基于MATLAB实现的DFE信道均衡算法及学习曲线绘制程序+使用说明文档.zip

%DFE判决反馈自适应均衡 clc; clear all; M=1000; N=5; L=11; H=[-0.557 -0.5 1.0 0.033 0.35]; a=0.0005; d=6; ee=zeros(1,M-d-L+1); for nn=1:1:200; x=rand(1,M); s=zeros(1,length(x)); x=x-0.5; for n=1:1:length(x) if x(n)>=0 x(n)=1; else x(n)=-1; end end y=filter(H,1,x); y=y+randn(1,M)/5; wf=zeros(1,L); wb=zeros(1,d); E1=1; E2=0; P=0; %while abs(E2-E1)>1e-5 E2=E1; E1=0; for m=d+L:1:M sum=0; sum1=0; sum2=0; for n=m-1:-1:m-L sum1=sum1+y(n)*wf(m-n); end for n=1:1:d sum2=sum2+s(m-d-n)*wb(n); end e=x(m-d)-sum1+sum2; for n=m-1:-1:m-L wf(m-n)=wf(m-n)+2*a*e*y(n); end for n=1:1:d wb(n)=wb(n)-2*a*e*s(m-d-n); %注意此处是减号，而上面是加号，这可以推导出来 end sum=sum1-sum2; if sum>=0 sum=1; else sum=-1; end s(m-d)=sum; E1=E1+e*e; ee(m-d-L+1)=ee(m-d-L+1)+e.^2; end E1=E1/(M-d-L+1); %end end ee=ee/200; M=10000; x=rand(1,M); x=x-0.5; for n=1:1:length(x) if x(n)>=0 x(n)=1; else x(n)=-1; end end y=filter(H,1,x); y=y+randn(1,M)/10; %下面进行测试 P=0; for m=d+L:1:M sum=zeros(1,M); sum1=zeros(1,M); sum2=zeros(1,M); for n=m-1:-1:m-L sum1(m)=sum1(m)+y(n)*wf(m-n); end for n=1:1:d sum2(m)=sum2(m)+s(m-d-n)*wb(n); end sum=sum1(m)-sum2(m); if sum>=0 sum=1; else sum=-1; end if sum~=x(m-d) P=P+1; end s(m-d)=sum; end str=sprintf('错误率是：'); disp(str); disp(100*(double(P)/(M-d-L+1))); hold on; plot(ee);