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;endext_input=[0input(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);