channel reciprocity can be

exploited as a special case.

e) Provides means to support mobility of users and maintain the connection under

mobility

6) Flexible beam steering algorithm interface jointly developed by MiWaveS partners. The

beam steering algorithm can be changed on run time in order to test and compare

multiple beam steering strategies.

7) Monitoring and tracing of link and hardware states as well as configuration through a

single user interface. This provides a means to debug the system behavior and understand

algorithm and protocol behavior in detail.

In summary, the MiWaveS demonstration platform is the only fully modifiable mmWave

demonstration system fully developed in a collaborative research project jointly by many

partners, which offers these features to date.

The remainder of this deliverable is structured as follows: Chapter 2 comprises the

different access link demonstrations. Chapter 3 covers backhaul link demonstrations. Chapter

4 presents the E-2-E application over backhaul and access links.



2. Access Link Demonstrations

Chapter 2 focuses on the single- and multi-user V-band access link. Four single and multi-

user tests are carried out to characterize different aspects of the demonstration system

1. Single-user hardware-centric test: testing the link connection and quality (data rate,

hop length) using the radios and antennas developed in MiWaveS.

2. Multi-user hardware-centric test: extending the single-user hardware centric test to

two users, also demonstrating the capability to use a wider transmission bandwidth.

3. Single-user algorithm-centric test: testing the beam alignment and tracking

performance based on the Sibeam radio.

4. Multi-user algorithm-centric test: extending the single-user algorithm-centric test to

two users, where the multi user access is organized in time-division multiplex (TDM).

The results presented in the following have been publicly presented in part in [22].

2.1 Single-User Hardware-Centric Demonstration in Dresden

This section presents demonstration results for the V-band access link system developed in

MiWaveS. The demonstration setup is briefly introduced in section 2.1.1. Section 2.1.2

presents results for testing the transmission range in a LOS setting. Demonstration results for a

NLOS setting are covered in section 2.1.3. These tests build on radio and antenna hardware

developed in MiWaveS and hence target object O6.1.

2.1.1 MiWaveS V-Band Access Link Setup

Figure 2—1 shows the demonstration hardware setup. Access point and user device have

been mounted on movable trolleys. The setup uses the following components (refer to

deliverable D5.5 [5] for detailed information about the components and to Appendix A1):

• User device radio receiver

• Access point radio transmitter: comprises an integrated V-band transceiver connected to a

beam-steerable Rotman lens antenna. The access point allows to steer five beams in

azimuth.

• Baseband unit: implements transmitter and receiver signal processing and provides control

capabilities for the radio (beam direction, receive gain, initialization)

• Power supplies for the AP and UD radio

• Reference signal generators for the base band (10 MHz) and the user device radio (18

MHz)

• Spectrum analyser to monitor the V-band radio PLL.



Figure 2—1 V-band access point and user device setup.

The setup implements a unidirectional transmission from the access point to the user

device. The output power of the digital base band, the gain of the user device radio receiver

and the beam of the access point transmitter can be controlled through the digital base band.

In order to test the link, data are transmitted at different data rates. Parameters such as

throughput, codeword error rate, SNR, and base band receive power can be monitored at the

receiver.

Figure 2—2 shows both AP and UD node along with the graphical user interface used to

monitor the link.

Figure 2—2. V-band access link setup



The required demonstration hardware and laboratory equipment is summarized in Table 2-1

and Table 2-2.

Table 2-1: Required hardware for hardware-centric demo.

Hardware (AP) Supplier Units

Digital baseband including DAC/ADC NI 1

RF V-band CEA 1

AP radio w/ steerable antenna VTT 1

Hardware (UD) Supplier Units


RF V-band CEA 1

100° 3dB beamwidth antenna V-band CEA 1

Table 2-2: Required laboratory equipment for hardware-centric demo.

Lab equipment Supplier Units

Control computer TUD 1

PLL monitoring TUD 2

Power supply TUD 2

Cables (base band, power supply) TUD -

10 MHz reference TUD 2

18 MHz reference NI 1

Baseband unit TUD 2

Trolley TUD 1

2.1.2 LOS Transmission Range Test

2.1.2.1 Introduction

This experiment is coupled to the access link parts of use cases 1, 2, and 5. The main goal is

to test whether high data rate can be provided to users throughout the cell. Therefore, the

KPIs “End user capacity” and “Access range” are assessed, by testing link quality parameters at

different AP-UD distances and using different beams provided by the AP.

2.1.2.2 Test conditions

The test conditions and link setup are shown in Figure 2—3 - Figure 2—6.

• The system setup provides a LOS connection plus some reflections from walls or

glass, see the geometry of the test environment in Figure 2—3, where material of wall

A is plaster; material of wall B is concrete; material of the floor is carpet; material of

the ceiling is concrete.

• The distance between the AP and UD is: 1, 2, 4, 8, 10, 15, 31.4 (m), where the tests

for the distance less than or equal to 10 m are done in the meeting room, see Figure

2—3, and others are done in the corridor, see

• Figure 2—5.

• Description of the AP’s antenna: the steerable antenna is placed on a fixed trolley

with height of 1.53 (m), see Figure 2—4.

• Description of the UD’s antenna: the 100° 3dB beamwidth antenna is placed on a

moving trolley with height of 1.53 (m), see Figure 2—4.



Figure 2—3: Test environment in a meeting room with AP and UD spaced up to 10 meters.

Figure 2—4: AP and UD prototypes set up in a meeting room.



Figure 2—5: Test environment in a corridor with AP and UD spaced up to 31.4 meters.

Figure 2—6: AP and UD prototypes set up in a corridor.

2.1.2.3 Measurement results

Receive Power at Constant Distance Using Different Beams

The purpose of this first test is to verify how uniform different beams cover the angular range,

i.e., how uniform they cover a certain sector of a mmWave small cell. For this purpose, the

receive power has been recorded in base band for each beam at constant transmit and receive

gain settings. The user device remained static. For each beam the access point was rotated in

order to maximize the receive power at the user device. The test has been conducted at 8 m

and 10 m distance

Results shown in Figure 2—7 show that all beams result in a similar receive power with a

maximum difference of 5-6 dB between the beam with the highest gain and the beam with the

lowest gain.



Figure 2—7. Base band receive power across different transmit beams.

6 dB difference in receive power corresponds to a factor of two in terms of changing the

distance in free space conditions. A small variation in terms of link quality can hence be

expected across beams. Code word error rate results in Figure 2—8 confirm a small variation of

the link quality across beams, i.e., the beam with the lowest receive power results in a slightly

increased error rate. Note that for these results the transmit and receive gain have been

optimized per beam to minimize the code word error rate.

Figure 2—8. Code word error rate across different beams at constant distance.

Measured Throughput versus Distance

The user device has been placed at different distances from access point ranging from 1m to

31 m. At each distance, data has been transmitted at different rates over all beams to test the

throughput. For a certain beam the access point has been rotated in order to maximize the

receive power at the user device. The parameters transmit gain and receive gain have been

optimized for the modulation coding scheme supporting the highest rate at this distance.

Code word error rate and throughput results are shown in Figure 2—9 and Figure 2—10,

respectively. Note that the throughput and error rate results have been averaged across the 5

transmit beams.



Figure 2—9. Code word error rate versus distance for different transmission rates.

Figure 2—10. Throughput versus distance for different transmission rates.

Close to the AP, data can be transmitted using 16 QAM modulation resulting in a maximum

throughput of about 1.6 GBit/s. For distances larger than 2 m, QPSK based transmission

schemes should be chosen. A throughput of close to 1 GBit/s is achieved up to 10 m distance.

A throughput of more than 550 Mbit/s could be maintained up to the maximum tested (cell

edge) distance of 31 m.



Figure 2—11. Throughput using different beams at different distances.

Figure 2—11 shows an example result which illustrates the variation of the throughput

across different beams for different distances. A small variation in data rate can be observed at

1 m and 2 m distance, where 16 QAM modulation would be used. The beam with the highest

receive power results in the highest throughput as expected. In consequence, different

maximum data rates are supported at the same distance but different angles, viewed from the

access point. This observation is attributed to the prototype antenna feed network

configuration, not optimized design and deviations in MMIC characteristics. For instance,

different beams use different power amplifiers and switches, each signal path has a certain

gain deviation. It can be expected to be minimized when switching to a larger scale

manufacturing of mmWave devices where process parameters are fine-tuned and optimized.

In order to interpret the throughput results in more detail, we investigate the constellation

before forward error correction decoding at the receiver in Figure 2—12 for different distances.

Each plot comprises more than 66.000 symbols which are transmitted per 102,4 us slot.

(a) 1 m.

0

200

400

600

800

1000

1200

1400

1 2 4 8 10 15 31,4

Th

rou

gh

pu

t (M

Bit

/s)

Distance between AP and UD (m)

16 QAM, coding rate 1/2

beam 1

beam 2

beam 3

beam 4

beam 5



(b) 4 m

(c) 8 m.

Figure 2—12: The received constellation diagram with the distance of 1, 4 and 8 meters.

It can be seen that the constellation becomes increasingly noisy at increasing distances, as

expected. In order to maximize the transmission range, the transmit gain has been increased

with increasing distance, causing non-linear distortions at the transmitter which are traded

against thermal noise at the receiver. BPSK and QPSK modulated signals can be transmitted at

a higher gain as compared to 16 QAM as a matter of their lower peak-to-average power ratio.

The non-linear compression can be observed for 16 QAM at 4 m in the plot above.

2.1.3 NLOS Transmission Test


The goal of this experiment is to test whether the access system can establish a connection

over NLoS links. This situation can arise in any access link setting coupled to use cases 1, 2 and

5.


The test environment is shown in Figure 2—13. The test conditions are as follows:

• Both the AP’s and UD’s antenna have the same height of 1.53 (m)

• LOS distance: 4m and NLOS distance: 4.34 m, see Figure 2—13.

• In the test environment, material of wall A is plaster w/ and w/o metal on the wall;

material of the floor is carpet; and material of the ceiling is concrete;

• One static beam setting at the AP (center beam with beam index 2).



0.85 m

TV

UD

23 deg23 degWall A (plaster w/ and w/o metal on the wall)

2 mBeam 2

AP 2 m

0.85 m

(a) Top view.

(b) without the metal plate on the wall (c) with the metal plate on the wall

Figure 2—13: The setup to test the reflection from wall A with and without metal on the wall.

2.1.3.3 Measurement results

In a first step the LOS link has been tested for reference. AP and UD have been aligned for

maximal receive power at the user device. The third out of five beams (middle beam) has been

chosen at the access point for transmission. In a second step, the TV set has been used to

block the LOS link as shown in Figure 2—13 b). All parameters were kept identical to the LOS

case. The AP has been rotated towards the wall as shown in Figure 2—13 a), in order to

maximize the receive power at the UD. The AP beam has been kept static and the AP was

rotated in order to mitigate the impact of different gains coupled to different AP beams and

have comparable NLOS / LOS results.

Table 2-3 lists both the LoS and NLoS downlink measurement results. It can be seen that

the receive power dropped by 15 dB comparing LOS and NLOS. The receive power was too low

in the NLOS case to decode data correctly. In addition, the receive gain was already at its

maximum setting (36 dB). In order to verify the actual presence of a specular reflection, a small

aluminium metal plate has been placed at the wall at the position shown in Figure 2—13 c). The

reduction in receive power was 2 dB compared to the LOS case, resulting in approximately the

same throughput.



Table 2-3: Measurement results.

Tx

gain

Rx

gain

Received

power

(dBFS)

SINR

(dB)

SNR

(dB)

Throughput (Mbit/s)

BPSK

1/5

QPSK

1/4

QPSK

1/2

QSPK

3/4

LoS

(for reference) 0.89 36 -7.7 10.4 16.1 147 320 665 957

NLoS,

w/o metal 0.89 36 -22.7 - - - - - -

NLoS,

w/ metal 0.89 36 -9.3 9.6 13.8 147 317 645 938

Additional experiments have been conducted with different transmission angles and

concrete walls instead of plaster cast walls, leading to similar trends.

Although this test represents only a small portion of possible LOS / NLOS transmission

situations it can be concluded that: in general, NLOS transmission is feasible but

• It should be expected that LOS and NLOS beams are received at very different power

levels, depending on reflecting surfaces, materials, geometric transmission setup, for

instance.

• Supporting LOS and NLOS over the cell area requires supporting a high dynamic range. A

NLOS link margin should added to LOS based link budget calculations.

• Finally, the tests were constrained to a single access point. In practice, multiple access

points are expected to cover a small cell, such that the connection could be handed over to

another access point in case no LOS or sufficiently strong NLOS path are available. The

placement of multiple access points, the access point density and the handover between

access points requires further experimental investigation.

2.1.4 Summary

The LOS transmission experiment showed that peak data rates up to 1.6 GBit/s could be

provided to a user in proximity of the access point using a bandwidth of 750 MHz. This is close

to the target peak rate range of 2-5 GBit/s. A cell edge user could still be served at 550 Mbit/s

at 31m distance to the AP. The range of maximum link distances per use case is 10 m - 100 m.

Achieving the maximum transmission range would require to adjust the link budget by about

10 dB. This could be achieved by means of more directive beams or a further reduction of

losses within the active access point antenna array.

2.2 Multi-User Hardware Centric Access Link Demonstration in Grenoble

This section presents additional demonstration results for the V-band access link system

developed in MiWaveS, targeting objective O6.1.

2.2.1 Hardware Setup

The radio and antenna hardware is the same as that used in the previous sub section 2.1.

However, in this test the baseband signal was provided by a signal generator at the Access

Point, and evaluated by a digital oscilloscope at the receiver terminal. The oscilloscope

performs data acquisition (detection, gain adjustment, time and frequency synchronization)

over a sequence with known modulation and given length, followed by a blind equalization. It



plots the signal constellation. Also, this test uses a transmission bandwidth of 1,76 GHz as

compared to 750 MHz (test in section 2.1), demonstrating the capability of mmWave radio

components and antennas, developed in MiWaveS, to support wider bandwidths.

The required demonstration hardware and laboratory equipment is summarized in Table

2-4 and Table 2-5.

Table 2-4: Required hardware for hardware-centric demo.


RF V-band CEA 1

AP radio w/ steerable antenna VTT 1


RF V-band CEA 1

100° 3dB beamwidth antenna V-band CEA 1

Table 2-5: Required laboratory equipment for hardware-centric demo.


Tektronix Digital Oscilloscope CEA 1

Spectrum analyzer CEA 1

Tektronix Signal generator CEA 1

Trolley CEA 1

2.2.2 Multi-User LOS Test

This experiment is coupled to the access link part of use case 5. The goal in this test is to

evaluate the beam switching function, and the level of interference at a second user when a

beam is steered towards a given user. Different distances and different angular spacing

between users were tested. KPIs are both quantitative and qualitative, in terms of EVM and

constellation shape.

A wireless downlink transmission has been carried out between the access point and a

user device as fas as 12 m using QPSK modulation. A bit rate of 3,5 Gbps was transmitted, and

received with an Error Vector Magnitude (EVM) of 22%. Note that in contrast to the previous

experiments with the digital base band, here there was no coding and framing. As indicated in

[17], overhead could be assumed to occupy about 13% of the transmit signal. Therefore, the

corresponding transmit bit rate would then be 3,04 Gbps.

Moreover the beam switching has been validated by using a horn antenna and spectrum

analyser as the second receiving user node. By changing the antenna beam control code, the

beam is switched from the user device to the spectrum analyser with a horn antenna (Figure

2—14). In this latter experiment, the distance to the access point was about 2m. Due to the

directivity of the antenna beams the access point is able to distinguish the two receiving nodes

separated by less than 1 m distance, which are located in two neighbouring beams of the

Rotman lens antenna. The signal received by the second user is then under the noise level. This

demonstration has been recorded in a short video and is available on the project website.



Figure 2—14: Access point beam switching between the User Device (top) and a spectrum analyser

with a horn antenna (down).

2.2.3 Summary

In this test, three different things have been proven:

- The ability for the components developed in the context of MiWaveS (radio and

antennas) to support bandwidths as large as 1, 76GHz

- A signal transmitted at 3,5Gbps (QPSK) can be received at a distance up to 12 m.

- The beams formed by the Rotman lens connected to a 4x8 elements antenna array can

separate two users at 2m, spaced by 1m (remember that the 3dB azimuth beamwidth

of one beam is 10°).

2.3 Single-User Algorithm-Centric Demonstration in Dresden

This section presents V-band access link results with focus on beam steering algorithms.

The demonstration setup is introduced in section 2.3.1. Section 2.3.2 presents beam



alignment-related results in a static setup. Section 2.3.3 summarizes beam tracking related

results including mobility at the user device. A summary is presented in section 2.3.4.

The tests reported in this section are part of the algorithm-centric demonstrations, using

the Sibeam radio and phased array antenna. The tests target objective O6.2 (demonstration of

the beam steering algorithm). The tests are coupled to the access link parts of use cases 1, 2,

and 5. The tests address the beam steering part of the reliability KPI.

Although throughput was not a main parameter of interest in the algorithm-centric

demonstration, a brief characterization test has been conducted for completeness. The reader

is referred to Appendix C for results.

2.3.1 Algorithm Centric V-Band Access Link Demonstration Setup

In the context of algorithm-centric demonstration, the Sibeam V-band transceiver with

integrated phased array antenna is used for these tests. Details about the Sibeam transceiver

are presented in deliverable D5.5 [5] and in appendix A2. The functionality of the beam

alignment algorithms is demonstrated for a LOS scenario in Section 2.3.2/2.3.3 and for a NLoS

scenario in Section 2.3.3.

Access point and user device use identical hardware setups as shown in Figure 2—15. The

hardware setup comprises a V-band transceiver including steerable phased array antenna and

power supply and a base band system, which are mounted on a portable trolley. This allows

investigating different channel conditions, as well as testing mobility at the user device.

Figure 2—15: The setup of one node.



The Sibeam radio phased array antenna can be controlled through beam steering

codebooks. Each code book entry corresponds to a different set of phase settings per antenna

element and steers a beam into a different direction.

Exhaustive Search Algorithm Description

One possibility is to sweep through all possible beam combinations until the best

alignment is found. However, this algorithm, commonly referred to as exhaustive search (ES),

requires to probe the channel �� ⋅ �� times, where �� is the transmit code book size and

�� is the receive codebook size. This probing overhead may become prohibitive in case that

the number of possible beam directions is becoming large.

Gradient Based Algorithm Description

A more efficient way to maximize the received power by changing the TX and RX beam

indices is introduced as follows: during an initial search serving to explore the general shape of

the function, the maximum of the receiving power as a function of the TX and RX steering

angle, will be detected. Then, based on initial search results, the numerical gradient will be

calculated and used for finding the local maximum received power and the corresponding best

beam pair. A diagram of this algorithmic approach is shown in Figure 2—16.

Figure 2—16: Flow diagram of gradient beam alignment algorithm

The algorithm is designed to perform beam alignment with a beam-switching mmW setup,

by using less beam pair evaluations compared to exhaustive search. By measuring the signal to

interference plus noise ratio (SINR) at the receiver, possible interference will be inherently

mitigated. A detailed analysis of the performance of the algorithm is given in [3].

The required demonstration hardware and the laboratory equipment are given in Table 2-6

and Table 2-7.



Table 2-6: Required hardware for algorithm-centric demo.



RF V-band Sibeam 1

Antenna V-band Sibeam 1



RF V-band Sibeam 1


Table 2-7: Required laboratory equipment for algorithm-centric demo.



Voltage sources TUD 2


Moving robot TUD 1

2.3.2 Automatic Beam Alignment Test


Based on the Sibeam radio and antenna arrays at the transmitter and receiver, the beam

steering performance is shown in this subsection. The goal of this test is to verify that the

beams at both the AP and UD can perfectly align by the gradient search compared with the

exhaustive search.


The setup is shown in Figure 2—17, where:

• AP’s height: 1.53 (m); UD’s height: 1.53 (m).

• Material of wall A: plaster w/ and w/o metal on the wall; material of wall B: concrete;

material of the floor: carpet; material of the ceiling: concrete;

• Number of candidates of steering vectors at the AP: 25; Number of candidates of

steering vectors at the UD: 25. All the steering angle defined in the codebook provides

the steering range from −60∘ to 60∘. • AP’s antenna array is fixed; UD’s antenna array is rotated 0∘, ±20∘, ±45∘. • Two beam searching methods are tested: exhaustive search and gradient search

introduced in Section 2.3.1.

The required demonstration hardware and the laboratory equipment are given in Table 2-6

and Table 2-7.



(a) Top view.

(b) The setup of the AP and UD for the distance of 8 meters.

Figure 2—17: The setup of algorithm-centric LoS SU measurement.

2.3.2.3 Test Results

The results by both the exhaustive and gradient-based searching algorithms are shown in

this section. Two KPIs are used to demonstrate the performance: downlink received power in

the baseband (see Figure 2—18) and normalized complexity (see Figure 2—21) that shows the

ratio of the number of search beam combination by the gradient search to the one by the

exhaustive search.

For each distance, the AGC is adjusted to achieve the received power of -7 dBFS with the

rotated single of 0∘ in the beginning. Then, the AGC is disabled for other tests, such as the

rotated angles of ±20∘, ±45∘ in order to test the functionality of beam switching.

The objective of the test to show that the gradient-based algorithm can achieve the same

received power as that of exhaustive one with much less complexity. Figure 2—18, the

difference of the received power by these two algorithms shows that the maximum deviation

is less than 0.8 dBFS, where the results by these two are detailed in Figure 2—19.



In Figure 2—19, at the distance of 4 m, the received power increased when the rotated

angles are −20∘, ±45∘ because of the strong reflection from the glass. The geometry of the

test with the rotated angle of −20∘ is shown in Figure 2—19.

Figure 2—18: Difference of the received power between the exhaustive and gradient-based

algorithms.

(a) Exhaustive search method.

(a) Gradient search method.

Figure 2—19: Measured received power versus distance.

-1

-0,8

-0,6

-0,4

-0,2

0

0,2

0,4

1 2 4 8

Dif

fere

nce

of

the

re

ceiv

ed

po

we

r (d

BF

S)


0 degree

20 degree

45 degree

-20 degree

-45 degree

-11

-10

-9

-8

-7

-6

-5

-4

1 2 4 8

Re

ceiv

ed

po

we

r (d

BFS

)


0 degree

20 degree

45 degree

-20 degree

-45 degree

-11

-10

-9

-8

-7

-6

-5

-4

1 2 4 8Re

ceiv

ed

po

we

r (d

BFS

)


0 degree

20 degree

45 degree

-20 degree

-45 degree



Figure 2—20: Geometry of the test with the rotated angle of −20∘.

In Figure 2—21, the normalized evaluation of number of searched beam combination is

calculated by

� numberofsearchedbeamcombinationsbythegradientsearchnumberofsearchedbeamcombinationsbytheexhaustivesearch$ × 100%

From Figure 2—18(a), we can find that the received power by these two search methods

achieve almost the same results, while the gradient search method only requires less than 10%

computational complexity than the exhaustive one. Since the millimeter wave channel shows

sparsity in the angle domain, it does not make sense to use exhaustive search beamforming

algorithm, although it is believed to achieve the maximum throughput. On the other hand, if

we roughly know where are the AoDs/AoAs, then the most efficient solution is to search the

neighboring beam pair, as the proposed gradient-based beam searching algorithm.

Figure 2—21: Normalized evaluation of searched beam combination versus distance.

0

2

4

6

8

10

1 2 4 8

No

rma

lize

d e

va

lua

tio

n o

f

sea

rch

ed

be

am

co

mb

ina

tio

n

(%)


UD's antenna array rotates 0 degree



2.3.3 Automatic Beam Tracking Test


The goal of this test is to verify beam tracking performance for mobile links. The objective

and use case of this test is defined in the beginning of Section 2.3.


The setup is shown in Figure 2—22, where

• AP’s height: 1.53 (m); UD’s height: 1.18 (m).

• Number of candidates of steering vectors at the AP: 25 (index from 0 to 24); Number

of candidates of steering vectors at the UD: 25 (index from 0 to 24). All the steering

angle defined in the codebook provides the steering range from −60∘ to 60∘. • UD speed: 1 (km/h). As shown in Figure 2—22, the robot carrying the UD equipment

moves following the white tape on the floor by a control system in Raspberry Pi, where

a regulation algorithm (e.g., image signal processing) is developed to control the

motors by images captured from the camera.

• The test environment can be roughly separated into two regions: LoS and NLoS regions

depending on the propagation direction of the AP and UD, see Figure 2—22.

(a) Top view

(b) The setup in the meeting room

Figure 2—22: The setup of algorithm-centric LoS mobile SU measurement.



2.3.3.3 Test results

The objective of this test is to proof the functionality of the beam tracking in both LoS and

NLoS scenarios. To this end, the UD is fixed on a robot which moves around a circle. When the

robot moves in the LoS region, supposedly the AP’s and UD’s beam indices are gradually

increasing or decreasing. On the other hand, when it moves in the NLoS region, the AP’s and

UD’s beam indices may correspond to the strongest reflection path.

The results by the exhaustive searching algorithms are shown in this section. Figure 2—23 -

Figure 2—24 show the selected beam indices at the AP and UD over time respectively. From

Figure 2—22(a), we can find that the UD is limited to move within a certain range of angle, so

that the selected beam indices of the AP in Region A (with LoS path) stably switches from 8 to

12, while in Region B (without LoS path), the AP beam index does not stably increase or

decrease; instead, it roughly switch between 13 and 14 because there is a strong reflection

from the wall (at time 80 s), see Fig. Figure 2—26. On the other hand, in Figure 2—24, the range

of the selected beam indices of the UD is large because the UD’s antenna array rotates ( in

region A and B.

The achievable throughput by QPSK modulation is shown in Figure 2—25. When the UD

stays in Region A, it is obvious that the throughput is much better than the result in Region B

because of the LoS connection. At time 80 s as introduced, there is a strong reflection form the

wall so that the throughput increase promptly. In region B, b.

Figure 2—23: The selected beam indices by the AP over time.



Figure 2—24: The selected beam indices by the UD over time.

Figure 2—25: The achievable UD Rx throughput.



Figure 2—26: Geometry of the NLoS path.

2.3.4 Summary

The performance of the beam steering for the static links and tracking for the mobile links

are evaluated. First, the beam steering results by the gradient search almost achieve the same

received power while the computational complexity is reduced by more than 90%, compared

with the exhaustive search. Second, the beam tracking performs well (achieving the

throughput 400 Mbit/s) when the system has the LoS link; however, the link is unstable when

it loses the LoS link.

2.4 Multi-User Algorithm-Centric Access Demonstration in Dresden

The tests reported in this section demonstrate that the MiWaveS system is able to connect

automatically to two user devices in TDM mode, using the beam steering capabilities

demonstrated in section 2.3, and maintain the connection under mobility. A detailed

description of the multi user access scheme is presented in deliverable D5.5 [5]. The tests are

carried out indoors in the same environment as compared to section 2.3, using the same base

band and radio hardware. The tests in this section target objective O6.2 and specifically the

reliability KPI for the multi user access link.

Throughout the tests, AP and UD are mounted at a height of 1.53 m. The distance between

AP and UDs varies between 1 m and 4 m, depending on the test. The required demonstration

hardware and the laboratory equipment are given in Table 2-8 and Table 2-9.

Table 2-8: Required hardware for the algorithm-centric multi-user demonstration.



RF V-band Sibeam 1




RF V-band Sibeam 2




Table 2-9: Required laboratory equipment for the algorithm-centric multi-user demonstration .



Voltage sources TUD 3


Throughout the tests, the beam steering code book illustrated in Figure 2—27 is used at

access point and user device. Note that this code book differs from the code book used in the

tests presented in section 2.3.

Figure 2—27. Beam steering code book used during the multi-user measurements. An angular range

of +/-35° azimuth is covered by 7 beams with a half power beam width of about 23°.

The code book covers an angular range of +/- 35° in azimuth using 7 equally spaced beams

with a half power beam width of about 23°. An additional wide beam with reduced gain is

comprised in the code book as well.

The main purpose of these tests is to address the reliability KPI for the access link, mainly

coupled to the access link part of use cases 1, 2, and 5. Therefore, three tests of increasing

complexity are carried out. In a first test, captured in section 2.4.1, we evaluate the automatic

connection setup to two static user devices. In a second test, captured in section 2.4.2 mobility

is introduced to one of the user devices. We evaluate automatic adjustment of radio

parameters in this case. In a third, final test, captured in section 2.4.3, both user devices are

randomly moved and we investigate the robustness and stability of the access link.

2.4.1 Connecting to Two Static User Devices


The purpose of this first basic test is twofold. Firstly, it is verified that the access point can

establish a connection to two static user devices placed at different locations. Secondly, we

compare the beam results obtained from an exhaustive search alignment algorithm to the

results obtained by the gradient algorithm, to verify the correct functionality of the gradient

based algorithm in a multi-user setup.


Two static setups, shown in Figure 2—28 and Erreur ! Source du renvoi introuvable. are

investigated. The distance between the AP and two UDs is 4 m. Both UDs are separated by 10°



and 60° respectively as shown in Figure 2—28 and Erreur ! Source du renvoi introuvable.. Note

that 60° separation between the UDs corresponds to the steering range covered in the code

book shown in Figure 2—27. The purpose of these setups is to evaluate whether the AP can

establish a connection to both UDs placed at very different angles. Throughout the test, the

automatic gain control at AP and UDs is enabled such that a target receive power in digital

base band of about -7 dBFs should be achieved.

(a) Top view. (b) The setup in the meeting room.

Figure 2—28: The 1st setup of multi-user measurement.

(a) Top view. (b) The setup in the meeting room.

Figure 2—29: The 2nd setup of multi-user measurement


It was observed that the access point successfully established a closed loop connection to

both user devices, regardless of the test setup and the beam steering algorithm under

investigation.

Detailed results are reported in Table 2-10. Firstly, it can be seen that the receive gain was

automatically adjusted such that the target receive power in digital base band was achieved

within a range of -6.7 dBFs – 8.3 dBFs. This is considered accurate as the gain can be adjusted

in 1 dB steps. Secondly, it can be seen that beam steering algorithm selected beams 0 or 1



(beams pointing left, viewed from the AP) for connecting to UD 0 (positioned left) and beams 5

or 6 (beams pointing right) for connecting to UD 1 (placed right), for test 1, which is plausible.

Likewise, the beams selected at the UD for connecting to the AP where 2 or 3 (middle

beams) for tests 1 and 2. This is plausible as well, as the UDs where pointed towards the AP.

The difference between the selection of Tx and Rx beams (1 beam index difference at

most) can be explained by the use of a separate Tx and Rx antenna array as part of the chipset,

where Tx and Rx beam directions, for the same beam index, may be slightly different.

Comparing exhaustive search and gradient based algorithm, it can be seen that the same

transmit beam indices have been chosen in all, except 1, cases. Small deviations in terms of

beam indices can be observed for the choice of receive beams. It is known from measurements

that some of the receive beams exhibit high side lobes. In such a case, it could happen that the

gradient based algorithm may select a local maximum rather than the global maximum, which

explains the different choice of beam indices as compared to exhaustive search.

Table 2-10. Results for the static multi user connection test.

Rx

Po

wer

dB

Fs

Rx

Bea

m

Tx B

eam

Rx

Po

wer

dB

Fs

Rx

Bea

m

Tx B

eam

Rx

Po

wer

dB

Fs

Rx

Bea

m

Tx B

eam

Rx

Po

wer

dB

Fs

Rx

Bea

m

Tx B

eam

Test 1 (5°)

Exh. Search -7,5 2 3 -8,20 3 4 -7,6 2 3 -7,2 2 3

Gradient -6,8 4 4 -8,30 3 4 -7,5 2 3 -7,1 3 3

Test 2 (30°)

Exh. Search -7,8 0 1 -7,50 5 6 -7,7 3 3 -7,0 2 3

Gradient -7,8 0 1 -8,20 5 6 -6,7 2 3 -7,1 2 3

UD1UD 0 UD 1

AP

UD 0

In summary, it shown that the system could successfully connect to two users placed at

different positions and steer the beams to two individual users correctly.

2.4.2 Maintaining the Connection to One Static and One Mobile User Device


The previous test in section 2.4.1 has verified that a connection to two user devices,

separated by different angles, could be established automatically. This test extends the

previous test by keeping one user device static and moving the other user device at pedestrian

velocities. The purpose of this test is to verify that the connection can be maintained under

mobility and the link parameters, such as beam and gain settings, are adjusted automatically

and correctly for the two user devices individually.


The test environment has been chosen similarly to the first test in section 2.4.1. UD0 is

placed at a static position as shown in Figure 2—30.



In a first test, shown in Figure 2—30 (a), UD1 is moved from position A at 1 m distance to

position B at 4 m distance and back. As part of this test, the receive power level of the link

between AP and UD1 is expected to vary by about 12 dB while the receive power level of the

link between AP and UD0 is expected to remain constant.

In a second test, shown in Figure 2—30 (b), the distance between AP and UD1 is kept static

at 4 m. The angle between AP and UD1 axis is varied between 5° and 30°. As part of this test,

the beam settings corresponding to the link between AP axis and UD1 need to be adjusted

automatically, while the beam settings corresponding to the link between AP axis and UD0 are

expected to remain static.

(a) Top view of the 1st test setup. (b) Top view of the 2nd test setup.

Figure 2—30: The setup of the measurement.


1st setup

This test refers to changing the distance between access point and UD1 while keeping the

distance between access point and UD0 constant as shown in Figure 2—30 (a). Two traces have

been captured at the access point for two sequential runs of this test. The first trace uses static

receive gain settings at access point and user devices, which have been optimized as follows

• UD0: receive gain at the UD optimized for 4 m distance (label UD 0 UL in Figure 2—

31)

• UD1: receive gain optimized for 1 m distance (label UD 1 UL in Figure 2—31)

• AP: receive gain optimized for 4 m distance (label UD 0/1 DL in Figure 2—31)

The second trace uses adaptive gain control. The receive power at both user devices over the

course of the test is plotted in Figure 2—31.



.

Figure 2—31: Receive power at the static UD0 and the mobile UD1. Left w/o AGC, right: w/AGC.

White/green: receive power at the AP (uplink), red/blue: receive power at the UDs (downlink).

From the left-hand side plot, it can be seen that the receive power at the static UD0

remains constant as expected. The receive power at the mobile UD1 drops by 12 dB which can

be expected for a 4-fold increase in distance in LOS conditions. Likewise, the uplink receive

power of the mobile UD1 at the AP is saturated at 1 m distance. It arrives at the target value of

7 dBFs at 4 m distance as expected. From the right-hand side plot, it can be seen that the

automatic gain control, including the impact of beam steering maintains a static base band

receive power at target level of -7dBFs. The receive power varies by up to +/- 1 dB compared

to the target level for the mobile UD0. The uplink sum throughput has been captured in Figure

2—32.

Figure 2—32: UL sum throughput using 42% of the resources for data transmission. Left w/o AGC,

right: w/AGC.

Note that only about 20% of the available resources have been allocated to uplink data

transmission in this test. These resources are evenly split between both user devices. 16 QAM

modulation with code rate ½ has been employed for transmission. The respective sum data

rate of both user devices in the uplink is about 280 Mbit/s. The instantaneous data rate, i.e.,

the data rate if 100% of all resources were allocated to UL data transmission, is 1398 Mbit/s.

This modulation coding scheme is expected to work almost errorless over the distances tested

in this test if all parameters (beams, receive gains) are adjusted correctly. From Figure 2—32

(left), it can be seen that at very close distances of UD1 (saturation), only UD0 contributes to

the sum uplink throughput. The maximum possible throughput (with this MCS) is achieved if



both user devices are located in 4 m distance. The throughput drops again as soon as UD1 is

moved back to 1 m distance and the access point receiver saturates. From Figure 2—32 (right),

it can be seen that the throughput can be kept at a constant level in case automatic gain

control is turned on, ensuring a reliable transmission throughout the test.

The transmit and receive beams at the access point are plotted in Figure 2—33. It can be

seen that the beams firstly point into the correct direction (UD0 is located left compared to the

AP bore sight direction and UD1 is located right compared to the antenna bore sight direction).

Secondly, it can be seen that the beams remain almost static as expected. One exception is the

transmit beam connecting to the static UD0. This beam toggles between two settings. This can

be attributed to an almost identical receive power coupled to the two beams.

Figure 2—33: Transmit and receive beam settings at the access point. Left: static UD0, right: mobile

UD1.

2nd setup

Similar to the first setup, two traces have been captured for two individual runs of this test.

The first trace uses static receive gain settings which have been optimized at both user devices

at the starting position of the test. The second trace uses adaptive gain control.

The receive power at both user devices over the course of the test is plotted in Figure 2—34.

Figure 2—34: Receive power at the static UD0 and the mobile UD1. Left w/o AGC, right: w/AGC.



From the left-hand side plot it can be observed that the receive power of the static UD0

remains constant as expected. The receive power of the mobile UD drops by up to 3dB over

the course of the movement. With arbitrary fine grained beam steering and beams of equal

gain in all directions it could be expected that the receive power would not vary at all in this

test. However, it is expected that the receive power would change much more drastically

without beam steering, as expected by the beam shape. From the right-hand side plot it can be

seen that the automatic gain control compensates the drop in receive power within an

accuracy of +/-1 dB compared to the target value of -7dBFs.

The transmit and receive beams at the access point are plotted in Figure 2—35. The beam

settings for the static UD0 remain static as expected (except for some toggling between two

adjacent beams at the AP transmitter). From the right-hand side plot it can be seen how the

access point tracks the movement of the mobile UD1 by first choosing beams pointing more

and more rightwards and then selecting beams which point more and more leftwards as the

UD1 is moved back into its initial position.

Figure 2—35: Transmit and receive beam settings at the access point. Left: static UD, right: mobile

UD.

2.4.3 Two Randomly Moving User Devices


In this test, the access point connects to two user devices which are moved at random at

pedestrian velocities. The goal of this test is to demonstrate that the MiWaveS system can

adapt to mobility and maintain a stable connection in a multi user setting, addressing the

reliability KPI.

2.4.3.2 Test Conditions

The test environment is identical to the tests in sections 2.3.1 and 2.3.2. The access point is

located statically. Two user devices are moved at random at pedestrian velocities as shown in

Figure 2—36 and Figure 2—37. The movement also included random rotations of the UD.



Figure 2—36: Test setup: two users moving at random

Figure 2—37: Two randomly moving user devices. View from the access point perspective.

AP and UDs are placed at 1.53 m height. The distance between AP and UDs varies between

1 m and 4 m. AP and UD employ the same beam steering code books comprising 7 narrow

high-gain beams (evenly spaced between +/- 35° in azimuth) and 1 lower-gain wide beam.

Throughout the test the receiver automatic gain control as well as initial beam alignment and

beam tracking were active.


Two traces of 60 s duration each have been captured (denoted “test run 1” and “test run

2” in the following).

Figure 2—38 shows the connection state for both connections (top). Note that “3”

corresponds to “connected”. It can be seen that UD0 is disconnected once and UD1 twice. The

link is automatically re-established in both cases. The bottom of Figure 2—38 shows the AGC

related settings for UD1. Note that the target receive power is -7dBFs (green line). Firstly, it

can be seen that the receive power can be maintained at the desired level, except for cases

were the maximum receive gain (65 dB) is selected. The two disconnection events of UD1

correspond to cases were the receive power is insufficient.



Figure 2—38: Test run 1: connection state of both user devices and AGC settings of UD 1

A similar result is obtained for test run 2 shown in Figure 2—39. Again, the system recovers

from disconnections. The disconnections are coupled to cases where the receive power is

insufficient.

Figure 2—39: Test run 2: connection state of both user devices and AGC settings of UD 1

Finally, we investigate the transmit beams selected at AP and UD for data transmission in

connected state for test run 1. Figure 2—40 illustrates the results. Note that beam indices larger

than 7 indicate situations where the respective UD was disconnected.



Figure 2—40: Test run 1: selected transmit beams at AP and UD over time for UD0 and UD1.

Consider for instance the situations highlighted in white circles. In these cases, the AP

beam remains static while the UD beam was gradually switched from the left to the right. This

situation corresponds to a rotation of the user device. Also, there are situation where the

beam tracking algorithm toggles between adjacent beams (green circle for UD1

measurement). However, the receive power (see green line in bottom of Figure 2—38) and the

receive gain (see white line in bottom of Figure 2—38) remain almost static. In this case the UD

was not moved and two adjacent beams achieved about the same receive power. This toggling

(though not harmful in the test case) could be avoided by adding hysteresis functionality to the

beam tracking algorithm.

2.4.4 Summary

The tests presented in this section verified that the MiWaveS system can automatically

connect an access point to two user devices placed at different positions. It has been verified

that the beam steering algorithm is able to adjust the beam settings properly per user. Also, it

has been shown that the link is robust under the impact of pedestrian-level mobility.

These tests could be extended by testing longer distances between AP and UDs. Also, the

beam steering algorithm can be extended with hysteresis functionality in order to avoid

toggling between two beams if they exhibit similar link quality. The inter-relation of automatic

gain control and beam steering algorithms is another topic worth further theoretical

exploration.



3. Backhaul Link Demonstrations

This chapter documents the V-band and E-band hardware-centric backhaul outdoor and

indoor tests done in Espoo, Finland (Sections 3.1 and 3.2) and in Grenoble, France (Section

3.3).

3.1 Hardware-Centric Backhaul Outdoor Measurements in Espoo

The main purpose of backhaul tests was to verify the operation and performance of radio

hardware and partly software as well as system suitability for the intended use cases. Also,

some insight into mmW propagation was gained. First feature to demonstrate outdoors with

backhaul radio hardware was the capability to work over long (50…400 meter) hops and

indoors over long (12…28 meter) corridors and open spaces. The effect of minor, partial

obstructions and reflective surfaces near by the radio hop was the second issue of interest.

Third was the effect of objects that were sporadically blocking the backhaul hop installed in

low elevation. A target was also to get some experience on how beam steerable antenna

would help installation, even though the hardware was a laboratory prototype and not

designed for real installation.

The main objective addressed in these tests is Objective 6.1 (Test of components), Chapter

1.2. Main KPIs addressed here are 1 (End user capacity), 2 (reliability), 3 (backhaul range) and 4

(efficiency of installation).

These tests address several key aspects of MiWaveS use cases, Table 1-1. Majority of

outdoor test setups represent typical urban street-level mobile backhaul cases (UC1).

Antennas were installed in varying low elevation positions in street canyons. Some of the

measurement setups also demonstrate how a small reconfigurable backhaul node with beam

steerable antenna could be used in temporary locations like in large public gatherings (UC2).

Indoor measurements demonstrate how backhaul could be arranged along indoor corridors

with a mmW radio and they also indicate the challenges to provide capacity from outdoors

(UC3). Environment used was a typical industrial office facility. Rural detached small-cell zones

and villages (UC4) was not in the scope of these measurements, but some idea of the

achievable outdoor mmW hop lengths and capacities were gained.

The backhaul link measurement campaign was carried out at Nokia headquarter campus

(Karaportti 3, Espoo, Finland) during 17–18 Jan. 2017. The results presented in the following

have been published in [20]. The outdoor BH radio hops are shown in the aerial picture in

Figure 3—1.



Figure 3—1: Location of measurement hops in Nokia campus in Espoo, Finland.

This is part of MiWaveS hardware-centric demonstrator verifications. A more detailed

description of the radio hardware setup is presented in appendix A.3.

Table 3-1: Required hardware for Espoo backhaul outdoor measurements.

Hardware (BH) Supplier Units

Digital baseband including DAC/ADC NOKIA 2

Baseband SW and algorithms NI 1

BH RF 70 GHz NOKIA 2

Steerable CTS antenna UR1 2

Table 3-2: Required laboratory equipment for Espoo backhaul outdoor measurements.


Control computer NOKIA 2

Tripod NOKIA 2

Scope (view-finder) 9x44 NOKIA 2

Power supply NOKIA 2

Cables (base band, power supply) NOKIA -

10 MHz reference clock NOKIA 2

Car / van NOKIA 1

Trolley NOKIA 2

3.1.1 Outdoor Long Hop Throughput Test

The backhaul system was tested over different distances ranging from 10 m to 400 m.

The average snow depth was 6 cm, the air temperature varied from -5 C° to -2 C°, and the

wind speed varied from 2 m/s to 4 m/s. Figure 3—2 shows the hop length measurement path in

the campus.



Figure 3—2: E-Band non-obstructed LOS long hop measurement path.

The LOS environment includes tall buildings with metal coating glasses, trees with few

leaves, pedestrian with lamp post and few static vehicles. The baseband unit of Rx was placed

inside the van (Figure 3—3) for the ease of the transportation while the radio-node was

elevated by tripod and located next to the van. There was unbreakable power supply for RX

and TX nodes.

Figure 3—3: Typical outdoor measurement setup.

The TX was fixed at one location based on the power supply outlet accessibility, Figure 3—4



Figure 3—4: Typical TX outdoor measurement location.

The link performance at different hop length was tested in a non-obstructed LOS

environment. This scenario includes light snow, snowdrift, several vehicles, and sparse lamp

post randomly distributed. As reference, the link performance in lab environment was also

provided wherein; the lab offers adjustable attenuator which was required to emulate larger

distances of up to 400 m in free space. The Rx location was chosen at 10 m, 20 m, 50 m, 103 m,

200 m, 300 m and 400 m respectively.

Throughput is the key parameter for link performance and the system capacity

evaluations, and it can be achieved at an acceptable error rate that is defined by the

application requirements. Typical values would be 1%-10% error rate prior to a retransmission

protocol. The current test system supports 7 different MCS corresponding to throughputs

between 147 Mbit/s and 2318 Mbit/s. Figure 3—5 shows the comparison of the throughput

measurement results with different MCS and hop length. Figure 3—6 presents the comparison

of the time domain SNR obtained in outdoor and lab emulated-distance environment. It

indicates that the maximum throughput can be maintained at close hop distance to 20 m, and

about 2 Gbit/s can be achieved up to 50 m, approximately 1 Gbit/s could be supported up to

300 m, and a reliable transmission was possible up to 400 m at the minimum throughput.

There is a big gap when switching between 16 QAM and QPSK (100-150 m), and this gap is

much higher than the FEC coding performance suggests. This gap is due to the increase in

transmit power which is possible for QPSK as compared to higher order modulation (increased

peak to average power ratio-PAPR). For 16QAM we had to reduce the transmit power

significantly (back off) in order to avoid non-linear distortions at the Tx as much as possible,

and we gradually increased the Tx power when transitioning from 16QAM 7/8 to 16QAM 1/2.



Figure 3—5: Comparison of the throughput measurement results with different MCS and hop

length. Solid line with circle marker “o” represent the outdoor measurements, and the dotted line with

start marker “*” represent the lab measurement with emulated hop length.

Figure 3—6 Comparison of the time domain SNR measurement results with different hop length.



Figure 3—7: QPSK constellation diagram at the Rx for hop distances at 10 m, 20 m, 50 m, 103 m,

200 m and 400 m.

3.1.2 Outdoor Easiness of Installation

Traditional mobile backhaul installation requires significant human effort for manually

aligning the directional antennas at both ends of the backhaul link. Hypothesis is that when

number of network elements in 5G era increase and topologies become more variable manual

alignment must be replaced with automation to achieve the technical and economic

performance targets.

The assessment was carried out at two hop lengths, 20 m and 100 m respectively. The

procedure was as follows: First, both Tx and Rx antennas were aligned accurately towards their

boresight direction with telescopic sight. Then the Tx node was misaligned three times to

random directions and a person manually adjusted the node with his raw eye. Finally, the

beam was switched with electrical control system at both ends to find the best combination.

The receiver baseband power was recorded at each step. The recorded results are shown in

Table 3-3. It indicates that to align the RF front-end with human interaction only was

challenging. Average received power deviated from its reference result 9.3 dB (98%) at 20m

and 7.3 dB (49%) at 100m. With the help of electronic beam switching function, the

corresponding deviations were 1.2 dB (13%) and 0.6 dB (4%). This enables longer or more

reliable hops with the same margin. The results indicate that coarse alignment can be

remarkably improved with automatic beam steering function. Unexpectedly both manual and

electric pointing accuracy were superior over the distance of 100 m compared to 20 m.

Table 3-3: Beam alignment accuracy measurements.

Received power 20 m, Trial # 100 m, Trial #

1 2 3 1 2 3

Manunal adjust, dBFS -16.1 -20.5 -16.3 -21.1 -20 -23.5

Man. adj.+Beam switching,

dBFS -9.0 -10.5 -9 -14.8 -14.9 -14.7

Telescopic ref, dBFS -8.3 -14.2



Figure 3—8: A viewfinder.

3.1.3 Outdoor Blockage: Pedestrians Walking Along the LoS Path

The effect of pedestrians walking close to the LOS ray was evaluated. The Tx and Rx were

placed in the middle of a pedestrian walk, facing each other perfectly and the separation was

100 m. Location in Figure 3—16 was used. The height of the Tx/Rx (from the top of the antenna

to the ground level) was adjusted to 1.85 m, 2 m, 2.1 m, and 2.2/2.5 m respectively. The

maximum radius of the 1st Fresnel zone in the middle of the hop at 73 GHz is 0.32 m and 2nd

zone 0.45 m, Figure 3—9. The results presented in the following have been published in [21].

Figure 3—9: Indicative top and side view showing the measurement campaign. Fresnel ellipsoid

included (not to scale)

To reveal the effect to the radio link performance, the Rx power trace was recorded for all

different height settings. Resolution of recording was 20.48 ms. Y-axis dBFS (Full Scale) refers

to the maximum excitation of the ADC. It can be observed from Fig. 6 that the average

received power was more or less constant except for the lowest tripod height for which it was

a bit attenuated and 2nd lowest height where is was slightly higher. When the height of both

radio front ends was lowered, the fluctuations become more severe (larger deviation). The



variation coefficient, which is the ratio of standard deviation to mean value, decreased from -

5.5 dB for the lowest height to -10.5dB for the highest height measured.

Figure 3—10: Measured trace of the Rx power for different Tx/Rx heights.

These findings indicate that blocking can be modelled as an obstacle penetrating the 1st

Fresnel zone. If we compare lowest and the 2nd lowest elevation, we see signal amplification

because the 1st zone is freed but the 2nd zone is blocked. These observations can also be

analyzed as power distribution histogram in Figure 3—11 where the lowest elevation shows the

highest variance. Also, the received power fluctuation depended on the way and posture of

pedestrian walking. The difference between minimum and maximum value is 12 dB and 50% of

observations fall within average ±0.9 dB range. Typical duration of sudden fading situation is in

order of 100 ms and rate of signal change is modest, typically less than 1 dB/100 ms.

Figure 3—11: Histogram of the measured Rx power.

3.1.4 Outdoor Blockage: Moving Cars Passing Across the LoS Path

The effect of a car passing across the radio hop was investigated for different heights of

transmitter and receiver. Measurement location in Figure 3—12 was used.

Rx p

ow

er, dB

FS

Co

unt



Figure 3—12: Car blocking and outdoor-to-indoor measurement location.

The car in use for evaluating the performance was a wagon type car, with roughly 1.46 m

roof height and 4.57 m body length (denoted as Car_S). The Tx and Rx were separated by 25.5

m and placed at the both sides of the pavement as shown in Figure 3—13.The maximum radius

of the 1st Fresnel zone is 0.16 m and the 2nd 0.23 m. The scenarios are summarized as follows:

a. Height of Tx and Rx: 1.8 m. Car_S was passing across with 10 km/h

b. Height of Tx and Rx: 1.6 m. Car_S was passing with 10 km/h multiple times

c. Height of Tx: 1.42 m, Rx: 1.57 m. (1) Few random persons walking, (2) Car_S passing

multiple times, (3) one person walking on the pavement, and (4) a large car with fast speed

passing across, see numbers in Figure 3—14 (c).

The received power for different scenarios is plotted in Figure 3—14. It can be observed

that at each height the virtual LOS ray was not blocked completely but Fresnel zones were just

partially obstructed. Comparing the signal strengths during car passes at different heights we

see they match quite nicely to the single knife-edge obstacle diffraction loss model [18]. As an

example, the first pass in Figure 3—14 (2) lasts 2.2 seconds and signal variation is 3.4 dB. We

observed constructive and destructive superposition in the signal. When car is entering, or

exiting the radio beam there is also sudden changes (glitches) in the signal that may be caused

by additive reflections from other car surfaces i.e. bonnet and windows.

Figure 3—13: Indicative description of the moving car interference measurement setup (not to

scale).



a)

b)

c)

Figure 3—14: Received Rx power for different events a) , b) and c). (1), (2), (3), (4) in Fig c)

correspond respectively to the scenarios described above in the text.

3.1.5 Indoor Coverage from Outdoors

The penetration loss through different kind of glasses was evaluated in office building.

Location is seen in Figure 3—12 and in Figure 3—15.

Rx p

ow

er, dB

FS

Rx

pow

er, dB

FS

Rx p

ow

er, dB

FS



Figure 3—15: Measuring different window glasses in indoor-to-outdoor setup.

1. Safety Glass, having two insulating glass layers with Argon filling in between. The outer

glass layer consists of two 4 mm glasses and thin PVB (Polyvinyl butyral) film in between, and

the inner glass layer has an additional thin metal coating. Standard window glass used in the

campus.

2. Selective Glass, like Safety Glass, double-pane glasses with one layer coated with metal

oxide film. It is 14 mm thick and with size of 75 cm2. Sample for characterization purposes.

3. Non-metal coated Glass, double-pane non-metal coated glass with 20 mm thickness

and 1.5 m2 size. Sample for characterization purposes.

The backhaul link was first set up at 13.6 m separation with one node placed inside

building at 1 m from the glass and the other was placed 12.6 m away from the glass (see Fig.

11 as the indicative description). This setup can be viewed as a typical deployment scenario

where the outdoor node is placed on a lamp post in about ~10 m distance from the window.

Both radio nodes were adjusted at equal height of 1.8 m from the top of the antenna to the

ground level. The transmission path was oriented perpendicular to the glass surface. The

reference measurement was taken with the door open. Similar procedure was performed to

the 2.5 m separation with Tx and Rx radio nodes adjusted to the height of 1.47 m. The

Selective Glass was also measured in lab environment in a close distance to provide additional

results for comparison.

The results of our measured glass penetration loss are summarized in Table 3-4. The

average penetration loss of the Safety Glass was 37.5 dB, and the Selective Glass was 35.9 dB.

The penetration loss was similar with a small variation as a matter of different coating

structure and materials.



Table 3-4: Glass penetration losses.

Scenarios, Tx/Rx separation Glass type Penetration Loss

Outdoor-indoor, 2.5 m Safety Glass 38.8 dB

Selective Glass 35.5 dB

Outdoor-indoor, 13.6 m Safety Glass 36.1 dB

Non-metal coated Glass 4.8 dB

Lab environment Selective Glass 36.2 dB

3.1.6 Outdoor Reflections

The link performance and effect of surrounding obstacles in a light obstructed LOS

scenario was also evaluated. The hop length for this scenario was 42.6 m and it included the

curve shaped safety windows, the lamp post evenly distributed between Tx and Rx, see Figure

3—16 as reference.

Figure 3—16: Partly obstructed LOS scenarios (snow is now shown), red x denotes the evenly

distributed lamp post.

Figure 3—17: Measured reflective and partly obstructive outdoor environments.

The impact of small obstacles is also evaluated in terms channel power delay profile (PDP),

Figure 3—18. Firstly, comparing the PDP for a cabled base band Tx-Rx link to the PDP of a wave-

guide connected transmitter-receiver link (include the E-band radio) it can be seen that the

additional analogue components cause as spread of the PDP, as well as an increase of the

noise floor. Secondly, by comparing the wave-guide connected results to the over the air (OTA)

transmission results, it can be seen that no additional reflections contribute to the power delay



profile. The channel can hence be regarded as a line of sight channel, regardless of the small

obstacles.

Figure 3—18: Channel power delay profile for various locations compared to base band and wave-

guide connected transmitter and receiver.

3.1.7 Conclusions

E-band outdoor measurements show that full rate backhaul connections reaching 100

meters can be achieved with flat beam-steerable CTS antenna developed in the MiWaveS

project. Connection with slower data rate can range up to 400 meters that reaches couple of

blocks in urban street-level environment. Manual beam switching test after visual initial

alignment show that electrical beam steering can improve link level after initial installation

misalignment. Building materials’ attenuation varies heavily and is an issue when trying to

provide indoor-to-outdoor connection. As expected, sporadic objects like cars or people

blocking the mmW hop cause attenuation to links, but quite low elevation (“human level”)

installations are still possible in providing reasonable backhaul link quality for very small cell

mmW access nodes.

3.2 Hardware-Centric Backhaul Indoor Measurements in Espoo

The 60 GHz access radio link (Appendix A2) and 70 GHz backhaul radio link (Appendix A3)

were measured in several indoor scenarios. The main purpose was to verify the operation and

performance of radios developed in backhaul application and get more experience of usage in

different environments. Indoor measurements were conducted in April 2017. The location was

the Nokia office building in Espoo, Finland.

Table 3-5: Required hardware for Espoo backhaul indoor measurements.

Hardware (BH) Supplier Units

Same as with BH Outdoor measurements NOKIA -


RF V-band Sibeam 2


0 10 20 30 40 50 60

-50

-40

-30

-20

-10

0

channel tap @ 750 MS/s

norm

aliz

ed P

DP

in d

B

Base BandE-Band Wave GuideE-Band OTA, diff. Locations



Table 3-6: Required laboratory equipment for Espoo backhaul indoor measurements.


Same as with BH Outdoor measurements NOKIA -

Large absorber NOKIA 1

3.2.1 Indoor Corridor

Access radio (AP + UD) was used in backhaul setup to reflect the probable in-band or self-

backhaul scenario where access radio is used to provide also backhaul capacity to the site.

Also, some insight into mmW indoor propagation was gained.

First measurement was performed in a narrow indoor corridor, Figure 3—19. Width of the

corridor is 1.55 m, maximum length 28 m and height 2.9-2.4 meters. Walls are made of

plasterboard, doors are metal. One of the center beams were selected manually in both ends

and radio alignment was retained at all distances.

It was earlier tested that beam combination [3; 3] (notation: [AP beam number; UE beam

number]) gives the strongest signal. This pair was used as a reference in the measurements.

Main beam deviates from mechanical center-line in azimuth direction 5.4°. AP and UE were

aligned so that signal strength was -10.1 dBFS. Sensitivity to beam selection was checked by

keeping mechanical alignment but manually changing beams. Neighboring combinations [3;2],

[4;2] and [4;3] gave a bit stronger signal strength -9.0…-9.3 dBFS.

Next the beam search scenario was tested in similar way. First AP was frozen to beam

number 3 while UD beam was manually stepped from 0…7. Same was repeated in the other

end (UD). Results are listed in Table 3-7.

Table 3-7. Signal strengths at different AP-UE beam pair combinations with 60 GHz access

demonstrator hardware.

Access Point beam fixed

Beam Nr. AP 3 3 3 3 3 3 3 3

Beam Nr. UD 0 1 2 3 4 5 6 7

Rx BB power, dBFS -14.9 -15.1 -9.4 -10.3 -14.1 -15.2 -15.1 -20.0

User Device beam fixed

Beam Nr. AP 0 1 2 3 4 5 6 7

Beam Nr. UD 3 3 3 3 3 3 3 3

Rx BB power, dBFS -18.1 -18.9 -15.6 10.3 -9.5 -13.6 -24.4 -15.5

It was also noticed that the received signal level (RSL) indicated by the access link

equipment (AP and UE) changed after the first few minutes. This was taken into account in the

measurements.



Figure 3—19: Narrow indoor corridor.

3.2.2 Indoor Corridor Reflections

In this measurement, the reference beam pair [3;3] was electrically selected and then each

end was manually rotated in azimuth plane to find reflections from the walls. Geometry for V-

band (a) and E-band (b) are in Figure 3—21.

Figure 3—20: Indoor corridor wall reflections in V-band (a) and E-band (b).



Measured signal strengths are in Table 3-8. As antenna beam pattern in V-band

demonstrator is not as narrow and symmetrical as in E-band, the points of reflection in (a) are

not as symmetric as in (b). Also, stronger than reference signal values may be due to summing

of side-lobe signals.

Table 3-8. Measured wall reflection signal strengths at V-band and E-band

Pointing location,

a) 60 GHz,

Ref. -10.3 dBFS

A B C

Pointing location,

b) 70 GHz,

ref. -7.7 dBFS

A B

Rx BB power,

dBFS -9.1 -6.6 -12.9

-7.2 -6.4

It can be seen that reflections from wall and door are strong and potentially provide good

multi-path channels. In E-band setup antenna beam is narrow with low sidelobes (“pencil

beam”), so the points of reflection are nicely in the middle of path.

3.2.3 Indoor Corridor Blockage

Indoor blockage measurements were conducted with 60 GHz access (Appenxix A2) and 70 GHZ

backhaul (Appendix A3) radios. Measurements were done in the same narrow corridor as

unobstructed test and a reference measurement was performed in a large indoor open space.

Human body and absorber (60x200 cm) blockage setups are shown in Figure 3—21.

Figure 3—21: Pictures from indoor corridor blockage measurements. a) 70 GHz with a large

absorber, b) human body blockage at 60 GHz.

For narrow corridor measurement, walkers (denoted as walker 1 and walker 3) were

walking one by one from AP towards UD and vice versa. The results of received baseband

power was shown in Figure 3—22 … Figure 3—24



Figure 3—22: Indoor human blockage profiles (dB full-scale) versus time in a narrow corridor.

From Figure 3—22 we can see that when person is close by antenna, and the blocked angle is

large, the attenuation is large. However, when person is moving in the middle of the beam

signal strength is almost the same as in non-blocking situation even the blockage is larger than

first Fresnel zones. To make a comparison, the human blockage measurement was also

conducted in a rather large open area with the same separation between AP and UD, Figure 3—

23. In this scenario, walkers (denoted as walker 1 and walker 2) were walking similar speed

from AP to UD. The blockage is more total during the whole pass as the signal drops below the

threshold level. Similar results were achieved with absorber.

Figure 3—23: Indoor human blockage profiles (dB full-scale) versus time in a wide indoor space.

Rx p

ow

er,

dB

FS

Rx p

ow

er,

dB

FS



Human body blockage measurement was also made with V-band radio 2 persons walking side

by side in large open indoor space, Figure 3—24. The attenuation profile is different as there is a

dynamic obstructed LoS path between the nodes.

Figure 3—24: Indoor human blockage profiles (dB full-scale) versus time in a wide indoor space, two

persons side by side.

3.2.4 Conclusions

Measurements with V-band radio indicate that indoor corridors are a good environment

for line-of-sight connections as the signal level attenuates less than in large open space. In

addition, indoor surfaces cause reflections that mitigate the blocking effects indoor as

beamforming antenna can utilize multipath channels. The relatively wide-beam steerable

antenna, as here in AP setup, performs better than narrow-beam antenna in blocking scenario.

In indoor scenario longest 28 meters LoS hops were reached with V- and E-band radios.

3.3 Hardware-Centric Backhaul Demonstrations Conducted in Grenoble

The goal of this test is to assess the link quality of the V-band backhauls developed in

MiWaveS and to check the throughput at various distances (here: 25m and 70m). Bandwidth is

that of an IEEE channel, i.e.1,76GHz. Link budgets calculated in [2] have shown the necessity of

high gain antennas at both ends of the backhaul link. One means to obtain such high gain is to

use lenses [11]. Two types of lenses have been developed in MiWaveS (dielectric and discrete).

In the following, in order to test these two antennas, we put a different type of lens at each

end of the link. However, one of the antenna having a gain much larger than the other, we

would have reached a yet higher distance by using the discrete lens at both ends.

Rx p

ow

er,

dB

FS



3.3.1 Hardware Setup

The V band backhaul front-end of the hardware-centric demonstration is composed of a

PCB identical to the User Device (UD) used in Section 2, but having a dedicated mechanical

fixture to set a fixed beam lens antenna in front of the UD node. See appendix A1.1 for details

about the user device. Two different lens antennas are used: a discrete lens (transmit array)

and a dielectric lens. In both cases the Tx/Rx patch antennas on the UD interposer board are

used as a feeder antenna. Figure 3—25 shows the UD node with the fixing plate for the planar

discrete lens. The dielectric lens with a similar type fixing plate is presented in Figure 3—26.

Figure 3—25: V band backhaul node with the mechanical fixing plate (left) and the discrete lens

antenna (right).

Figure 3—26: V band backhaul node with the mechanical fixing plate (left) and the dielectric lens

antenna (right).

The source patch antenna is set in the focal plane of the lens in order to form a fixed

directive beam. The dielectric lens, associated to a single patch, has a gain of 26.7 dBi. The

planar discrete lens has a higher antenna gain of 32dB.

The required demonstration hardware and laboratory equipment is summarized in Table 3-9

and Table 3-10.



Table 3-9: Required hardware for hardware-centric demo


RF and antenna V-band from UD terminal CEA+ST 1

Dielectric lens V-band ST 1

Discrete lens V-band CEA 1

Table 3-10: Required laboratory equipment for hardware-centric demo


Tektronix Digital Oscilloscope CEA 1

Tektronix signal generator CEA 1

Trolley CEA 2

3.3.2 Backhaul Tests

The goal in these tests is to evaluate the backhaul performance in terms of distance and QoS,

using two different setups at each end: the discrete lens and a dielectric lens, having different

gains. The tests are designed towards fulfilling O6.1, and are related to Use cases 1,2, 4 and 5

as described in Section 1.2.

3.3.2.1 Standalone Transmitter Performance:

The standalone transmitter performance is measured over the air with modulated signals.

The bandwidth is 1,76GHz in V-band. Similar to Section 2.2, the baseband signal is provided by

a signal generator and evaluated by a digital oscilloscope at the receiver. In this standalone

evaluation, the transmit signal waveforms are received by a horn antenna and directly

sampled by a 70 GHz ATI oscilloscope. The oscilloscope performs the digital down-conversion,

per block synchronization and decision feedback equalization to obtain the modulation

constellation. An EVM of 9 % (-21 dB) has been measured for 16QAM (transmitted raw bit rate

of 7 Gbps) and 10 % (-20 dB) for 64QAM (transmitted raw bit rate of 9 Gbps), which indicate a

very good transmit signal quality. Figure 3—27 and Figure 3—28 show the received signal

constellation and spectrum for 16QAM and 64QAM modulations.

Figure 3—27: Characterization of standalone transmitter. Performance measured at horn antenna :

received signal constellation and spectrum for 16QAM modulation.



Figure 3—28: Characterization of standalone transmitter. Performance measured at horn antenna :

received signal constellation and spectrum for 64QAM modulation.

3.3.2.2 Backhaul Transmission Performance

A wireless transmission between two backhaul nodes (one with the dielectric lens and the

other the transmit array discrete lens) has been carried out at 25 m link distance by using

uncoded 16QAM modulation (7 Gbps, 15% EVM), and at 70 m link distance by using uncoded

QPSK modulation (3,5 Gbps, 22% EVM). We remind that the bandwidth is 1,76Ghz, which on

the one hand shows that the antenna and RF developed within MiWaveS can cover such a

large bandwidth, and on the other hand explains the high throughput compared to Espoo

experiments at 750MHz. This demonstration has been recorded in a short video and is

available on the project website.

Figure 3—29: V band backhaul demonstration at CEA premises.



Taking into account that the transmit array (discrete lens) is more directive (32 dBi) than

the dielectric lens (24 dBi), one can expect a longer range by using transmit array antennas at

both ends of the link (transmitter and receiver). Neglecting the effect of oxygen absorption on

the 60GHz signal (15dB/km), considering that the LOS path loss is that of free space, the link

budget is inversely proportional to d2, where d is the distance between transmitter and

receiver. Thus if we had used the same discrete antenna lens on both ends of the backhaul

link, we would have added 8 dB to the link budget, and thus multiplied the distance by 2,5,

which means that we could have transmitted

- A QPSK signal at 3,5 Gbps at 2,5x70m =175 m

- A 16QAM signal at 7 Gbps at 2,5 x 25m = 62,5m.

Here, we remind again that these bitrates correspond to uncoded and unframed data.

Reduction by a factor of 13% gives the equivalent framed data.

We can see that, then, the backhaul distances are compatible with Use Case 5, as described in

Section 1.2.

3.3.3 Summary

We have performed an indoor backhaul measurement campaign, using two kinds of lens: a

dielectric lens at one end, and a discrete lens (transmitarray) at the other end. The

transmitarray gain is 9dB higher than that of the dielectric lens. We proved that we could

transmit a significant high bit rate signal (6 Gbs) at a distance of 25m, which might seem short,

but a simple calculation shows that with a transmitarray on both sides, the 9dB additional gain

would have allowed the same transmission at a 62m distance, which would certainly be

relevant for Use Case 5.



4. End-to-End Application Demonstrations in Dresden

The demonstrations presented in this chapter show how the mmWave backhaul and

access systems demonstrated individually in previous chapters have been augmented to run

an actual application over the mmWave link. This is part of the final demonstration integration

activities within MiWaveS. Section 4.1 demonstrates unidirectional end-to-end video

streaming over a two-hop link comprising E-band backhaul and V-band access using the

hardware centric demonstration systems presented in sections 2.1, 2.2 and 3.1. Section 4.2

illustrates bi-directional data connectivity for the algorithm centric access link setup presented

in sections 2.3 and 2.4. This bi-directional data connectivity is further used to connect an

application running at the user device side to the internet.

The demonstrations are planned to be shown during the final project review meeting in

July 2017.

4.1 Hardware-Centric E-2-E Backhaul and Access Application Demonstration

The software layers comprised in the hardware-centric demonstration system, shown in

Figure 1—4, mainly implement real time wide band physical layer processing and manual

control of the link parameters. Forward error correction and the option to choose across a

selection of data rates enable a reliable and error free data transmission. This system has been

augmented with a UDP data interface as shown in Figure 4—1.

Figure 4—1: Functionality added to the hardware centric software implementation to enable uni-

directional UDP traffic.

The Ethernet interface which is mainly used to control and monitor the system is also used

to deliver and receive payload data using UDP functionality. On the transmitter side, a UDP

interface accepts UDP data packets from an external source with a static payload size of 1316

bytes. These packets are forwarded to the L1_DRV layer which prepends a header to the UDP

packets and inserts them into transport blocks in a preconfigured manner for further forward

error correction encoding and modulation at the FPGA. At the receiver, functionality has been

added on the L1_DRV layer to parse transport blocks which have been correctly decoded for

the UDP packet header. Once a header is detected, the respective packet is forwarded to the



UDP interface and transferred to an external pre-configured data sink over the Ethernet

interface.

This functionality can be used in combination with the VLC video player to stream video

files over a single mmWave hop and display them at the receiver. It can also be used to stream

a video over two hops as shown in Figure 4—2.

Figure 4—2: E-2-E demonstration setup for streaming a video over two mmWave hops.

This setup comprises four base band units, two E-band backhaul radio units, a V-band

access point radio transmitter and a V-band user device radio receiver. The E-band access

point backhaul receiver relays received UDP packets to a separate V-Band access point

transmitter. E-band and V-band radios provide beam steering capabilities which can be

adjusted manually through the base band user interface in parallel to the data transmission to

optimize the link quality.



4.2 Algorithm-Centric E-2-E Access Application Demonstration

The software layers comprised in the algorithm-centric demonstration system, shown in

Figure 1—4, augment the hardware-centric demonstration functionality with layer 1 control

and layer 2 MAC functionality. This functionality enables a bidirectional link with automatic

beam control based beam steering algorithms executed as part of the layer 2 MAC

functionality. This system has been augmented with bi-directional UDP data connectivity as

shown in Figure 4—3.

Figure 4—3: Functionality added to the algorithm-centric software implementation to enable bi-

directional data connectivity.

The Ethernet interface which is mainly used to control and monitor the system is also used

to deliver and receive payload data using UDP functionality, similar to section 4.1. A UDP

interface accepts data with a variable payload size of up to 1472 bytes. Basic layer 2 RLC (Radio

Link Control) functionality has been added to encapsulate UDP packets into MAC SDUs SDUs

(Service Data Unit), including generation of respective header information, at the transmitter

side. Likewise, on the receiver side, UDP packets are extracted, controlled by header

information, and forwarded to the UDP interface. UDP traffic can be sent in both directions

simultaneously, enabling a bi-directional data link over the mmWave system.

The UDP functionality can be used for unidirectional video streaming, similar to the

functionality introduced in section 4.1.

The bi-directional UDP connectivity is further exploited to provide internet connectivity

over the mmWave access link as shown in Figure 4—4.



Figure 4—4: E-2-E demonstration setup for providing internet connectivity over the V-Band

mmWave access link.

In order to achieve internet connectivity, UDP tunnelling functionality has been added at

AP and UD side. In this demo, the UDP tunnel is implemented using OpenVPN. Task of the UDP

tunnel is to encapsulate IP packets into UDP packets and forward them to the UDP interface

offered by the mmWave system. Likewise, the encapsulated IP packets are extracted from UDP

packets received from the mmWave system and forwarded to their correct destination. This

functionality has been used at the user device side to connect to an internet video streaming

service.

Figure 4—5 shows the laboratory hardware setup which implements the block diagram

shown in Figure 4—4.

Figure 4—5: Laboratory setup used to test the algorithm-centric E-2-E application demonstration.

The screenshots in Figure 4—6 show a close-up view of the access point graphical user

interface and the beam settings. In this test, the MiWaveS project website was accessed over

the mmWave access link as shown on the right of Figure 4—6.



Figure 4—6: Left: access point user interface showing beam settings and scheduling information.

Right: MiWaveS project website accessed at the user device over the mmWave link and Wireshark-

based inspection of the connection.

Figure 4—7 illustrates the monitoring of the UDP tunnel at server (connected to the access

point) and client (connected to the user device).

Figure 4—7. Left: OpenVPN server status monitoring and Wireshark-based inspection of the

connection, running on the Linux PC connected to the access point. Right: OpenVPN status monitoring

on the Windows PC connected to the user device.

4.3 Summary

UDP data connectivity has been added to MiWaveS demonstration systems. For hardware-

centric demonstrations, it allows to stream videos unidirectionally over a two-hop link

backhaul and access link, were the access point acts as a relay. Bi-directional UDP data

connectivity is available for the algorithm centric demonstrations. This has been exploited to

connect an application running at the user device side to the internet. This setup allows to

demonstrate an actual application including data exchange over a mmWave link even under

mobility.

Currently, the mapping of UDP packets to MAC SDUs or transport blocks does support

mapping of one UDP packet to one MAC SDU or transport block, respectively, which limits the

data rate. The data rate offered by mmWave link can be further exploited by adding

concatenation and segmentation functionality, i.e., concatenating multiple UDP packets into

one MAC SDU or transport block.



5. Summary and Conclusions

This deliverable summarizes the nine different demonstrations and tests conducted as part

of MiWaveS. In particular, the experiments were guided by the two WP 6 objectives: O6.1 to

demonstrate the components developed in MiWaveS and O6.2 to demonstrate algorithms

developed in WP2. O6.1 has been evaluated using the hardware-centric variant of the

demonstration system, while O6.2 has been evaluated using the algorithm-centric variant of

the demonstration system. In addition important KPIs, derived from use cases were evaluated

during the experiments.

Chapter 2 covered four different indoor access link experiments. Firstly, using the digital

base band system developed in the project, it was shown in hardware-centric experiments that

radio components developed in MiWaveS can cover cells up to about 30 m with a cell edge

rate of about 550 Mbit/s. Close to the AP, 1.6 GBit/s throughput were achieved. Additional

experiments using signal generators and analysers verified that the components are suited for

wider-bandwidth transmission.

Secondly, automatic beam alignment and tracking were verified to operate as expected in

single and multi-user algorithm centric experiments, also under the impact of mobility. That is,

a reliable mmWave link could be automatically established and maintained. In the single user

context, the MiWaveS advanced beam alignment algorithm have been shown to require

significantly less channel probing resources as compared to exhaustive search baseline

algorithms. Resources not used for channel probing were used to automatically schedule a

payload transmission.

NLOS conditions were also tested briefly. As expected, different reflecting surfaces were

found to have major impact on the receive power, requiring higher link margins in order to

guarantee a reliable transmission. More general conclusions would require additional system

level experiments including multiple access points and the option to hand over connections.

Chapter 3 focussed on indoor and outdoor backhaul link experiments. It was shown that

full data rate range to 100 meters while a stable connection can be maintained up to 400 m in

the E-band using radio and antenna components developed in MiWaveS. It was also briefly

verified that the steering capability built into the E-band antenna can lead to an easier

installation of the backhaul link.

For the V-band backhaul it has been verified that data can be transmitted reliably over

about 28-70 m using two different antenna types at backhaul transmitter and receiver. This

range is expected to be even larger (by a factor of 2,5), using the higher-gain version of the two

at both ends of the link.

Chapter 4 illustrated the transmission of video content over two hops (E band backhaul

and V-band access), combining the hardware-centric backhaul and access link demonstration

system presented in chapter 2 and 3.

A second demonstration shows internet access over the algorithm centric V-band access

link, with internet traffic being transmitted in up- and downlink simultaneously. This

demonstration proofs the correct functionality of the closed loop mmWave system developed

in MiWaveS.



Future research should extend the experiments conducted in MiWaveS towards multi-

access point settings in order to test also system level features such as hand-over. Also, the

joint optimization and test of gain control and beam steering require further theoretical work

and practical test.



6. References

[1] MiWaveS project, Description of work – v19, October 9, 2013.

[2] MiWaveS, “Definition of the heterogeneous network: topology, use cases, and link

budgets”, Deliverable D1.1.1, August 2014.

[3] MiWaveS, “Detailed specification of demonstrator setups and functionality”, Deliverable

D6.1, October 2014.

[4] MiWaveS, “Backhaul link tests and presentation of demonstrator subset 1”, Deliverable

D6.2, December 2015.

[5] MiWaveS, “Integrated Analog Front-Ends, Protocol and Software Infrastructure and

Beamforming Implementation”, Deliverable D5.5, April 2017.

[6] MiWaveS, “Implementation of digital base band processing for mmWave communication

on NI PXI”, deliverable D5.4, June 2016.

[7] MiWaveS, “Detailed specification of demonstrator setups and functionality”, deliverable

D6.1, October 2014.

[8] M. Cudak, A. Ghosh, T. Kovarik, R. Ratasuk, T.A. Thomas, F.W. Vook, P. Moorut, “Moving

Towards mmW-Based Beyond-4G (B-4G) Technology”, 2013 IEEE 77th Vehicular

Technology Conference (VTC Spring), Dresden, Germany, 2–5 June 2013.

[9] A. Gosh, T.A. Thomas, M.C. Cudak, R. Ratasuk, P. Moorut, F.W. Vook, T.S. Rappaport, G.R.

Mac Cartney, Shu Sun, Shuai Nie “Millimeter-Wave Enhanced Local Area Systems: A

High-Data-Rate Approach for Future Wireless Networks”, IEEE Journal on Selected Areas

in Communications, vol. 32, no. 6, June 2014, pp. 1152-1163.

[10] MiWaveS, “Beamsteering functional description”, Deliverable D2.2, June 2015.

[11] MiWaveS, “Antenna technologies for mmWave access and backhaul communications”,

Deliverable D4.5, September 2016

[12] MiWaveS, “60-90 GHz transceiver technologies”, Deliverable D3.6, October 2016

[13] MiWaveS “60 GHz transceiver for the user terminal” deliverable D3.5, July 2016.

[14] M. Cudak, A. Ghosh, T. Kovarik, R. Ratasuk, T.A. Thomas, F.W. Vook, P. Moorut, “Moving

Towards mmW-Based Beyond-4G (B-4G) Technology”, 2013 IEEE 77th Vehicular

Technology Conference (VTC Spring), Dresden, Germany, 2–5 June 2013.

[15] A. Gosh, T.A. Thomas, M.C. Cudak, R. Ratasuk, P. Moorut, F.W. Vook, T.S. Rappaport, G.R.

Mac Cartney, Shu Sun, Shuai Nie “Millimeter-Wave Enhanced Local Area Systems: A

High-Data-Rate Approach for Future Wireless Networks”, IEEE Journal on Selected Areas

in Communications.

[16] V. Frascolla, M. Faerber, G. Romano, L. Dussopt, E. Calvanese-Strinati, R. Sauleau, L.

Ranta-aho, J. Putkonen, V. Kotzsch, J. Valino, “Challenges and opportunities for

millimeter-wave mobile access standardisation”, IEEE Globecom, Austin, United States,

Dec 8-12 2014.

[17] MiWaveS “Status of the Digital Baseband Implementation” Deliverable D5.1, December

2014

[18] ITU-R, “Propagation by diffraction”, Recommendation ITU-R P.526-13, November 2013.

[19] MiWaveS, “Dynamic self-organising network functional description and algorithms”,

Deliverable D2.4, December 2015.



[20] Z. Du, K. Aronkytö, J. Putkonen, J. Kapanen, E. Ohlmer, D. Swist, “5G E-band Backhaul

System Measurements in Urban Street-Level Scenarios”, EuMW’17, Nürnberg, Germany,

October 9-13 2017.

[21] Z. Du, K. Aronkytö, J. Putkonen, J. Kapanen, E. Ohlmer, D. Swist, “5G E-band Backhaul

System Evaluations - Focus on Moving Objects and Outdoor to Indoor Transmission”,

EuCNC’17, Oulu, Finland, June 12-15 2017.

[22] T. Kadur, H.-L. Chiang, E. Ohlmer, C. Felber, M. Ullmann, D. Swist, J. Säily, A. Lamminen,

M. Kaunisto, J. Aurinsalo, L. Marnat, L. Dussopt, S. Mayrargue, „Millimeter Wave V-Band

Link – Proof of Concept Setup and First Results“, EuCNC’17, Oulu, Finland, June 12-15

2017.



Appendix A. Details About Different mmWave Radio Setups

A.1 MiWaveS V-Band Access Link Radio Setup

A.1.1 User Device Antenna and Front-End Description

The 60 GHz transceiver (CEA and ST-Fr) has been fully depicted in [13]. It is intended to be

used both in indoor (Wireless HD, IEEE 802.11ad) applications and outdoor 5G connectivity.

The transceiver covers the four IEEE channels from 57 to 66 GHz and supports single carrier

and OFDM modulated signals (up to 16QAM), thanks to its wide bandwidth, linearity, and low

phase noise.

Figure A—1: User Device, antenna and transceiver

The user device receiver employs an antenna with a bandwidth of 17,6% (57-68GHz), a gain of

7dB and a half power beam width of 100°.

A.1.2 Access Point Antenna and Front-End Description

The access point front-end consists of an active switched beam Rotman lens antenna and a

V band transceiver board. The transceiver board is similar to the user device transceiver board.

The main difference is that in the case of the user device the Tx and Rx antennas are integrated

on the transceiver board while in the access point, the transceiver board has coaxial V band Tx

and Rx connectors for external Tx and Rx antenna arrays. A specific attention has been paid to

these connections in order to limit inter-connection losses.

The antenna board is assembled on a non-metallic material as a metal could have an effect

on the Rotman lens behavior.

.

Figure A—2: The assembled V band access point front-end



Active Rotman lens antenna arrays are used as switched beam access point antenna. The

antenna board includes separate antenna arrays for Rx and Tx. Each array consists of 32 (8*4

array, eight elements in horizontal and four elements in vertical cut) aperture coupled patch

elements. Both arrays are fed by a Rotman lens beam-former which corresponds to a 3-bit

phase shifter. The Rotman lens has five beam ports and eight array ports. Each array port is

connected to one array column which contains four vertical patch elements. The antenna

covers an angle range of +/- 30 degrees in the azimuth plane with five switched beams. In the

elevation plane the antenna beam is fixed. The performance parameters of the 4*8 patch

antenna array with Rotman lens beam-former are given Table A-1.

Table A-1: Performance figures of access point transmitter.

Frequency range 57 – 66 GHz

Array size 4*8 patch elements (Rx and Tx)

Number of beams 5 beams (azimuth cut)

Beam directions 0, +/- 12, +/-23 degrees (azimuth cut)

Az. beamwidth (-3 dB) 10 degrees (azimuth cut)

El. beamwidth (-3 dB) 25 degrees (elevation cut)

Antenna gain 13.5 dBi (at beam port LNA input and

beam port PA output)

PA output power (corresponds to the

mean output power of the transceiver

board)

12 dBm

Front-end 25.5 dBm

A.2 Sibeam V-Band Access Link Radio Setup

The radio frontend is using an off-the-shelf RF transceiver produced by SiBeam, which targets

the use case of replacing fiber communication by a wireless link at 60 GHz. The specific IC used

(SiI6340), contains the RF up/down-conversion, gain stages, phase shifters and antennas in one

package. With phase shifters and antennas being integrated, it allows for beam-steering

research and demonstrations in the V band.

The IC is integrated on a separate transceiver module that contains a clock reference as well as

decoupling capacitors for the power rails. The module also includes certain power supply

components for generating the voltages used by the radio frontend. Using a custom flex cable,

the module is connected to a dedicated NI Interface board. The NI Interface board breaks out

the various control and baseband I/Q connectors to interface with the baseband

demonstrator. It also provides the supply power to the SiBeam frontend. Figure A—3 provides

an overview of the frontend and its cabling.

In order to adjust between the receiver and ADC baseband I/Q levels and mode, there is an

additional RX Level Adjustment Board required. All I/Q connections are assumed to be length-

matched SMA cables to prevent additional I/Q mismatch being introduced to the setup.



Figure A—3: Setup for using the SiBeam Phased Array Antenna.

The initialization and real-time control from the baseband is provided via matching connectors

for the NI 6583. Two separate connections for both single ended as well as differential control

lines are required to connect to the interface board.

The SiBeam transceiver modules contain individual reference oscillators which have an

absolute tolerance of +/- 20 ppm. They cannot be locked to an external reference frequency.

For an RF system, a resulting carrier frequency offset cannot be avoided and thus needs to be

compensated in the baseband implementation. The maximum frequency offset under worst

case conditions would be 40 ppm offset, which is about 2.5 MHz for a 62.64 GHz carrier.

Results obtained in laboratory measurements suggest frequency offsets in the range of a few

100 kHz also due to the fact that the modules are used in the same lab environment and

ambient temperature.

The transceiver is used in TDD mode. At one given point in time, either the receive path or the

transmit path will be active. The switching between the two states takes roughly 2 us,

excluding settling times that the overall system may require on top of that.

In the receive chain, several gain stages are used to amplify the received signal. Like other

components, the gain can be controlled using a high-speed bus-based control interface. The

overall settling time of the gain stages excluding the control interface latency is below 100ns.

In Figure A—4, the beam steering solution inside the SiI6340 is shown. There is a phase shifter

value assigned for each element. 12 elements per direction are available which leads to 24

antenna elements total being integrated into the package. Each phase shifter has a resolution

of 2 bits, resulting in the discrete settings of 0°/90°/180°/270°. The settings can be controlled

digitally using the high-speed control interface. The overall settling time of the analogue phase

shifters is below 100ns excluding the control interface latency.



Figure A—4: Simplified transceiver block diagram explaining the beam steering architecture.

By default, the configuration is enabling all antenna elements. In combination with the right

code word for the phase shifters, a narrow beam pattern is formed. The end user can adjust

the beam settings through beam steering code books which comprise pre-defined phase

settings. The beam steering code book used in the demonstrator is provided by SiBeam. It is

optimized for covering the azimuth plane (one dimension) with a steering range of {-60°,…,60°}

in 5 degree steps. The central beam of the code book has a half power beam width of about

22°. The half power beam width increases towards higher steering angles. It is about 33° at +-

50°.

The maximal antenna gain is 18 dBi, resulting in an EIRP of 30 dBm.

A.3 70 GHz Backhaul Radio

The E-band backhaul hop consists of a transmit node and a receive node as shown in Figure

A—5. Each node is separated into base band processing system and E-band radio with beam-

steerable CTS antenna, mounted on a tripod. Two commercial telescopic sights with maximum

9x optical zooming were mounted close to the antenna for link alignment purposes

The E-band radio hardware was built at Nokia Bell Labs Espoo using components provided

by MiWaveS projects partners. SiversIMA provides the transceiver modules to the E-band (71-

76 GHz) backhaul system. The current transceiver has been enhanced by external local

oscillator (LO) and analog front-end (AFE) boards. The external transmitter/receiver (Tx/Rx)

LOs and SPDT switch with on/off switching allow the transceiver to use time division duplex

(TDD) operation scheme. The AFE board provides the intermediate frequency (IF) to baseband

frequency conversion required for interfacing with the baseband platform. The CTS antenna

combined transmit/receive port is connected to the individual transmit and receive ports of

the mmW converter through a SPDT duplex waveguide switch.

The base band transmitter and receiver are implemented in LabVIEW on the National

Instruments PXI platform. Signal processing is carried out in real time on FPGAs, paired with

physical layer control functionality which is executed on a real-time controller. The system

employs single carrier modulation operating at a symbol rate of 750 MS/s. The data rate can

be varied between 147 Mbit/s – 2318 Mbit/s on a per-slot time scale, where each slot has a

duration of 102.4 us. Rate variation is achieved by varying the MCS and the code rate of the



3GPP-LTE compliant turbo code. The base band system provides manual control of receive and

transmit gains as well as transmit/receive antenna beam directions.

Figure A—5: E-band backhaul radio setup in laboratory.

Synthesizer

Up-converter

Down-converter

Up-converter

Down-converter

Synthesizer

Synthesizer

Synthesizer

x6

x6

TX_I

TX_Q

RX_Q

RX_I

AFE2 SIVERS

TX

RX

4.1 GHz 77.60 GHz

76.48GHz

12.7466... GHz

12.933... GHz

73.5 GHz

2.98 GHz

73.5 GHzIF

LO

RF

LO

RFIF

Baseband

Tx LO

Rx LO

Figure A—6: Block diagram and frequency scheme of E-band BH radio system.

Figure A—7: E-band backhaul radio unit used in measurements: a) back-view, b) side-view. Instead

of fixed-beam horn antenna a steerable beam



Appendix B. Hardware-centric Single-User V-Band Access –

Detailed Throughput results.

This section refers to the hardware-centric single-user access link tests conducted in

Dresden (see section 2.1.2). For different distance and beams, the system throughout by three

modulation and coding schemes (MCSs) is evaluated. Intuitively, the throughput degrades

when the UD is far away the AP, see Figure B—1. In Figure B—1(a)-(c), we can find that beam 3

has the worst beamforming gain. On the other hand, bema 4 has the best one, which enables

the communication with BPSK and QPSK for the distance up to 31.4 meters.

(a) The theoretical throughput by BPSK 1/5 is 147 (Mbit/s).

(b) The theoretical throughput by QPSK 3/4 is 967 (Mbit/s.

140

142

144

146

148

1 2 4 8 10 15 31,4Th

rou

gh

pu

t (M

Bit

/s)


BPSK, coding rate 1/5

beam 1

beam 2

beam 3

beam 4

beam 5

0

200

400

600

800

1000

1 2 4 8 10 15 31,4

Th

rou

gh

pu

t (M

Bit

/s)


QPSK, coding rate 3/4

beam 1

beam 2

beam 3

beam 4

beam 5



(c) The theoretical throughput by 16QAM 1/2 is 1398 (Mbit/s).

Figure B—1: The measured throughput with respect to distance.

-100

400

900

1400

1 2 4 8 10 15 31,4

Th

rou

gh

pu

t (M

Bit

/s)


16 QAM, coding rate 1/2

beam 1

beam 2

beam 3

beam 4

beam 5



Appendix C. Algorithm-centric Single User V-band Access:

Peak Throughput Test

The scope of the algorithm-centric V-band access link setup used throughout the

experiments in sections 2.3 and 2.4 is mainly to test beam steering algorithms and the overall

correct functioning of the MiWaveS higher layer and protocol implementation. Nevertheless,

brief tests have been conducted to test for the peak throughput in proximity of the access

point.

For this purpose, the AP transmitter and the UD receiver where placed in a LOS

propagation environment as shown in Figure 4—5, at a distance of 1.3 m. The best transmit-

receive beam combination, which maximized the receive power was chosen, using the

codebook presented in Figure 2—27. The output power of the base band system and the

receive gain of the V-band radio transceiver where adjusted in order to maximize the

throughput.

Figure C—1 presents results indicating that the peak throughput of 2.318 GBit/s (16 QAM at

code rate 7/8) could be almost achieved (2.298 GBit/s were achieved at a code word error rate

of about 1%).

Figure C—1. Peak throughput test using the algorithm-centric V-band access link radios.

Additional tests were carried out at 2 m, 4 m, and 8 m distance. It was found that a

throughput of 1.350 GBit/s could be maintained up to 8 m (16 QAM code rate ½ at a code

word error rate of 3.5%).

miwaves d6.5 final cleanfinal - cordis · 2017. 11. 20. · miwaves deliverable d6.5 dissemination...

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