MIMO-OFDM系统仿真

clear all;clc;frmLen = 300; % frame length帧长numPackets = 10; % number of packets帧数Nsamp=frmLen*numPackets;EbNo = 2:2:20; % Eb/No varying to 20 dBNt = 4; % maximum number of Tx antennasNr = 2; % maximum number of Rx antennasN_FFT=400;Nc=N_FFT;hStr = RandStream(mt19937ar, Seed, 55408);% Create QPSK mod-demod objectsP = 4; % modulation orderqpskmod = modem.pskmod(M, P, SymbolOrder, Gray);qpskdemod = modem.pskdemod(qpskmod);% Create comm.OSTBCEncoder and comm.OSTBCCombiner System objects hOSTBCEnc = comm.OSTBCEncoder(. NumTransmitAntennas, Nt); hOSTBCComb = comm.OSTBCCombiner(. NumTransmitAntennas, Nt,. NumReceiveAntennas, Nr);%rho = 0.7; % Correlation coefficient = antenna correlationRsym = 10e3; % Input symbol rateRbit = Rsym * log2(P); % Input bit rateNos = 4; % Oversampling factorts = (1/Rbit) / Nos; % Input sample period 12.5usfs=Rbit*Nos;% tau = 0 0.4 0.9*1e-6; % Path delays, in seconds% pdb = 0 -15 -20; % Average path gains, in dB% dop = doppler.rounded; % Doppler spectrum, with default parametersfd = 0.5; % h = mimochan(Nt, Nr, ts, fd, tau, pdb); % MIMO channel object% h.KFactor = 4; % Rician K-factor on first path% h.DopplerSpectrum = dop; % Doppler spectrum of MIMO objectTxCorrelationMatrix = toeplitz(1 rho rho2 rho3); % Transmit correlation matrixRxCorrelationMatrix =toeplitz(1 rho);delays=0, 5e-5, 10e-5;delay_samp=round(delays./ts);% Create MIMO channel System object hChan = comm.MIMOChannel(. SampleRate, fs,. MaximumDopplerShift, fd,. NumTransmitAntennas, Nt,. NumReceiveAntennas, Nr,. TransmitCorrelationMatrix, TxCorrelationMatrix,. ReceiveCorrelationMatrix, RxCorrelationMatrix,. PathDelays, delays,. KFactor, 4,. AveragePathGains, 0, -15, -20,. NormalizePathGains, false,. PathGainsOutputPort, true);% Set up a figure for visualizing BER results% h = gcf; grid on; hold on;% set(gca, yscale, log, xlim, EbNo(1), EbNo(end), ylim, 1e-4 1);% xlabel(Eb/No (dB); ylabel(BER); set(h,NumberTitle,off);% set(h, renderer, zbuffer); set(h,Name,Transmit vs. Receive Diversity);% title(Transmit vs. Receive Diversity);cp=1/8*Nc;% ofdmmod=zeros(Nc*numPackets,Nt);% ofdmdemod=zeros(Nc*numPackets,Nr); tranSignal=zeros(cp+Nc)*numPackets,Nt);% Loop over several EbNo pointsfor ii = 1:length(EbNo) data = randi(hStr, 0 P-1, Nsamp, 1); % data vector per user modData= modulate(qpskmod, data); % QPSK modulation % Alamouti Space-Time Block Encoder encData = step(hOSTBCEnc , modData); % Alamouti Space-Time Block Encoder, G2, full rate for i=1:Nt enc=reshape(encData(:,i),Nc,numPackets); ofdmmod=sqrt(Nc)*ifft(enc,N_FFT); trans=ofdmmod(Nc-cp+1:Nc,:);ofdmmod; tranSignal(:,i)=reshape(trans,(cp+Nc)*numPackets,1); end % idx =(1:N_FFT)+(packetIdx-1)*N_FFT ; chanOut, pathGains = step(hChan, tranSignal); % rxSignal(idx,:) = filter(h, encData); rxSignal=awgn(chanOut,EbNo(ii); l2=zeros(cp+Nc)*numPackets,1,Nt,Nr); l3=zeros(cp+Nc)*numPackets,1,Nt,Nr);% l2(1:end,1,:,:)=pathGains(1:end-1,2,:,:); l2(delay_samp(2)+1:end,1,:,:)=pathGains(1:end-delay_samp(2),2,:,:); l3(delay_samp(3)+1:end,1,:,:)=pathGains(1:end-delay_samp(3),3,:,:); H(:,1,:,:)=pathGains(:,1,:,:)+l2+l3;% H=pathGains(:,1,:,:); for i=1:numPackets H_r(1+(i-1)*Nc:i*Nc,:,:,:)=H(1+cp+(i-1)*(Nc+cp):i*(Nc+cp),:,:,:); end for j=1:Nr recv_cp=reshape(rxSignal(:,j),cp+Nc,numPackets); recv=recv_cp(cp+1:Nc+cp,:); ofdmdem=fft(recv,N_FFT)/sqrt(Nc); ofdmdemod(:,j)=reshape(ofd