ceshi1.m

该MATLAB程序评估了viterbi算法在衰落信道下的卷积译码的性能

%蒙特卡罗仿真
%
E=2;     %每比特的能量
k=1;
G=[1 0 1;1 1 1];
input=[1 0 1 0 1 1 1 0];
dsource=cnv_encd(G,k,input);
N=length(dsource);

% 通过AWGN信道
for i=1:N
%matched filter output
%soft-decision
   %产生的高斯噪声均值为0，方差为1
   if(dsource(i)==0)
       r0(i)=E+gngauss(1);
       r1(i)=gngauss(1);
   else 
       r0(i)=gngauss(1);
       r1(i)=E+gngauss(1);
   end;
   %detector follows
%hard decision
   if(r0(i)>r1(i))
       decis(i)=0;
   else
       decis(i)=1;
   end;
end;
%硬判决维特比译码
[decoder_output,survivor_state,cumulated_metric]=viterbi(G,k,decis);