ex_07_12_1.m

清华大学胡广书教授< 数字信号处理理论算法实现>>第二版一书的配套题解和电子课件一书《数字信号处理题解及电子课件》（2007年5月出版）的matlab源程序。

%  ex_07_12_1.m :  习题 7.12


clear all;
clc;
N = 1000;
Fs = 1000;
b = [1, 0, 0,0,0,0,-3,0,0,0,0,0,3,0,0,0,0,0,-1];
a = [1, -3 ,3, -1];
[H,w] = freqz(b,a,N,Fs);
h = impz(b,a,19);
Hr = abs(H);
Hr=Hr/216;
Hr = 20*log10(Hr);
Hp = angle(H);
Hp = unwrap(Hp);
subplot(221);plot(w,Hr);
subplot(222);plot(w,Hp);