digitalprogress.zip_FFT算法_constantly177_hello2md_数字信号处理实验_汉宁窗

clear all; N=15; n=0:14; WH=0.54-0.46*(cos(2*pi*n/((N-1)+eps)));%海明窗 hd=sin(0.25*pi*(n-(N-1)/2+eps))./(pi*(n-(N-1)/2+eps)); h1=hd.*WH; N=64; H1=fft(h1,N); n=0:N-1; w=2*pi/64*n; subplot(2,2,1); plot(w,(20*log10(abs(H1))));%幅度曲线 grid xlabel('w/rad'); ylabel('20lg|H(jw)|/dB'); title('幅度曲线和相频曲线（n=15)'); n=0:N-1; w=2*pi/64*n; subplot(2,2,3); plot(w,unwrap(phase(H1)));%相频曲线 grid xlabel('w/rad'); clear all; N=33 n=0:32; WH=ones(1,33); hd=sin(0.25*pi*(n-(N-1)/2+eps))./(pi*(n-(N-1)/2+eps)); h1=hd.*WH; N=64; H1=fft(h1,N); n=0:N-1; w=2*pi/64*n; subplot(2,2,2); plot(w,(20*log10(abs(H1))));%幅度曲线 grid xlabel('w/rad'); ylabel('20lg|H(jw)|/dB'); title('幅度曲线和相频曲线（n=33)'); n=0:N-1; w=2*pi/64*n; subplot(2,2,4); plot(w,unwrap(phase(H1)));%相频曲线 grid xlabel('w/rad');