用希尔伯特变换可以实现包络检波!
clear all; close all;
t=0:200;
x1=sin(8*pi*t/100)+1;
subplot(411);plot(t,x1);title('信号');
x2=4*sin(40*pi*t/100);
subplot(412);plot(t,x2);title('载波');
x3=(1+x1).*x2;
subplot(413);plot(t,x3);title('调幅信号');
x4=abs(hilbert(x3));
subplot(414);plot(t,x4);title('解调信号');
对载波进行滤波即可
或者用diff函数求极大极小值点,连起来就是包络