40t.m

来自「包含50个数字信号处理方面的matlab程序」· M 代码 · 共 23 行

wc=0.25*pi;N=21;
n=[0:1:N-1];
hd=ideal_lp(wc,N);
w_han=(boxcar(N))';%矩形窗
h=hd.*w_han; 
[db,mag,pha,grd,w]=freqz_m(h,1);
subplot(2,1,1);stem(n,h,'.');title('h(n)');grid;hold on;
subplot(212);plot(w/pi,db,'y');xlabel('w/pi');ylabel('dB');hold on;
w_han=(hamming(N))';%海明窗
h=hd.*w_han; 
[db,mag,pha,grd,w]=freqz_m(h,1);
subplot(2,1,1);stem(n,h,'*');title('h(n)');grid;hold on;
subplot(212);plot(w/pi,db,'b');xlabel('w/pi');ylabel('dB');hold on;
w_han=(hanning(N))';%汉宁窗
h=hd.*w_han;
[db,mag,pha,grd,w]=freqz_m(h,1);
subplot(2,1,1);stem(n,h,'.');title('h(n)');grid;hold on;
subplot(212);plot(w/pi,db,'r');xlabel('w/pi');ylabel('dB');hold on;
w_han=(blackman(N))';%布莱克曼窗
h=hd.*w_han;
[db,mag,pha,grd,w]=freqz_m(h,1);
subplot(2,1,1);stem(n,h,'.');title('h(n)');grid;hold on;
subplot(212);plot(w/pi,db,'g');xlabel('w/pi');ylabel('dB');hold on;