3.2 Fft-to-symbols (receiver) (matlab)

%% FFT to Symbols (RECEIVER) % ------------------------------------------------------------------------% Description: Takes a received OFDM signal that has been demodulated to % baseband and corrected for frequency/phase offset, and% extracts the complex envelope of each carrier. This % converts the time domain signal into a descrete set of% symbols that can be mapped to binary words. %% Inputs: re - Real channel of OFDM symbol % im - Imaginary channel of OFDM symbol% num_subcarriers - Number of subcarriers used in OFDM symbol % Outputs: symbols - Extracted complex envelopes of each subcarrierfunction symbols = fft2sym(re, im, num_subcarriers)%%size_of_fft = size(re,2); % Implicit size of fft output = fft(re+j*im); % Time domain signal was generated using ifft()symbols = [ output(2:1+num_subcarriers/2) output(size_of_fft+1-num_subcarriers/2:size_of_fft) ];% Save only the FFT samples that contain complex symbols as specified % by the number of subcarriers.end