rx_qpsk_demod.m

MATLAB Simulation of OFDM System

function soft_bits = rx_qpsk_demod(rx_symbols)
%  rx_symbols:  48*n_data_syms
soft_bits = zeros(2*size(rx_symbols,1), size(rx_symbols,2));
%回忆在调制时，[00 01 10 11]分别映射成exp(j*[-3/4*pi 3/4*pi -1/4*pi 1/4*pi])
%解调后[-1-1 -11 1-1 11]/sqrt(2)

bit0 = real(rx_symbols); 
bit1 = imag(rx_symbols);

soft_bits(1:2:size(soft_bits, 1),:) = bit0;
soft_bits(2:2:size(soft_bits, 1),:) = bit1;