spread.m

book:simulation and softeware radiao for mibole code:psk-based digital transmission schemes ofdm

% Program 5-7
% spread.m
%
% Data spread function
%
% Programmed by M.Okita and H.Harada
%

function [iout, qout] = spread(idata, qdata, code1)

% ****************************************************************
%   idata   : ich data sequcence
%   qdata   : qch data sequcence
%   iout    : ich output data sequence
%   qout    : qch output data sequence
%   code1    : spread code sequence
% ****************************************************************

switch nargin
case { 0 , 1 }
    error('lack of input argument');
case 2
    code1 = qdata;
    qdata = idata;
end

[hn,vn] = size(idata);
[hc,vc] = size(code1);

if hn > hc
    error('lack of spread code sequences');
end

iout = zeros(hn,vn*vc);
qout = zeros(hn,vn*vc);

for ii=1:hn
    iout(ii,:) = reshape(rot90(code1(ii,:),3)*idata(ii,:),1,vn*vc);
    qout(ii,:) = reshape(rot90(code1(ii,:),3)*qdata(ii,:),1,vn*vc);
end

%******************************** end of file ********************************