zdft.m

用MATLAB实现数字信号处理的程序

%N=16有限序列的DFT、IDFT结果
%DFT
N=16;
n=0:1:N-1;          %时域采样
xn=sin(n*pi/8)+sin(n*pi/4);
k=0:1:N-1;          %频域采样
Wn=exp(-j*2*pi/N);
Nk=n'*k;
WnNk=Wn.^Nk;
Xk=xn*WnNk;
subplot(2,1,1),stem(n,xn);
subplot(2,1,2),stem(k,abs(Xk));
pause

%IDFT
N=16;
n=0:1:N-1;          %时域采样
k=0:1:N-1;          %频域采样
Wn1=exp(j*2*pi/N);
Nk=n'*k;
WnNk1=Wn1.^Nk;
xn1=(Xk*WnNk1)./N;
subplot(2,1,1),stem(k,abs(Xk));
subplot(2,1,2),stem(n,real(xn1));