1 ## Copyright (C) 2007 Sylvain Pelissier <sylvain.pelissier@gmail.com>
3 ## This program is free software; you can redistribute it and/or modify it under
4 ## the terms of the GNU General Public License as published by the Free Software
5 ## Foundation; either version 3 of the License, or (at your option) any later
8 ## This program is distributed in the hope that it will be useful, but WITHOUT
9 ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
13 ## You should have received a copy of the GNU General Public License along with
14 ## this program; if not, see <http://www.gnu.org/licenses/>.
17 ## @deftypefn {Function File} {@var{y} =} bsc (@var{data}, @var{p})
18 ## Send @var{data} into a binary symetric channel with probability
19 ## @var{p} of error one each symbol.
22 function [ndata] = bsc(data,p)
23 if (nargin < 1); usage('ndata = bsc(data,p)'); end
25 if(isscalar(p) ~= 1 || p > 1 || p < 0)
26 error('p muste be a positive scalar less than one');
29 if(any(data(:) ~= floor(data(:))) || any(data(:) > 1) || any(data(:) < 0))
30 error('data must be a binary sequence');
35 ndata(find(data == 0)) = randsrc(size(ndata(find(data == 0)),1),size(ndata(find(data == 0)),2),[-1 -2;1-p p]);
36 ndata(find(data == 1)) = randsrc(size(ndata(find(data == 1)),1),size(ndata(find(data == 1)),2),[1 0;1-p p]);
37 ndata(find(ndata == -1)) = 0;
38 ndata(find(ndata == -2)) = 1;