Example Design Templates

This chapter explains details about the CS design templates provided with ADS. These templates are available to help you develop custom CS designs:

WLAN 802.11a/g Transmission Test Design Example

WLAN 802.11a/g BER Test Design Example

WMAN 802.16e Downlink Transmission Test Design Example

WMAN 802.16e Uplink Transmission Test Design Example

WMAN 802.16e Downlink BER Test Design Example

WMAN 802.16e Uplink BER Test Design Example

MATLAB-Based Test Design Example

When using these examples, be sure to change only the parameters values that are defined in the top-level schematic in the VAR blocks with the following names:

Only these schematic values are used to set up and run the design. Changing values other than these will have unexpected results.

For some of the examples, the upper limit allowed for the NumberSegments might be too large to actually enable the simulation to run. If you set this value too large, a message will display the allowed upper limit. If you use this displayed upper limit, the simulation might still fail to run and you will need to reduce the value used for NumberSegments to a value less than the displayed upper limit.

WLAN 802.11a/g Transmission Test Design Example

The design example is available from the ADS main window in File > Example Project > Connected_Solutions > STW_E4438C_896XX_prj .
STW_E4438C_896XX_prj provides WLAN 802 11a/g transmitter test and measurement design example based on IEEE Standard 802.11a-1999 and 802.11g-2003. Designs in this project include:

Overview

The WLAN 802 11a/g Transmission Test Design provides connection to an RF hardware device under test (DUT) to determine the performance of the DUT by activating various design measurements. This design provides signal measurements for RF envelope, signal power (including CCDF), constellation, spectrum, and EVM.

The signal and most measurements are designed according to the WLAN 802 11a/g specification.

This design can generate an RF modulated signal with optional impairments, send the signal to the input of the RF DUT through an Agilent Electronic Signal Generator (ESG), receive the signal from the RF DUT output through an Agilent Vector Signal Analyzer (VSA), and display the measurement results in a data display.

Signal Segment Structure

The WLAN 802.11a signal segment structure is illustrated in 802.11a Burst Structure and OFDM Training Structure. Each burst, separated by an Idle Interval, is composed of the Short Preamble, Long Preamble, SIGNAL, and DATA fields. PLCP means physical layer convergence procedure , PSDU means PLCP service data units , GI means guard interval .

For this description, GI is set to 0.25 and Bandwidth is set to 20 MHz (resulting in OFDM_SymbolTime = 4 µ).

Channel coding, interleaving, mapping and IFFT processes are also included in SIGNAL and DATA parts generation. The SIGNAL field and each individual Data field (part of the overall DATA field) have a time duration defined as OFDM_SymbolTime and includes a GuardInterval. OFDM_SymbolTime depends on the Bandwidth (=64/Bandwidth).

802.11a Burst Structure

OFDM Training Structure

WLAN RF power delivered into a matched load is the average power delivered in the WLAN burst excluding the burst idle time. RF Signal Envelope shows the RF envelope for an output RF signal with 10 dBm power. RF Signal CCDF shows the RF CCDF for the output RF signal with 10 dBm power.RF Signal Spectrum shows the RF Spectrum for the output RF signal with 10 dBm power.

RF Signal Envelope

Based on the IEEE 802.11g - 2003 standard, different 11g modulations such as differential binary phase shift keying (DBPSK), differential quadrature phase shift keying (DQPSK), complementary code keying (CCK), packet binary convolutional coding (PBCC), DSSS-OFDM and OFDM are used. A complete 802.11g system supports all types of modulations, and a soft-switching is performed from one to another type of modulation signals. This design does not simultaneously support all types of modulations defined by 802.11g standard; however, it supports the OFDM portion of the 802.11g signals.

RF Signal CCDF

The 802.11g OFDM signal has the same frame structure as 802.11a except carrier frequency. The 802.11a system works on 5 GHz bands and 802.11g works on 2.4 GHz bands.

RF Signal Spectrum

Instrument Compatibility

WLAN designs are compatible with the Agilent Signal Studio Software, Agilent ESG, and Agilent VSA models described in Agilent Instrument Compatibility.

Signal Studio Models ESG Models VSA Models
802.11 Signal Studio Revision A.02.01 with support for IEEE 802.11 2001 W-LAN a/b/g standards for use with Agilent ESG and PSG Vector Signal Generators; requires Option 417. E4438C, Firmware Revision C.03.40 89600 Series, software version 4.xx/5.xx

For information about the following products, see the Agilent Technologies web site:

WLAN 802 11a/g Transmission Test Design Parameters

The following table summarizes the WLAN 802 11a/g transmission test specific design parameters.

WLAN 802 11a/g Design Parameter Summary
Description Values Default Range Type Unit Symbol
Signal Setup
Data Rate (Mbps) 53.3 Mbps, 55 Mbps, 80 Mbps, 106.7 Mbps, 110 Mbps, 160 Mbps, 200 Mbps, 320 Mbps, 400 Mbps, 480 Mbps 480 Mbps   enum   R
Data Length (Number of PSDU Octets)   512 [1,4095] float    
Signal Bandwidth   528 MHz (0,10566] float Hz  

This section provides detailed descriptions of the OFDM UWB design parameters.

Signal Setup

Data Rate (Mbps) Modulation Coding Rate (R) <th <th <th
6 BPSK 1/2 1 48 24
9 BPSK 3/4 1 48 36
12 QPSK 1/2 2 96 48
18 QPSK 3/4 2 96 72
24 16-QAM 1/2 4 192 96
27 16-QAM 9/16 4 192 108
36 16-QAM 3/4 4 192 144
48 64-QAM 2/3 6 288 192
54 64-QAM 3/4 6 288 216

Advanced Signal Setup

The following parameters may be optionally set. The design will typically perform well with the default settings. The OversamplingRatio parameter must typically be set to a larger value when RF interferers are enabled for the generated signal.

Variables

The variables listed in Test Bench Constants for WLAN Signal Setup and Test Bench Equations (Derived from Test Bench Parameters and Exported to Data Display) are defined for use in the design and data display.

Constant Value
MinFFT_Size 64 (= 2^6)
BitsPerByte 8
ServiceBits 16
TailBits 6
Ratio Oversampling ratio related to the OversamplingOption as Ratio = 2^OversamplingOption
DataBitsPerOFDMSymbol Dependent on DataRate (see DataRate Dependent Values).
OFDMSymbolsPerBurst (int ((ServiceBits+BitsPerByte*DataLength+TailBits)/ DataBitsPerOFDMSymbol))+Tail
TailCondition ServiceBits+BitsPerByte*DataLength+TailBits - DataBitsPerOFDMSymbol *(int ((ServiceBits+BitsPerByte*DataLength+TailBits)/ DataBitsPerOFDMSymbol))
Tail if (TailCondition = 0) then 0 else 1
Data Display Parameter Equation with Test Bench Parameters
OFDM_SymbolTime MinFFT_Size*(1+GuardInterval)/Bandwidth. The duration for one OFDM symbol.
OFDM_SymbolsPerBurst OFDMSymbolsPerBurst. The number of OFDM symbols in the Data field of a burst.
OFDM_SymbolGuardInterval GuardInterval. The guard interval (as a ratio of OFDM_SymbolTime) associated with each OFDM symbol.
IdleTime IdleInterval. The duration of the zero level idle field at the front of each burst.
ShortPreambleTime 8.0 usec. The duration of the short preamble field after the idle field in each burst.
LongPreambleTime 8.0 usec. The duration of the long preamble field after the short preamble field in each burst.
SIGNAL_Time OFDM_SymbolTime. The duration of the SIGNAL field after the long preamble field in each burst.
DataTime OFDM_SymbolsPerBurst*OFDM_SymbolTime. The duration of the Data field after the SIGNAL field in each burst.
BurstTime IdleTime + ShortPreambleTime + LongPreambleTime + SIGNAL_Time + DataTime
BytesPerBurst DataLength. The number of bytes of data in the Data field in each burst.
BitRate Dependent on DataRate (see DataRate Dependent Values). The bit rate for the transmitted WLAN signal.
TimeStep 1/Bandwidth/(2^OversamplingRatio). The signal time step
SignalSegmentTime The WLAN Burst time.
SamplesPerSegment (((2+2*1.25+(1+OFDM_SymbolsPerBurst)*(1+OFDM_SymbolGuardInterval))*MinFFT_Size + IdleTime*Bandwidth)*(2^OversamplingRatio)
DataRate DataBitsPerOFDMSymbol BitRate
Mbps_6 24 6e6
Mbps_9 36 9e6
Mbps_12 48 12e6
Mbps_18 72 18e6
Mbps_24 96 24e6
Mbps_27 108 27e6
Mbps_36 144 36e6
Mbps_48 192 48e6
Mbps_54 216 54e6

Baseline Performance

References

  1. IEEE Std 802.11a-1999, "Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: High-speed Physical Layer in the 5 GHz Band," 1999.
    http://standards.ieee.org/getieee802/download/802.11a-1999.pdf
  2. ETSI TS 101 475 v1.2.1, "Broadband Radio Access Networks (BRAN); HIPERLAN Type 2; Physical (PHY) layer," November, 2000.
    http://webapp.etsi.org/workprogram/Report_WorkItem.asp?WKI_ID=9949
  3. IEEE P802.11g/D8.2, "Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Further Higher Data Rate Extension in the 2.4 GHz Band," April, 2003.
    http://shop.ieee.org/ieeestore/Product.aspx?product_no=SH95134
  4. CCITT, Recommendation O.151(10/92).
  5. CCITT, Recommendation O.153(10/92).

WLAN Links

European Radiocommunications Office: http://www.ero.dk
U.S. Frequency Allocations Chart: http://www.ntia.doc.gov/osmhome
IEEE 802.11b Compliance Organization: http://www.wi-fi.org}
HomeRF Resource Center: http://www.palowireless.com/homerf/
IEEE 802.11 Working Group: http://grouper.ieee.org/groups/802/11/index.html

WLAN 802.11a/g BER Test Design Example

The design example is available from the ADS main window in File > Example Project > Connected_Solutions > STW_E4438C_896XX_prj .
STW_E4438C_896XX_prj provides a WLAN 802 11a/g BER test and measurement design example based on IEEE Standard 802.11a-1999 and 802.11g-2003. The design in this project includes:

Overview

The WLAN 802 11a/g BER Test Design provides connection to an RF hardware device under test (DUT) to determine the performance of the DUT by activating various design measurements. This design provides signal measurements for BER/PER performance.

The signal and most measurements are designed according to the WLAN 802 11a/g specification.

This design can generate an RF modulated signal with optional impairments, send the signal to the input of the RF DUT through an Agilent Electronic Signal Generator (ESG), receive the signal from the RF DUT output through an Agilent Vector Signal Analyzer (VSA), and display the measurement results in a data display.

Signal Segment Structure

The WLAN 802.11a signal segment structure is illustrated in 802.11a Burst Structure and OFDM Training Structure. Each burst, separated by an Idle Interval, is composed of the Short Preamble, Long Preamble, SIGNAL, and DATA fields. PLCP means physical layer convergence procedure , PSDU means PLCP service data units , GI means guard interval .

For this description, GI is set to 0.25 and Bandwidth is set to 20 MHz (resulting in OFDM_SymbolTime = 4 µ).

Channel coding, interleaving, mapping and IFFT processes are also included in SIGNAL and DATA parts generation. The SIGNAL field and each individual Data field (part of the overall DATA field) have a time duration defined as OFDM_SymbolTime and includes a GuardInterval. OFDM_SymbolTime depends on the Bandwidth (=64/Bandwidth).

802.11a Burst Structure

OFDM Training Structure

WLAN RF power delivered into a matched load is the average power delivered in the WLAN burst excluding the burst idle time. RF Signal Envelope shows the RF envelope for an output RF signal with 10 dBm power. RF Signal CCDF shows the RF CCDF for the output RF signal with 10 dBm power. RF Signal Spectrum shows the RF Spectrum for the output RF signal with 10 dBm power.

RF Signal Envelope

Based on the IEEE 802.11g - 2003 standard, different 11g modulations such as differential binary phase shift keying (DBPSK), differential quadrature phase shift keying (DQPSK), complementary code keying (CCK), packet binary convolutional coding (PBCC), DSSS-OFDM and OFDM are used. A complete 802.11g system supports all types of modulations, and a soft-switching is performed from one to another type of modulation signals. This design does not simultaneously support all types of modulations defined by 802.11g standard; however, it supports the OFDM portion of the 802.11g signals.

RF Signal CCDF

The 802.11g OFDM signal has the same frame structure as 802.11a except carrier frequency. The 802.11a system works on 5 GHz bands and 802.11g works on 2.4 GHz bands.

RF Signal Spectrum

Instrument Compatibility

WLAN designs are compatible with the Agilent Signal Studio Software, Agilent ESG, and Agilent VSA models described in Agilent Instrument Compatibility.

Signal Studio Models ESG Models VSA Models
802.11 Signal Studio Revision A.02.01 with support for IEEE 802.11 2001 W-LAN a/b/g standards for use with Agilent ESG and PSG Vector Signal Generators; requires Option 417. E4438C, Firmware Revision C.03.40 89600 Series, software version 4.xx/5.xx

For information about the following products, see the Agilent Technologies web site:

WLAN 802 11a/g BER Test Design Parameters

The following table summarizes the WLAN 802 11a/g BER test specific design parameters.

WLAN 802 11a/g BER Design Parameter Summary
Description Values Default Range Type Unit Symbol
Signal Setup
Data Rate (Mbps) 53.3 Mbps, 55 Mbps, 80 Mbps, 106.7 Mbps, 110 Mbps, 160 Mbps, 200 Mbps, 320 Mbps, 400 Mbps, 480 Mbps 480 Mbps   enum   R
Data Length (Number of PSDU Octets)   512 [1,4095] float    
Signal Bandwidth   528 MHz (0,10566] float Hz  

This section provides detailed descriptions of the WLAN 802.11a/g design parameters.

Signal Setup

Data Rate (Mbps) Modulation Coding Rate (R) <th <th <th
6 BPSK 1/2 1 48 24
9 BPSK 3/4 1 48 36
12 QPSK 1/2 2 96 48
18 QPSK 3/4 2 96 72
24 16-QAM 1/2 4 192 96
27 16-QAM 9/16 4 192 108
36 16-QAM 3/4 4 192 144
48 64-QAM 2/3 6 288 192
54 64-QAM 3/4 6 288 216

Advanced Signal Setup

The following parameters may be optionally set. The design will typically perform well with the default settings. The OversamplingRatio parameter must typically be set to a larger value when RF interferers are enabled for the generated signal.

Variables

The variables listed in Test Bench Constants for WLAN Signal Setup and Test Bench Equations (Derived from Test Bench Parameters and Exported to Data Display) are defined for use in the design and data display.

Constant Value
MinFFT_Size 64 (= 2^6)
BitsPerByte 8
ServiceBits 16
TailBits 6
Ratio Oversampling ratio related to the OversamplingOption as Ratio = 2^OversamplingOption
DataBitsPerOFDMSymbol Dependent on DataRate (see DataRate Dependent Values).
OFDMSymbolsPerBurst (int ((ServiceBits+BitsPerByte*DataLength+TailBits)/ DataBitsPerOFDMSymbol))+Tail
TailCondition ServiceBits+BitsPerByte*DataLength+TailBits - DataBitsPerOFDMSymbol *(int ((ServiceBits+BitsPerByte*DataLength+TailBits)/ DataBitsPerOFDMSymbol))
Tail if (TailCondition = 0) then 0 else 1
Data Display Parameter Equation with Test Bench Parameters
OFDM_SymbolTime MinFFT_Size*(1+GuardInterval)/Bandwidth. The duration for one OFDM symbol.
OFDM_SymbolsPerBurst OFDMSymbolsPerBurst. The number of OFDM symbols in the Data field of a burst.
OFDM_SymbolGuardInterval GuardInterval. The guard interval (as a ratio of OFDM_SymbolTime) associated with each OFDM symbol.
IdleTime IdleInterval. The duration of the zero level idle field at the front of each burst.
ShortPreambleTime 8.0 usec. The duration of the short preamble field after the idle field in each burst.
LongPreambleTime 8.0 usec. The duration of the long preamble field after the short preamble field in each burst.
SIGNAL_Time OFDM_SymbolTime. The duration of the SIGNAL field after the long preamble field in each burst.
DataTime OFDM_SymbolsPerBurst*OFDM_SymbolTime. The duration of the Data field after the SIGNAL field in each burst.
BurstTime IdleTime + ShortPreambleTime + LongPreambleTime + SIGNAL_Time + DataTime
BytesPerBurst DataLength. The number of bytes of data in the Data field in each burst.
BitRate Dependent on DataRate (see DataRate Dependent Values). The bit rate for the transmitted WLAN signal.
TimeStep 1/Bandwidth/(2^OversamplingRatio). The signal time step
SignalSegmentTime The WLAN Burst time.
SamplesPerSegment (((2+2*1.25+(1+OFDM_SymbolsPerBurst)*(1+OFDM_SymbolGuardInterval))*MinFFT_Size + IdleTime*Bandwidth)*(2^OversamplingRatio)
DataRate DataBitsPerOFDMSymbol BitRate
Mbps_6 24 6e6
Mbps_9 36 9e6
Mbps_12 48 12e6
Mbps_18 72 18e6
Mbps_24 96 24e6
Mbps_27 108 27e6
Mbps_36 144 36e6
Mbps_48 192 48e6
Mbps_54 216 54e6

Baseline Performance

References

  1. IEEE Std 802.11a-1999, "Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: High-speed Physical Layer in the 5 GHz Band," 1999.
    http://standards.ieee.org/getieee802/download/802.11a-1999.pdf
  2. ETSI TS 101 475 v1.2.1, "Broadband Radio Access Networks (BRAN); HIPERLAN Type 2; Physical (PHY) layer," November, 2000.
    http://webapp.etsi.org/workprogram/Report_WorkItem.asp?WKI_ID=9949
  3. IEEE P802.11g/D8.2, "Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Further Higher Data Rate Extension in the 2.4 GHz Band," April, 2003.
    http://shop.ieee.org/ieeestore/Product.aspx?product_no=SH95134
  4. CCITT, Recommendation O.151(10/92).
  5. CCITT, Recommendation O.153(10/92).

WLAN Links

European Radiocommunications Office: http://www.ero.dk
U.S. Frequency Allocations Chart: http://www.ntia.doc.gov/osmhome
IEEE 802.11b Compliance Organization: http://www.wi-fi.org
HomeRF Resource Center: http://www.palowireless.com/homerf/
IEEE 802.11 Working Group: http://grouper.ieee.org/groups/802/11/index.html

WMAN 802.16e Downlink Transmission Test Design Example

The design example is available from the ADS main window in File > Example Project > Connected_Solutions > STW_WMAN_16e_OFDMA_DownLink_prj .
STW_WMAN_16e_OFDMA_DownLink_prj provides a WMAN_802_16e_DL_TX test and measurement design example based on IEEE Standard 802.16e-1999 and 802.16e-2003.

Overview

The generic Transmission Test Design provides connection to an RF hardware device under test (DUT) to determine the performance of the DUT by activating various design measurements. This design provides signal measurements for RF envelope, signal power (including CCDF), constellation, spectrum, and EVM.

The signal and most measurements are designed according to the generic specification.

This design can generate an RF modulated signal with optional impairments, send the signal to the input of the RF DUT through an Agilent Electronic Signal Generator (ESG), receive the signal from the RF DUT output through an Agilent Vector Signal Analyzer (VSA), and display the measurement results in a data display.

Signal Segment Structure

The Mobile WiMAX 802.16e downlink signal is for mobile WiMAX OFDMA defined per the specification section 8.4 WirelessMAN-OFDMA PHY (256-point FFT OFDM) in IEEE Std 802.16-2004 and IEEE 802.16e-2005. Downlink describes the signal from the base station to the mobile unit.

The major specifications for the WirelessMAN-OFDMA PHY physical layer are listed in Mobile WiMAX 802.16e PHY Physical Layer Major Specifications.

Specification Settings
Information data rate up to 70 Mbps at 20 MHz bandwidth
Modulation BPSK, QPSK, 16-QAM, 64-QAM
Error correcting code CC, CTC, BTC
Coding rate 1/2, 2/3, 3/4
2048, 1024, 512
Number of data subcarriers variable
Number of pilot subcarriers variable
Number of total subcarriers used variable
Number of lower frequency guard subcarriers variable
Number of higher frequency guard subcarriers variable
n:Sampling factor For channel bandwidths that are a multiple of 1.75 MHz then n = 8/7
G: Ratio of CP time to "useful" time 1/4, 1/8, 1/16, 1/32
BW: Nominal channel bandwidth From 1.5 MHz to 28 MHz
Tb: Useful symbol time
Tg: CP time
Ts: OFDM symbol time

Mobile WiMAX 802.16e frame format in TDD mode (set with the Frame Mode parameter) is shown in 802.16e OFDMA Frame Structure for TDD Mode.

In TDD mode, 70% of the frame time is allocated for the downlink subframe.

In FDD mode, 100% of the frame time will be used for the downlink and uplink subframes and the Downlink Ratio parameter will be not be used.

802.16e OFDMA Frame Structure for TDD Mode

Mobile WiMAX 802.16e downlink subframe format is illustrated in 802.16e OFDMA Downlink Subframe Structure. The X-axis represents time. The Y-axis represents frequency subchannels.

802.16e OFDMA Downlink Subframe Structure

The downlink subframe starts with one preamble which consists of a OFDM symbol, followed by the PUSC zone where FCH, DL-MAP and UL-MAP are allocated. The FCH information will be sent on the first four adjacent subchannels with successive logical subchannel numbers in the PUSC zone. The DL-MAP message immediately follows FCH. The UL-MAP message is always allocated on the third and fourth OFDM symbols if ULMAP_Enable ( Activate UL-MAP Insertion ) is set to YES .

If ZoneType ( Zone Type ) is DL_PUSC, then a single PUSC zone is defined (a in 802.16e OFDMA Downlink Subframe Structure). If ZoneType ( Zone Type ) is DL_FUSC or DL_OFUSC, then two zones are defined: one is the PUSC zone where FCH is allocated, the other is the FUSC or OFUSC zone for allocating data bursts (b in 802.16e OFDMA Downlink Subframe Structure). ZoneNumOfSym ( Number of OFDM Symbols ) is defined as the number of OFDM symbols for the zone which is allocated data bursts. One downlink frame contains a maximum 8 data bursts except FCH, DL-MAP and UL-MAP, and each burst contains only one MAC PDU. Among these bursts, only one FEC-encoded burst is supported which is randomized, RS-CC coded and interleaved. Other bursts will be provided PN sequences as their coded source respectively.

For DL_PUSC, the total number of symbols in the downlink subframe is ( 1+ZoneNumOfSym ); For DL_FUSC or DL_OFUSC, the total number of symbols in the downlink subframe is ( 1+2+ULMAP_Enable ×2+ ZoneNumOfSym ), where 1 represents the preamble, the first 2 represents the FCH and DL-MAP, the second 2 represents the UL-MAP, ULMAP_Enable is 1 when set to YES and 0 when set to NO .

Zone type ULMAP_Enable NPreamble <th NUL-MAP NData NFrame
DL_PUSC YES 1 2 2 ZoneNumOfSym-2 1+ZoneNumOfSym
DL_PUSC NO 1 2 0 ZoneNumOfSym-2 1+ZoneNumOfSym
DL_FUSC YES 1 2 2 ZoneNumOfSym 5+ZoneNumOfSym
DL_FUSC NO 1 2 0 ZoneNumOfSym-2 3+ZoneNumOfSym
DL_OFUSC YES 1 2 2 ZoneNumOfSym 5+ZoneNumOfSym
DL_OFUSC NO 1 2 0 ZoneNumOfSym 3+ZoneNumOfSym

After encoding, the encoded burst is mapped to the constellation. Other bursts without FEC, are provided a PN sequence as their coded bits and mapped to the constellation according to their Rate_ID ( Rate ID for Burst Modulation and Coding Rate ). The FEC-encoded burst is concatenated with non-coded bursts. The FCH and DL-MAP are combined and mapped to the constellations. The same actions are performed on UL-MAP.

The physical indices of data subcarriers and pilot subcarriers for each burst are calculated for the subframe. The data sequences and pilot sequences are placed to their physical subcarrier location. Then the useful subcarriers are randomized. The same actions are performed on FCH & DL-MAP and UL-MAP. After IFFT and cyclic prefix insertion, the idle interval and downlink payloads (bursts, FCH & DL-MAP, UL-MAP) are combined with zero-padding bits if needed. In addition, uplink position will be preserved and filled with zeros before downlink payload if FrameMode ( Frame Mode ) is TDD.

The zone boosting is performed according to the parameter of GroupBitmask (which for this downlink design have all bits set to 1). At last, oversampling is implemented by a transmitter filter.

Note
With default parameter settings, the DL-MAP occupies 26 subchannels, and the UL-MAP occupies 23 subchannels. Sometimes the subchannels occupied by DL-MAP or UL-MAP may exceed the available subchannels. This condition will be discovered during parameter Range Check and an error message will be reported.

The relationships between the WiMax source parameters and the waveform SignalSegmentTime , SamplesPerSegment , and waveform modeling TimeStep are made available in the design data displays and listed in Design Equations (Derived from Design Parameters and Exported to Data Display).

Generic RF power delivered into a matched load is the average power delivered over the full frame. RF Signal Envelope shows the RF envelope for an output RF signal with 10 dBm power.

RF Signal Envelope

RF CCDF shows the generic RF CCDF curve for a 10 dBm signal compared to the CCDF for a signal with a Gaussian power distribution.

RF CCDF

RF Spectrum shows the generic spectrum.

RF Spectrum

Instrument Compatibility

Generic designs are compatible with the Agilent Signal Studio Software, Agilent ESG, and Agilent VSA models described in Agilent Instrument Compatibility.

Signal Studio Models ESG Models VSA Models
Agilent Signal Studio for 802.16 OFDMA, Version 1.2.1.0, for use with Agilent ESG and PSG Vector Signal Generators Agilent ESG Agilent Vector Signal Analyzer (VSA)

For more information about the following products, see the Agilent Technologies web site:

WMAN 802.16e Downlink Transmission Test Design Parameters

The following table summarizes the technology-specific design parameters.

Design Parameter Summary
Description Values Default Range Type Unit Symbol
Signal Setup
Number of Bursts   1 [1,8] int   NB
Burst#1 Rate ID for Burst Modulation and Coding Rate QPSK 1/2, QPSK 3/4, 16QAM 1/2, 16QAM 3/4, 64QAM 1/2 64QAM 2/3 64QAM 3/4 64QAM 5/6 QPSK 1/2   enum    
Advanced Signal Setup
Random Number Generator Seed   1234567 [0,∞ ) int    
Nominal RF Bandwidth BW 1.25 MHz, BW 3.5 MHz, BW 4.375 MHz, BW 5 MHz, BW 7 MHz, BW 8.75 MHz, BW 10 MHz, BW 14 MHz, BW 15 MHz, BW 17 MHz, BW 20 MHz, BW 28 MHz BW 10 MHz   enum    
Oversampling Ratio Option Ratio 1, Ratio 2, Ratio 4 Ratio 2   enum    
FFT Size FFT 2048, FFT 1024, FFT512 FFT 1024   enum    
Cyclic Prefix G 1/4, G 1/8, G 1/16, G 1/32 G 1/8   enum    
Frame Mode FDD, TDD FDD   enum    
Downlink Ratio (%)   50 [1,99] float    
Frame Duration Time 2 ms, Time 2.5 ms, Time 4 ms, Time 5 ms, Time 8 ms, Time 10 ms, Time 12.5 ms, Time 20 ms, Time 5 ms   enum    
Starting Frame Number in Subframe (HEX)   0 [0:0xffffff] int    
Increase Frame Number in Consecutive Frames NO, YES NO   query    
CRC32 Mode MSB First, LSB First MSB First   enum    
Downlink Signal Setup
Preamble Index   3 [0,113] int    
Permutation Base   9 [0,31] int    
PRBS ID   0 [0,31] int    
FEC-Encoded Burst Index   1 [1,NB] int    
Data Pattern PN9, PN15, FIX4, _4_1_4_0, _8_1_8_0, _16_1_16_0, _32_1_32_0, _64_1_64_0, S_QPSK, S_16-QAM, S_64-QAM PN9   enum    
FEC-Coding Type CC, CTC CC   enum    
FEC-Repetition Coding RC none, RC 2, RC 4, RC 6 RC none   enum    
Zone Setup
Number of OFDM Symbols   24 [1,1212]      
Zone Type DL_PUSC, DL_FUSC, DL_OFUSC DL_PUSC   enum    
Activate DL-MAP Insertion NO, YES NO   query    
DL-MAP Coding Type CC, CTC CC   enum    
DL-MAP Repetition Coding RC none, RC 2, RC 4, RC 6 RC none   enum    
DCD Count   1 [0,255] int    
Activate UL-MAP Insertion NO, YES NO   query    
UL-MAP Coding Type CC, CTC CC   enum    
UL-MAP Rate ID for Burst Modulation and Coding Rate QPSK 1/2, QPSK 3/4, 16QAM 1/2, 16QAM 3/4, 64QAM 1/2, 64QAM 2/3, 64QAM 3/4, 64QAM 5/6 QPSK 1/2   enum    
UL-MAP Repetition Coding RC none, RC 2, RC 4, RC 6 RC none   enum    
UL-MAP Power Boosting   0 (−∞,∞) float dB  
Burst Setup
Symbol Offset   Burst #1-4: 2 Burst #5-8: 4 [0,1211] int    
Subchannel Offset   Burst #1:0 Burst #2: 7 Burst #3: 14 Burst #4: 14 Burst #5: 0 Burst #6: 7 Burst #7: 14 Burst #8: 21 [0,59] int    
Number of Symbols   Burst #1:20 Burst #2-8: 2 [1,1212] int    
Number of Subchannels   Burst #1:30 Burst #2-8: 7 [1,60] int    
Power Boosting   0 (−∞,∞) int dB  
MAC PDU Payload Byte Length   Burst #1:200 Burst #2-8: 32 [1,4095] int    
Measurement Setup
EVM Setup
Data Collection Start Time   0.0 (0,∞) float sec  
Average Type   OFF, RMS (Video) OFF enum    
Frames to Average (for AverageType = RMS)   5 [1, ∞) int    
Perform Pulse Search NO, YES YES   query    
Symbol Timing Adjustment (in % of FFT Time)   -3.125 [-G100:0] float    
Track Amplitude NO, YES NO   query    
Track Phase NO, YES YES   query    
Track Timing NO, YES NO   query    
Equalizer Training Method Chan Estimation Seq Only, Chan Estimation Seq and Data, Chan Estimation Seq and Pilots Chan Estimation Seq Only   enum    
Constellation Setup
Start Frame Number   1 [0, ∞) int   CS
Stop Frame Number   2 [CS,∞) int    
CCDF Setup
Data Collection Start Time   0.0 [0,∞) float sec  
Number of Symbols Used   200 [1, ∞) int    
Number of Points in CCDF Curve   1200 [0,∞) int    
1This parameter provides values for bursts 1 through 8.

This section provides detailed descriptions of the design parameters.

Signal Setup

Number of Bursts
Specifies the number of bursts. If the Zone Type is DL_PUSC , then the bursts are associated with Zone#0. Otherwise, the bursts are associated with Zone#1 (the second zone).
Burst #(1-8) Rate ID for Burst Modulation and Coding Rate
Specifies the modulation type and the coding rate. The Rate ID of 64QAM 5/6 is only available when the FEC-Coding Type is set to CTC .

Advanced Signal Setup

The following parameters may be optionally set. The design will typically perform well with the default settings.

Random Number Generator Seed
Specifies the seed for the random number generator.
Nominal RF Bandwidth
Specifies the nominal bandwidth for the modulated signal.
Oversampling Ratio Option
Specifies the signal oversampling ratio.
FFT Size
Specifies the size of the Fast Fourier Transform.
Cyclic Prefix
Sets the cyclic prefix time (also referred to as Guard Interval) as a fraction of the inverse FFT time. The cyclic prefix time is used to eliminate inter-symbol and inter-carrier interference. Each OFDMA symbol is transmitted for a slightly longer time than the active (or useful) symbol time. This extra time is the cyclic prefix time.
Frame Mode
Specifies the duplexing method which should be FDD or TDD. In FDD transmission, the downlink occupies the entire frame and the respective gaps (zeros) are automatically adjusted to fill the frame.
Downlink Ratio (%)
Specifies the percentage (1 to 99) of the frame time to be used for the downlink subframe. The parameter is only active when the Frame Mode is TDD .
Frame Duration
Specifies the time duration of the generated waveform frame.
Staring Frame Number in Subframe (HEX)
Specifies the subframe starting frame number in hexadecimal.
Increase Frame Number in Consecutive Frames
Specifies whether the frame number for the downlink subframe is increased in consecutive frames. When set to YES , the frame numbers in Frame#0, Frame#1, Frame#2, Frame#3 will be Starting Frame Number , Starting Frame Number +1, Starting Frame Number +2, Starting Frame Number +3. When set to NO , then the frame numbers in Frame#0, Frame#1, Frame#2, Frame#3 will all be Starting Frame Number .
CRC32 Mode
Specifies the method for CRC32 calculation appended to MAC PDU. For consistency with 802.16-2004 Cor1/D5, set to MSB first . Set to LSB first for consistency with 802.16-2004 Cor1/D3.

Downlink Signal Setup

Preamble Index
Specifies the index value (0 to 113) that determines the ID Cell values (0 to 31) and segment index (0 to 2) according to the standard.
Permutation Base
Specifies the basis of downlink permutation to be used in initialization vector of the PRBS generator for subchannel randomization in the zone and in STC_DL_Zone_IE() in DL-MAP message.
PRBS ID
Specifies the PRBS ID which may be used in initialization vector of the PRBS generator for subchannel randomization and in STC_DL_Zone_IE() in DL-MAP message.
FEC-Encoded Burst Index
Specifies the index for the downlink burst with FEC (Forward Error Correction).
Data Pattern
Specifies the transmitted data pattern.

PN9 is a 511-bit pseudo-random test pattern generated according to CCITT Recommendation O.153

PN15 is a 32767-bit pseudo-random test pattern generated according to CCITT Recommendation O.151

FIX4 is a zero-stream

x_1_x_0 (where x equals 4, 8, 16, 32, or 64) generates a periodic bit stream, with the period being 2 x. In one period, the first x bits are 1s and the second x bits are 0s.
S_QPSK, S_16-QAM or S_64-QAM generates test messages for receiver sensitivity measurement.
S_QPSK = [0xE4, 0xB1, 0xE1, 0xB4]
S_16-QAM = [0xA8, 0x20, 0xB9, 0x31, 0xEC, 0x64, 0xFD, 0x75]
S_64-QAM = [0xB6, 0x93, 0x49, 0xB2, 0x83, 0x08, 0x96, 0x11, 0x41, 0x92, 0x01, 0x00, 0xBA, 0xA3, 0x8A, 0x9A, 0x21, 0x82, 0xD7, 0x15, 0x51, 0xD3, 0x05, 0x10, 0xDB, 0x25, 0x92, 0xF7, 0x97, 0x59, 0xF3, 0x87, 0x18, 0xBE, 0xB3, 0xCB, 0x9E, 0x31, 0xC3, 0xDF, 0x35, 0xD3, 0xFB, 0xA7, 0x9A, 0xFF, 0xB7, 0xDB]
FEC-Coding Type
Specifies the forward error correction coding type for each burst. CC generates Convolutional Coding. CTC generates Convolutional Turbo Coding.
FEC-Repetition Coding
Specifies the forward error correction repetition coding for each burst. Set to RC none , no repetition coding is generated. RC 2 , RC 4 , RC 6 generates repetition coding of 2, 4, and 6 respectively.

Zone Setup

Number of OFDM Symbols
Specifies the number of Orthogonal Frequency Division Modulation symbols in the zone. The value must be a multiple of two when Zone Type is DL_PUSC and must be be a multiple of one when Zone Type is DL_FUSC or DL_OFUSC .
Zone Type
Specifies the zone type.
Activate DL-MAP Insertion
When set to YES, then a burst will carry the downlink map.
DL-MAP Coding Type
Specifies the forward error correction coding type for the burst carrying the DL-MAP. CC generates Convolutional Coding. CTC generates Convolutional Turbo Coding.
DL-MAP Repetition Coding
Specifies the forward error correction repetition coding for the burst carrying the DL-MAP. Set to RC none , no repetition coding is generated. RC 2 , RC 4 , RC 6 generates repetition coding of 2, 4, and 6 respectively.
DCD Count
Specifies the DCD count which is used in DL-MAP and DCD messages. This is incremented by one (modulo 256) whenever there is a downlink configuration change.
Activate UL-MAP Insertion
When set to YES , a burst carries the uplink map.
UL-MAP Coding Type
Specifies the forward error correction coding type for the burst carrying the UL-MAP. CC generates Convolutional Coding. CTC generates Convolutional Turbo Coding.
UL-MAP Rate ID for Burst Modulation and Coding Rate
Specifies the modulation type and the coding rate for the burst carrying the UL-MAP. The Rate ID of 64QAM 5/6 is only available when the UL- MAP Coding Type is set to CTC .
UL-MAP Repetition Coding
Specifies the forward error correction repetition coding for the burst carrying the UL-MAP. Set to RC none , no repetition coding is generated. RC 2 , RC 4 , RC 6 generates repetition coding of 2, 4, and 6 respectively.
UL-MAP Power Boosting
Specifies the power boosting, in dB, for the burst carrying UL-MAP and UCD messages.

Burst Setup

Symbol Offset, Subchannel Offset, Number of Symbols, Number of Subchannels
Symbol Offset , along with Subchannel Offset , Number of Symbols and Number of Subchannels specify the position and range for each rectangular burst as shown in Downlink Rectangular Burst Structure.

Downlink Rectangular Burst Structure

Power Boosting
Specifies the power boosting value in dB for a specific burst.
MAC PDU Payload Byte Length
Specifies the MAC PDU payload byte length for a specific burst with forward error coding.

Measurement Setup

Constellation Setup

Start Frame Number
Specifies the starting frame number for constellation setup.
Stop Frame Number
Specifies the stopping frame number for constellation setup.

CCDF Setup

Data Collection Start Time
Specifies the data collection start time.
Number of Symbols Used
Specifies the number of symbols used to determine CCDF.
Number of Points in CCDF Curve
Specifies the number of points in the CCDF curve.

EVM Setup

The EVM measurement for a WiMax 802.16e (OFDMA) downlink signal provides these available results:

Results prefixed with Avg_ are averaged over the number of frames specified by the user (if Average Type is set to RMS (Video) ). Results that are not prefixed with Avg_ are results versus frame.

All the results mentioned above are saved and displayed in the status window. The following results are only displayed in the status window:

Power in dB, RCE in dB, and DataRCE in dB for each analyzed data burst are also displayed on the status window. For a detailed description of the measurement, see EVM Measurement Description.

Data Collection Start Time
Specifies the time at which data collection begins.
Average Type
Specifies video averaging or no averaging.
Frames to Average (For RMS Averaging)
Specifies the number of frames to average for video averaging. Averaging type must be set to RMS.
Perform Pulse Search
Toggles the operating state of the pulse search.
Symbol Timing Adjustment (in % of FFT Time)
Specifies the timing adjustment as a percentage of FFT time.
Track Amplitude
Specifies amplitude tracking.
Track Phase
Specifies phase tracking.
Track Timing
Specifies timing tracking.
Equalizer Training Method
Specifies training method for equalization.

EVM Measurement Description

The following is a brief description of the algorithm used in this component and a detailed description of its parameter usage.

In the following, SignalSegmentTime is defined in Design Equations (Derived from Design Parameters and Exported to Data Display).

  1. Starting at the time instant specified by Data Collection Start Time , the measurement captures a signal segment of length 2 x SignalSegmentTime . If Perform Pulse Search is set to YES , this signal segment is searched in order for an RF burst to be detected. If the signal has multiple RF bursts in a SignalSegmentTime , then the first burst detected is analyzed. Some 802.16e OFDMA signals do not have RF burst characteristics, rather they look like a series of bursts with no "off" time between them. These signals resemble a "continually on" signal with embedded preambles. To demodulate signals that do not appear to be made up of RF bursts, Perform Pulse Search should be set to OFF and Data Collection Start Time should be set to the beginning of the downlink subframe you want to analyze. Otherwise, no pulse will be detected and no measurement will be performed.
    After an RF burst is detected, the I and Q envelopes of the input signal are extracted. The I and Q envelopes then pass to a complex algorithm that performs synchronization, demodulation, and EVM analysis. The algorithm that performs the synchronization, demodulation, and EVM analysis is the same used in the Agilent 89600 VSA.
  2. If Average Type is set to OFF , only one frame is analyzed. If Average Type is set to RMS (Video) , after the first frame is analyzed the signal segment corresponding to it is discarded and new signal samples are collected from the input to fill in the signal buffer of length 2 x SignalSegmentTime . A second frame is analyzed and the process repeats until Frames To Average frames are processed.
    If a frame is misdetected for any reason, the results from its analysis are discarded. The EVM results obtained from all successfully detected, demodulated, and analyzed frames are averaged to give the final averaged results. The EVM results from each successfully analyzed pulse are also recorded (in the variables that are not prefixed with Avg_ ).
  3. The Symbol Timing Adjustment parameter sets the percentage of symbol time before the symbol end where the FFT is performed. Normally, when demodulating an OFDMA symbol, the cyclic prefix time (guard interval) is skipped and an FFT is performed on the last portion of the symbol time. However, this means that the FFT will include the transition region between this symbol and the following symbol. To avoid this, it is generally beneficial to back away from the end of the symbol time and use part of the guard interval. The Symbol Timing Adjustment parameter controls how far the FFT part of the symbol is adjusted away from the end of the symbol time. The value is in terms of percent of the used (FFT) part of the symbol time. Note that this parameter value is negative, because the FFT start time is moved back by this parameter. SymbolTimingAdjust Definition explains this concept. When setting this parameter, be careful to not back away from the end of the symbol time too much because this may make the FFT include corrupt data from the transition region at the beginning of the symbol time.

SymbolTimingAdjust Definition
  1. The Track Amplitude , Track Phase , and Track Timing parameters specify whether the analysis will track amplitude, phase, and timing changes in the pilot subcarriers. 802.16e performs demodulation relative to the data in pilot carriers embedded in the signal. These pilot carriers replace data-carrying elements of the signal and allow some kinds of impairments to be removed or "tracked out." Many impairments will be common to all pilot carriers and can be measured as the "common pilot error." When these parameters are set to YES the analysis will track amplitude, phase, and timing changes in the pilot subcarriers and apply corrections to the pilot and data subcarriers.
    The flexibility to allow users to individually enable or disable tracking functions and provides useful troubleshooting capability, since modulation errors can be examined with and without the benefit of particular types of pilot tracking.
  2. The Equalizer Training Method parameter sets the type of training used for the equalizer. When demodulating an 802.16e signal, an equalizer is used to correct for linear impairments in the signal path, such as multi-path.

When Chan Estimation Seq Only is selected the equalizer is trained using the Channel Estimation Sequence in the preamble of the OFDMA burst. After this initialization, the equalizer coefficients are held constant while demodulating the rest of the burst. This equalizer training method complies with the description in section (8.4.12.3) "Transmit Constellation Error and Test Method" of the 802.16-2004 standard. However, for signals whose impairments change during the burst it might result in measured RCE (EVM) values that are higher compared to if the equalizer were trained over the entire burst.

When Chan Estimation Seq & Data is selected the equalizer is trained by analyzing the entire OFDMA burst and using the Channel Estimation Sequence (contained in the preamble) and the all the subcarriers in the Data symbols. This type of equalizer training generally gives a more accurate estimate of the true response of the transmission channel and so results in lower RCE (EVM) measured values. However, it is more complicated and more computationally expensive to implement and therefore less likely to be used in practical receivers.

When Chan Estimation Seq & Pilots is selected the equalizer is trained by analyzing the entire OFDMA burst and using the Channel Estimation Sequence (contained in the preamble) and the pilot subcarriers in the Data symbols. This gives results very similar to the Chan Estimation Seq & Data option without the excessive computational complexity.

Variables

The variables listed in Design Constants for Signal Setup and Design Equations (Derived from Design Parameters and Exported to Data Display) are defined for use in the design and data display.

Constant Value
IdleInterval 0
FrameDuration integer value for the selected `Frame Duration'; 0 for 2 ms, ...., 7 for 20 ms
OversamplingOption integer value for the selected 'Oversampling Ratio Option'; 0 for Ratio 1, 1 for Ratio 2, 2 for Ratio 4
BandWidth integer value for the selected 'Nominal RF Bandwidth'; 0 for 1.25 MHz, ..., 11 for 28 MHz
NumOfSymInZone 24
G integer value for the selected 'Cyclic Prefix'; 0 for 1/4, 1 for 1/8, 2 for 1/16, 3 for 1/32
FFTSize integer value for the selected 'FFT Size'; 0 for 2048, 1 for 1024, 2 for 512
FrameDur_Table {2 ms, 2.5 ms, 4 ms, 5 ms, 8 ms, 10 ms, 12.5 ms, 20 ms}
SignalSegmentTime FrameDur_Table[FrameDuration+1] + IdleInterval
CommonBW_new if(0==int(Bandwidth)) then 1.25e6 elseif (1==int(Bandwidth)) then 3.5e6 elseif (2==int(Bandwidth)) then 4.375e6 elseif (3==int(Bandwidth)) then 5e6 elseif (4==int(Bandwidth)) then 7e6 elseif (5==int(Bandwidth)) then 8.75e6 elseif (6==int(Bandwidth)) then 10e6 elseif (7==int(Bandwidth)) then 14e6 elseif (8==int(Bandwidth)) then 15e6 elseif (9==int(Bandwidth)) then 17e6 elseif (10==int(Bandwidth)) then 20e6 elseif (11==int(Bandwidth)) then 28e6 else 3.5e6 endif
n_num if(0==fmod(int(CommonBW_new),1750000)) then 8 elseif(0==fmod(int(CommonBW_new),1500000)) then 28 elseif(0==fmod(int(CommonBW_new),1250000)) then 28 elseif(0==fmod(int(CommonBW_new),2750000)) then 28 elseif(0==fmod(int(CommonBW_new),2000000)) then 28 else 8 endif
n_den if(0==fmod(int(CommonBW_new),1750000)) then 7 elseif(0==fmod(int(CommonBW_new),1500000)) then 25 elseif(0==fmod(int(CommonBW_new),1250000)) then 25 elseif(0==fmod(int(CommonBW_new),2750000)) then 25 elseif(0==fmod(int(CommonBW_new),2000000)) then 25 else 7 endif
RF_Bandwidth floor(CommonBW_new*n_num/(n_den*8000))*8000
RF_SamplingRate RF_Bandwidth*(2^int(OversamplingOption))
TimeStep 1/RF_SamplingRate
SamplesPerSegment SignalSegmentTime/TimeStep
SymLen 2048/(2^int(FFTSize))*(1+CyclicPrefix)*(2^int(OversamplingOption))
FilterDelayTime 30/RF_SamplingRate*(2^int(OversamplingOption))

Baseline Performance

References

  1. IEEE Std 802.16-2004, Part 16: Air Interface for Fixed Broadband Wireless Access Systems, Section 8.4 WirelessMAN-OFDMA PHY , October 1, 2004.
  2. IEEE Std 802.16e-2005, Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Section 8.4 WirelessMAN-OFDMA PHY , December 7, 2005.

WiMax 802.16e Related Links

http://standards.ieee.org/getieee802/802.16.html
http://www.ieee.org/

WMAN 802.16e Uplink Transmission Test Design Example

The design example is available from the ADS main window in File > Example Project > Connected_Solutions > STW_WMAN_16e_OFDMA_UpLink_prj .
STW_WMAN_16e_OFDMA_UpLink_prj provides a WMAN_802_16e_UL_TX test and measurement design example based on IEEE Standard 802.16e-1999 and 802.16e-2003.

Overview

The generic Transmission Test Design provides connection to an RF hardware device under test (DUT) to determine the performance of the DUT by activating various design measurements. This design provides signal measurements for RF envelope, signal power (including CCDF), constellation, spectrum, and EVM.

The signal and most measurements are designed according to the generic specification.

This design can generate an RF modulated signal with optional impairments, send the signal to the input of the RF DUT through an Agilent Electronic Signal Generator (ESG), receive the signal from the RF DUT output through an Agilent Vector Signal Analyzer (VSA), and display the measurement results in a data display.

Signal Segment Structure

The Mobile WiMAX 802.16e Uplink signal is for mobile WiMAX OFDMA defined per the specification section 8.4 WirelessMAN-OFDMA PHY in IEEE Std 802.16-2004 and IEEE 802.16e-2005.

The uplink signal is from the mobile unit to the base station.

The major specifications for the WirelessMAN-OFDMA PHY physical layer are listed in Mobile WiMAX-OFDMA PHY Physical Layer Major Specifications.

Specification Settings
Information data rate up to 70 Mbps at 20 MHz bandwidth
Modulation BPSK, QPSK, 16-QAM, 64-QAM
Error correcting code CC, CTC, BTC
Coding rate 1/2, 2/3, 3/4
2048, 1024, 512
Number of data subcarriers variable
Number of pilot subcarriers variable
Number of total subcarriers used variable
Number of lower frequency guard subcarriers variable
Number of higher frequency guard subcarriers variable
n:Sampling factor For channel bandwidths that are a multiple of 1.75 MHz then n = 8/7
G: Ratio of CP time to "useful" time 1/4, 1/8, 1/16, 1/32
BW: Nominal channel bandwidth From 1.5 MHz to 28 MHz
Tb: Useful symbol time
Tg: CP time
Ts: OFDM symbol time

Mobile WiMAX 802.16e Uplink frame format in TDD mode (set with the Frame Mode parameter) is shown in 802.16e OFDMA Frame Structure for TDD Mode. In TDD mode, 70% (set with the Downlink Ratio parameter) of the frame time is allocated for the downlink subframe which will be filled with zeros. In FDD mode, 100% of the frame time will be used for the downlink and uplink subframes and the Downlink Ratio parameter will be not be used.

802.16e OFDMA Frame Structure for TDD Mode

Mobile WiMAX 802.16e Uplink subframe format is illustrated in Mobile WiMAX 16e OFDMA UL Subframe Structure. The X-axis represents time. The Y-axis represents frequency subchannels.

Mobile WiMAX 16e OFDMA UL Subframe Structure

The uplink subframe includes only one zone (alternative PUSC or OPUSC) which contains a maximum of 8 bursts with each carrying one MAC PDU. Among these bursts, only one FEC-encoded burst is supported whose coding type can be set to CC or CTC . Other bursts are provided PN sequences as their coded source respectively. Both TDD mode and FDD mode can be supported for the uplink source.

After encoding, the encoded burst is mapped to the constellation. Other bursts without FEC, are provided with PN sequence as their coded bits and mapped to the constellation according to their Rate_ID ( Rate ID for Burst Modulation and Coding Rate ). The FEC-encoded burst is concatenated with non-coded bursts.
The physical indices of data subcarriers and pilot subcarriers for each burst are calculated. The data sequences and pilot sequences are placed to their physical subcarrier location. Then the useful subcarriers are randomized. After IFFT and cyclic prefix insertion, the idle interval and uplink payload are combined with zero padding bits if needed. In addition, downlink position will be preserved and filled with zeros before uplink payload if Frame Mode is TDD . At last, oversampling is implemented by a transmitter filter.

The relationships between the WiMax source parameters and the waveform modeling SignalSegmentTime , SamplesPerSegment and TimeStep are made available in the design data displays and defined in Design Equations (Derived from Design Parameters and Exported to Data Display).

Generic RF power delivered into a matched load is the average power delivered over the full frame. RF Signal Envelope shows the RF envelope for an output RF signal with 10 dBm power.

RF Signal Envelope

RF CCDF shows the generic RF CCDF curve for a 10 dBm signal compared to the CCDF for a signal with a Gaussian power distribution.

RF CCDF

RF Spectrum shows the generic spectrum.

RF Spectrum

Instrument Compatibility

Generic designs are compatible with the Agilent Signal Studio Software, Agilent ESG, and Agilent VSA models described in Agilent Instrument Compatibility.

Signal Studio Models ESG Models VSA Models
Agilent Signal Studio for 802.16 OFDMA, Version 1.2.1.0, for use with Agilent ESG and PSG Vector Signal Generators Agilent ESG Agilent Vector Signal Analyzer (VSA)

For information about the following products, see the Agilent Technologies web site:

WMAN 802.16e Uplink Transmission Test Design Parameters

The following table summarizes the technology-specific design parameters.

Description Values Default Range Type Unit Symbol
Number of Bursts   1 [1,8] int   NB
Burst#<a href="#1113844"><sup>1</sup></a> Rate ID for Burst Modulation and Coding Rate QPSK 1/2, QPSK 1/2   enum    
Random Number Generator Seed   1234567 [0,∞) int    
Nominal RF Bandwidth BW 1.25 MHz, BW 10 MHz   enum    
Oversampling Ratio Option Ratio 1, Ratio 2, Ratio 1   enum    
FFT Size FFT 2048, FFT 1024   enum    
Cyclic Prefix G 1/4, G 1/8, G 1/16, G 1/32 G 1/8   enum    
Frame Mode FDD, TDD FDD   enum    
Downlink Ratio (%)   50 [1,99] float    
Frame Duration Time 2 ms, Time 5 ms   enum    
Starting Frame Number in Subframe (HEX)   0 [0:0xffffff] int    
Increase Frame Number in Consecutive Frames NO, YES NO   query    
CRC32 Mode MSB First, LSB First MSB First   enum    
Preamble Index   3 [0,113] int    
Permutation Base   9 [0,69] int    
FEC-Encoded Burst Index   1 [1,NB] int    
Data Pattern PN9, PN9   enum    
FEC-Coding Type CC, CTC CC   enum    
FEC-Repetition Coding RC none, RC 2, RC 4, RC 6 RC none   enum    
Number of OFDM Symbols   24 [1,1212]      
Zone Type UL_PUSC, UL_PUSC   enum    
Symbol Offset   Burst #1, 3, 5, 7: 0 [0,1211] int    
Subchannel Offset   Burst #1: 0 [0,59] int    
Assigned Slots   7 [1,6868] int    
Power Offset   0 (−∞,∞) int dB  
MAC PDU Payload Byte Length   32 [1,4095] int    
Data Collection Start Time   0.0 (0,∞) float sec  
Average Type   Off, RMS (Video) Off enum    
Frames to Average (for AverageType = RMS   5 [1, ∞) int    
Perform Pulse Search NO, YES YES   query    
Symbol Timing Adjustment (in % of FFT Time)   -3.125 [-G*100:0] float    
Track Amplitude NO, YES NO   query    
Track Phase NO, YES YES   query    
Track Timing NO, YES NO   query    
Equalizer Training Method Chan Estimation Seq Only, Chan Estimation Seq Only   enum    
Start Frame Number   1 [0, ∞) int   CS
Stop Frame Number   2 [CS,∞) int    
Data Collection Start Time   0.0 [0,∞) float sec  
Number of Symbols Used   200 [1, ∞) int    
Number of Points in CCDF Curve   1200 [0,∞) int    
<a href="#1113845"><sup>1</sup></a>This parameter provides values for bursts 1 through 8.

This section provides detailed descriptions of the design parameters.

Signal Setup

Number of Bursts
Specifies the number of bursts.
Burst #(1-8) Rate ID for Burst Modulation and Coding Rate
Specifies the modulation type and the coding rate. The Rate ID 64QAM 5/6 is only available when the FEC-Coding Type is set to CTC .

Advanced Signal Setup

The following parameters may be optionally set. The design will typically perform well with the default settings.

Random Number Generator Seed
Specifies the seed for the random number generator.
Nominal RF Bandwidth
Specifies the nominal bandwidth for the modulated signal.
Oversampling Ratio Option
Specifies the signal oversampling ratio.
FFT Size
Specifies the size of the Fast Fourier Transform.
Cyclic Prefix
Sets the cyclic prefix time (also referred to as Guard Interval) as a fraction of the inverse FFT time. The cyclic prefix time is used to eliminate inter-symbol and inter-carrier interference. Each OFDMA symbol is transmitted for a slightly longer time than the active (or useful) symbol time. This extra time is the cyclic prefix time.
Frame Mode
Specifies the duplexing method which should be FDD or TDD. In FDD transmission, the uplink occupies the entire frame and the respective gaps (zeros) are automatically adjusted to fill the frame.
Downlink Ratio (%)
Specifies set the percentage (1 to 99) of the frame time to be used for the downlink subframe. The parameter is only active when the `Frame Mode' is TDD.
Frame Duration
Specifies the time duration of the generated waveform frame.
Staring Frame Number in Subframe (HEX)
Specifies the subframe starting frame number in hexadecimal.
Increase Frame Number in Consecutive Frames
Specifies whether the frame number for the downlink subframe is increased in consecutive frames. When set to YES , the frame numbers in Frame#0, Frame#1, Frame#2, Frame#3 will be Starting Frame Number , Starting Frame Number +1, Starting Frame Number +2, Starting Frame Number +3. When set to NO , then the frame numbers in Frame#0, Frame#1, Frame#2, Frame#3 will all be Starting Frame Number .
CRC32 Mode
Specifies the method for CRC32 calculation appended to MAC PDU. For consistency with 802.16-2005, set to MSB first. Set to LSB first for consistency with 802.16-2004.

Uplink Signal Setup

Preamble Index
Specifies the index value (0 to 113) that determines the ID Cell values (0 to 31) and segment index (0 to 2) according to the standard.
Permutation Base
Specifies the permutation base that will be used in this uplink zone.
FEC-Encoded Burst Index
Specifies the index for the downlink burst with FEC (forward error correction).
Data Pattern
Specifies the transmitted data pattern.
PN9 is a 511-bit pseudo-random test pattern generated according to CCITT Recommendation O.153
PN15 is a 32767-bit pseudo-random test pattern generated according to CCITT Recommendation O.151
FIX4 is a zero-stream
x_1_x_0 (where x equals 4, 8, 16, 32, or 64) generates a periodic bit stream, with the period being 2 x. In one period, the first x bits are 1s and the second x bits are 0s.
S_QPSK, S_16-QAM or S_64-QAM generates test messages for receiver sensitivity measurement.
S_QPSK = [0xE4, 0xB1, 0xE1, 0xB4]
S_16-QAM = [0xA8, 0x20, 0xB9, 0x31, 0xEC, 0x64, 0xFD, 0x75]
S_64-QAM = [0xB6, 0x93, 0x49, 0xB2, 0x83, 0x08, 0x96, 0x11, 0x41, 0x92, 0x01, 0x00, 0xBA, 0xA3, 0x8A, 0x9A, 0x21, 0x82, 0xD7, 0x15, 0x51, 0xD3, 0x05, 0x10, 0xDB, 0x25, 0x92, 0xF7, 0x97, 0x59, 0xF3, 0x87, 0x18, 0xBE, 0xB3, 0xCB, 0x9E, 0x31, 0xC3, 0xDF, 0x35, 0xD3, 0xFB, 0xA7, 0x9A, 0xFF, 0xB7, 0xDB]
FEC-Coding Type
Specifies the forward error correction coding type for each burst. CC generates Convolutional Coding. CTC generates Convolutional Turbo Coding.
FEC-Repetition Coding
Specifies the forward error correction repetition coding for each burst. Set to RC none, no repetition coding is generated. RC 2 , RC 4 , RC 6 generates repetition coding of 2, 4, and 6 respectively.

Zone Setup

Number of OFDM Symbols
Specifies the number of Orthogonal Frequency Division Modulation symbols in the zone. The value must be a multiple of three because the uplink zone is divided into slots of 3 symbols x 1 subchannel (section 8.4.3.1 in 802.16-2004/Cor/D3).
Zone Type
Specifies the zone type which can be set to PUSC or OPUSC .

Burst Setup

Symbol Offset
Specifies the position of each burst on the horizontal axis (x) to avoid any burst overlap.
Subchannel Offset
Specifies the position of each burst on the vertical axis (y) to avoid any burst overlap.
Assigned Slots
Specifies the total available slots for each burst.
Power Offset
Specifies the power offset of each burst in dB.
MAC PDU Payload Byte Length
Specifies the MAC PDU payload byte length for a specific burst with forward error coding.

Measurement Setup

Constellation Setup

Start Frame Number
Specifies the starting frame number for constellation setup.
Stop Frame Number
Specifies the stopping frame number for constellation setup.

CCDF Setup

Data Collection Start Time
Specifies the data collection start time.
Number of Symbols Used
Specifies the number of symbols used to determine CCDF.
Number of Points in CCDF Curve
Specifies the number of points in the CCDF curve.

EVM Setup

The EVM measurement for a WiMax 802.16e (OFDMA) downlink signal provides these available results:

Results prefixed with Avg_ are averaged over the number of frames specified by the user (if Average Type is set to RMS (Video) ). Results that are not prefixed with Avg_ are results versus frame.

All the results mentioned above are saved and displayed in the status window. The following results are only displayed in the status window:

Data Collection Start Time
Specifies the time at which data collection begins.
Average Type
Specifies video averaging or no averaging.
Frames to Average (For RMS Averaging)
Specifies the number of frames to average for video averaging. Averaging type must be set to RMS .
Perform Pulse Search
Toggles the operating state of the pulse search.
Symbol Timing Adjustment (in % of FFT Time)
Specifies the timing adjustment as a percentage of FFT time.
Track Amplitude
Specifies amplitude tracking.
Track Phase
Specifies phase tracking.
Track Timing
Specifies timing tracking.
Equalizer Training Method
Specifies training method for equalization.

EVM Measurement Description

The following is a brief description of the algorithm used in this component and a detailed description of its parameter usage.

  1. Starting at the time instant specified by Data Collection Start Time , the measurement captures a signal segment of length 2 x SignalSegmentTime . If Perform Pulse Search is set to YES , this signal segment is searched in order for an RF burst to be detected. If the signal has multiple RF bursts in a SignalSegmentTime , then the first burst detected is analyzed. Some 802.16e OFDMA signals do not have RF burst characteristics, rather they look like a series of bursts with no "off" time between them. These signals resemble a "continually on" signal with embedded preambles. To demodulate signals that do not appear to be made up of RF bursts, Perform Pulse Search should be set to OFF and Data Collection Start Time should be set to the beginning of the downlink subframe you want to analyze. Otherwise, no pulse will be detected and no measurement will be performed.
    After an RF burst is detected, the I and Q envelopes of the input signal are extracted. The I and Q envelopes then pass to a complex algorithm that performs synchronization, demodulation, and EVM analysis. The algorithm that performs the synchronization, demodulation, and EVM analysis is the same used in the Agilent 89600 VSA.
  2. If Average Type is set to OFF , only one frame is analyzed. If Average Type is set to RMS (Video) , after the first frame is analyzed the signal segment corresponding to it is discarded and new signal samples are collected from the input to fill in the signal buffer of length 2 x SignalSegmentTime . A second frame is analyzed and the process repeats until Frames To Average frames are processed.
    If a frame is misdetected for any reason, the results from its analysis are discarded. The EVM results obtained from all successfully detected, demodulated, and analyzed frames are averaged to give the final averaged results. The EVM results from each successfully analyzed pulse are also recorded (in the variables that are not prefixed with Avg_ ).
  3. The Symbol Timing Adjustment parameter sets the percentage of symbol time before the symbol end where the FFT is performed. Normally, when demodulating an OFDMA symbol, the cyclic prefix time (guard interval) is skipped and an FFT is performed on the last portion of the symbol time. However, this means that the FFT will include the transition region between this symbol and the following symbol. To avoid this, it is generally beneficial to back away from the end of the symbol time and use part of the guard interval. The Symbol Timing Adjustment parameter controls how far the FFT part of the symbol is adjusted away from the end of the symbol time. The value is in terms of percent of the used (FFT) part of the symbol time. Note that this parameter value is negative, because the FFT start time is moved back by this parameter. SymbolTimingAdjust Definition explains this concept. When setting this parameter, be careful to not back away from the end of the symbol time too much because this may make the FFT include corrupt data from the transition region at the beginning of the symbol time.

SymbolTimingAdjust Definition
  1. The Track Amplitude , Track Phase , and Track Timing parameters specify whether the analysis will track amplitude, phase, and timing changes in the pilot subcarriers. 802.16e performs demodulation relative to the data in pilot carriers embedded in the signal. These pilot carriers replace data-carrying elements of the signal and allow some kinds of impairments to be removed or "tracked out." Many impairments will be common to all pilot carriers and can be measured as the "common pilot error." When these parameters are set to YES the analysis will track amplitude, phase, and timing changes in the pilot subcarriers and apply corrections to the pilot and data subcarriers.
    The flexibility to allow users to individually enable or disable tracking functions and provides useful troubleshooting capability, since modulation errors can be examined with and without the benefit of particular types of pilot tracking.
  2. The Equalizer Training Method parameter sets the type of training used for the equalizer. When demodulating an 802.16e signal, an equalizer is used to correct for linear impairments in the signal path, such as multi-path.

When Chan Estimation Seq Only is selected the equalizer is trained using the Channel Estimation Sequence in the preamble of the OFDMA burst. After this initialization, the equalizer coefficients are held constant while demodulating the rest of the burst. This equalizer training method complies with the description in section (8.4.12.3) "Transmit Constellation Error and Test Method" of the 802.16-2004 standard. However, for signals whose impairments change during the burst it might result in measured RCE (EVM) values that are higher compared to if the equalizer were trained over the entire burst.

When Chan Estimation Seq & Data is selected the equalizer is trained by analyzing the entire OFDMA burst and using the Channel Estimation Sequence (contained in the preamble) and the all the subcarriers in the Data symbols. This type of equalizer training generally gives a more accurate estimate of the true response of the transmission channel and so results in lower RCE (EVM) measured values. However, it is more complicated and more computationally expensive to implement and therefore less likely to be used in practical receivers.

When Chan Estimation Seq & Pilots is selected the equalizer is trained by analyzing the entire OFDMA burst and using the Channel Estimation Sequence (contained in the preamble) and the pilot subcarriers in the Data symbols. This gives results very similar to the Chan Estimation Seq & Data option without the excessive computational complexity.

Variables

The variables listed in Design Constants for Signal Setup and Design Equations (Derived from Design Parameters and Exported to Data Display) are defined for use in the design and data display.

Design Constants for Signal Setup
Constant Value
IdleInterval 0
FrameDuration integer value for the selected `Frame Duration'; 0 for 2 ms, ...., 7 for 20 ms
OversamplingOption integer value for the selected 'Oversampling Ratio Option'; 0 for Ratio 1, 1 for Ratio 2, 2 for Ratio 4
BandWidth integer value for the selected 'Nominal RF Bandwidth'; 0 for 1.25 MHz, ..., 11 for 28 MHz
NumOfSymInZone 24
G integer value for the selected 'Cyclic Prefix'; 0 for 1/4, 1 for 1/8, 2 for 1/16, 3 for 1/32
FFTSize integer value for the selected 'FFT Size'; 0 for 2048, 1 for 1024, 2 for 512
Data Display Parameter Equation with Test Bench Parameters
FrameDur_Table {2 ms, 2.5 ms, 4 ms, 5 ms, 8 ms, 10 ms, 12.5 ms, 20 ms}
SignalSegmentTime FrameDur_Table[FrameDuration+1] + IdleInterval
CommonBW_new if(0==int(Bandwidth)) then 1.25e6 elseif (1==int(Bandwidth)) then 3.5e6 elseif (2==int(Bandwidth)) then 4.375e6 elseif (3==int(Bandwidth)) then 5e6 elseif (4==int(Bandwidth)) then 7e6 elseif (5==int(Bandwidth)) then 8.75e6 elseif (6==int(Bandwidth)) then 10e6 elseif (7==int(Bandwidth)) then 14e6 elseif (8==int(Bandwidth)) then 15e6 elseif (9==int(Bandwidth)) then 17e6 elseif (10==int(Bandwidth)) then 20e6 elseif (11==int(Bandwidth)) then 28e6 else 3.5e6 endif
n_num if(0==fmod(int(CommonBW_new),1750000)) then 8 elseif(0==fmod(int(CommonBW_new),1500000)) then 28 elseif(0==fmod(int(CommonBW_new),1250000)) then 28 elseif(0==fmod(int(CommonBW_new),2750000)) then 28 elseif(0==fmod(int(CommonBW_new),2000000)) then 28 else 8 endif
n_den if(0==fmod(int(CommonBW_new),1750000)) then 7 elseif(0==fmod(int(CommonBW_new),1500000)) then 25 elseif(0==fmod(int(CommonBW_new),1250000)) then 25 elseif(0==fmod(int(CommonBW_new),2750000)) then 25 elseif(0==fmod(int(CommonBW_new),2000000)) then 25 else 7 endif
RF_Bandwidth floor(CommonBW_new*n_num/(n_den*8000))*8000
RF_SamplingRate RF_Bandwidth*(2^int(OversamplingOption))
TimeStep 1/RF_SamplingRate
SamplesPerSegment SignalSegmentTime/TimeStep
SymLen 2048/(2^int(FFTSize))*(1+CyclicPrefix)*(2^int(OversamplingOption))
FilterDelayTime 30/RF_SamplingRate*(2^int(OversamplingOption))

Baseline Performance

References

  1. IEEE Std 802.16-2004, Part 16: Air Interface for Fixed Broadband Wireless Access Systems, Section 8.4 WirelessMAN-OFDMA PHY , October 1, 2004.
  2. IEEE Std 802.16e-2005, Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Section 8.4 WirelessMAN-OFDMA PHY , December 7, 2005.

WiMax 802.16e Related Links

http://standards.ieee.org/getieee802/802.16.html
http://www.ieee.org/

WMAN 802.16e Downlink BER Test Design Example

The design example is available from the ADS main window in File > Example Project > Connected_Solutions > STW_WMAN_16e_OFDMA_DownLink_prj .
STW_WMAN_16e_OFDMA_DownLink_prj provides a WMAN_802_16e_DL_RX test and measurement design example based on IEEE Standard 802.16e-1999 and 802.16e-2003.

Overview

The generic BER Test Design provides connection to an RF hardware device under test (DUT) to determine the BER/PER performance of the DUT.

The signal and most measurements are designed according to generic.

This design can generate an RF modulated signal with optional impairments, send the signal to the input of the RF DUT through an Agilent Electronic Signal Generator (ESG), receive the signal from the RF DUT with a RF output through an Agilent Vector Signal Analyzer (VSA) with one channel and an Agilent 16900 Series Logic Analysis System, and display the measurement results in a data display. For the RF DUT with baseband I, Q outputs through an Agilent Vector Signal Analyzer (VSA) with two channels, BER test designs also can be used.

Signal Segment Structure

The Mobile WiMAX 802.16e downlink signal is for mobile WiMAX OFDMA defined per the specification section 8.4 WirelessMAN-OFDMA PHY (256-point FFT OFDM) in IEEE Std 802.16-2004 and IEEE 802.16e-2005. Downlink describes the signal from the base station to the mobile unit.

The major specifications for the WirelessMAN-OFDMA PHY physical layer are listed in Mobile WiMAX-OFDMA PHY Physical Layer Major Specifications.

Specification Settings
Information data rate up to 70 Mbps at 20 MHz bandwidth
Modulation BPSK, QPSK, 16-QAM, 64-QAM
Error correcting code CC, CTC, BTC
Coding rate 1/2, 2/3, 3/4
2048, 1024, 512
Number of data subcarriers variable
Number of pilot subcarriers variable
Number of total subcarriers used variable
Number of lower frequency guard subcarriers variable
Number of higher frequency guard subcarriers variable
n:Sampling factor For channel bandwidths that are a multiple of 1.75 MHz then n = 8/7
G: Ratio of CP time to "useful" time 1/4, 1/8, 1/16, 1/32
BW: Nominal channel bandwidth From 1.5 MHz to 28 MHz
Tb: Useful symbol time
Tg: CP time
Ts: OFDM symbol time

Mobile WiMAX 802.16e frame format in TDD mode (set with the Frame Mode parameter) is shown in 802.16e OFDMA Frame Structure for TDD Mode.

In TDD mode, 70% of the frame time is allocated for the downlink subframe.

In FDD mode, 100% of the frame time will be used for the downlink and uplink subframes and the Downlink Ratio parameter will be not be used.

802.16e OFDMA Frame Structure for TDD Mode

Mobile WiMAX 802.16e downlink subframe format is illustrated in 802.16e OFDMA Downlink Subframe Structure. The X-axis represents time. The Y-axis represents frequency subchannels.

802.16e OFDMA Downlink Subframe Structure

The downlink subframe starts with one preamble which consists of a OFDM symbol, followed by the PUSC zone where FCH, DL-MAP and UL-MAP are allocated. The FCH information will be sent on the first four adjacent subchannels with successive logical subchannel numbers in the PUSC zone. The DL-MAP message immediately follows FCH. The UL-MAP message is always allocated on the third and fourth OFDM symbols if ULMAP_Enable ( Activate UL-MAP Insertion ) is set to YES .

If ZoneType ( Zone Type ) is DL_PUSC, then a single PUSC zone is defined (a in 802.16e OFDMA Downlink Subframe Structure). If ZoneType ( Zone Type ) is DL_FUSC or DL_OFUSC, then two zones are defined: one is the PUSC zone where FCH is allocated, the other is the FUSC or OFUSC zone for allocating data bursts (b in 802.16e OFDMA Downlink Subframe Structure). ZoneNumOfSym ( Number of OFDM Symbols ) is defined as the number of OFDM symbols for the zone which is allocated data bursts. One downlink frame contains a maximum 8 data bursts except FCH, DL-MAP and UL-MAP, and each burst contains only one MAC PDU. Among these bursts, only one FEC-encoded burst is supported which is randomized, RS-CC coded and interleaved. Other bursts will be provided PN sequences as their coded source respectively.

For DL_PUSC, the total number of symbols in the downlink subframe is ( 1+ZoneNumOfSym ); For DL_FUSC or DL_OFUSC, the total number of symbols in the downlink subframe is ( 1+2+ULMAP_Enable × 2+ZoneNumOfSym ), where 1 represents the preamble, the first 2 represents the FCH and DL-MAP, the second 2 represents the UL-MAP, ULMAP_Enable is 1 when set to YES and 0 when set to NO .

Zone type ULMAP_Enable NPreamble <th NUL-MAP NData NFrame
DL_PUSC YES 1 2 2 ZoneNumOfSym-2 1+ZoneNumOfSym
DL_PUSC NO 1 2 0 ZoneNumOfSym-2 1+ZoneNumOfSym
DL_FUSC YES 1 2 2 ZoneNumOfSym 5+ZoneNumOfSym
DL_FUSC NO 1 2 0 ZoneNumOfSym-2 3+ZoneNumOfSym
DL_OFUSC YES 1 2 2 ZoneNumOfSym 5+ZoneNumOfSym
DL_OFUSC NO 1 2 0 ZoneNumOfSym 3+ZoneNumOfSym

After encoding, the encoded burst is mapped to the constellation. Other bursts without FEC, are provided a PN sequence as their coded bits and mapped to the constellation according to their Rate_ID ( Rate ID for Burst Modulation and Coding Rate ). The FEC-encoded burst is concatenated with non-coded bursts. The FCH and DL-MAP are combined and mapped to the constellations. The same actions are performed on UL-MAP.

The physical indices of data subcarriers and pilot subcarriers for each burst are calculated for the subframe. The data sequences and pilot sequences are placed to their physical subcarrier location. Then the useful subcarriers are randomized. The same actions are performed on FCH & DL-MAP and UL-MAP. After IFFT and cyclic prefix insertion, the idle interval and downlink payloads (bursts, FCH & DL-MAP, UL-MAP) are combined with zero-padding bits if needed. In addition, uplink position will be preserved and filled with zeros before downlink payload if FrameMode ( Frame Mode ) is TDD.

The zone boosting is performed according to the parameter of GroupBitmask (which for this downlink design have all bits set to 1). At last, oversampling is implemented by a transmitter filter.

Note
With default parameter settings, the DL-MAP occupies 26 subchannels, and the UL-MAP occupies 23 subchannels. Sometimes the subchannels occupied by DL-MAP or UL-MAP may exceed the available subchannels. This condition will be discovered during parameter Range Check and an error message will be reported.

The relationships between the WiMax source parameters and the waveform SignalSegmentTime , SamplesPerSegment , and waveform modeling TimeStep are made available in the design data displays and listed in Design Equations (Derived from Design Parameters and Exported to Data Display).

Generic RF power delivered into a matched load is the average power delivered over the full frame. RF Signal Envelope shows the RF envelope for an output RF signal with 10 dBm power.

RF Signal Envelope

RF Spectrum shows the generic spectrum.

RF Spectrum

Instrument Compatibility

Generic designs are compatible with the Agilent Signal Studio Software, Agilent ESG, Agilent VSA, and Agilent LA models described in Agilent Instrument Compatibility.

Signal Studio Models ESG Models VSA Models LA Models
Agilent Signal Studio for 802.16 OFDMA, Version 1.2.1.0, for use with Agilent ESG and PSG Vector Signal Generators Agilent ESG Agilent Vector Signal Analyzer (VSA) Agilent Logic Analysis System

For information about the following products, see the Agilent Technologies web site:

WMAN 802.16e Downlink BER Test Design Parameters

The following table summarizes the technology-specific design parameters.

Description Values Default Range Type Unit Symbol
Number of Bursts 1 [1,8] int NB
Burst#<a href="#1115208"><sup>1</sup></a> Rate ID for Burst Modulation and Coding Rate QPSK 1/2, 64QAM 1/2 enum
Random Number Generator Seed 1234567 [0,∞) int
Nominal RF Bandwidth BW 1.25 MHZ, BW 10 MHZ enum
Oversampling Ratio Option Ratio 1, Ratio 2, Ratio 2 enum
FFT Size FFT 2048, FFT 1024 enum
Cyclic Prefix G 1/4, G 1/8, G 1/16, G 1/32 G 1/8 enum
Frame Mode FDD, TDD FDD enum
Downlink Ratio (%) 50 [1,99] float
Frame Duration Time 2 ms, Time 5 ms enum
Starting Frame Number in Subframe (HEX) 0 [0:0xffffff] int
Increase Frame Number in Consecutive Frames NO, YES NO query
CRC32 Mode MSB First, LSB First MSB First enum
Preamble Index 3 [0,113] int
Permutation Base 9 [0,31] int
PRBS ID 0 [0,31] int
FEC-Encoded Burst Index 1 [1,NB] int
Data Pattern PN9, PN9 enum
FEC-Repetition Coding RC none, RC 2, RC 4, RC 6 RC none enum
Number of OFDM Symbols 24 [1,1212]
Zone Type DL_PUSC, DL_PUSC enum
Activate DL-MAP Insertion NO, YES NO query
Activate UL-MAP Insertion NO, YES NO query
Symbol Offset Burst #1-4: 2 [1,1211] int
Subchannel Offset Burst #1:0 [0,59] int
Number of Symbols Burst #1:20 [1,1212] int
Number of Subchannels Burst #1:30 [0,60] int
Power Boosting 0 (−∞,∞) int dB
MAC PDU Payload Byte Length Burst #1:200 [0,4095] int
<a href="#1115209"><sup>1</sup></a>This parameter provides values for bursts 1 through 8.

This section provides detailed descriptions of the design parameters.

Signal Setup

Number of Bursts
Specifies the number of bursts. If the Zone Type is DL_PUSC , then the bursts are associated with Zone#0. Otherwise, the bursts are associated with Zone#1 (the second zone).
Burst #(1-8) Rate ID for Burst Modulation and Coding Rate
Specifies the modulation type and the coding rate. The Rate ID of 64QAM 5/6 is only available when the FEC-Coding Type is set to CTC .

Advanced Signal Setup

The following parameters may be optionally set. The design will typically perform well with the default settings.
Random Number Generator Seed
Specifies the seed for the random number generator.
Nominal RF Bandwidth
Specifies the nominal bandwidth for the modulated signal.
Oversampling Ratio Option
Specifies the signal oversampling ratio.
FFT Size
Specifies the size of the Fast Fourier Transform.
Cyclic Prefix
Sets the cyclic prefix time (also referred to as Guard Interval) as a fraction of the inverse FFT time. The cyclic prefix time is used to eliminate inter-symbol and inter-carrier interference. Each OFDMA symbol is transmitted for a slightly longer time than the active (or useful) symbol time. This extra time is the cyclic prefix time.
Frame Mode
Specifies the duplexing method which should be FDD or TDD. In FDD transmission, the downlink occupies the entire frame and the respective gaps (zeros) are automatically adjusted to fill the frame.
Downlink Ratio (%)
Specifies the percentage (1 to 99) of the frame time to be used for the downlink subframe. The parameter is only active when the Frame Mode is TDD .
Frame Duration
Specifies the time duration of the generated waveform frame.
Staring Frame Number in Subframe (HEX)
Specifies the subframe starting frame number in hexadecimal.
Increase Frame Number in Consecutive Frames
Specifies whether the frame number for the downlink subframe is increased in consecutive frames. When set to YES , the frame numbers in Frame#0, Frame#1, Frame#2, Frame#3 will be Starting Frame Number , Starting Frame Number +1, Starting Frame Number +2, Starting Frame Number +3. When set to NO , then the frame numbers in Frame#0, Frame#1, Frame#2, Frame#3 will all be Starting Frame Number .

Downlink Signal Setup

Preamble Index
Specifies the index value (0 to 113) that determines the ID Cell values (0 to 31) and segment index (0 to 2) according to the standard.
Permutation Base
Specifies the basis of downlink permutation to be used in initialization vector of the PRBS generator for subchannel randomization in the zone and in STC_DL_Zone_IE() in DL-MAP message.
PRBS ID
Specifies the PRBS ID which may be used in initialization vector of the PRBS generator for subchannel randomization and in STC_DL_Zone_IE() in DL-MAP message.
FEC-Encoded Burst Index
Specifies the index for the downlink burst with FEC (Forward Error Correction).
Data Pattern
Specifies the transmitted data pattern.
PN9 is a 511-bit pseudo-random test pattern generated according to CCITT Recommendation O.153
PN15 is a 32767-bit pseudo-random test pattern generated according to CCITT Recommendation O.151
FIX4 is a zero-stream
x_1_x_0 (where x equals 4, 8, 16, 32, or 64) generates a periodic bit stream, with the period being 2 x. In one period, the first x bits are 1s and the second x bits are 0s.
S_QPSK, S_16-QAM or S_64-QAM generates test messages for receiver sensitivity measurement.
S_QPSK = [0xE4, 0xB1, 0xE1, 0xB4]
S_16-QAM = [0xA8, 0x20, 0xB9, 0x31, 0xEC, 0x64, 0xFD, 0x75]
S_64-QAM = [0xB6, 0x93, 0x49, 0xB2, 0x83, 0x08, 0x96, 0x11, 0x41, 0x92, 0x01, 0x00, 0xBA, 0xA3, 0x8A, 0x9A, 0x21, 0x82, 0xD7, 0x15, 0x51, 0xD3, 0x05, 0x10, 0xDB, 0x25, 0x92, 0xF7, 0x97, 0x59, 0xF3, 0x87, 0x18, 0xBE, 0xB3, 0xCB, 0x9E, 0x31, 0xC3, 0xDF, 0x35, 0xD3, 0xFB, 0xA7, 0x9A, 0xFF, 0xB7, 0xDB]
FEC-Repetition Coding
Specifies the forward error correction repetition coding for each burst. Set to RC none , no repetition coding is generated. RC 2 , RC 4 , RC 6 generates repetition coding of 2, 4, and 6 respectively.

Zone Setup

Number of OFDM Symbols
Specifies the number of Orthogonal Frequency Division Modulation symbols in the zone. The value must be a multiple of two when Zone Type is DL_PUSC and must be be a multiple of one when Zone Type is DL_FUSC or DL_OFUSC .
Zone Type
Specifies the zone type.
Activate DL-MAP Insertion
When set to YES , then a burst will carry the downlink map.
Activate UL-MAP Insertion
When set to YES , then a burst will carry the uplink map.

Burst Setup

Symbol Offset, Subchannel Offset, Number of Symbols, Number of Subchannels
Symbol Offset , along with Subchannel Offset , Number of Symbols and Number of Subchannels specify the position and range for each rectangular burst as shown in Downlink Rectangular Burst Structure.

Downlink Rectangular Burst Structure

Power Boosting
Specifies the power boosting value in dB for a specific burst.
MAC PDU Payload Byte Length
Specifies the MAC PDU payload byte length for a specific burst with forward error coding.

Variables

The variables listed in Design Constants for Signal Setup and Design Equations (Derived from Design Parameters and Exported to Data Display) are defined for use in the design and data display.

Constant Value
IdleInterval 0
FrameDuration integer value for the selected `Frame Duration'; 0 for 2 ms, ...., 7 for 20 ms
OversamplingOption integer value for the selected 'Oversampling Ratio Option'; 0 for Ratio 1, 1 for Ratio 2, 2 for Ratio 4
BandWidth integer value for the selected 'Nominal RF Bandwidth'; 0 for 1.25 MHz, ..., 11 for 28 MHz

Design Equations
(Derived from Design Parameters and Exported to Data Display)
FrameDur_Table {2 ms, 2.5 ms, 4 ms, 5 ms, 8 ms, 10 ms, 12.5 ms, 20 ms}
SignalSegmentTime FrameDur_Table[FrameDuration+1] + IdleInterval
CommonBW_new if(0==int(Bandwidth)) then 1.25e6 elseif (1==int(Bandwidth)) then 3.5e6 elseif (2==int(Bandwidth)) then 4.375e6 elseif (3==int(Bandwidth)) then 5e6 elseif (4==int(Bandwidth)) then 7e6 elseif (5==int(Bandwidth)) then 8.75e6 elseif (6==int(Bandwidth)) then 10e6 elseif (7==int(Bandwidth)) then 14e6 elseif (8==int(Bandwidth)) then 15e6 elseif (9==int(Bandwidth)) then 17e6 elseif (10==int(Bandwidth)) then 20e6 elseif (11==int(Bandwidth)) then 28e6 else 3.5e6 endif
n_num if(0==fmod(int(CommonBW_new),1750000)) then 8 elseif(0==fmod(int(CommonBW_new),1500000)) then 28 elseif(0==fmod(int(CommonBW_new),1250000)) then 28 elseif(0==fmod(int(CommonBW_new),2750000)) then 28 elseif(0==fmod(int(CommonBW_new),2000000)) then 28 else 8 endif
n_den if(0==fmod(int(CommonBW_new),1750000)) then 7 elseif(0==fmod(int(CommonBW_new),1500000)) then 25 elseif(0==fmod(int(CommonBW_new),1250000)) then 25 elseif(0==fmod(int(CommonBW_new),2750000)) then 25 elseif(0==fmod(int(CommonBW_new),2000000)) then 25 else 7 endif
RF_Bandwidth floor(CommonBW_newn_num/(n_den8000))8000
RF_SamplingRate RF_Bandwidth(2^int(OversamplingOption))
TimeStep 1/RF_SamplingRate
SamplesPerSegment SignalSegmentTime/TimeStep

Baseline Performance

References

  1. IEEE Std 802.16-2004, Part 16: Air Interface for Fixed Broadband Wireless Access Systems, Section 8.4 WirelessMAN-OFDMA PHY , October 1, 2004.
  2. IEEE Std 802.16e-2005, Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Section 8.4 WirelessMAN-OFDMA PHY , December 7, 2005.

WiMax 802.16e Related Links

http://standards.ieee.org/getieee802/802.16.html
http://www.ieee.org/

WMAN 802.16e Uplink BER Test Design Example

The design example is available from the ADS main window in File > Example Project > Connected_Solutions > STW_WMAN_16e_OFDMA_UpLink_prj .
STW_WMAN_16e_OFDMA_UpLink_prj provides a WMAN_802_16e_UL_RX test and measurement design example based on IEEE Standard 802.16e-1999 and 802.16e-2003.

The generic BER Test Design provides connection to an RF hardware device under test (DUT) to determine the BER/PER performance of the DUT.

The signal and most measurements are designed according to generic.

This design can generate an RF modulated signal with optional impairments, send the signal to the input of the RF DUT through an Agilent Electronic Signal Generator (ESG), receive the signal from the RF DUT with a RF output through an Agilent Vector Signal Analyzer (VSA) with one channel and an Agilent 16900 Series Logic Analysis System, and display the measurement results in a data display. For the RF DUT with baseband I, Q outputs through an Agilent Vector Signal Analyzer (VSA) with two channels, BER test designs also can be used.

Signal Segment Structure

The Mobile WiMAX 802.16e Uplink signal is for Mobile WiMAX OFDMA defined per the specification section 8.4 WirelessMAN-OFDMA PHY (256-point FFT OFDM) in IEEE Std 802.16-2004, IEEE Std 802.16e-2005. The uplink signal is from the mobile unit to the base station.

The major specifications for the WirelessMAN-OFDMA PHY physical layer are listed in Mobile WiMAX-OFDMA PHY Physical Layer Major Specifications.

Specification Settings
Information data rate up to 70 Mbps at 20 MHz bandwidth
Modulation BPSK, QPSK, 16-QAM, 64-QAM
Error correcting code CC, CTC, BTC
Coding rate 1/2, 2/3, 3/4
2048, 1024, 512
Number of data subcarriers variable
Number of pilot subcarriers variable
Number of total subcarriers used variable
Number of lower frequency guard subcarriers variable
Number of higher frequency guard subcarriers variable
n:Sampling factor For channel bandwidths that are a multiple of 1.75 MHz then n = 8/7
G: Ratio of CP time to "useful" time 1/4, 1/8, 1/16, 1/32
BW: Nominal channel bandwidth From 1.5 MHz to 28 MHz
Tb: Useful symbol time
Tg: CP time
Ts: OFDM symbol time

Mobile WiMAX 802.16e Uplink frame format in TDD mode (set with the Frame Mode parameter) is shown in 802.16e OFDMA Frame Structure for TDD Mode. In TDD mode, 70% of the frame time is allocated for the downlink subframe which will be filled with zeros. In FDD mode, 100% of the frame time will be used for the downlink and uplink subframes and the Downlink Ratio parameter will be not be used.

802.16e OFDMA Frame Structure for TDD Mode

Mobile WiMAX 802.16e Uplink subframe format is illustrated in Mobile WiMAX 16e OFDMA UL Subframe Structure. The X-axis represents time. The Y-axis represents frequency subchannels.

Mobile WiMAX 16e OFDMA UL Subframe Structure

The uplink subframe includes only one zone (alternative PUSC or OPUSC) which contains a maximum of 8 bursts with each carrying one MAC PDU. Among these bursts, only one FEC-encoded burst is supported whose coding type can be set to CC or CTC . Other bursts are provided PN sequences as their coded source respectively. Both TDD mode and FDD mode can be supported for the uplink source.

After encoding, the encoded burst is mapped to the constellation. Other bursts without FEC, are provided PN sequence as their coded bits and mapped to the constellation according to their Rate_ID ( Rate ID for Burst Modulation and Coding Rate ). The FEC-encoded burst is concatenated with non-coded bursts.

The physical indices of data subcarriers and pilot subcarriers for each burst are calculated. The data sequences and pilot sequences are placed to their physical subcarrier location. Then the useful subcarriers are randomized. After IFFT and cyclic prefix insertion, the idle interval and uplink payload are combined with zero padding bits if needed. In addition, downlink position will be preserved and filled with zeros before uplink payload if Frame Mode is TDD . At last, oversampling is implemented by a transmitter filter.

The relationships between the WiMax source parameters and the waveform SignalSegmentTime , SamplesPerSegment , and waveform modeling TimeStep are made available in the design data displays and listed in Design Equations (Derived from Design Parameters and Exported to Data Display).

Generic RF power delivered into a matched load is the average power delivered over the full frame. RF Signal Envelope shows the RF envelope for an output RF signal with 10 dBm power.

RF Signal Envelope

RF Spectrum shows the generic spectrum.

RF Spectrum

Instrument Compatibility

Generic designs are compatible with the Agilent Signal Studio Software, Agilent ESG, Agilent VSA, and Agilent LA models described in Agilent Instrument Compatibility.

Signal Studio Models ESG Models VSA Models LA Models
Agilent Signal Studio for 802.16 OFDMA, Version 1.2.1.0, for use with Agilent ESG and PSG Vector Signal Generators Agilent ESG Agilent Vector Signal Analyzer (VSA) Agilent Logic Analysis System

For information about the following products, see the Agilent Technologies web site:

WMAN 802.16e Uplink BER Test Design Parameters

The following table summarizes the technology-specific design parameters.

Description Values Default Range Type Unit Symbol
Number of Bursts   1 [1,8] int   NB
Burst#<a href="#1116162"><sup>1</sup></a> Rate ID for Burst Modulation and Coding Rate QPSK 1/2, QPSK 1/2   enum    
Random Number Generator Seed   1234567 [0,∞) int    
Nominal RF Bandwidth BW 1.25 MHZ, BW 10 MHZ   enum    
Oversampling Ratio Option Ratio 1, Ratio 2, Ratio 1   enum    
FFT Size FFT 2048, FFT 1024   enum    
Cyclic Prefix G 1/4, G 1/8, G 1/16, G 1/32 G 1/8   enum    
Frame Mode FDD, TDD FDD   enum    
Downlink Ratio (%)   50 [1,99] float    
Frame Duration Time 2 ms, Time 5 ms   enum    
Starting Frame Number in Subframe (HEX)   0 [0:0xffffff] int    
Preamble Index   3 [0,113] int    
Permutation Base   9 [0,31] int    
FEC-Encoded Burst Index   1 [1,NB] int    
Data Pattern PN9, PN9   enum    
FEC-Repetition Coding RC none, RC 2, RC 4, RC 6 RC none   enum    
Number of OFDM Symbols   24 [1,1212]      
Zone Type UL_PUSC, UL_PUSC   enum    
Symbol Offset   Burst #1, 3, 5, 7: 0 [1,6868] int    
Subchannel Offset   Burst #1: 0 [0,59] int    
Assigned Slots   280 [1,1212] int    
Power Offset   0 (−∞,∞) int dB  
MAC PDU Payload Byte Length   Burst #1:200 [0,4095] int    
<a href="#1116163"><sup>1</sup></a>This parameter provides values for bursts 1 through 8.

This section provides detailed descriptions of the design parameters.

Signal Setup

Number of Bursts
Specifies the number of bursts. If the Zone Type is UL_PUSC , then the bursts are associated with Zone#0. Otherwise, the bursts are associated with Zone#1 (the second zone).
Burst #(1-8) Rate ID for Burst Modulation and Coding Rate
Specifies the modulation type and the coding rate. The Rate ID of 64QAM 5/6 is only available when the FEC-Coding Type is set to CTC .

Advanced Signal Setup

The following parameters may be optionally set. The design will typically perform well with the default settings.

Random Number Generator Seed
Specifies the seed for the random number generator.
Nominal RF Bandwidth
Specifies the nominal bandwidth for the modulated signal.
Oversampling Ratio Option
Specifies the signal oversampling ratio.
FFT Size
Specifies the size of the Fast Fourier Transform.
Cyclic Prefix
Sets the cyclic prefix time (also referred to as Guard Interval) as a fraction of the inverse FFT time. The cyclic prefix time is used to eliminate inter-symbol and inter-carrier interference. Each OFDMA symbol is transmitted for a slightly longer time than the active (or useful) symbol time. This extra time is the cyclic prefix time.
Frame Mode
Specifies the duplexing method which should be FDD or TDD. In FDD transmission, the downlink occupies the entire frame and the respective gaps (zeros) are automatically adjusted to fill the frame.
Downlink Ratio (%)
Specifies the percentage (1 to 99) of the frame time to be used for the downlink subframe. The parameter is only active when the Frame Mode is TDD .
Frame Duration
Specifies the time duration of the generated waveform frame.
Staring Frame Number in Subframe (HEX)
Specifies the subframe starting frame number in hexadecimal.

Uplink Signal Setup

Preamble Index
Specifies the index value (0 to 113) that determines the ID Cell values (0 to 31) and segment index (0 to 2) according to the standard.
Permutation Base
Specifies the basis of downlink permutation to be used in initialization vector of the PRBS generator for subchannel randomization in the zone and in STC_UL_Zone_IE() in UL-MAP message.
FEC-Encoded Burst Index
Specifies the index for the downlink burst with FEC (Forward Error Correction).
Data Pattern
Specifies the transmitted data pattern.
PN9 is a 511-bit pseudo-random test pattern generated according to CCITT Recommendation O.153
PN15 is a 32767-bit pseudo-random test pattern generated according to CCITT Recommendation O.151
FIX4 is a zero-stream
x_1_x_0 (where x equals 4, 8, 16, 32, or 64) generates a periodic bit stream, with the period being 2 x. In one period, the first x bits are 1s and the second x bits are 0s.
S_QPSK, S_16-QAM or S_64-QAM generates test messages for receiver sensitivity measurement.
S_QPSK = [0xE4, 0xB1, 0xE1, 0xB4]
S_16-QAM = [0xA8, 0x20, 0xB9, 0x31, 0xEC, 0x64, 0xFD, 0x75]
S_64-QAM = [0xB6, 0x93, 0x49, 0xB2, 0x83, 0x08, 0x96, 0x11, 0x41, 0x92, 0x01, 0x00, 0xBA, 0xA3, 0x8A, 0x9A, 0x21, 0x82, 0xD7, 0x15, 0x51, 0xD3, 0x05, 0x10, 0xDB, 0x25, 0x92, 0xF7, 0x97, 0x59, 0xF3, 0x87, 0x18, 0xBE, 0xB3, 0xCB, 0x9E, 0x31, 0xC3, 0xDF, 0x35, 0xD3, 0xFB, 0xA7, 0x9A, 0xFF, 0xB7, 0xDB]
FEC-Repetition Coding
Specifies the forward error correction repetition coding for each burst. Set to RC none , no repetition coding is generated. RC 2 , RC 4 , RC 6 generates repetition coding of 2, 4, and 6 respectively.

Zone Setup

Number of OFDM Symbols
Specifies the number of Orthogonal Frequency Division Modulation symbols in the zone. The value must be a multiple of two when Zone Type is UL_PUSC and must be be a multiple of one when Zone Type is UL_FUSC or UL_OFUSC .
Zone Type
Specifies the zone type.

Burst Setup

Symbol Offset
Specifies the position of each burst on the horizontal axis (x) to avoid any burst overlap.
Subchannel Offset
Specifies the position of each burst on the vertical axis (y) to avoid any burst overlap.
Assigned Slots
Specifies the total available slots for each burst.
Power Offset
Specifies the power offset of each burst in dB.
MAC PDU Payload Byte Length
Specifies the MAC PDU payload byte length for a specific burst with forward error coding.

Variables

The variables listed in Design Constants for Signal Setup and Design Equations (Derived from Design Parameters and Exported to Data Display) are defined for use in the design and data display.

Constant Value
IdleInterval 0
FrameDuration integer value for the selected `Frame Duration'; 0 for 2 ms, ...., 7 for 20 ms
OversamplingOption integer value for the selected 'Oversampling Ratio Option'; 0 for Ratio 1, 1 for Ratio 2, 2 for Ratio 4
BandWidth integer value for the selected 'Nominal RF Bandwidth'; 0 for 1.25 MHz, ..., 11 for 28 MHz
Data Display Parameter Equation with Test Bench Parameters
FrameDur_Table {2 ms, 2.5 ms, 4 ms, 5 ms, 8 ms, 10 ms, 12.5 ms, 20 ms}
SignalSegmentTime FrameDur_Table[FrameDuration+1] + IdleInterval
CommonBW_new if(0==int(Bandwidth)) then 1.25e6 elseif (1==int(Bandwidth)) then 3.5e6 elseif (2==int(Bandwidth)) then 4.375e6 elseif (3==int(Bandwidth)) then 5e6 elseif (4==int(Bandwidth)) then 7e6 elseif (5==int(Bandwidth)) then 8.75e6 elseif (6==int(Bandwidth)) then 10e6 elseif (7==int(Bandwidth)) then 14e6 elseif (8==int(Bandwidth)) then 15e6 elseif (9==int(Bandwidth)) then 17e6 elseif (10==int(Bandwidth)) then 20e6 elseif (11==int(Bandwidth)) then 28e6 else 3.5e6 endif
n_num if(0==fmod(int(CommonBW_new),1750000)) then 8 elseif(0==fmod(int(CommonBW_new),1500000)) then 28 elseif(0==fmod(int(CommonBW_new),1250000)) then 28 elseif(0==fmod(int(CommonBW_new),2750000)) then 28 elseif(0==fmod(int(CommonBW_new),2000000)) then 28 else 8 endif
n_den if(0==fmod(int(CommonBW_new),1750000)) then 7 elseif(0==fmod(int(CommonBW_new),1500000)) then 25 elseif(0==fmod(int(CommonBW_new),1250000)) then 25 elseif(0==fmod(int(CommonBW_new),2750000)) then 25 elseif(0==fmod(int(CommonBW_new),2000000)) then 25 else 7 endif
RF_Bandwidth floor(CommonBW_new*n_num/(n_den*8000))*8000
RF_SamplingRate RF_Bandwidth*(2^int(OversamplingOption))
TimeStep 1/RF_SamplingRate
SamplesPerSegment SignalSegmentTime/TimeStep

Baseline Performance

References

  1. IEEE Std 802.16-2004, Part 16: Air Interface for Fixed Broadband Wireless Access Systems, Section 8.4 WirelessMAN-OFDMA PHY , October 1, 2004.
  2. IEEE Std 802.16e-2005, Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Section 8.4 WirelessMAN-OFDMA PHY , December 7, 2005.

WiMax 802.16e Related Links

http://standards.ieee.org/getieee802/802.16.html
http://www.ieee.org/

MATLAB-Based Test Design Example

This design example is available from the ADS main window in File > Example Project > Connected_Solutions > STW_MATLAB_prj .
STW_MATLAB_prj is a MATLAB-based design example that provides transmission test and measurement. The design in this project includes:

Overview

The MATLAB Connected Solutions Design with MATLAB-based signal source and measurement provides connection to an RF hardware DUT (Device Under Test) to determine the performance of the DUT by activating various design measurements. This design provides signal measurements for RF envelope, signal power (including CCDF), constellation, spectrum, and EVM.

The original baseband data is generated in ADS, and then modulated by using a MATLAB qam modulation function. For measurement of DUT output signal, a constellation measurement based in MATLAB is used. Other measurements are provided by ADS Ptolemy.

This design can generate an RF modulated signal with optional impairments, and then sends the signal to the input of the DUT through an Agilent Electronic Signal Generator (ESG). The RF DUT output through an Agilent Vector Signal Analyzer (VSA) is recorded and processed by the design, and then displayed.

The design is a template that can be customized by the user's MATLAB code, and test the user's DUT in ADS.

Test Signals Generated by MATLAB Function

The test signal for the MATLAB design is generated by using MATLAB function through an ADS-MATLAB link. To understand the test signal generation, push into the STW_MATLAB_Source design in the STW_MATLAB_E4438C_896XX.dsn . As can be seen from the MATLAB-Based Signal Source design shown in Signal Source Based on MATLAB Code, an ADS Ptolemy model DataPattern, D1, is used to generate random bits. The data bits are then converted to an integer signal by a BitsToInt model, D2.

Pack_M model, P1, packs the integer data to matrix form for the input of MatLibLink, M1. In M1, MATLAB function qammod.m is used to modulate the input random data to BPSK, QPSK, 16 QAM or 64 QAM data. The output of M1 is a signal with matrix format. Using BusSplit2, B1, UnPk_M, U1, U2 and RectToCx, R30, the output becomes complex signal, then is filtered by a RaisedCosineCx model, R1. The RaisedCosineCx filter, R1, can be turned ON or OFF by using a design parameter, Apply RC Filter to Source Constellation Measurement . The GainCx is used to normalize the output signal.

The user can customize this MATLAB Source design for generating custom signals. The user only needs to use their own MATLAB signal generation function in M1 to replace the qammod.m.

The parameter Setup defines the user's own MATLAB function; SetupPerm defines parameters to be passed into the MallabLibLink model; Function defines the main MATLAB function. In current settings, all m files (MATLAB functions) are stored in the directory $HPEESOF_DIR/adsptolemy/templates. The m files can also be stored under directory STW_MATLAB_prj/data. In this case, the user specifies the m file name without any path location for Setup and Function parameters.

Signal Source Based on MATLAB Code

RF Signal Envelope through RF Spectrum show the RF envelope, RF CCDF, and RF Spectrum for an output RF signal generated by the MATLAB design with -10 dBm power.

RF Signal Envelope

RF Signal CCDF

RF Spectrum

Test Measurement Provided by MATLAB Function

A test measurement for the design is provided by using MATLAB function through an ADS-MATLAB link. To understand the test measurement, push into the STW_MATLAB_Measurement design in the STW_MATLAB_E4438C_896XX.dsn. As shown in Measurement Based on MATLAB Code, a RaisedCosineCx filter, R2, is used as receiving filter. A Pack_M model, P5, packs the complex data into matrix form to input to MatLibLink, M2. In M2, MATLAB function scatterplot is used to display the constellation for the DUT output RF signal.

The user can customize this MATLAB measurement by using their own MATLAB function in M2 to replace the scatterplot .

The M2 parameter Setup defines the user's own MATLAB function to set up the MATLAB code; SetupPerm defines parameters to be passed into the MallabLibLink model; Function defines user's own main MATLAB function. In current settings, all m files (MATLAB functions) are stored in directory $HPEESOF_DIR\adsptolemy\templates. All m files can also be stored under directory STW_MATLAB_prj\data. In this case, the user specifies each m file name without any path location for Setup and Function parameters.

Measurement Based on MATLAB Code

RF Signal Constellation shows the RF envelope for an output RF signal generated by the MATLAB design with 10 dBm power.

RF Signal Constellation

Instrument Compatibility

The MATLAB design is compatible with the Agilent ESG, and Agilent VSA models described in Agilent Instrument Compatibility.

Agilent Instrument Compatibility
ESG Models VSA Models
E4438C, Firmware Revision C.03.40 Option 417 - "802.11 WLAN" Software Personality (Signal Studio) 89600 Series, software version 4.xx/5.xx Option B7R - "WLAN Modulation Analysis"

For information about the following products, see the Agilent Technologies web site:

MATLAB Test Design Parameters

The following tables summarize the MATLAB design parameters:

Description Values Default Range Type Unit Symbol
Modulation Type BPSK, QAM, 16QAM, 64QAM 16QAM   enum    
Sampling Rate   .05 MHz [1:inf) float FREQUENCY  
Signal Segment Time Interval   2 µ [0.2:inf) float TIME  
Enable Raised Cosine Filter   YES   query    
Filter Upsampling Ratio   8 [1:inf) int    
Filter Input Length (samples)   16 [1:inf) int    
Excess Bandwidth   0.22 [0:1] float    
Square-Root Raised Cosine Pulse   YES   query    
Apply RC Filter to Source Constellation Measurement   YES   query    
Measurement Start Time   4 usec [0:inf) float TIME  
Apply RC Filter to Constellation Measurement   YES   query    

This section provides detailed descriptions of the MATLAB design parameters.

Signal Setup

Modulation Type
Specify data modulation type.
Sampling Rate
Specify signal sampling rate.
Signal Segment Time Interval
Specify signal segment time interval.

Signal RC Filter Setup

Enable Raised Cosine Filter
Specify enable raised cosine filter or not.
Filter Upsampling Ratio
Specify up sampling ratio for modulated signal.
Filter Input Length (samples)
Specify RC filter input length per samples.
Excess Bandwidth
Specify RC filter excess bandwidth.
Square-Root Raised Cosine Pulse
Specify Square-Root Raised Cosine Pulse or not.
Apply RC Filter to Source Constellation Measurement
Specify Apply RC Filter to Source Constellation Measurement or not.

Measurement Setup

Measurement Start Time
Specify Measurement Start Time.
Apply RC Filter to Constellation Measurement
Specify Apply RC Filter to Constellation Measurement or not.

Baseline Performance

References

  1. IEEE Std 802.11a-1999, "Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: High-speed Physical Layer in the 5 GHz Band," 1999.
    http://standards.ieee.org/getieee802/download/802.11a-1999.pdf
  2. ETSI TS 101 475 v1.2.1, "Broadband Radio Access Networks (BRAN); HIPERLAN Type 2; Physical (PHY) layer," November, 2000.
    http://webapp.etsi.org/workprogram/Report_WorkItem.asp?WKI_ID=9949
  3. IEEE P802.11g/D8.2, "Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Further Higher Data Rate Extension in the 2.4 GHz Band," April, 2003.
    http://shop.ieee.org/ieeestore/Product.aspx?product_no=SH95134
  4. CCITT, Recommendation O.151(10/92).
  5. CCITT, Recommendation O.153(10/92).

WLAN Links

European Radiocommunications Office: http://www.ero.dk
U.S. Frequency Allocations Chart: http://www.ntia.doc.gov/osmhome
IEEE 802.11b Compliance Organization: http://www.wi-fi.org
HomeRF Resource Center: http://www.palowireless.com/homerf/
IEEE 802.11 Working Group: http://grouper.ieee.org/groups/802/11/index.html

 

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