qam4_mod.m

OFDM通信系统抗多径衰落干扰研究,顺便求OFDM系统中关于频谱偏移的估计与补偿的

function [qam_out] = Qam4_mod(qam_in)
%% 4QAM 调制函数
%% 输入： 矩阵，列数必须是4的倍数，01序列
%% 输出： 矩阵，4qam调制后的矩阵
global QamTable
global bitPerSymbol;
QamTable = [ -1-i, 1-i, -1+i, 1+i ];
[ m, n ] = size(qam_in);
qam_out = zeros(m,n/bitPerSymbol);
for k = 1:m
    QamTmp = reshape(qam_in(k,:),bitPerSymbol,n/bitPerSymbol)';
    QamTmpTmp = bi2de( QamTmp, 'left-msb');
    qam_out(k, :) = QamTable( QamTmpTmp+1 );
end