wlanFieldIndices

Create a WLAN HE SU configuration object with default settings and use it to generate a waveform.

cfgHE = wlanHESUConfig;
cbw = cfgHE.ChannelBandwidth;
waveform = wlanWaveformGenerator(1,cfgHE);

Get the WLAN field indices. Use them to isolate the HE-SIG-A field.

ind = wlanFieldIndices(cfgHE);
rxSIGA = waveform(ind.HESIGA(1):ind.HESIGA(2),:);

Perform OFDM demodulation to extract the HE-SIG-A field.

sigaDemod = wlanHEDemodulate(rxSIGA,'HE-SIG-A',cbw);

Return the pre-HE OFDM information and use it to extract the demodulated HE-SIG-A data symbols.

preHEInfo = wlanHEOFDMInfo('HE-SIG-A',cbw);
siga = sigaDemod(preHEInfo.DataIndices,:);

Recover the HE-SIG-A information bits and other information, assuming no channel noise. Display the parity check result.

noiseVarEst = 0;
[bits,failCRC] = wlanHESIGABitRecover(siga,noiseVarEst);
disp(failCRC);

   0

Create a VHT-format configuration object for a multiple-input/multiple-output (MIMO) transmission using a 160 MHz channel bandwidth. Generate the corresponding VHT waveform.

cfg = wlanVHTConfig('MCS',8,'ChannelBandwidth','CBW160', ... 
    'NumTransmitAntennas',2,'NumSpaceTimeStreams',2);
txSig = wlanWaveformGenerator([1;0;0;1],cfg);

Determine the component PPDU field indices for the VHT format.

ind = wlanFieldIndices(cfg)

ind = struct with fields:
       LSTF: [1 1280]
       LLTF: [1281 2560]
       LSIG: [2561 3200]
    VHTSIGA: [3201 4480]
     VHTSTF: [4481 5120]
     VHTLTF: [5121 6400]
    VHTSIGB: [6401 7040]
    VHTData: [7041 8320]

The VHT PPDU waveform is composed of eight fields, including seven preamble fields and one data field.

Extract the VHT-STF from the transmitted waveform.

stf = txSig(ind.VHTSTF(1):ind.VHTSTF(2),:);

Verify that the VHT-STF has dimension 640-by-2, corresponding to the number of samples (80 for each 20-MHz bandwidth segment) and the number of transmit antennas.

disp(size(stf))

   640     2

Configure a VHT-format configuration object with two paths.

vht = wlanVHTConfig('NumTransmitAntennas',2,'NumSpaceTimeStreams',2);

Generate a random PSDU and create the corresponding VHT waveform.

txPSDU = randi([0 1],8*vht.PSDULength,1);
txSig = wlanWaveformGenerator(txPSDU,vht);

Pass the signal through a TGac 2x2 MIMO channel.

tgacChan = wlanTGacChannel('NumTransmitAntennas',2,'NumReceiveAntennas',2, ...
    'LargeScaleFadingEffect','Pathloss and shadowing');
rxSigNoNoise = tgacChan(txSig);

Add AWGN to the received signal. Set the noise variance for the case in which the receiver has a 9-dB noise figure.

nVar = 10^((-228.6+10*log10(290)+10*log10(80e6)+9)/10);
awgnChan = comm.AWGNChannel('NoiseMethod','Variance','Variance',nVar);
rxSig = awgnChan(rxSigNoNoise);

Determine the indices for the VHT-LTF and extract the field from the received signal.

indVHT = wlanFieldIndices(vht,'VHT-LTF');
rxLTF = rxSig(indVHT(1):indVHT(2),:);

Demodulate the VHT-LTF and estimate the channel coefficients.

dLTF = wlanVHTLTFDemodulate(rxLTF,vht);
chEst = wlanVHTLTFChannelEstimate(dLTF,vht);

Extract the VHT-Data field and recover the information bits.

indData = wlanFieldIndices(vht,'VHT-Data');
rxData = rxSig(indData(1):indData(2),:);
rxPSDU = wlanVHTDataRecover(rxData,chEst,nVar,vht);

Determine the number of bit errors.

numErrs = biterr(txPSDU,rxPSDU)

numErrs = 
0

Create a WLAN HE MU configuration object and use it to generate an HE MU waveform with packet extension and an oversampling factor.

cfg = wlanHEMUConfig(192);
cfg.User{1}.NominalPacketPadding = 16; 
bits = [1; 0; 0; 1];
osf = 3;
waveform = wlanWaveformGenerator(bits,cfg,OversamplingFactor=osf);

Return and display the PPDU field indices.

ind = wlanFieldIndices(cfg,OversamplingFactor=osf);
disp(ind)

      LSTF: [1 480]
      LLTF: [481 960]
      LSIG: [961 1200]
     RLSIG: [1201 1440]
    HESIGA: [1441 1920]
    HESIGB: [1921 2400]
     HESTF: [2401 2640]
     HELTF: [2641 3600]
    HEData: [3601 11280]
      HEPE: [11281 11520]