clc
Fs = 16000; % Sampling rate of signal
Fc = 4000; % Carrier frequency
Ft = 100;
t = [0:2000]'/Fs; % Sampling times
s = sin(2*pi*Ft*t);%調(diào)制信號

a = modulate(s,Fc,Fs,'fm');%調(diào)制1
subplot(2,1,1);
plot(s);
subplot(2,1,2);
plot(a);
pause


dev = 500; % Frequency deviation in modulated signal

b = fmmod(s,Fc,Fs,dev); %fmmod 調(diào)制2

z = fmdemod(b,Fc,Fs,dev); %fmdemod 解調(diào)

subplot(2,1,1);

plot(a);pause
subplot(2,1,2);
plot(z);
zz = fft(b, 1024);%fft
f = 1000*(0:512)/1024;
yy = zz.* conj(zz) / 1024;
plot(f,yy(1:513)) 
fs = 8.192*10^3;%8192 
fc = 2.048*10^3;%2048 
ft = 100; 
t = [0: 1/fs: 2000/fs]'; 
x = sin(2*pi*ft*t);%100 
subplot(2,1,1); 
plot(x);  
pause
y = cos(2*pi*fc*t + cumsum(x)); 
subplot(2,1,2); 
plot(y);  
pause
z = fft(y, 512); 
f = 1000*(0:256)/512; 
yy = z.* conj(z) / 512; 
plot(f,yy(1:257))