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| -rw-r--r-- | gnuradio-core/src/python/gnuradio/blks2impl/qpsk.py | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/qpsk.py b/gnuradio-core/src/python/gnuradio/blks2impl/qpsk.py new file mode 100644 index 000000000..f62ae232c --- /dev/null +++ b/gnuradio-core/src/python/gnuradio/blks2impl/qpsk.py @@ -0,0 +1,79 @@ +# +# Copyright 2005,2006 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. +# + +""" +QPSK modulation. + +Demodulation is not included since the generic_mod_demod +doesn't work for non-differential encodings. +""" + +from gnuradio import gr, modulation_utils2 +from gnuradio.blks2impl.generic_mod_demod import generic_mod + + +# Default number of points in constellation. +_def_constellation_points = 4 +# Whether differential coding is used. +_def_differential = False +_def_gray_coded = True + +# ///////////////////////////////////////////////////////////////////////////// +# QPSK constellation +# ///////////////////////////////////////////////////////////////////////////// + +def qpsk_constellation(m=_def_constellation_points): + if m != _def_constellation_points: + raise ValueError("QPSK can only have 4 constellation points.") + return gr.constellation_qpsk() + +# ///////////////////////////////////////////////////////////////////////////// +# QPSK modulator +# ///////////////////////////////////////////////////////////////////////////// + +class qpsk_mod(generic_mod): + + def __init__(self, constellation_points=_def_constellation_points, + differential=_def_differential, + gray_coded=_def_gray_coded, + *args, **kwargs): + + """ + Hierarchical block for RRC-filtered QPSK modulation. + + The input is a byte stream (unsigned char) and the + output is the complex modulated signal at baseband. + + See generic_mod block for list of parameters. + """ + + constellation = gr.constellation_qpsk() + if constellation_points != 4: + raise ValueError("QPSK can only have 4 constellation points.") + if differential or not gray_coded: + raise ValueError("This QPSK mod/demod works only for gray-coded, non-differential.") + super(qpsk_mod, self).__init__(constellation, differential, gray_coded, *args, **kwargs) + +# +# Add these to the mod/demod registry +# +modulation_utils2.add_type_1_mod('qpsk', qpsk_mod) +modulation_utils2.add_type_1_constellation('qpsk', qpsk_constellation) |