problem with Fast Fourier Transform (FFT)

Hello,

This is part of my code to convert data in time domain using ifft.

 for k = 1:numSymbols,
        y= y + data(k)*exp(j*2*pi*Fsub(k)*t);
 end

and how do i write the fft if i wanna change y back into frequency domain?..

Answer 1

[Image Analyst]

ffty = fft(y);
% Get back
y = ifft(ffty);