mpsk源代码.txt

来自「mpsk的源代码 里面是一个txt文档下载后可以再matlab程序上直接运行」· 文本 代码 · 共 52 行

M=8;
 %  signal noisy ratio
 esnodb=1:10;
 esno=10.^(esnodb/10);
 es=1;
 no=10.^(-esnodb/10);
 sigma=sqrt(no/2);
 
 for m=1:length(esnodb);
     error(m)=0;
     s_data(m)=0;
while error(m)<=1000
        %input data
        da=ceil(rand(1,10000)*M);
       % QPSK modulation.
        iin=sqrt(es)*cos((2*pi/M)*(da-1));
        qin=sqrt(es)*sin((2*pi/M)*(da-1));
       %AWGN channel
        AWGNi=randn(1,length(da))*sigma(m);
        AWGNq=randn(1,length(da))*sigma(m);        
      % data transmitted throng AWGN channel
        ich=iin+AWGNi;
        qch=qin+AWGNq;
     %distance counter
      for i=1:M
         d(i,:)=(ich-cos((2*pi/M)*(i-1))).^2+(qch-sin((2*pi/M)*(i-1))).^2;
     end
    %judge the nearest piont
      for j=1:length(qch)
          dd(j)=find(d(:,j)==min(d(:,j)));
          if dd(j)~=da(j)
              error(m)=error(m)+1;
          end
      end
      s_data(m)=s_data(m)+10000;
  end
end
% bit error ratio counter
pe=error./s_data;

%display the result
% the result of theory
ps=erfc(sqrt(esno)*sin(pi/M));

semilogy(esnodb,pe,'b * -');hold on;
semilogy(esnodb,ps,'rd-');

xlabel('Es/N0(dB)');ylabel('BER');
legend('the result of simulation','the result of theory');