信号的调制与解调MATLAB（AM/PM/FM)_am调制与解调源码

1.例题

 2.代码

clear 
%表示a(t)
t=0:0.01:3;
a(1:100)=1;
a(101:200)=-1;
a(201:301)=1;
 
fs=1;   %抽样频率
fc=0.3; %载波频率
 
%调制
y1=modulate(a,fc,fs,'am');%幅度调制
y2=modulate(a,fc,fs,'fm');%频率调制
y3=modulate(a,fc,fs,'pm',1);%相位调制
 
%解调
a1=demod(y1,fc,fs,'am');
a2=demod(y2,fc,fs,'fm');
a3=demod(y3,fc,fs,'pm',1);
 
%绘出相关波形
figure(1);
subplot(211)
plot(t,a);ylabel('a(t)');grid on;
axis([0 4 -1.5 1.5])
figure(2)
subplot(321)
plot(y1);title('幅度调制');grid on;
subplot(322)
plot(a1);title('AM解调后的信号');grid on;
subplot(323)
plot(y2);title('频率调制');grid on;
subplot(324)
plot(a2);title('FM解调后的信号');grid on;
subplot(325)
plot(y3);title('相位调制');grid on;
subplot(326)
plot(a3);title('PM解调后的信号');grid on;

3.运行结果