Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / communications-1.1.1 / genqammod.m

diff --git a/octave_packages/communications-1.1.1/genqammod.m b/octave_packages/communications-1.1.1/genqammod.m
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+## Copyright (C) 2006 Charalampos C. Tsimenidis
+##
+## This program is free software; you can redistribute it and/or modify it under
+## the terms of the GNU General Public License as published by the Free Software
+## Foundation; either version 3 of the License, or (at your option) any later
+## version.
+##
+## This program is distributed in the hope that it will be useful, but WITHOUT
+## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+## details.
+##
+## You should have received a copy of the GNU General Public License along with
+## this program; if not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{y} =} genqammod (@var{x}, @var{c})
+##
+## Modulates an information sequence of intergers @var{x} in the range
+## @code{[0 @dots{} M-1]} onto a quadrature amplitude modulated signal 
+## @var{y}, where  @code{M = length(c) - 1} and @var{c} is a 1D vector 
+## specifing the signal constellation mapping to be used. An example of
+## combined 4PAM-4PSK is
+##
+## @example
+## @group
+##  d = randint(1,1e4,8);
+##  c = [1+j -1+j -1-j 1-j 1+sqrt(3) j*(1+sqrt(3)) -1-sqrt(3) -j*(1+sqrt(3))];
+##  y = genqammod(d,c);
+##  z = awgn(y,20);
+##  plot(z,'rx')
+## @end group
+## @end example
+## @end deftypefn
+## @seealso{genqamdemod}
+
+function y=genqammod(x,c)
+
+if nargin<2
+       usage("y = genqammod (x, c)");   
+endif    
+
+m=0:length(c)-1;
+if ~isempty(find(ismember(x,m)==0))
+       error("x elements should be integers in the set [0, length(c)-1].");
+endif  
+
+y=c(x+1);
+
+%!assert(genqammod([0:7],[-7:2:7]),[-7:2:7])
+%!assert(genqammod([0:7],[-7 -5 -1 -3 7 5 1 3]),[-7 -5 -1 -3 7 5 1 3])