FSK-prelast

data1(1:100) = 0;
data1(101:200) = 1;
function keying(data ,fzero ,fone)
if(fone >fzero)
  fs = 4* fone
else
  fs = 4 * fzero
endif

Ts = 1/fs;


L = size(data,2) - Ts;
t = 0:Ts:L;
t1 = 0:Ts:(L/fs);

for i = 1:size(data,2)
 if(data(i) == 0)
  f(i) = fzero;

  else
   f(i) = fone;

 endif
 endfor

signal = sin(2*pi*f.*t1);
N = length(signal);


X_mags = abs(fftshift(fft(signal)));
bin_vals = [0 : N-1];
N_2 = ceil(N/2);
fax_Hz = (bin_vals-N_2)*fs/N;
subplot(2,1,1)
plot(fax_Hz, X_mags)
xlabel('Frequency (Hz)')
ylabel('Magnitude');
title('Double-sided Magnitude spectrum (Hertz)');
axis tight
subplot(2,1,2)
plot(t1,signal)
endfunction

keying(data1,2,5)