ICI cancellation in OFDM matlab code

hi i am posting self cancellation code but i have some doubts
clc;
clear all;
close all;

ep= [0 0.15 0.3];

EbNo= 1:15;

NS= 100; % No of OFDM symbols to transmit

modulation= 'qam';
M=2;

N= 52; % No of carriers in OFDM symbol

BPS= N*log2(M); % No of bits per OFDM symbol

carriers= (1:52)+ 2;

ifftsize= 64; % IFFT size

% Input Bit Stream is normally Distributed
input_bit_stream = sign(randn(1,BPS*NS));
input_bit_stream(input_bit_stream == -1) = 0;
% PERFORM SERIAL TO PARALLEL CONVERSION
% work on whole data stream at once
disp('Serial to Parallerl Conversion')
parallel_data = StoP(input_bit_stream, log2(M));
% PERFORM MODULATION
% using indicated modulation type and M-ary alphabet
disp(['Modulating with ' modulation ' and ' num2str(M) '-ary Alphabet'])
modulated_data = dmodce(parallel_data, 1, 1, modulation, M);
%modulated_data = (modulated_data/max(abs(modulated_data)));
% CREATE OFDM SYMBOLS
disp('Transmitting OFDM symbols')
odd_carriers = carriers(1:2:52);
even_carriers = carriers(2:2:52);
for ll= 1:length(ep)
for l=1:length(EsNo)
k = 1;
for n = 1:NS
ofdm_symbol1 = zeros(1,ifftsize);
ofdm_symbol2 = zeros(1,ifftsize);
% MAP to carriers
ofdm_symbol1(odd_carriers) = modulated_data(k:k+25);
ofdm_symbol1(even_carriers) = -modulated_data(k:k+25);
ofdm_symbol2(odd_carriers) = modulated_data(k+26:k+51);
ofdm_symbol2(even_carriers) = -modulated_data(k+26:k+51);
% Time Signal to transmit
tx_signal1 = (ifft(ofdm_symbol1,ifftsize));
tx_signal2 = (ifft(ofdm_symbol2,ifftsize));
% DOPPLER SHIFT
rx_signal1 = tx_signal1.*exp(j*pi*ep(ll)/ifftsize*(0:ifftsize-1));
rx_signal2 = tx_signal2.*exp(j*pi*ep(ll)/ifftsize*(0:ifftsize-1));
% ADD NOISE
rx_signal1 = awgn(rx_signal1, EsNo(l),0);
rx_signal2 = awgn(rx_signal2, EsNo(l),0);
% FFT
received_ofdm1 = fft(rx_signal1, ifftsize);
received_ofdm2 = fft(rx_signal2, ifftsize);
demod_sym1 = .5*(received_ofdm1(odd_carriers)-received_ofdm1(even_carriers));
demod_sym2 = .5*(received_ofdm2(odd_carriers)-received_ofdm2(even_carriers));
received_ofdm3 = [demod_sym1 demod_sym2];
% Extract data from carriers in OFDM symbol
received_symbols(k:k+51) = received_ofdm3;
k = k + 52;
end
% PERFROM DEMODULATION
disp('Performing Demodulation')
received_data = ddemodce(received_symbols, 1, 1, modulation, M);
%PERFORM PARALLEL TO SERIAL CONVERSION
disp('Performing Parallel to Serial Converion')
output_bit_stream = PtoS(received_data, log2(M));
% CALCULATE BER
disp('Calculating BER ')
BER(ll,l)= sum(xor(input_bit_stream, output_bit_stream))/length(input_bit_stream);
end
end


the above code have small problems. it has two functions StoP,PtoS,dmodce,ddmodce. i don't know these functions can u plz change it as normal using reshape and qam mod functions and repost it here