to get real data for the complex vector

i am trying to implement the qam modulated MIMO-OFDM system when i take the IFFT of the modulated data i am getting the complex valued signal . i have to get the integer valued after the IFFT is taken . how do i get the integer valued for the modulated signal by using IFFT . my code is given below

clc
M=16;
k=log2(M);
fft_size=64;
nsym=10000;
source=randi([0 1],1,nsym);
xsym=bi2de(reshape(source,k,length(source)/k).','left-msb').';
qam_mod=qammod(xsym,M);
sp=qam_mod.';
ifft_data=ifft(sp);