iir_fliter.m

基于LMS算法的自适应滤波器的MATLAB仿真

clear;
clf;
N=256;
Fs=600;
dt=1/Fs;

for k=1:N
    f1=300
    f2=100
    y(k)=sin(2*pi*f1*k*dt)+sin(2*pi*f2*k*dt)+sin(2*(f1+20)*k*dt)
end
lp=200;
wn1=2*lp/Fs;
[z1,p1,k1]=CHEBY1(3,0.5,wn1,'high')
[B,A]=CHEBY1(3,0.5,wn1,'high')

yy(1)=0;
yy(2)=0;
b(1)=0.0580;
b(2)=-0.1741;
b(3)=0.1741;
b(4)=-0.0580;
a(1)=1;
a(2)=1.1795;
a(3)=0.918;
a(4)=0.2742;

n=254;
   for  i=1:n
        yy1(i)=b(4)*y(i+3)+b(3)*y(i+2)+b(2)*y(i+1)+b(1)*y(i)+a(4)*yy1(i+2)+a(3)*yy1(i+1)+a(2)*yy1(i);
   end
y=fft(y,N)
pyy=y.*conj(y);
f=(0:(N/2-1));
figure(1);

plot(f,ppy(1:N/2))

y=fft(yy1,N);
ppy=y.*conj(y);
f=(0:(N/2-1));
figure(2);
plot(f,ppy(1:N/2))