notchlms.m

自己编写的自适应notch fileter算法

%sin干扰对消

t =0:1/1500:2;
s0 = 0.1*cos(0.65+cos(500*pi*t));
t =2:1/1500:4;
s1 = 0.1*cos(0.8+cos(500*pi*t));
q=length(t);
n=1;
while n<=q
    s(n)=s0(n);
    n=n+1;
end
while n<=q*2
    s(n)=s1(n-q);
    n=n+1;
end
n=1:q*2;
subplot(231)
plot(n,s);
axis([2,6000,-0.3,0.3]);
title('噪声源信号曲线图');

q=q*2;
rnd1 = normrnd(0,0.031,[q 1]); 
subplot(232)
plot(n,rnd1);
axis([0,6000,-0.3,0.3]);
title('干扰信号曲线图');

x = s' + rnd1;
subplot(233)
plot(n,x);
axis([0,6000,-0.3,0.3]);
title('存在干扰的噪声源信号曲线图');

d=x;

N=50;
delta=0.25;
M=length(x)-10;

y=zeros(1,M);
h=zeros(1,N);
e=zeros(1,N);   
for n=(N+1):M
   xx=x(n-1:-1:n-N);
   y(n)=h*xx;
   e(n)=d(n)-y(n);
   h=h+delta*e(n)*xx';
end


subplot(234)
i=[1:M];
plot(i,y);
axis([1,M,-0.3,0.3]);
title('估计出的正选信号');


subplot(235)
i=[1:M];
plot(i,e)
axis([1,M,-0.3,0.3]);
title('去掉正选干扰信号后的宽带信号');