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| author | Johnathan Corgan <jcorgan@corganenterprises.com> | 2009-10-12 18:46:56 -0700 |
|---|---|---|
| committer | Johnathan Corgan <jcorgan@corganenterprises.com> | 2009-10-12 18:46:56 -0700 |
| commit | 4df83569c130c1f4fe2aba3e1b5dd1419272f22f (patch) | |
| tree | f64ccf30880228ab639ff06c971603e214b6303f /gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py | |
| parent | 83ddffdaa968c5131228346b5f3f2ca123b759c7 (diff) | |
| parent | 3eeb2720664ec7cb67e60d4f8a01b933ddba0143 (diff) | |
Merge branch 'sync' of git@gnuradio.org:trondeau into master
This merge adds polyphase clock recovery, implements new PAM demodulators
that use it, and also moves GRC examples to gnuradio-examples component.
See merge commit diff for updated files post merge.
* 'sync' of git@gnuradio.org:trondeau: (54 commits)
Reverting dqpsk to be mpsk_receiver based and not change its behavior.
Fixing initialization of timing gains. Alpha should be < 1, and beta should be << 1.
This splits the rate into a fractional an integer value, which allows the loop to adjust the fractional rate while the integer rate keeps the increments moving properly. Allows the max rate deviation to be independent of the integer rate. Scaling of the differential taps also allows alpha and beta to operate independent of the rate when fractional samples per symbol are used. Slightly more tolerant to large signal values, but they still should be close to +/-1.
Fixing compiler warnings.
Adding dqpsk2 block to makefile for installation.
Adding DQPSK version that uses the PFB timing sync block (dqpsk2).
Minor fixes for logging.
Fixing import of UI file.
Temporary working dbpsk2 example until we match everything.
Working DBPSK implementation with new PFB clock recovery block. The feedforward AGC wasn't playing nicely, the frequency aquistion range was increased to swing half the sample rate in either direction, and the number of filter phases to use was increased to 32.
A bit of code cleanup.
Starting to rework QT app to control new PFB clock recovery alg.
Making old dbpsk work again to compare against new version.
Adding new DBPSK block with new PFB clock recovery alg.
Revert "More additions to PAM timing simulation."
More additions to PAM timing simulation.
Using 2-PAM by default.
Cleaning up GRC PAM timing example and adding ability to do M-ary PAM.
Cleaning up constructor.
Moving filter number decision to start work function.
...
Diffstat (limited to 'gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py')
| -rw-r--r-- | gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py b/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py new file mode 100644 index 0000000000..4541b453b3 --- /dev/null +++ b/gnuradio-core/src/python/gnuradio/blks2impl/dbpsk2.py @@ -0,0 +1,351 @@ +# +# 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 BPSK modulation and demodulation. +""" + +from gnuradio import gr, gru, modulation_utils +from math import pi, sqrt +import psk +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 = 0.1 +_def_timing_alpha = 0.100 +_def_timing_beta = 0.010 +_def_timing_max_dev = 1.5 + + +# ///////////////////////////////////////////////////////////////////////////// +# DBPSK modulator +# ///////////////////////////////////////////////////////////////////////////// + +class dbpsk2_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 differential BPSK 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 baud >= 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 log: Log modulation data to files? + @type log: bool + """ + + gr.hier_block2.__init__(self, "dbpsk_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(self._samples_per_symbol, int) or self._samples_per_symbol < 2: + raise TypeError, ("sbp must be an integer >= 2, is %d" % self._samples_per_symbol) + + ntaps = 11 * self._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(psk.binary_to_gray[arity]) + else: + self.symbol_mapper = gr.map_bb(psk.binary_to_ungray[arity]) + + self.diffenc = gr.diff_encoder_bb(arity) + + self.chunks2symbols = gr.chunks_to_symbols_bc(psk.constellation[arity]) + + # pulse shaping filter + self.rrc_taps = gr.firdes.root_raised_cosine( + self._samples_per_symbol, # gain (samples_per_symbol since we're + # interpolating by samples_per_symbol) + 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) + + # Connect + self.connect(self, self.bytes2chunks, self.symbol_mapper, self.diffenc, + self.chunks2symbols, self.rrc_filter, self) + + if verbose: + self._print_verbage() + + if log: + self._setup_logging() + + + def samples_per_symbol(self): + return self._samples_per_symbol + + def bits_per_symbol(self=None): # static method that's also callable on an instance + return 1 + bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. RTFM + + def add_options(parser): + """ + Adds DBPSK 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]") + parser.add_option("", "--no-gray-code", dest="gray_code", + action="store_false", default=True, + 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(dbpsk2_mod.__init__, + ('self',), options) + extract_kwargs_from_options=staticmethod(extract_kwargs_from_options) + + + def _print_verbage(self): + print "\nModulator:" + print "bits per symbol: %d" % self.bits_per_symbol() + print "Gray code: %s" % self._gray_code + print "RRC roll-off factor: %.2f" % self._excess_bw + + def _setup_logging(self): + print "Modulation logging turned on." + self.connect(self.bytes2chunks, + gr.file_sink(gr.sizeof_char, "tx_bytes2chunks.dat")) + self.connect(self.symbol_mapper, + gr.file_sink(gr.sizeof_char, "tx_graycoder.dat")) + self.connect(self.diffenc, + gr.file_sink(gr.sizeof_char, "tx_diffenc.dat")) + self.connect(self.chunks2symbols, + gr.file_sink(gr.sizeof_gr_complex, "tx_chunks2symbols.dat")) + self.connect(self.rrc_filter, + gr.file_sink(gr.sizeof_gr_complex, "tx_rrc_filter.dat")) + + +# ///////////////////////////////////////////////////////////////////////////// +# DBPSK demodulator +# +# Differentially coherent detection of differentially encoded BPSK +# ///////////////////////////////////////////////////////////////////////////// + +class dbpsk2_demod(gr.hier_block2): + + def __init__(self, + samples_per_symbol=_def_samples_per_symbol, + excess_bw=_def_excess_bw, + costas_alpha=_def_costas_alpha, + timing_alpha=_def_timing_alpha, + timing_max_dev=_def_timing_max_dev, + gray_code=_def_gray_code, + verbose=_def_verbose, + log=_def_log): + """ + Hierarchical block for RRC-filtered differential BPSK demodulation + + The input is the complex modulated signal at baseband. + The output is a stream of bits packed 1 bit per byte (LSB) + + @param samples_per_symbol: samples per symbol >= 2 + @type samples_per_symbol: float + @param excess_bw: Root-raised cosine filter excess bandwidth + @type excess_bw: float + @param costas_alpha: loop filter gain + @type costas_alpha: float + @param timing_alpha: timing loop alpha gain + @type timing_alpha: float + @param timing_max: timing loop maximum rate deviations + @type timing_max: 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, "dbpsk2_demod", + gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature + gr.io_signature(1, 1, gr.sizeof_char)) # Output signature + + self._samples_per_symbol = samples_per_symbol + self._excess_bw = excess_bw + self._costas_alpha = costas_alpha + self._timing_alpha = timing_alpha + self._timing_beta = _def_timing_beta + self._timing_max_dev=timing_max_dev + self._gray_code = gray_code + + if samples_per_symbol < 2: + raise TypeError, "samples_per_symbol must be >= 2, is %r" % (samples_per_symbol,) + + arity = pow(2,self.bits_per_symbol()) + + # Automatic gain control + self.agc = gr.agc2_cc(0.6e-1, 1e-3, 1, 1, 100) + #self.agc = gr.feedforward_agc_cc(16, 1.0) + + self._costas_beta = 0.25 * self._costas_alpha * self._costas_alpha + # Allow a frequency swing of +/- half of the sample rate + fmin = -0.5 + fmax = 0.5 + + self.clock_recov = gr.costas_loop_cc(self._costas_alpha, + self._costas_beta, + fmax, fmin, arity) + + # symbol timing recovery with RRC data filter + nfilts = 32 + ntaps = 11 * samples_per_symbol*nfilts + taps = gr.firdes.root_raised_cosine(nfilts, nfilts, 1.0/float(self._samples_per_symbol), self._excess_bw, ntaps) + self.time_recov = gr.pfb_clock_sync_ccf(self._samples_per_symbol, + self._timing_alpha, + taps, nfilts, nfilts/2, self._timing_max_dev) + self.time_recov.set_beta(self._timing_beta) + + # Do differential decoding based on phase change of symbols + self.diffdec = gr.diff_phasor_cc() + + # find closest constellation point + rot = 1 + rotated_const = map(lambda pt: pt * rot, psk.constellation[arity]) + self.slicer = gr.constellation_decoder_cb(rotated_const, range(arity)) + + if self._gray_code: + self.symbol_mapper = gr.map_bb(psk.gray_to_binary[arity]) + else: + self.symbol_mapper = gr.map_bb(psk.ungray_to_binary[arity]) + + # unpack the k bit vector into a stream of bits + self.unpack = gr.unpack_k_bits_bb(self.bits_per_symbol()) + + if verbose: + self._print_verbage() + + if log: + self._setup_logging() + + # Connect + self.connect(self, self.agc, + self.clock_recov, + self.time_recov, + self.diffdec, self.slicer, self.symbol_mapper, self.unpack, 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 1 + bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. RTFM + + def _print_verbage(self): + print "\nDemodulator:" + print "bits per symbol: %d" % self.bits_per_symbol() + print "Gray code: %s" % self._gray_code + print "RRC roll-off factor: %.2f" % self._excess_bw + print "Costas Loop alpha: %.2f" % self._costas_alpha + print "Costas Loop beta: %.2f" % self._costas_beta + print "Timing alpha gain: %.2f" % self._timing_alpha + print "Timing beta gain: %.2f" % self._timing_beta + print "Timing max dev: %.2f" % self._timing_max_dev + + def _setup_logging(self): + print "Modulation logging turned on." + self.connect(self.pre_scaler, + gr.file_sink(gr.sizeof_gr_complex, "rx_prescaler.dat")) + self.connect(self.agc, + gr.file_sink(gr.sizeof_gr_complex, "rx_agc.dat")) + self.connect(self.rrc_filter, + gr.file_sink(gr.sizeof_gr_complex, "rx_rrc_filter.dat")) + self.connect(self.clock_recov, + gr.file_sink(gr.sizeof_gr_complex, "rx_clock_recov.dat")) + self.connect(self.time_recov, + gr.file_sink(gr.sizeof_gr_complex, "rx_time_recov.dat")) + self.connect(self.diffdec, + gr.file_sink(gr.sizeof_gr_complex, "rx_diffdec.dat")) + self.connect(self.slicer, + gr.file_sink(gr.sizeof_char, "rx_slicer.dat")) + self.connect(self.symbol_mapper, + gr.file_sink(gr.sizeof_char, "rx_symbol_mapper.dat")) + self.connect(self.unpack, + gr.file_sink(gr.sizeof_char, "rx_unpack.dat")) + + def add_options(parser): + """ + Adds DBPSK demodulation-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)") + parser.add_option("", "--costas-alpha", type="float", default=None, + help="set Costas loop alpha value [default=%default] (PSK)") + parser.add_option("", "--gain-alpha", type="float", default=_def_timing_alpha, + help="set timing symbol sync loop gain alpha value [default=%default] (GMSK/PSK)") + parser.add_option("", "--gain-beta", type="float", default=_def_timing_beta, + help="set timing symbol sync loop gain beta value [default=%default] (GMSK/PSK)") + parser.add_option("", "--timing-max-dev", type="float", default=_def_timing_max_dev, + help="set timing symbol sync loop maximum deviation [default=%default] (GMSK/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( + dbpsk2_demod.__init__, ('self',), options) + extract_kwargs_from_options=staticmethod(extract_kwargs_from_options) +# +# Add these to the mod/demod registry +# +modulation_utils.add_type_1_mod('dbpsk2', dbpsk2_mod) +modulation_utils.add_type_1_demod('dbpsk2', dbpsk2_demod) |