%陷波器，將原始輸入信號(cos+寬帶噪聲)中的cos由參考輸入信號對消

%參考輸入
derta=0.5;
t =0:0.01:99;
s2 = 0.1*cos(derta+1.8*cos(pi*0.5*t));

subplot(231)
q=length(t);
plot(t,s1);
axis([0,t(q),-0.3,0.3]);
title('噪聲源信號1曲線圖');



%s2 = 0.1*sin(pi*0.5*t);
%subplot(232)
%plot(t,s2);
%axis([0,t(q),-0.3,0.3]);
%title('90移位曲線圖');
%hold on;

%(cos+寬帶噪聲)
d1 = normrnd(0,0.0521,[q 1]); 
subplot(233)
plot(t,d1);
axis([0,t(q),-0.6,0.6]);

d=zeros(1,2001);
d=s2'+d1;
subplot(234)
plot(t,d);
axis([0,t(q),-0.6,0.6]);
title('信號源曲線圖');

w1=0;
w2=0;
y=zeros(1,length(d));
e=zeros(1,length(d));
for n=1:length(d)
    y(n)=w1*s1(n)+w2*s2(n);
    e(n)=d(n)-y(n);
    w1=w1+2*0.02185*e(n)*s1(n);
    w2=w2+2*0.02185*e(n)*s2(n);
end
    
subplot(235)
n=1:q;
plot(n,y,'r');
axis([1,q,-0.3,0.3]);
title('notch估計輸出');

%輸出只剩寬帶噪聲
subplot(236)
n=1:q;
plot(n,e);
axis([1,q,-0.6,0.6]);
title('噪聲對消器輸出');

hold off;