cm_sm41.m

完成一个利用矩形信号星座图的M=16的QAM通信系统的MONTECARLO仿真

function p= cm_sm41( snr_in_dB )
%CM_SM41 Summary of this function goes here
%   Detailed explanation goes here

N=10000;
d=1;
Eav=10*d^2;
snr_in_dB1=snr_in_dB;
snr=10^(snr_in_dB1/10);
sgma=sqrt(Eav/(8*snr));
M=16;

for i=1:N,
    temp=rand;
    dsource(i)=1+floor(M*temp);
end;


mapping=[-3*d 3*d;
    -d 3*d;
    d 3*d;
    3*d 3*d;
    -3*d d;
    -d d;
    d d;
    3*d d;
    -3*d -d;
     -d -d;
    d -d;
    3*d -d;
     -3*d -3*d;
     -d -3*d;
     d -3*d;
   3*d -3*d];
for i=1:N,
    qam_sig(i,:)=mapping(dsource(i),:);
    end;

    %%%%%%%%%%%%%%%%%
    for i=1:N,
        [n(1) n(2)]=gngauss(sgma);
        r(i,:)=qam_sig(i, : )+n;
    end;
    
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%
    numoferr=0;
    for i=1:N,
        
        for j=1:M,
            metrics(j)=(r(i,1) -mapping(j,1))^2+(r(i,2) -mapping (j,2))^2;
        end;
        [min_metric decis]=min(metrics);
        if (decis~=dsource(i)),
            numoferr=numoferr+1;
        end;
    end;
    p=numoferr/(N);