synchro_cross_correlation.m

A SISO 20M OFDM system based on IEEE802.11n standard, using Matlab.

%
% 摨婜専弌傾儖僑儕僘儉 (憡屳憡娭丆峝敾掕傪梡偄傞)
%

function   max_add = synchro_cross_correlation(shift_rec_dat, short_pre, Num_data_sym);

    % 摨婜寁嶼帪娫(僒儞僾儖悢)
    MAX_LEN = 401;
    % 嶲徠怣崋傪峝敾掕
    for I=1:160
        if real(short_pre(I)) >= 0
            hd_sp(I) = 1;
        else
            hd_sp(I) = -1;
        end
        if imag(short_pre(I)) >= 0
            hd_sp(I) = hd_sp(I) + i;
        else
            hd_sp(I) = hd_sp(I) - i;
        end
    end
    %憡娭抣偺寁嶼
    for I=1:MAX_LEN
        total_corelation(I)=sum(hd_sp .* conj(shift_rec_dat(1+I:160+I)));
    end

    for I=1:MAX_LEN
        total_corelation(I) = ((abs(real(total_corelation(I))))^2) + ((abs(imag(total_corelation(I))))^2);
    end
    %嵟戝抣偺専弌
    max_add=0;
    max_corelation=0;
    for I=1:MAX_LEN
        if max_corelation <= total_corelation(I)
            max_corelation = total_corelation(I);
            max_add = I;
        end
    end

    max_corelation;