%%% 用來實現直擴基帶解調
%********************************************************
%        This function does the DS-SS modulation
%%       AUTHOR: Wenbin Luo
%	     DATE  : 04/28/01
%%		 SYNOPSIS: x = ds_demod(c,y)
%		 c ---> user code (column vector)
%y->tmp=c*x,y=tmp(:)(ds-ss modulated signal,column vector)
%x->input signal(row vector)
%******************************************************

function x = ds_demod(c,y)
tmp = reshape(y, length(c), length(y)/length(c));
tmp = tmp';
%x is a column vector
x = tmp * c;
% convert to row vector
x = x';