rx_qam16_demod.m

matlab的调制解调

% 16_QAM　信号解调，注意接收符号向量rx_symbols是列向量

function soft_bits = rx_qam16_demod(rx_symbols)

% Each symbol consists of 4 bits
% 每个符号由４个比特组成；
soft_bits = zeros(4*size(rx_symbols,1), size(rx_symbols,2)); 

bit0 = real(rx_symbols);
bit2 = imag(rx_symbols);

bit1 = 2/sqrt(10)-(abs(real(rx_symbols)));
bit3 = 2/sqrt(10)-(abs(imag(rx_symbols)));

soft_bits(1:4:size(soft_bits,1),:) = bit0;
soft_bits(2:4:size(soft_bits,1),:) = bit1;
soft_bits(3:4:size(soft_bits,1),:) = bit2;
soft_bits(4:4:size(soft_bits,1),:) = bit3;