程序Program1_1是用MATLAB对一个正弦信号进行仿真的程序
% Program1_1 % This program is used to generate a discrete-time sinusoidal signal and draw its plot clear, % Clear all variables 清除所有变量 close all, % Close all figure windows 关闭所有图形窗口 n = -20: 20; % Specify the interval of time指定时间间隔 w0 = 0.2*pi; % Specify the angular frequency指定角频率 x = sin(w0*n); % Generate the signal 生成的信号 stem(n,x,'k.') % Open a figure window and plot 打开图形窗口并绘制图形 title('Sinusoidal signal x[n]') xlabel('Time Index n')
绘制如图所示
程序Program1_2绘制了不同角频率时的正弦信号的波形
clear,close all, n = -20: 20; w0 = 0*pi; w1 = 0.1*pi; w2 = 0.2*pi; w3 = 0.8*pi; w4 = 0.9*pi; w5 = 1*pi; w6 = 1.1*pi; w7 = 1.2*pi; x0 = cos(w0*n); x1 = cos(w1*n); x2 = cos(w2*n); x3 = cos(w3*n); x4 = cos(w4*n); x5 = cos(w5*n); x6 = cos(w6*n); x7 = cos(w7*n); subplot(421), stem(n,x0,'k.') ,ylabel('w0=0') subplot(422), stem(n,x1,'k.') ,ylabel('w0=0.1*pi') subplot(423), stem(n,x2,'k.') ,ylabel('w0=0.2*pi') subplot(424), stem(n,x3,'k.') ,ylabel('w0=0.8*pi') subplot(425), stem(n,x4,'k.') ,ylabel('w0=0.9*pi') subplot(426), stem(n,x5,'k.') ,ylabel('w0=1*pi') subplot(427), stem(n,x6,'k.') ,ylabel('w0=1.1*pi') subplot(428), stem(n,x7,'k.') ,ylabel('w0=1.2*pi')
绘制图像如图
程序Program1_3用来仿真下面形式的离散时间信号
% Program1_3 % This program is used to generate a discrete-time sequence % and draw its plot clear, % Clear all variables close all, % Close all figure windows n = -5:5; % Specify the interval of time, the number of points of n is 11. 指定时间间隔，n的点数为11。 x = [0, 0, 0, 0, 0.1, 1.1, -1.2, 0, 1.3, 0, 0]; % Generate the signal 生成的信号 stem(n,x,'.') % Open a figure window and draw 打开图形窗口并绘制 the plot of x[n] grid on, title ('A discrete-time sequence x[n]') xlabel ('Time index n')
% Program1_4 % This program is used to generate a discrete-time sinusoidal signal % and draw its plot clear, % Clear all variables close all, % Close all figure windows n = -5:5; % Specify the interval of time x = [zeros(1,4), 0.1, 1.1, -1.2, 0, 1.3, zeros(1,2)]; % Generate the sequence stem (n,x,'.') % Open a figure window and draw the plot of x[n] grid on, title ('A discrete-time sequence x[n]') xlabel ('Time index n')
x = [zeros(1,4) x zeros(1, 2)] 来实现 一行四个零，一行两个零
