%*************************************************************************************
%         This function does the DS-SS modulation
%
%         AUTHOR: Wenbin Luo
%			 DATE  : 04/28/01
%
%			 SYNOPSIS: y = ds_mod(c,x)
%			 c ---> user code (column vector)
%         x ---> input signal (row vector)
%         y ---> tmp = c*x, y = tmp(:) (ds-ss modulated signal, column vector)
%***********************************************************************************

function y = ds_mod(c,x)
tmp = c*x;
y = tmp(:);