ms14_2.m

《数字信号处理实验(MATLAB版)》这

xn1=[0,1,2,3,0,0];         %建立x1(n)序列
xn2=[1,1,1,0,0,0];         %建立x2(n)序列
N=length(xn1);      
n=0:N-1;k=0:N-1; 
Xk1=fft(xn1,N);            %由x1(n)的FFT求X1(k) 
Xk2=fft(xn2,N);            %由x2(n)的FFT求
Yk=Xk1.*Xk2;               %Y(k)=X1(k)X2(k) 
yn=ifft(Yk,N)              %由Y(k)的IFFT求y(n)
yn=abs(yn)
subplot(2,3,1),stem(n,xn1,'k');
title('x1(n)');
subplot(2,3,2),stem(n,xn2,'k'); 
title('x2(n)');
subplot(2,3,3),stem(n,yn,'k'); 
title('y(n)');
subplot(2,3,4),stem(k,abs(Xk1),'k'); 
title('X1(k)');
subplot(2,3,5),stem(k,abs(Xk2),'k'); 
title('X2(k)');
subplot(2,3,6),stem(k,abs(Yk),'k'); 
title('Y(k)');