qpsktwo_two.zip_mimo_mimo qpsk_mimo qpsk_mimo接收端_qpsktwo_two

% function BER2=qpsktwo_two(X) % % close all; % clc ; % clear all; N=10^6; M=4; % N=X/2; sn1=randi([0,1],1,2*N); % 产生服从均匀分布的二进制信源1 mn1=ones(1,length(N)); %%%%%%%%%%%%%%% 信号1 QPSK调制，将sn变为四进制序列mn %%%%%%%%%% for i=1:N mn1(i)=sn1(2*i-1)+sn1(2*i)*2; end qpsk1=pskmod(mn1,M); sn2=randi([0,1],1,2*N); %产生服从均匀分布的二进制信源2 mn2=ones(1,length(N)); %%%%%%%%%%%%%%% 信号2 QPSK调制，将sn变为四进制序列mn %%%%%%%%%% for i=1:N mn2(i)=sn2(2*i-1)+sn2(2*i)*2; end qpsk2=pskmod(mn2,M); %%%%%%%%%%%%%%%%%%%%%%%%% 得到瑞利信道矩阵 %%%%%%%%%%%%%%%%%%%%%%% Ray00=randn(1,N)+randn(1,N)*1i; Ray01=randn(1,N)+randn(1,N)*1i; Ray10=randn(1,N)+randn(1,N)*1i; Ray11=randn(1,N)+randn(1,N)*1i; %%%%%%%%%%%%%%%%%%%%%%% 信号经过瑞利信道 %%%%%%%%%%%%%%%%%%%%% rqpsk1=Ray00.*qpsk1+Ray01.*qpsk2; rqpsk2=Ray10.*qpsk1+Ray11.*qpsk2; %%%%%%%%%%%%%%%%%%%%%%% 得到瑞利信道的逆矩阵h^-1 %%%%%%%%%%%%%%%%%% for j=1:N h=[Ray00(j),Ray01(j);Ray10(j),Ray11(j)]; hinv=h^-1; Rayinv00(j)=hinv(1,1); Rayinv01(j)=hinv(1,2); Rayinv10(j)=hinv(2,1); Rayinv11(j)=hinv(2,2); end SNR=[0:2:20]; % 信噪比 for n=1:length(SNR) %%%%%%%%%%%%%%%%%% 两信号附加噪声 %%%%%%%%%%%%%%%%%%%%%% Eb=1/2; % 信号比特功率 Eb_No=10^(SNR(n)/10); % 线性信噪比 No=Eb/Eb_No; % 噪声功率wgn noise1=sqrt(No/2)*((randn(1,N))+(randn(1,N))*1i); noise2=sqrt(No/2)*((randn(1,N))+(randn(1,N))*1i); rnqpsk1=rqpsk1+noise1; %加入高斯白噪声 rnqpsk2=rqpsk2+noise2; %加入高斯白噪声 %%%%%%%%%%%%%%%%%% 两信号迫0均衡 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% u1=Rayinv00.*rnqpsk1+Rayinv01.*rnqpsk2; u2=Rayinv10.*rnqpsk1+Rayinv11.*rnqpsk2; %%%%%%%%%%%%%%%%% 两信号QPSK解调 %%%%%%%%%%%%%%%%%%%%%% deray1=pskdemod(u1,M);%解调 tn1=zeros(1,2*N); for j=1:N; tn1(2*j-1)=rem(deray1(j),2); tn1(2*j)=(deray1(j)-tn1(2*j-1))/2; end deray2=pskdemod(u2,M);%解调 tn2=zeros(1,2*N); for j=1:N; tn2(2*j-1)=rem(deray2(j),2); tn2(2*j)=(deray2(j)-tn2(2*j-1))/2; end [num,BER2(n)]=biterr([sn1,sn2],[tn1,tn2]);%计算误码率 end theory = 0.5 * (1 - sqrt((10 .^ (SNR / 10)) ./ (1 + 10 .^ (SNR / 10)))); figure semilogy(SNR,BER2,'kx--'); hold on; semilogy(SNR, theory, 'r-'); axis([0 20 1e-6 1]); grid on; xlabel('SNR=Eb/No(dB)'); ylabel('BER'); title('two-two QPSK误码率性能'); legend('BER-simulated','BER-theory'); % %saveas(gcf,'双发双收','jpg')