fmmod.m

这是关于数字通信的一些程序,希望对大家有所帮助

t0=0.2;
ts=0.001;
fc=250;
kf=100;
snr=20;
fs=1/ts;
t=[-t0/2:ts:t0/2];
df=0.25;
m=sinc(100*t);
int_m(1)=0;
for i=1:length(t)-1
    int_m(i+1)=int_m(i)+m(i)*ts;
    echo off;
end
echo on;
[M,m,df1]=fftseq(m,ts,df);
M=M/fs;
f=[0:df1:df1*(length(m)-1)]-fs/2;
u=cos(2*pi*fc*t+2*pi*kf*int_m);
[U,u,df1]=fftseq(u,ts,df);
U=U/fs;
[v,phase]=env_phas(u,ts,250);
phi=unwrap(phase);
dem=(1/(2*pi*kf))*(diff(phi)/ts);
subplot(2,1,1)
plot(t,m(1:length(t)))
subplot(2,1,2)
plot(t,dem(1:length(t)))