tx_16qam_mod.asv

OFDM的在瑞利信道下的与单载波信号的识别算法

  
function mod_symbols = tx_16qam_mod(bits_in)
% 16-QAM modulation
% Constellation refers to IEEE 802.11a stand. page 20, subclause (17.3.5.7)
full_len = length(bits_in);
m = 1;
for k = -3:2:3
    for l = -3:2:3
        table(m) = (k + j * l)/sqrt(10); % power normalization
        m = m+1;
     end;
end;
table = table([0 1 3 2 4 5 7 6 12 13 15 14 8 9 11 10] + 1); % Gray code mapping pattern for 16-QAM
inp = reshape(bits_in,4,full_len/4);
mod_symbols = table([8 4 2 1] * inp + 1);  % maps transmitted bits into 16QAM symbols