宽带瑞丽衰减信道下误码率对比,包括OFDM,OTFS,C-OFDM,C-OTFS,调制方式为16QAM-源码

clc; clear; close all; warning off; addpath(genpath(pwd)); %-------------------------------------------------------------------------- % Define simulation parameters %-------------------------------------------------------------------------- M = 16; % Modulation alphabet k = log2(M); % Bits/symbol cpSize = 0.07; % OFDM cyclic prefix size scs = 15e3; % Subcarrier spacing Hz Bw = 10e6; % System bandwidth Hz ofdmSym = 14; % No. OFDM symbols / subframe EbNo = (-3:1:30)'; % Range of energy/bit to noise power ratio velocity = 120; % Velocity of mobile rx relative tx km/hr codeRate = 2/4; % FEC code rate used maxIterations = 25; % Set maximum no. of iterations for LDPC decoder totalBits = 1e6; % The approx. total no. of bits simulated repeats = 1; % Number of simulation repetitions %-------------------------------------------------------------------------- % Initialise Simulation Components %-------------------------------------------------------------------------- % Initialise OFDM Mod/Demod variables numSC = pow2(ceil(log2(Bw/scs))); % Calc. nearest base-2 no. of OFDM subcarriers cpLen = floor(cpSize * numSC); % Calc. cyclic prefix length numDC = (numSC - 12); % Calc. number of data carriers % Initialise the AWGN channel awgnChannel = comm.AWGNChannel('NoiseMethod','Variance', 'VarianceSource','Input port'); errorRate = comm.ErrorRate('ResetInputPort',true); errorRate1 = comm.ErrorRate('ResetInputPort',true); % Initialise the LDPC coder/decoder parityCheck_matrix = dvbs2ldpc(codeRate); % Generate DVB-S.2 paraity check matrix ldpcEncoder = comm.LDPCEncoder(parityCheck_matrix); % Create encoder system object ldpcDecoder = comm.LDPCDecoder(parityCheck_matrix); % Create decoder system object ldpcDecoder.MaximumIterationCount = maxIterations; % Assign decoder's maximum iterations noCodedbits = size(parityCheck_matrix,2); % Find the Codeword length % Create Vectors for storing error data berOFDM = zeros(length(EbNo),3); berCOFDM = zeros(length(EbNo),3); berOTFS = zeros(length(EbNo),3); berCOTFS = zeros(length(EbNo),3); errorStats_coded = zeros(1,3); errorStats_uncoded = zeros(1,3); for repetition=1:repeats % Repeat simulation multiple times with a unqique channel for each repeat % Generate and Encode data [dataIn, dataBits_in, codedData_in, packetSize, numPackets, numCB] = dataGen(k,numDC,ofdmSym,totalBits,codeRate,ldpcEncoder); % Generate Rayleigh Fading Channel Impulse Response txSig_size = zeros((numSC+cpLen),ofdmSym); % Assign the size of the channel rayChan = multipathChannel(cpSize, scs, txSig_size, velocity); % Create fading channel impulse response % QAM Modulator qamTx = qammod(dataIn,M,'InputType','bit','UnitAveragePower',true); % Apply QAM modulation parallelTx = reshape(qamTx,[numDC,ofdmSym*packetSize]); % Convert to parallel % Add nulls at index 1 guardbandTx = [zeros(1,ofdmSym*packetSize); parallelTx]; % Add 11 nulls around DC guardbandTx = [guardbandTx(1:(numDC/2),:); zeros(11,ofdmSym*packetSize); guardbandTx((numDC/2)+1:end,:)]; %-------------------------------------------------------------------------- % OFDM BER Calculation %-------------------------------------------------------------------------- % Calculate SNR snr = EbNo + 10*log10(codeRate*k) + 10*log10(numDC/((numSC))); % Multicarrier Modulation frameBuffer = guardbandTx; % Create a 'buffer' so subframes can be individually modulated txframeBuffer = []; % Initilaise matrix for w = 1:packetSize ofdmTx = modOFDM(frameBuffer(:,1:ofdmSym),numSC,cpLen,ofdmSym); % Apply OFDM modulation to a subframe of data frameBuffer(:, 1:ofdmSym) = []; % Delete modulated data from frameBuffer txframeBuffer = [txframeBuffer;ofdmTx]; % Add modulated subframe to transmit buffer end % Loop through different values of EbNo for m = 1:length(EbNo) % Loop through the of packets to be transmitted for j = 1:numPackets rxframeBuffer = []; % Initialise matrix % Transmit each subframe individually for u = 1:packetSize % Remove next subframe from the transmit buffer txSig = txframeBuffer( ((u-1)*numel(ofdmTx)+1) : u*numel(ofdmTx) ); % Apply Channel to input signal fadedSig = zeros(size(txSig)); % Pre-allocate vector size for i = 1:size(txSig,1) % Perform elementwise... for j = 1:size(txSig,2) % ...matrix multiplication fadedSig(i,j) = txSig(i,j).*rayChan(i,j); end end % AWGN Channel release(awgnChannel); powerDB = 10*log10(var(fadedSig)); % Calculate Tx signal power noiseVar = 10.^(0.1*(powerDB-snr(m))); % Calculate the noise variance rxSig = awgnChannel(fadedSig,noiseVar); % Pass the signal through a noisy channel % Equalisation eqSig = equaliser(rxSig,fadedSig,txSig,ofdmSym); % Demodulation rxSubframe = demodOFDM(eqSig,cpLen,ofdmSym); % Apply OFDM demodulation rxframeBuffer = [rxframeBuffer';rxSubframe']'; % Store demodulated subframe in rx buffer end % Remove all null carriers parallelRx = rxframeBuffer; parallelRx((numDC/2)+1:(numDC/2)+11, :) = []; % Remove nulls around the DC input parallelRx(1:1, :) = []; % Remove nulls at index 1 qamRx = reshape(parallelRx,[numel(parallelRx),1]);% Convert to serial % Uncoded demodulation of entire packet dataOut = qamdemod(qamRx,M,'OutputType','bit','UnitAveragePower',true);% Apply QAM demodulation codedData_out = randdeintrlv(dataOut,4831); % De-interleave data codedData_out(numel(codedData_in)+1:end) = []; % Remove pad bits errorStats_uncoded = errorRate(codedData_in,codedData_out,0); % Collect error statistics % Coded demodulation of entire packet powerDB = 10*log10(var(qamRx)); % Calculate Rx signal power noiseVar = 10.^(0.1*(powerDB-(EbNo(m) + 10*log10(codeRate*k) - 10*log10(sqrt(numDC))))); % Calculate the noise variance dataOut = qamdemod(qamRx,M,'OutputType', 'approxllr','UnitAveragePower',true,'NoiseVariance',noiseVar);% Apply QAM demodulation codedData_out1 = randdeintrlv(dataOut,4831); % De-interleave data codedData_out1(numel(codedData_in)+1:end) = []; % Remove pad bits % Decode individual code blocks dataBits_out = []; % Initialise matrix dataOut_buffer = codedData_out1; for q = 1:numCB dataBits_out = [dataBits_out;ldpcDecoder(dataOut_buffer(1:noCodedbits))]; % Decode data & add it to the data bits out matrix