ms14_6.m

《数字信号处理实验(MATLAB版)》这

T0=[0.5,0.25,0.125,0.125]; %输入不同的Ts和N值
N0=[256,256,256,2048];  
for r=1:4;
   Ts=T0(r);N=N0(r);
   n=0:N-1;
   D=2*pi/(Ts*N);
	xa=exp(-0.01*n*Ts).*(sin(2*n*Ts)+sin(2.1*n*Ts)+sin(2.2*n*Ts));     %建立xa(nT)
	k=floor(-(N-1)/2:(N-1)/2);
   Xa=Ts*fftshift(fft(xa,N))
   [r,Xa(1)]
   subplot(2,2,r);plot(k*D,abs(Xa),'k');
   axis([1,3,1.1*min(abs(Xa)),1.1*max(abs(Xa))]);
end