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Diffstat (limited to 'gnuradio-core/src/python/gnuradio/blks2impl/qam64.py')
| -rw-r--r-- | gnuradio-core/src/python/gnuradio/blks2impl/qam64.py | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/qam64.py b/gnuradio-core/src/python/gnuradio/blks2impl/qam64.py new file mode 100644 index 0000000000..5509f37458 --- /dev/null +++ b/gnuradio-core/src/python/gnuradio/blks2impl/qam64.py @@ -0,0 +1,208 @@ +# +# Copyright 2005,2006,2007 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. +# + +# See gnuradio-examples/python/digital for examples + +""" +differential QPSK modulation and demodulation. +""" + +from gnuradio import gr, gru, modulation_utils +from math import pi, sqrt +import qam +import cmath +from pprint import pprint + +# default values (used in __init__ and add_options) +_def_samples_per_symbol = 2 +_def_excess_bw = 0.35 +_def_gray_code = True +_def_verbose = False +_def_log = False + +_def_costas_alpha = None +_def_gain_mu = 0.03 +_def_mu = 0.05 +_def_omega_relative_limit = 0.005 + + +# ///////////////////////////////////////////////////////////////////////////// +# QAM64 modulator +# ///////////////////////////////////////////////////////////////////////////// + +class qam64_mod(gr.hier_block2): + + def __init__(self, + samples_per_symbol=_def_samples_per_symbol, + excess_bw=_def_excess_bw, + gray_code=_def_gray_code, + verbose=_def_verbose, + log=_def_log): + + """ + 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. + + @param samples_per_symbol: samples per symbol >= 2 + @type samples_per_symbol: integer + @param excess_bw: Root-raised cosine filter excess bandwidth + @type excess_bw: float + @param gray_code: Tell modulator to Gray code the bits + @type gray_code: bool + @param verbose: Print information about modulator? + @type verbose: bool + @param debug: Print modualtion data to files? + @type debug: bool + """ + + gr.hier_block2.__init__(self, "qam64_mod", + gr.io_signature(1, 1, gr.sizeof_char), # Input signature + gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature + self._samples_per_symbol = samples_per_symbol + self._excess_bw = excess_bw + self._gray_code = gray_code + + if not isinstance(samples_per_symbol, int) or samples_per_symbol < 2: + raise TypeError, ("sbp must be an integer >= 2, is %d" % samples_per_symbol) + + ntaps = 11 * samples_per_symbol + + arity = pow(2, self.bits_per_symbol()) + + # turn bytes into k-bit vectors + self.bytes2chunks = \ + gr.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST) + + if self._gray_code: + self.symbol_mapper = gr.map_bb(qam.binary_to_gray[arity]) + else: + self.symbol_mapper = gr.map_bb(qam.binary_to_ungray[arity]) + + self.diffenc = gr.diff_encoder_bb(arity) + + rot = 1.0 + print "constellation with %d arity" % arity + rotated_const = map(lambda pt: pt * rot, qam.constellation[arity]) + self.chunks2symbols = gr.chunks_to_symbols_bc(rotated_const) + + # pulse shaping filter + self.rrc_taps = gr.firdes.root_raised_cosine( + self._samples_per_symbol, # gain (sps since we're interpolating by sps) + self._samples_per_symbol, # sampling rate + 1.0, # symbol rate + self._excess_bw, # excess bandwidth (roll-off factor) + ntaps) + + self.rrc_filter = gr.interp_fir_filter_ccf(self._samples_per_symbol, self.rrc_taps) + + if verbose: + self._print_verbage() + + if log: + self._setup_logging() + + # Connect + self.connect(self, self.bytes2chunks, self.symbol_mapper, self.diffenc, + self.chunks2symbols, self.rrc_filter, self) + + def samples_per_symbol(self): + return self._samples_per_symbol + + def bits_per_symbol(self=None): # staticmethod that's also callable on an instance + return 6 + bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. RTFM + + def _print_verbage(self): + print "bits per symbol = %d" % self.bits_per_symbol() + print "Gray code = %s" % self._gray_code + print "RRS roll-off factor = %f" % self._excess_bw + + def _setup_logging(self): + print "Modulation logging turned on." + self.connect(self.bytes2chunks, + gr.file_sink(gr.sizeof_char, "bytes2chunks.dat")) + self.connect(self.symbol_mapper, + gr.file_sink(gr.sizeof_char, "graycoder.dat")) + self.connect(self.diffenc, + gr.file_sink(gr.sizeof_char, "diffenc.dat")) + self.connect(self.chunks2symbols, + gr.file_sink(gr.sizeof_gr_complex, "chunks2symbols.dat")) + self.connect(self.rrc_filter, + gr.file_sink(gr.sizeof_gr_complex, "rrc_filter.dat")) + + def add_options(parser): + """ + Adds QAM modulation-specific options to the standard parser + """ + parser.add_option("", "--excess-bw", type="float", default=_def_excess_bw, + help="set RRC excess bandwith factor [default=%default] (PSK)") + parser.add_option("", "--no-gray-code", dest="gray_code", + action="store_false", default=_def_gray_code, + help="disable gray coding on modulated bits (PSK)") + add_options=staticmethod(add_options) + + + def extract_kwargs_from_options(options): + """ + Given command line options, create dictionary suitable for passing to __init__ + """ + return modulation_utils.extract_kwargs_from_options(qam64_mod.__init__, + ('self',), options) + extract_kwargs_from_options=staticmethod(extract_kwargs_from_options) + + +# ///////////////////////////////////////////////////////////////////////////// +# QAM16 demodulator +# +# ///////////////////////////////////////////////////////////////////////////// + +class qam64_demod(gr.hier_block2): + + def __init__(self, + samples_per_symbol=_def_samples_per_symbol, + excess_bw=_def_excess_bw, + costas_alpha=_def_costas_alpha, + gain_mu=_def_gain_mu, + mu=_def_mu, + omega_relative_limit=_def_omega_relative_limit, + gray_code=_def_gray_code, + verbose=_def_verbose, + log=_def_log): + + gr.hier_block2.__init__(self, "qam64_demod", + gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature + gr.io_signature(1, 1, gr.sizeof_char)) # Output signature + + # do this + pass + + def bits_per_symbol(self=None): # staticmethod that's also callable on an instance + return 6 + bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. RTFM + +# +# Add these to the mod/demod registry +# +# NOT READY TO BE USED YET -- ENABLE AT YOUR OWN RISK +#modulation_utils.add_type_1_mod('qam64', qam64_mod) +#modulation_utils.add_type_1_demod('qam16', qam16_demod) |