cdma2000matlab仿真代码

% 1/2卷积编码QPSK通过单径瑞利衰落信道，比较不同的交织长度对性能的影响 clear; frameNum=80; %帧数 frameLength = 640;%帧长度 constraintLength = 5;%卷积码约束长度 Generator = [23 33];%卷积码生成多项式 R=1/2;%码率 snr_in_dB=0:10;%设置仿真的信噪比范围 Pe = zeros(1,size(snr_in_dB,2));%初始化误比特率存储空间 theo_Pe = zeros(1,size(snr_in_dB,2));%初始化理论误比特率存储空间 numSamplesPerSymbol = 8;%采样率 BitRate = 16000; %比特率 BaudRate = BitRate/2;%码符号率 SymbolDuration = 1/BaudRate; hTransmitFilter = raisedcos1(BitRate,BaudRate);%得到载波 hReceiveFilter = hTransmitFilter; % 发送 % 外层循环为信噪比循环，内层循环为对每个数据帧的处理过程 for i1 =1:length(snr_in_dB)%初始化信噪比 snr = 10^(snr_in_dB(i1)/10);%将对数信噪比转化为自然值 errNum = 0;%初始化错误数 for i2 = 1:frameNum s = randsrc(1,frameLength,[0,1]); %产生随机数据源 BitStream = convEN(s,constraintLength,Generator);%卷积编码 interleaved=matintrlv(BitStream,28,length(BitStream)/28);%交织 BitStreamLength=length( BitStream); [BitStreamOne,BitStreamTwo] = SerialToParallel(interleaved);%串并变换 [I_SymbolsTx,Q_SymbolsTx] =QPSKEncoder(BitStreamOne,BitStreamTwo);% QPSK编码 [I_WaveformTx,Q_WaveformTx] = TransmitFilter(I_SymbolsTx,Q_SymbolsTx,hTransmitFilter,numSamplesPerSymbol);%量化,卷积 % 计算比特能量 Eb1 = sum(I_WaveformTx.*I_WaveformTx)/(BitStreamLength/2);%计算两路信号能量 Eb2 = sum(Q_WaveformTx.*Q_WaveformTx)/(BitStreamLength/2); No1 = (Eb1+Eb2)/(snr*R);%计算噪声能量 %经瑞利信道 [I_Waveformfade,Q_Waveformfade,fadingFactor] = simulationrey(I_WaveformTx,Q_WaveformTx); %加高斯噪声 [I_WaveformRx,Q_WaveformRx]=simulationAwgn(I_Waveformfade,Q_Waveformfade,No1,fadingFactor); %接收 [I_SymbolsRx,Q_SymbolsRx] = ReceiveFilter(I_WaveformRx,Q_WaveformRx, hReceiveFilter,numSamplesPerSymbol);%经接受滤波器 [BitStreamOneRx,BitStreamTwoRx] = QPSKDecoder(I_SymbolsRx,Q_SymbolsRx);%QPSK解调 interleavedRx= ParallelToSerial(BitStreamOneRx,BitStreamTwoRx);%并串变换 BitStreamRx=matdeintrlv(interleavedRx,28,length(BitStream)/28);%解交织 Dec_s = convDE(BitStreamRx,constraintLength,Generator);%维特比译码 errNum = errNum + length(find( s ~=Dec_s(1:frameLength)));%求错误比特数 end Pe(i1) =errNum/(frameNum*frameLength);%不同信噪比下的误比特率 theo_Pe(i1)=0.5*(1-1/sqrt(1+1/snr));%不同信噪比下的理论误比特率 end; semilogy(snr_in_dB,Pe,'r*-',snr_in_dB,theo_Pe,'g*-');%画出误比特率图像 hold grid on; xlabel('SNR (dB)') ylabel('Pe') legend('Pe','Theory',4)