fir4.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
%图形比较
nn=[N1 N2 N3];
N=max(nn);
subplot(3,1,1);
stem(w1,'-r'); axis([0 N 0 1.2]);
title('矩形窗');
grid;
subplot(3,1,2);
plot(w2,'-r'); axis([0 N 0 1.2]);
title('汉明窗');
grid;
subplot(3,1,3);
plot(w3,'-r'); axis([0 N 0 1.2]);
title('汉纳窗');
grid;