复件 复件 复件 sim_fsk.m

基于MATLAB的FSK信号仿真及其频谱分析

%sim FSK
clc
clear
f0=2300;
f1=11;
f=10.3;
n=128;   %dot /peroid
Ts=1/f0/n;
T=1/f;
t=0:Ts:4*T;
fi=0;
dfi=0;
for i=1:length(t)
    if(mod(t(i),T)<T/2)
      dfi=2*pi*f0*Ts+2*pi*f1*Ts;
    %   s(i)=sin(2*pi*f0*t(i)+2*pi*f1*t(i));
    else
    %   s(i)=sin(2*pi*f0*t(i)+2*pi*f1*((2*floor(t(i)/T)+1)*T-t(i)));
      dfi=2*pi*f0*Ts-2*pi*f1*Ts;
    end
  fi=fi+dfi;
  s(i)=sin(fi);
end
plot(t,s);
grid
fs=1/Ts;
df=1/(length(t)*Ts);
y = fft(s,length(t)); 
m = abs(y);
f_v=0:df:(fs-df);
figure
plot(f_v,m);
grid