fir5.m

matlab离散信号时域分析

%三个窗函数的比较
Wp=0.6*pi;Ws=0.4*pi;Ap=1;As=45;
N3=ceil(6.2*pi/(Wp-Ws));
N3=mod(N3+1,2)+N3;
M3=N3-1;
N2=ceil(7*pi/(Wp-Ws));
N2=mod(N2+1,2)+N2;
M2=N2-1;
N1=ceil(1.8*pi/(Wp-Ws));
N1=mod(N1+1,2)+N1;
M1=N1-1;
w1=ones(1,N1); %矩形窗
w2=hamming(N2)';%汉明窗
w3 = hanning(N3)';%汉纳窗

%幅频的比较
k=linspace(-pi,pi,512);
mag1=freqz(w1,[1],k);
mag2=freqz(w2,[1],k);
mag3=freqz(w3,[1],k);
plot(k/pi,abs(mag1),'--b',k/pi,abs(mag2),'-r',k/pi,abs(mag3),'-.b'); 

legend('矩形窗幅度响应','汉明窗幅度响应','汉纳窗幅度响应');

title('三种窗函数的幅度特性');