HE/DataDecoding.m

function [] = DataDecoding(rx)

%% HE-Data Decoding
% The updated <matlab:edit('wlanHERecoveryConfig.m') wlanHERecoveryConfig>
% object for each user can then be used to recover the PSDU bits for each
% user in the HE-Data field.

cfgDataRec = trackingRecoveryConfig;
cfgDataRec.PilotTracking = pilotTracking;

fprintf('Decoding HE-Data...\n');
for iu = 1:numUsers
    % Get recovery configuration object for each user
    user = cfgUsers{iu};
    if strcmp(pktFormat,'HE-MU')
        fprintf(' Decoding User:%d, STAID:%d, RUSize:%d\n',iu,user.STAID,user.RUSize);
    else
        fprintf(' Decoding RUSize:%d\n',user.RUSize);
    end

    heInfo = wlanHEOFDMInfo('HE-Data',chanBW,user.GuardInterval,[user.RUSize user.RUIndex]);

    % HE-LTF demodulation and channel estimation  
    rxHELTF = rx(pktOffset+(ind.HELTF(1):ind.HELTF(2)),:);
    heltfDemod = wlanHEDemodulate(rxHELTF,'HE-LTF',chanBW,user.GuardInterval, ...
        user.HELTFType,[user.RUSize user.RUIndex]);
    [chanEst,pilotEst] = heLTFChannelEstimate(heltfDemod,user);

    % Number of expected data OFDM symbols
    symLen = heInfo.FFTLength+heInfo.CPLength;
    numOFDMSym = (ind.HEData(2)-ind.HEData(1)+1)/symLen;

    % HE-Data demodulation with pilot phase and timing tracking
    % Account for extra samples when extracting data field from the packet
    % for sample rate offset tracking. Extra samples may be required if the
    % receiver clock is significantly faster than the transmitter.
    maxSRO = 120; % Parts per million
    Ne = ceil(numRxSamples*maxSRO*1e-6); % Number of extra samples
    Ne = min(Ne,rxWaveLen-numRxSamples); % Limited to length of waveform
    numRxSamplesProcess = numRxSamples+Ne;
    rxData = rx(pktOffset+(ind.HEData(1):numRxSamplesProcess),:);
    if user.RUSize==26
        % Force CPE only tracking for 26-tone RU as algorithm susceptible
        % to noise
        cfgDataRec.PilotTracking = 'CPE';
    else
        cfgDataRec.PilotTracking = pilotTracking;
    end
        [demodSym,cpe,peg] = heTrackingOFDMDemodulate(rxData,chanEst,numOFDMSym,user,cfgDataRec);

    % Estimate noise power in HE fields
    demodPilotSym = demodSym(heInfo.PilotIndices,:,:);
    nVarEst = heNoiseEstimate(demodPilotSym,pilotEst,user);

    % Equalize
    [eqSym,csi] = heEqualizeCombine(demodSym,chanEst,nVarEst,user);

    % Discard pilot subcarriers
    eqSymUser = eqSym(heInfo.DataIndices,:,:);
    csiData = csi(heInfo.DataIndices,:);

    % Demap and decode bits
    rxPSDU = wlanHEDataBitRecover(eqSymUser,nVarEst,csiData,user,'LDPCDecodingMethod','layered-bp');

    % Deaggregate the A-MPDU
    [mpduList,~,status] = wlanAMPDUDeaggregate(rxPSDU,wlanHESUConfig);
    if strcmp(status,'Success')
        fprintf('  A-MPDU deaggregation successful \n');
    else
        fprintf('  A-MPDU deaggregation unsuccessful \n');
    end

    % Decode the list of MPDUs and check the FCS for each MPDU
    for i = 1:numel(mpduList)
        [~,~,status] = wlanMPDUDecode(mpduList{i},wlanHESUConfig,'DataFormat','octets');
        if strcmp(status,'Success')
            fprintf('  FCS pass for MPDU:%d\n',i);
        else
            fprintf('  FCS fail for MPDU:%d\n',i);
        end
    end
 
    % Plot equalized constellation of the recovered HE data symbols for all
    % spatial streams per user
    hePlotEQConstellation(eqSymUser,user,ConstellationDiagram,iu,numUsers);

    % Measure EVM of HE-Data symbols
    release(EVM);
    EVM.ReferenceConstellation = wlanReferenceSymbols(user);
    rmsEVM = EVM(eqSymUser(:));
    fprintf('  HE-Data EVM:%2.2fdB\n\n',20*log10(rmsEVM/100));
    
    % Plot EVM per symbol of the recovered HE data symbols
    hePlotEVMPerSymbol(eqSymUser,user,EVMPerSymbol,iu,numUsers);
    
    % Plot EVM per subcarrier of the recovered HE data symbols
    hePlotEVMPerSubcarrier(eqSymUser,user,EVMPerSubcarrier,iu,numUsers);
end
end