BER in OFDM systems

hi matlabers, i am trying to compute BER in ofdm but did not get the curve that i look for.anyone can help me?this is my code..

 dataType = '16QAM'; % Modulation format.
 totalSubcarriers = 1024; % Number of total subcarriers.
 numSymbols = 16; % Data block size.
 Fs = 5e6; % System bandwidth.
 Ts = 1/Fs; % System sampling rate.
 Nos = 4; % Oversampling factor.
 Nsub = totalSubcarriers;
 Fsub = [0:Nsub-1]*Fs/Nsub; % Subcarrier spacing
 numRuns = 1000; % Number of runs.
 M=16;
 EbN0dB = [0:999];

 for n = 1:numRuns,
    % Generate random data.
    if dataType == '16QAM'
       ipBit = randint(1,numSymbols,M);
   %Data Modulation
   ipMod = (1/sqrt(10))*qammod(ipBit,M); % 16QAM modulation
    end

    % Time range of the OFDM symbol.dataType = '16QAM'; % Modulation   format.

    % Time range of the OFDM symbol.
    t = [0:Ts/Nos:Nsub*Ts];

    % OFDM modulation.

    for k = 1:numSymbols,
        y= ipMod(k)*exp(j*2*pi*Fsub(k)*t);
        data_rx = y.*exp(-j*2*pi*Fsub(k)*t); 
        data_rx = data_rx(:,1);
   end

 ipBitHat = qamdemod(data_rx*sqrt(10),M); 
 nErr(n) = size(find(ipBit - ipBitHat),2);

 end

 simBer = nErr/numSymbols;
 semilogy(EbN0dB,simBer,'bx-','LineWidth',2,'MarkerSize',5);
 axis([0 16 10^-5 1]);
 grid on