www.gusucode.com > wlan 源码程序 matlab案例代码 > wlan/DetectHTMFFormatWaveformExample.m
%% Detect HT-MF Format Waveform % Perform format detection on a WLAN high throughput mixed format (HT-MF) % waveform. %% % Generate an HT-MF waveform and add noise to the transmitted waveform. cbw = 'CBW20'; cfgTx = wlanHTConfig('ChannelBandwidth',cbw); tx = wlanWaveformGenerator([1;0;0;1],cfgTx); snr = 10; rxSig = awgn(tx,snr); %% Demodulate Received Signal and Perform Channel Estimation % * Determine indices for the L-LTF for the 20 MHz bandwidth waveform. For % this calculation, define local variables for the sample rate and duration % of the L-STF and L-LTF fields in seconds. % * Demodulate the L-LTF. % * Perform channel estimation using the L-LTF. % * Estimate the noise variance. sr = 20e6; Tlstf = 8e-6; Tlltf = 8e-6; idxlltf = Tlstf*sr+(1:Tlltf*sr); lltfDemod = wlanLLTFDemodulate(rxSig(idxlltf,:),cbw); chEst = wlanLLTFChannelEstimate(lltfDemod,cbw); noiseVarEst = 10^(-snr/20); %% Detect Signal Format % * Determine indices for the three symbols following the L-LTF. For a 20 % MHz bandwidth waveform, the duration for three symbols is 12 $\mu s$. % * Perform format detection. idxDetectionSymbols = (Tlstf+Tlltf)*sr+(1:12e-6*sr); in = rxSig(idxDetectionSymbols,:); format = wlanFormatDetect(in,chEst,noiseVarEst,cbw)