H_kaiser.m

clear all;
wb=0.317*pi;ws=0.272*pi; As=65;  %wsǸͨƵʲwaҪע
tr_width=wb-ws; %ɴ
N=(ceil((As-7.95)*2*pi/(14.36*tr_width)+1))/2;    %㿭󴰵ij
disp(['ijΪ',num2str(N)]);   %MatlabʾNֵ
beta=0.1102*(As-8.7);   %㿭󴰵λбֵϵ
n=[0:1:N-1];
disp(['λбΪ',num2str(beta)]);    %Matlabʾλбֵ
w_kai=(kaiser(N,beta))';    %󴰺
wc=(ws+wb)/2;
hd=ideal_lp(pi,N)-ideal_lp(wc,N);   %庯
h=hd.*w_kai;    %ʵӦ=Ӧ*󴰺
[db,mag,pha,grd,w]=freqz_m(h,[1]);  %ƵӦĸdbΪӦwΪӦƵֵȱʾ
figure(3)
plot(w/pi,db,':r');title('Ӧ/dB  Highpass');
axis([0 1.1 -120 10]);grid;xlabel('ԦΪλƵ');ylabel('ֱ/dB');