performance review of pico base station in indoor environments · performance review of pico base...

Aalto UniversitySchool ofElectrical Engineering

Performance review of Pico base stationin Indoor Environments

Inam Ullah, Edward Mutafungwa, Professor Jyri Hämäläinen

Outline

Motivation

Simulator Development

Winprop Tool

Simulation Parameters

Performance Metrics

Simulation Results

Conclusions

2

Motivation

• Traditional Mobile network’s coverage and capacity areinsufficient for high data services especially in indoorenvironments.

• The HetNets (Heterogeneous networks) is one of thesolution by adding small cells to bring network closer touser and enhance the system performance.

• Pico base station deployment can ensures good quality ofin-building coverage & capacity.

• Credible channel models are difficult to find for lower frequencies as well as forstreet level interference propagation.

• WinProp is standard software tool in the domain of wireless propagation andradio network planning for different environments.

• Includes different channel models to predict the path losses for geographic areas.• www.awe-communications.de

Why Winprop tool?

• Four tri-sectored macro base station (MBS)• Building of interest comprises five storeys with several buildings around• Pico base stations (PBS) deployed inside the building

Simulated Area (Winprop Tool)

Location 1 Location 2

Pico Deployments

PARAMETER VALUES/ MODELLING ASSUMPTIONS

Simulation resolution • Indoor areas: 1 m Outdoor areas: 10 m

Height of prediction results • Indoor areas: 1.5 m above floor level• Outdoor areas: 1.5 m

Building properities• Materials include concrete, wood, steel, brick etc.• Individual material properties (permeability,

vertical/horizental transmission losses, diffraction lossesetc.) defined in WinProp (WallMan)

Pico base station parameters

• Deployment height: 1.5 m above floor level• Directional antenna pattern (Weighted Bilinear Interpolation (WBI))• Transmision power: 2 W• Antenna gain: 5 dBi• Antenna azimuth: Pico 1 (90°), Pico 2 (270°)• Antenna downtilt: 0° for all picos

Operating frequency(for both macro and pico) • 800 MHz & 2100 MHz

Propagation modelling • Dominant path model used for both indoor and outdoor areas• Waveguiding effect considered (for distance upto 20 m)

Winprop Simulation Parameters

Winprop Simulation Parameters

Access Point Antenna Heights (m)

Macro Site 1 Antenna 1 50



Macro Site 2Antenna 1 25









Pico Base Station (First floor) 2.5

Pico Base Station (Second floor) 6.2

Parameter ValueBandwidth 10 MHz,48 PRBs for Data & 2 PRBs for signalling

Thermal Noise Power Spectral Density -174 dBm/Hz

SINR efficiency (SINReff) 0.85

Bandwidth efficiency (Weff) 0.42

Antenna Configuration MIMO 2*2

MBS Parameters

MBS Transmit Power 46 dBm

Pico Base Station Parameters

Pico Transmit Power 33 dBm

Matlab Simulation Parameters

Pico 1 (1st floor) Pico 2 (1st Floor)

Simulated Maps• This slide shows the received power maps of first floor for PBSs.• Both picos are deployed at the first floor at location 1 & 2.• In the given maps, it is noticed that PBS have good received signal

level in the part of buildings near around the PBS.

Pico 1 (2nd floor) Pico 1 (5th Floor)

Simulated Maps• This slide shows the received power maps of second and fifth floor

for pico 1 base station.• In the given maps, it is observed that the received signal power

level decreases with the increased height of the building , due tomultiple reflection of signal with inner structure of the building.

System Methodology

• In current study, two floors (Floor 1 & 2) has been assumed, where 4 userequipments (UE) has been dropped randomly in each of two floors.

• All indoor UEs are force to connect to Pico even in parts of the buildingwhere the Macro signal might be stronger. Though they may connect to PBSwith good reference signal received power (RSRP).

• Round robin scheduling is used to assign network resources to each UE.

• Two different scenarios proposed for PBS deployments.Ø Single Pico deployment (i.e.; Pico 1 at location 1, floor 1)Ø Two Picos deployment (i.e.; Pico 1 at location 1, floor 1 & Pico 2 at location 2, floor 2)

Performance Metrics

• The performance metrics used in this study are the cumulativedistribution function (CDF) of;Ø SINR (Signal-to-Interference- & Noise-Ratio) per PRBØ Indoor User Equipment (UE) Throughput

• Simulation has been done for two carrier frequencies. (i.e. 800 &2100 MHz) in two difference interference environments.Ø When Indoor Pico UEs receive Co-channel interference from MBS.Ø When Indoor Pico UEs don't receive the Co-channel interference from MBS.

Single PICO deployed at Location 1,Floor 1

Pico 1 at Location 1, Floor 1

Single Pico deployment at Location 1, Floor 1

CDF of SINR per PRB & UE Throughput (800MHz)• This slide shows the SINR and throughput performance of indoor UEs in different

interference environment at carrier frequency of 800 MHz.• Comparing blue and black curves, It is observe that PBS yields worse SINR and

throughput performance upto 70 % indoor UEs due to reception of high co-channelinterference from MBS (Its worthy to mention that 4 indoor UEs randomly deployed insecond floor.). Though, PBS provides good coverage in first floor.

• Moreover, the PBS have significantly improved the indoor UEs performance in terms ofSINR as well as throughput, if orthogonal operating frequency resources are allocatedfor PBS. Here the Picos UEs do not receive co-channel interference from MBS.

CDF of SINR per PRB & UE Throughput (2100MHz)

• This slide shows the SINR and throughput performance of indoor UEs in differentinterference environment at carrier frequency of 2100 MHz.

• It has been noticed that PBS and MBS have same performance levels as discussed inprevious slide for 800 MHz.

Two PICOs deploymentPico 1 at Location 1, Floor 1Pico 2 at Location 2, Floor 2

Two Pico Deployments



CDF of SINR per PRB & UE Throughput (800MHz)• This slide shows the SINR and throughput performance of indoor UEs for the case, when

PBS are deployed in both floors at proposed locations (i.e., location 1 & 2).• Given results show that system performance has been improved by deploying two PBS

as compared to Macro only networks.• Moreover, the performance gain can be improved by operating the PBS on separate

carrier frequencies rather then sharing frequencies with MBS. Though, the UEs servedby each PBS receive interference from each PBS.

Pico interferenceincludedPico interference

included

CDF of SINR per PRB & UE Throughput (2100MHz)

Pico interferenceincludedPico interference

included

• This slide shows the SINR and throughput performance of indoor UEs in differentinterference environment at carrier frequency of 2100 MHz.

• Comparatively, It has been noticed that PBS and MBS have same performance levels asdiscussed in previous slide for 800 MHz.

Single Pico versus Two Picos(800MHz)• In this slide, the comparative analyses of single versus two PBS deployment was done. The PBS

has been allocated separate operating frequencies then MBS. Hence, the indoor PICO UEs onlyreceive co-channel interference from the non serving PBS (in case of two PBS deployment).

• Results show that comparatively single Pico enhanced the system gain in terms of SINR as wellas UE throughputs (on average level ) then two Picos deployment.

• The reason is that indoor Picos UEs still receiving co-channel interference from the non servingPBS (in two PBS deployment), because, both the PBSs are sharing the same resource pool.Hence, single pico deployment will yields improved gains for the two floor cases. Need tostudy more.

Pico interferenceincluded Pico interference

included

Conclusions• System is heavily interference limited in both cases 800 & 2100 MHz.• Pico performance gain is small, when its shares network resources

with MBS (Due to Co-channel interference from nearby MBS).• SINR and UE throughput levels are very large, when orthogonal

resources are allocated for PBS (Co-channel interference omittedfrom nearby MBS).

• Hints concerning to indoor public safety (PS) relaying• If PS system applies its own frequency and macro network

deployment is scarce, then indoor relay may provide high datarates on access link. Though, the backhaul link is still bottleneck.

• Hence, relaying is feasible, if resource split is enabled betweendirect and access link.

Revised Plan for HEWINETS-WP1

Item / Scenario Remarks Status1 Review of channel models for street

level propagation in 400 MHzWinprop Ray tracing tool has been used to calculat the pathloss estimation and Implemented in Matlab tool forsimulations

Done

2 Comparisons between 400MHz and2600MHz propagation especially instreet level propagation

Winprop Ray tracing tool has been used to calculat the pathloss estimation and Implemented in Matlab tool forsimulations

Done

3 Indoor penetration comparison for 10MHz bandwdith at carrier frequencies400, 800 and 2000 MHz.

Comparative results for relaying performance has beengenerated via Matlab simulations

Done

4 Indoor penetration comparison for 5MHz bandwdith at carrier frequencies400, 800 and 2000 MHz.

Comparative results for relaying performance has beengenerated via Matlab simulations

Done

5 Local impact of interferenceinvestigated using e.g. blocking areaaround the relay as a measure.

Free space path loss model were used for calculating therelaying interference experienced by outdoor commercialUEs located around relay in the radius of 50 meter.

Done

6 Variation of required TX power inrelay related to applied carrierfrequency

Propagation models first needed. Some studies might bepossible to do using ray tracing tool.

Undone

7 Guide: How to read performanceresults?

Detailed report has been written on plots & figures, inorder to help the reader to understand results.

Done

8 Uplink results for single relay case This requires development of uplink relay simulator Undone

Thank you very muchfor your time

Supporting Slides

Pico Antenna Pattern 1/3

• We could start with a simple pattern of the figurebelow. This is horizontal antenna pattern

-180deg 180deg

5dBi

-70deg 70deg-15deg 15deg0dBi

-10dBi

100deg-100deg

)(qHG

• This is the vertical antenna pattern, denoted as

-180deg 180deg

0dBi

-70deg 70deg-15deg 15deg-3dBi

100deg-100deg

)(yVG


• Total antenna pattern is of the form

• Note that gain pattern is given in decibel scale.• Pico transmission power is 2W (=33dBm)

)()(),( yqyq VH GGG +=


• 2D antenna partterns (vertical and horizental) should beconverted to 3D pattern in WinProp for propagationmodelling

• Four different conversion algorithms available in WinProp– Algorithm 1: Arithmetic Mean (AM)– Algorithm 2: Bilinear Interpolation (BI)– Algorithm 3: Weighted Bilinear Interpolation (WBI)– Algorithm 4: Horizontal Projection Interpolation (HPI)

• We compared the conversion results of all algorithms andhave settled for Algorithm 3: WBI– Most accurate conversion, particularly in the horizental plane– Further implementation details of algorithm here: F. Gil et al, A

3D Interpolation Method for Base-Station-Antenna RadiationPatterns, IEEE Ant. & Prop. Mag., Vol. 43, No.2, April 2001.

Winporp Antenna Pattern

• 2x2D pattern to 3D pattern conversion resultfor using WBI algorithm

Winporp Antenna Pattern 1/3

• Plot of horizental pattern after conversion 3Dpattern conversion


• Plot of vertical pattern after conversion 3Dpattern conversion


performance review of pico base station in indoor environments · performance review of pico base...

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