MATLAB迭代法计算信道容量 程序源码.zip

%用迭代法计算信道容量; %inputp最佳输入分布（不唯一）; %k迭代步数; %c2信道容量; function [c2 inputp k]=C(P,eps) if nargin~=2 eps=1e-10; end [r,s]=size(P); back=[];%后验概率矩阵; inputp=ones(r,1)/r;%初始化输入概率分布; c1=1;%信道容量初始化; %.......................................................................... for k=0:1000 for i=1:r for j=1:s lamda=sum(inputp.*P(:,j)); back(j,i)=inputp(i)*P(i,j)/lamda; end end s3=[]; for i=1:r s2=[]; for j=1:s if back(j,i)~=0 s2=[s2 (P(i,j)*(log(back(j,i))))]; end end s3=[s3 exp(sum(s2))]; end inputp(1:r)=s3/sum(s3); c2=log(sum(s3)); c2=c2*log2(exp(1)); if abs(c2-c1)/c2>eps c1=c2; else return; end end