fft_hamm.m

Matlab环境下带控制面板的低通、高通滤波器设计

N=1024;
L=161;
n=0:L-1;
whm=0.54-0.46*cos(2*pi*n/(L-1));
x(1:L)=xn(21:(20+L)).*whm;
x((L+1):N)=0;    %Zero Padding
Xk=abs(fft(x));
XkM=max(Xk);
f=(0:(N/2-1))*fs/N;
Xkh=Xk(1:(N/2))/XkM;
subplot(2,2,1)
plot(f,20*log10(Xkh))
AXIS([0 10 -35 1]);
xlabel('f in kHz')
ylabel('X(2*pi*f) in dB')
title('input (digital) signal spectrum (Hamming Window)')