mykey3.m

基于变步长LMS在干扰抵消中的应用

clear all;
syorder=8;a=0.97;
r=50/100000;
umax=0.005;
umin=0.0005;
ta=200;tb=0.05;
[signal,fs]=wavread('speech');
signal=signal';
n=length(signal);
d=zeros(n+syorder-1,syorder);
wk=zeros(syorder,n);
en=zeros(1,n);
uk=en;
uk(1)=umax;
sum=0;
noise=zeros(1,n);
noise=awgn(noise,5);
noise=[zeros(1,syorder-1),noise];
signal=[zeros(1,syorder-1),signal];
dn=signal+noise;
for i=1:n
    d(i+syorder-1,:)=noise(i+syorder-1:-1:i);
end
for i=1:(n-1)
    y(i)=d(i+syorder-1,:)*wk(:,i);
   en(i)=dn(i+syorder-1)-y(i);
   uk(i)=tb*[1/(1+exp(-ta*en(i)*en(i)))-0.5];
   wk(:,i+1)=wk(:,i)+2*uk(i)*en(i)*d(i+syorder-1,:)';
   

end
%subplot(3,1,1)
%plot(1:n,en,'r');
%grid;
%title('en');
%subplot(3,1,2);
%plot(1:n+syorder-1,signal,'b');
%grid
%title('signal');
%subplot(3,1,3);
%plot(1:n+syorder-1,dn,'b');
%grid
%title('N2n1');