function [sig,sig_length] = OFDM_TX(num_carriers,num_zeros,prefix_length,input) % OFDM Transmitter - DC removed % sig is the output signal % length is the length of the output signal % num_carriers - number of sub-carriers (power of 2) % num_zeros - number of zeros minus 1 (DC) in output spectrum (odd) % prefix_length - length of cyclic prefix % input - input dimensions (length = number_carriers - num_zeros - 1) if (length(input) + num_zeros + 1 ~= num_carriers) fprintf('error in lengths\n'); return; end ext_input = [0 input(1:length(input)/2) zeros(1,num_zeros) input((1+length(input)/2) : length(input))]; output_1 = ifft(ext_input); sig = [output_1((num_carriers - prefix_length + 1) : num_carriers) output_1]; sig_length = length(sig);