YLUPKUJ.rar_USB编程_UW96_drivingn5v

clear all; SNR=0:1:30; snr=10.^(SNR/10); sigma=sqrt(2./snr);%噪声与信号的幅度比值 K=400000; %未调制信号长度，信号越长，曲线越精确 data=randint(1,K); %%%%%%%%%%%%%%%%%%%%设置参数%%%%%%%%%%%%%%%%%%%%%%%% nt=4;%发射天线数 nr=1;%接收天线数 n=4; %调制方式QPSK %%%%%%%%%%%%%%%%%%%%QPSK信号调制%%%%%%%%%%%%%%%%%%%% npskdata=npsk(n,data);%调用调制方式子函数 x=npskdata; %调制后信号 %%%%%%%%%%%%%%%%%%%Alamouti%%%%%%%%%%%%%%%%%%%%%%%% for k=1:length(SNR) error_symbol=0;%对每一个信噪比下的误符号率清零 for i=1:length(npskdata)/4 x1=x(4*i-3); x2=x(4*i-2); %对信源进行空时操作，每两个数据符号一起 x3=x(4*i-1); x4=x(4*i); %对信源进行空时操作，每两个数据符号一起 X=[x1 -x2 -x3 -x4 x1' -x2' -x3' -x4' x2 x1 x4 -x3 x2' x1' x4' -x3' x3 -x4 x1 x2 x3' -x4' x1' x2' x4 x3 -x2 x1 x4' x3' -x2' x1'];%空时发射信号矩阵 h=rey(nt,nr); %调用信道子函数 noise=sigma(k).*rey(8,nr); R=sqrt(1/2).*h*X+noise;%接收信号矩阵 % y=zeros(1,nt); % y(1)= r(1,1)*H(1,1)'+r(1,2)*H(1,2)'+r(1,3)*H(1,3)'+r(1,4)*H(1,4)'+r(1,5)'*H(1,1)+r(1,6)'*H(1,2)+r(1,7)'*H(1,3)+r(1,8)'*H(1,4); % y(2)= r(1,1)*H(1,2)'-r(1,2)*H(1,1)'-r(1,3)*H(1,4)'+r(1,4)*H(1,3)'+r(1,5)'*H(1,2)-r(1,6)'*H(1,1)-r(1,7)'*H(1,4)+r(1,8)'*H(1,3); % y(3)= r(1,1)*H(1,3)'+r(1,2)*H(1,4)'-r(1,3)*H(1,1)'-r(1,2)*H(1,2)'+r(1,5)'*H(1,3)+r(1,6)'*H(1,4)-r(1,7)'*H(1,1)-r(1,8)'*H(1,2); % y(4)=-r(1,1)*H(1,4)'-r(1,2)*H(1,3)'+r(1,3)*H(1,2)'-r(1,2)*H(1,1)'-r(1,5)'*H(1,4)-r(1,6)'*H(1,3)+r(1,7)'*H(1,2)-r(1,8)'*H(1,1); H=[h(1) h(2) h(3) h(4) h(2) -h(1) h(4) -h(3) h(3) -h(4) -h(1) h(2) h(4) h(3) -h(2) -h(1) h(1)' h(2)' h(3)' h(4)' h(2)' -h(1)' h(4)' -h(3)' h(3)' -h(4)' -h(1)' h(2)' h(4)' h(3)' -h(2)' -h(1)']; r=zeros(1,8); r=[R(1) R(2) R(3) R(4) R(5)' R(6)' R(7)' R(8)']; y=zeros(nt,1); y=H'*r.'; y=y.'; %进行最大似然检测 DEC_X=judge(y); %统计符号错误的总数 if DEC_X(1)~=x1 error_symbol=error_symbol+1; end if DEC_X(2)~=x2 error_symbol=error_symbol+1; end if DEC_X(3)~=x3 error_symbol=error_symbol+1; end if DEC_X(4)~=x4 error_symbol=error_symbol+1; end end SER(k)=error_symbol/length(npskdata); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%画图%%%%%%%%%%%%%%%%%%%%%%%%%%%%% semilogy(SNR,SER,'b*-'); grid on legend('STBC4C QPSK(4TX 1RX)') title('QPSK调制下的速率为1/2的4天线复信号STBC在慢瑞利衰减信道上的误符号率性能') xlabel('信噪比/dB'); ylabel('误符号率'); hold on