p2_2.m

Digital Signal Processing-A Computer-Based Approach(Second Edition)Sanjit K.Mitra实验指导书练习题matlab程序

% Program P2_2
% Time-Shifting Properties of DTFT
close all ; clear all;
w = -pi:2*pi/255:pi; wo = 0.4*pi; D = 10;
num = [1 2 3 4 5 6 7 8 9];
h1 = freqz(num, 1, w); h2 = freqz([zeros(1,D) num], 1, w);
subplot(2,2,1);plot(w/pi,abs(h1));grid
title('Magnitude Spectrum of Original Sequence')
subplot(2,2,2);plot(w/pi,abs(h2));grid
title('Magnitude Spectrum of Time-Shifted Sequence')
subplot(2,2,3);plot(w/pi,unwrap(angle(h1)));grid
title('Phase Spectrum of Original Sequence')
subplot(2,2,4);plot(w/pi,unwrap(angle(h2)));grid
title('Phase Spectrum of Time-Shifted Sequence')