code.m

ＭＩＭＯ－ＯＦＤＭ系统仿真

function X_code=code(X_bit,RATE,CODE,N_FFT)
%编码
global STRU;
global AddZero;

if CODE==1
    [antenna_Tx N]=size(X_bit);
    switch RATE
        case 1/2
            STRU = poly2trellis(7,[133 171]);  %编码器结构
        case 1/3
            STRU = poly2trellis(7,[133 165 171]);
        case 2/3
            STRU = poly2trellis(4,[337 155 26]);
    end
    for i=1:antenna_Tx
        X_code(i,:) = convenc(X_bit(i,:), STRU);  %对信源bits编码
    end
    [antenna_Tx code_length]=size(X_code);
    if rem(code_length,N_FFT)~=0
        AddZero=N_FFT-rem(code_length,N_FFT);
    end
    X_code=[X_code zeros(antenna_Tx,AddZero)];
else
    X_code=X_bit;
end