stabilization.m

IIR数字低通滤波器的直接设计(最小均方法）

clear
clc

format long e
f1 = 3000;
f2 = 5000;
 
fc = (f1 + f2)/2;
fs = 5 * fc;
T = 1/fs;

a = [1.473375000000000e-001 4.214000000000001e-001 6.390499999999999e-001 6.400249999999996e-001 4.221500000000000e-001 1.473625000000002e-001];
b = [3.765142584746059e-001 1.487855109015699e-016 7.809150177077390e-001 9.945916284593060e-001 5.087511661543884e-009 2.967574572953157e-001];
[z,p,k] = tf2zp(a,b);
ap = angle(p);
rp = abs(p);
%polar(ap,rp,'*')
%pause
%H = filt(a,b,T)
%bode(H)
%pause


bc = [b,0 0 0 0 0 0];
bk = fft(bc);
abk = abs(bk);
lbk = log(abk);
nbk = hilbert(lbk);
nreal = abk.*cos(-j.*nbk);
nimag = abk.*sin(-j.*nbk);
nnbk = nreal+j.*nimag
nb = ifft(nnbk);
bs = nb(:,1:6);
[z1,p1,k1]=tf2zp(a,bs);
ap1 = angle(p1);
rp1 = abs(p1);
%polar(ap1,rp1,'*')
%pause
Hs = filt(a,bs,T)
bode(Hs)