xcorryy.m

ＯＦＤＭ宽带无线系统的链路级的仿真程序（多天线

% calculate xcorr across the 1st dimension, gives same result as matlab
% bulit-in function, but much much faster
function y = xcorryy(x)
% x is 2 dimension.  calculate xcorr across 1st dimension
y = zeros(size(x));
for k = 1:size(x,1)
    tmp = [zeros(k-1,size(x,2));x];
    x2 = tmp(1:size(x,1),:);
    y(k,:) = sum(x.*x2,1);
end