p2_3.m

该程序用于讨论各种离散时间信号和系统的性质及特性。

% Program P2_3
% Generate the input sequences
clf;
n = 0:40;
a = 2;b = -3;
x1 = cos(2*pi*0.1*n);
x2 = cos(2*pi*0.4*n);
x3 = cos(2*pi*0.1*(n-1));
x4 = cos(2*pi*0.4*(n-1));
x = a*x1 + b*x2;
y1 = x1.*x3;
y2 = x2.*x4;
y = x.*(a*x3+b*x4);
yt = a*y1 + b*y2; 
d = y - yt; % Compute the difference output d[n]
% Plot the outputs and the difference signal
subplot(3,1,1)
stem(n,y);
ylabel('Amplitude');
title('Output Due to Weighted Input: a \cdot x_{1}[n] + b \cdot x_{2}[n]');
subplot(3,1,2)
stem(n,yt);
ylabel('Amplitude');
title('Weighted Output: a \cdot y_{1}[n] + b \cdot y_{2}[n]');
subplot(3,1,3)
stem(n,d);
xlabel('Time index n');ylabel('Amplitude');
title('Difference Signal');