n7617a technical overview -...

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N7617A Signal Studio for WLAN (for E4438C and E8267D) Technical Overview

Construct WLAN Waveforms with Ease

Signal Studio for WLAN enables you to easily create 802.11a/b/g/j/p/n waveforms that comply with IEEE WLAN MAC and PHY specifications. The software’s intuitive graphical user interface provides convenient access to the physical and basic MAC layer parameters. The flexible software licensing provides the versatility to generate 802.11a/b/g/j/p waveforms and 802.11n waveforms for component and receiver testing with considerable cost differentiation. Download your WLAN waveform files to the E4438C ESG or E8267D PSG vector signal generator for playback.

Free 14-Day Trial

Download the software today to investigate the signal creation capability and generate test signals using a free 14- day trial license. After the trial license expires, each vector signal generator must be licensed separately to play back waveforms created by the software. For more information, visit:

www.agilent.com/find/signalstudio

Key Features

• Flexible software licenses for IEEE 802.11a/b/g/j/p WLAN and 802.11n WLAN to test receivers (Advanced Capability) and components (Basic Capability) on multiple source platforms

Key Features (continues)

• Create 802.11a/b/g/j/p WLAN waveforms

o Up to 3 data carriers

o Different coding rates and modulation types (OFDM, DSSS and PBCC)

o Intuitive setup of MAC header and MAC FCS

o Fully or partially coded channel (convolutional coder, interleaver, Scrambler, PBCC encoder)

o Pre-impairments with skew I/Q phase and up to 20 paths static multipoint reflection on waveform

• Create 802.11n WLAN waveform

o Scalable MIMO system (Mx2, Mx3, Mx4 (M<=4)) for receiver test and transmitter test

o Flexible spatial stream mapping and MIMO parameter setting; MCS index 0 to 32, 20 MHz/ 40 MHz bandwidth, short guard interval

o Operating mode: Legacy, Mixed Mode, Green Field

o Phase coherent multiple ESGs configuration

o Fading and channel models A~F for MIMO

o Aggregation mode (A-MPDU) in MAC layer

o Space time block coding (STBC)

o Switched output on one ESG solution

• Built-in Microsoft.Net-based API for programmable contrs

• Control signal generator functions remotely through the software

o I/Q adjustments and triggering

o Calibrated AWGN (requires E4438C option 403)

N7617A Technical Overview

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Configure Waveforms Quickly and Easily

Signal Studio for 802.11 WLAN provides a flexible, intuitive graphical user interface that makes operation easy and straightforward. All signal and hardware parameters are conveniently set in a windows interface. Graphical displays make it easy to confirm the parameters you’ve chosen, such as coding and modulation, payload data setup, distribution of power (CCDF), and power envelope.

Figure 1. Graphical displays show frame setup, as well as pre-download CCDF and power analysis tools.

Save Configurations as Quick Setup Buttons Start by customizing the parameters in a configuration to create signals you need. Save your custom configurations as Quick Setups for later use. Create a library of different scenarios tailored to meet your specific testing requirements.

Add Real-Time AWGN and Pre-impairments If your signal generator is equipped with the optional calibrated AWGN capability (E4438C-403), you can add real- time AWGN to the WLAN signal without using a stand-alone noise generator. Through the intuitive software interface, it is convenient to add pre-impairments with skew I/Q phase and up to 20 paths static multipoint reflection on waveform.

Expand Your Test Capability with Agilent Baseband Studio Products These capabilities are available with the E4438C ESG signal generator.

• Add channel impairments to WLAN signals with the Agilent N5115 Baseband Studio for Fading solution

• Access digital IQ and digital IF test signals with the Agilent N5102A Baseband Studio Digital Signal Interface Module


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Supported Standards

Waveforms created using Signal Studio for 802.11 WLAN comply with Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications as defined in the following IEEE publications: IEEE Std 802.11a-1999, IEEE Std 802.11b-1999, IEEE P802.11g/D8.2, Apr 2003, IEEE P802.11j/D1.6, August 2004, IEEE P802.11p/D0.23,August 2005, IEEE 802.11-05/1102r4 (Joint Proposal: High Throughput Extension to the 802.11 Standard: PHY), IEEE 802.11-03/940r4 (TGn Channel Models). The Signal Studio for 802.11 WLAN software can provide test signals for the 802.11 physical layers shown in the following table.

Standard IEEE 802.11a

IEEE 802.11b

IEEE 802.11g

IEEE 802.11j

IEEE 802.11p

IEEE 802.11n

IEEE Approval Date

1999 1999 2003 2004 2005 2006 (draft)

Modulation Up to 64QAM on 52 OFDM sub-carriers

CCK PBCC

OFDM: up to 64QAM on 52 OFDM sub-carriers

DSSS: CCK PBCC ERP-PBCC

Up to 64QAM on 52 OFDM sub-carriers

Up to 64QAM on 52 OFDM sub-carriers

Up to 64QAM on 108 OFDM sub-carriers (standard not yet defined)

Data Rate (Mbps)

6, 12, or 24 Optional: 9, 18, 36, 48, or 54

1, 2, 5.5, and 11

1, 2, 5.5, 6, 11, 12, 24 Optional: 9, 18, 22, 33, 36, 48, 54

20 MHz bandwidth:

6, 9, 12, 18, 24,36, 48, or 54

10 MHz bandwidth:

3, 4.5, 6, 9, 12 18, 24, 27

20 MHz bandwidth:

6, 9, 12, 18, 24,36, 48, or 54

10 MHz bandwidth:

3, 4.5, 6, 9, 12 18, 24, 27

6-600Mbps

Frequency Band (GHz)

5.150 to 5.250 (U-NII) 5.250 to 5.350 (U-NII) 5.47 to 5.725 (Europe) 5.725 to 5.825 (U-NII)

2.412 to 2.484

2.412 to 2.484

4.90 to 5 5.03 to 5.091

5.850 to 5.925

2.412 to 2.484 5.150 to 5.250 (U-NII) 5.250 to 5.350 (U-NII) 5.47 to 5.725 (Europe) 5.725 to 5.825 (U-NII)


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Component Test

Use the basic mode to access the software’s physical layer (PHY) frame setup parameters and quickly generate statistically correct 802.11a/b/g/j/p and 802.11n signals to test transmission or receiver chain components, such as preamplifiers, filters, combiners or amplifiers. Configure individual carrier elements and channel coding parameters such as modulation type, payload data, partially coded channel data, coding rate, preamble and amplitude. Set the generation mode to unframe or frame, and select the baseband filter to provide adequate stress on the components being tested.

Figure 2. Use basic mode to generate statistically correct 802.11a/b/g/j/p or 802.11n signals

Receiver Test The advanced mode provides additional features to help you create IEEE 802.11 WLAN standard-compliant frame structures for testing receiver designs in all stages of development. Use the baseband signal to perform demodulation and decoding verification on ASIC and DSP chips. To thoroughly test the demodulation capabilities of a receiver, a test signal that is fully coded is necessary. This level of coding enables you to determine if each functional stage of a receiver is operating correctly, and enables you to use this test signal to perform FER/PER and BER measurements.

Signal Studio for 802.11 WLAN creates fully coded frames, that enable you to use this test signal to perform your FER and PER measurements. The MAC parameters include MAC header setting, selectable MAC FCS, sequence control, data type, and data length. The user’s equipment can compare the FCS transmitted from the source to determine how many packets were sent from the source to the receiver were lost to measure PER. The receiver can determine if there is a missing frame or if the frame has been retransmitted by looking at the sequence control field. A multiframe waveform with an incrementing Sequence Control field can be created. For 802.11n option, MAC also support Aggregation MPDU mode. Each frame can be fully coded with convolutional coding or scrambling, and interleaving. You also have the flexibility to configure individual frame parameters, such as modulation type, coding rate and preamble type.


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Figure 3. Analyze your WLAN signal using the Agilent 89600 Series vector signal analysis software (v 6.1) with Option B7R, 802.11 WLAN modulation analysis.

Microsoft .Net-Based API The Microsoft .NET-based application programming interface (API) is provided to enable systematic and efficient configuration of complex WLAN 802.11a/b/g/j/p/n waveform. It allows programmatic setting of signal parameters by importing custom data sets or using programming loops and mathematical functions rather than manually entering data in the Signal Studio graphical user interface. The entire signal configuration and playback process can easily be automated in your own programming environment using the API. Included with the software is a full API. Use the API to set parameters either programmatically or by using an API graphical user interface. The API's built-in Help System provides programming examples that you can easily leverage.


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Licensing Options The N7617A offers flexible licensing options that allow you to choose the capability you need for component or receiver testing and verification.

Refer to Licensing for detailed licensing information.

Basic 802.11 WLAN License Designed to meet your component test needs, the basic 802.11 WLAN license provides the following capability:

802.11a/b/g/j/p option: 802.11n option:

• Modulation Type

o OFDM (10MHz/20MHz Bandwidth)

o DSSS-OFDM

o DSSS/PBCC/CCK

o ERP-PBCC(PBCC 22 and PBCC 33)

• Multi-carrier support (up to 3 carriers)

• Baseband I/Q Impairments

• OFDM Sub-carrier mask

• Multipath (20 paths)

• Data Source Type

o All zeros, PN9, PN15, user-defined file

• Multiframe Control

• Scalable MIMO solution:

o MxN, 1 SG switching between different waveforms

o Mx2, 2 SG with 1 or 2 internal ARB

o Mx3, 3 SG

o Mx4, 4 SG

• Compatible with EWC 1.27 and IEEE802.11n daft in Jan.2006

• MCS Index from 0 to 32

• Operating Mode

o Legacy

o Mixed Mode

o Green Field

• 20MHz/40MHz Bandwidth

• Space time block coding (STBC)

• Baseband I/Q impairments

• MIMO Channel

o A, B, C, D, E, F, User-define


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Advanced 802.11 WLAN License The advanced 802.11 WLAN license includes all the capability of the basic license, plus additional features and flexibility to generate fully channel-coded 802.11 WLAN waveform and is suitable for both of the receiver testing and component testing.

The following features are only supported by the advanced 802.11 WLAN

802.11a/b/g/j/p option: 802.11n option:

• Channel Encoder ON/OFF

o Scrambler ON/OFF

o Convolutional Encoder ON/OFF

o OFDM Scrambler and Reserved Service Bits (For 802.11a/j/p, 802.11g OFDM)

o PBCC Encoder ON/OFF

o DSSS Scrambler (For 802.11b and 802.11g DSSS)

• MAC

o MAC Header

o MAC FCS

o Sequence number

• Channel Encoder ON/OFF

o Scrambler ON/OFF

o Convolutional Encoder ON/OFF

o Interleaver ON/OFF

• MAC

o Aggregation MPDU

o MAC Header

o MAC FCS

o Sequence number


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Performance Characteristics

802.11a/g/j/p OFDM E4438C Vector Signal Generator

EVM < 1% (typical)

@2.4/5.8 GHz

–1dBm

E8267D Vector Signal Generator

EVM < 0.8% (typical)

@2.412 GHz

–1dBm

< 0.6% (typical)

@5.805 GHz

6dBm

Instrument and software settings are listed below. The EVM was measured with an 89641A vector signal analyzer with Option B7R.

Software Settings

Data rate 54 Mbps Modulation 64 QAM Encoder 3/4 Scrambler On Interleaver On Scrambler initialization

5D

Support carrier setup

all channels active

Idle interval 100us OSR 2 Window length 8 Data type PN15 Data length 1024

Signal Generator Settings

Reconstruction filter

thru

ALC On RF blanking Off Modulation Attenuation

8 to 10 dBm

89641A Settings

Frequency 2.4/5.8 GHz Span 20MHz Range optimal RMS video average

20

802.11b/g DSSS E4438C Vector Signal Generator

EVM < 1% (typical)

@2.412 GHz

–1dBm

E8267D Vector Signal Generator

EVM < 0.7% (characteristic)

@2.412 GHz

8dBm


Software Settings

Data rate 11 Mbps High Rate Modulation

CCK

DSSS Scrambler On Interleaver On Idle interval 100 us OSR 2 Data type PN15 Data length 1024



thru

ALC On RF blanking Off Modulation Attenuation

8 to 10 dBm

89641A Settings

Frequency 2.4/5.8 GHz Span default for the standard Range optimal RMS video average

20


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802.11n OFDM E4438C Vector Signal Generator

EVM < 1% (typical)

@2.412 GHz

5dBm

< 1% (typical)

@5.805 GHz

0dBm


Software Settings

MCS Index 15 Bandwidth 20MHz Encoder rate 5/6 Scrambler On Interleaver On Scrambler initialization

5D

Idle interval 20us OSR 2 Window length 16 Aggregation MPDU

On

Data type PN15 Data length 1024



thru

ALC On RF blanking Off Runtime Scaling 70% Modulation Attenuation

8 to 10 dBm

ESG sync./lock scheme

A, B and C *

89641A Settings

Frequency 2.4/5.8 GHz Span default for 11n HT Range optimal

A. Without baseband timing alignment; Without RF phase coherency

B. With baseband timing alignment; Without RF phase coherency

C. With baseband timing alignment; With RF phase coherency

Baseband timing alignment (Common Baseband Clock) needs ESG Option HEC;

RF Phase Coherency needs ESG Option HBC (4~6GHz) and HCC (0.25~4GHz)


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802.11n Characteristic Performance Legend for pictures below:

o Dark blue curve -measured phase difference.

o Light blue curve -mean value of phase difference, (every 20 points).

o Pink line -Fitted line from the dark blue curve; shows the trend of the phase difference.

Signal Generator Setting: -10 dBm, 2.412GHz; Signal Analyzer: Agilent dual channel 89641S (VXI). Phase difference and other noise introduced by the analyzer has been removed from the results. Characteristic results: each plot is the representative of the 3 results achieved on 3 sets of 2-ESG systems.

1. Performance of configuration A: 2 ESG MIMO system without common baseband clock and without RF phase coherency

Phase Difference vs. Time

-1-0.5

00.5

11.5

22.5

33.5

44.5

5

0 120 240 360 480 600 720

Time in Minute (240 points every 60 minutes)

Pha

se D

iffer

ence

inD

egre

e

Phase Difference 20 per. Mov. Avg. (Phase Difference) Linear (Phase Difference)

26 Degree °C; 240 test points per 60 minutes.

2.8 degree phase change over 12 hours, 1.5 degree average peak-to-peak phase difference jitter

3 degree phase change per degree Celsius temperature

2. Performance of configuration B: 2 ESG MIMO system with common baseband clock and without RF phase coherency

26 Degree °C; 240 test points per 60 minutes.

5.8 degree phase change over 12 hours, 1.5 degree average peak-to-peak phase difference jitter.

3.5 degree phase change per degree Celsius temperature


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3. Performance of configuration C: 2 ESG MIMO system with common baseband clock and with RF phase coherency

26 Degree °C; 240 test points per 60 minutes

0.17 degree phase change over 12 hours, 0.15 degree average peak-to-peak phase difference jitter.

0.03 degree phase change per degree Celsius temperature

Conclusion Refer to 802.11n Characteristic Performance Analysis for details in N7617A online documentation.

PDA (Phase Difference A): Jitter (noise like vibration) in dark blue curve, caused by phase noise.

PDB (Phase Difference B): Change trend shown by pink line, caused by ambient temperature drift.

PDA is dominant; PDB is negligible.

Worst case equivalent RMS EVM: could be used as a reference to evaluate phase difference impact on MIMO measurements. (Only apply to worst test case and direct mapping MIMO; may not be seen from typical measurements.)

EVMrms(worst case equivalent) = 0.0031167* PhaseDifferencepeak-to-peak

1.5 degree peak-to-peak phase difference: worst case equivalent EVMrms = 0.0047. (0.47%)

0.15 degree peak-to-peak phase difference: worst case equivalent EVMrms = 0.00047. (0.047%)

Configuration C is needed for beam forming related tests, and recommended for other high precision MIMO tests.

Configuration B is needed for MIMO tests where phase lock of baseband clocks is needed.


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Ordering Information N7617A Signal Studio for 802.11 WLAN Configuration

Model /Option

Description Requires Not Compatible

N7617A Signal Studio for WLAN 802.11a/b/g/j/p/n

Functionality Options

N7617A-203

Basic 802.11a/b/g/j/p WLAN for component test

N7617A-204

Basic 802.11n WLAN for component test

N7617A-213

Advanced 802.11a/b/g/j/p WLAN for receiver test

Option 203

N7617A-214

Advanced 802.11n WLAN for receiver test

Option 204

Connectivity Options1

N7617A-101

License for connecting to E4438C signal generator

Option 203 or 204

N7617A-102

License for connecting to E8267D signal generator

Option 203 Option 204 and 2142;

1 Only one connectivity option can be ordered for each platform.

2 802.11n WLAN is not applicable for PSG.

PSG Recommended Configuration1

Model Option

Description Notes

E8267D PSG vector signal generator Requires firmware C.04.61 or later

E8267D-520

Frequency range from 250 KHz to 20 GHz

Recommended, can substitute E8267D-532 or -544

E8267D-602

Internal baseband generator (64 MSa memory)

One of the following baseband generator options is required to use the software: E8267D-601or 602. E8267D-602 is recommended for its larger memory size.

E8267D-005 6 GB internal hard drive Recommended

1 802.11n WLAN is not applicable for PSG.


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ESG Recommended Configuration Model/Option Description Notes E4438C ESG vector signal generator Requires firmware C.04.60 or later

E4438C-506 250 kHz to 6 GHz frequency range

Recommended

E4438C-602 Internal baseband generator (64 MSa memory)

One of the following baseband generator options is required to use the software: E4438C-001, -002, -601, -602. E4438C-602 is recommended for its larger memory size

E4438C-005 6 GB internal hard drive Recommended

E4438C-403 Calibrated noise personality Recommended, required for C/N capability

E4438C-UNJ Enhanced phase noise performance (requires option 506)

Only required for 802.11n WLAN capability

E4438C-HEC

Special option, provides external baseband generator 200-400 MHz clock input (The standard E4438C only provides an external baseband Ref input)

Only required for 802.11n WLAN to achieve baseband phase coherency between multiple ESGs

E4438C-HCC

Special option, provides 250 MHz to 4 GHz IN & OUT on the rear panel of the E4438C

Only required for 802.11n WLAN to achieve 0.25-4 GHz RF phase coherency between multiple ESGs

E4438C-HBC

Special option, provides 4 GHz to 6 GHz IN & OUT on the rear panel of the E4438C (requires option HCC and 506) (I-bar OUT and Q-bar OUT connectors will be removed from the rear panel)

Only required for 802.11n WLAN to achieve 4-6 GHz RF phase coherency between multiple ESGs

1. For 802.11n WLAN, an E4400B or E4423B external arb clock is also required to achieve baseband phase coherency between multiple ESGs. 2. For 802.11n WLAN, an Z5623AK11 distribution network is also required to achieve RF phase coherency between multiple ESGs.


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Additional Information

For more information about Signal Studio software and Baseband Studio products including release notes, user interface descriptions, tutorials, and installation information, read the online documentation at the following websites:

Signal Studio Software www.agilent.com/find/signalstudio

Baseband Studio Software www.agilent.com/find/basebandstudio

Related Literature MIMO Wireless LAN PHY Layer [RF] Operation & Measurement, Application Note, Literature number 5989- 3443EN

IEEE 802.11 Wireless LAN PHY Layer [RF] Operation & Measurement, Application Note, Literature number 5988- 5411EN

Signal Generators - Vector, Analog, and CW Models, Selection Guide, literature number 5965-3094E.

Agilent E4438C Vector Signal Generator, Brochure, Literature number 5988- 3935EN

Agilent E4438C Vector Signal Generator, Data Sheet, Literature number 5988- 4039EN

Agilent E4438C Vector Signal Generator, Configuration Guide, Literature number 5988- 4085EN

Agilent PSG Signal Generators, Brochure, Literature number 5989-1324EN

Agilent E8267D PSG Vector Signal Generator, Data Sheet, Literature number 5989-0697EN

Agilent E8267D PSG Vector Signal Generator, Configuration Guide, Literature number 5989-1326EN

Web Resources For more information, visit:

www.agilent.com www.agilent.com/find/esg www.agilent.com/find/psg www.agilent.com/find/wlan www.agilent.com/find/signalstudio www.agilent.com/find/basebandstudio

www.agilent.com/find/emailupdates

Get the latest information on the products and applications you select.

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Contacting Agilent Technologies

For more information on Agilent Technologies’ products, applications or services, please contact your local Agilent office. The complete list is available at: www.agilent.com/find/contactus

Phone or Fax

United States: (tel) 800 829 4444 (fax) 800 829 4433

Canada: (tel) 877 894 4414 (fax) 800 746 4866

China: (tel) 800810 0189 (fax) 800 820 2816

Europe: (tel) 31 20 547 2111

Japan: (tel) (81) 426 56 7832 (fax) (81) 426 56 7840

Korea: (tel) (080) 769 0800 (fax) (080) 769 0900

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Taiwan: (tel) 0800 047 866 (fax) 0800 286 331

Other Asia Pacific Countries: (tel) (65) 6375 8100 (fax) (65) 6755 0042 Email: [email protected]

Contacts revised: 4/25/05

Product specifications and descriptions in this document subject to change without notice.

© Agilent Technologies, Inc. 2006

n7617a technical overview -...

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