How to generate FSK modulator?

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Sin j 2021-9-12

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https://ww2.mathworks.cn/matlabcentral/answers/1451734-how-to-generate-fsk-modulator

评论： Eric 2021-9-29

I want generate a FSK Modulator and Demodulator. I specify a sampling rate of 44.1 kHz. For a baud rate of 500 1/s, this sampling rate should equate to 44100/500=88.2 samples per symbol. Instead, I am generating 44100 samples per symbol (from T1), thus transmitting at 1 baud instead of 500. It would be nice if you can help me with this problem.

Fb=500;
M=2;
m=log2(M);
num_bit=m*Fb;
Tb = 1/Fb; % Data rate % Bit period
Fs= 44100; %Sampling Freq
A= 1; % Amplitude 
Fc1=7000; % Trägerfrequenz für Input 0
Fc2=9000; % Trägerfrequenz für Input 1
T1=Tb/Fs:Tb/Fs:Tb;
t=length(T1);
x= randi ([0 1], 50, 1); % random binary data
N_x=length(x);
% Modulation
modu=[];
for (n=1:1:N_x) 
 if x(n)==0;
 carr=A*sin(2*pi*Fc1*T1); % Carrier Signal
 else
 carr=A*sin(2*pi*Fc2*T1);
 end
 
 modu=[modu carr];
end
y = modu'; 
 op1 = conv(y, sin(2*pi*Fc1*T1)); % Korrelation mit Trägerfrequenz für Input 0
 op2 = conv(y, sin(2*pi*Fc2*T1)); % Korrelation mit Trägerfrequenz für Input 1
 xHat = [real(op1(t+1:t:end)) > real(op2(t+1:t:end))]; 