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Diffstat (limited to 'gr-digital/python/digital/constellation_map_generator.py')
| -rw-r--r-- | gr-digital/python/digital/constellation_map_generator.py | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/gr-digital/python/digital/constellation_map_generator.py b/gr-digital/python/digital/constellation_map_generator.py new file mode 100644 index 0000000000..bf689676c3 --- /dev/null +++ b/gr-digital/python/digital/constellation_map_generator.py @@ -0,0 +1,52 @@ +#!/usr/bin/env python +# +# Copyright 2013 Free Software Foundation, Inc. +# +# This file is part of GNU Radio +# +# GNU Radio 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, or (at your option) +# any later version. +# +# GNU Radio 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 GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +def constellation_map_generator(basis_cpoints, basis_symbols, k, pi): + ''' + Uses the a basis constellation provided (e.g., from + psk_constellation.psk_4()) and the the k and permutation index + (pi) to generate a new Gray-coded symbol map to the constellation + points provided in the basis. + + The basis_cpoints are the constellation points of the basis + constellation, and basis_symbols are the symbols that correspond + to the constellation points. + + The selection of k and pi will provide an automorphism the + hyperoctahedral group of the basis constellation. + + This function returns a tuple of (constellation_points, + symbol_map). The constellation_points is a list of the + constellation points in complex space and the symbol_map is a list + of the log2(M)-bit symbols for the constellation points (i.e., + symbol_map[i] are the bits associated with + constellation_points[i]). + ''' + const_points, s = basis() + symbols = list() + for s_i in s: + tmp = 0 + for i,p in enumerate(pi): + bit = (s_i >> i) & 0x1 + tmp |= bit << p + symbols.append(tmp ^ k) + return (const_points, symbols) |