diff options
| -rw-r--r-- | src/demod/cqpsk.py | 345 | ||||
| -rwxr-xr-x | src/demod/osmosdr-tetra_demod_fft.py | 255 |
2 files changed, 600 insertions, 0 deletions
diff --git a/src/demod/cqpsk.py b/src/demod/cqpsk.py new file mode 100644 index 0000000..6be6ee7 --- /dev/null +++ b/src/demod/cqpsk.py @@ -0,0 +1,345 @@ +# +# Copyright 2005,2006,2007 Free Software Foundation, Inc. +# +# cqpsk.py (C) Copyright 2009, KA1RBI +# +# 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 PI/4 CQPSK modulation and demodulation. +""" + +from gnuradio import gr, gru, analog, blocks, digital, filter +from math import pi, sqrt +import cmath +from pprint import pprint + +# default values (used in __init__ and add_options) +_def_samples_per_symbol = 10 +_def_excess_bw = 0.35 +_def_gray_code = True +_def_verbose = False +_def_log = False + +_def_costas_alpha = 0.15 +_def_gain_mu = None +_def_mu = 0.5 +_def_omega_relative_limit = 0.005 + + +# ///////////////////////////////////////////////////////////////////////////// +# CQPSK modulator +# ///////////////////////////////////////////////////////////////////////////// + +class cqpsk_mod(gr.hier_block2): + + def __init__(self, + samples_per_symbol=_def_samples_per_symbol, + excess_bw=_def_excess_bw, + 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 verbose: Print information about modulator? + @type verbose: bool + @param debug: Print modualtion data to files? + @type debug: bool + """ + + gr.hier_block2.__init__(self, "cqpsk_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 + + 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 = 8 + + # turn bytes into k-bit vectors + self.bytes2chunks = \ + gr.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST) + + # 0 +45 1 [+1] + # 1 +135 3 [+3] + # 2 -45 7 [-1] + # 3 -135 5 [-3] + self.pi4map = [1, 3, 7, 5] + self.symbol_mapper = gr.map_bb(self.pi4map) + self.diffenc = gr.diff_encoder_bb(arity) + self.chunks2symbols = gr.chunks_to_symbols_bc(psk.constellation[arity]) + + # pulse shaping filter + self.rrc_taps = filter.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 = filter.interp_fir_filter_ccf(self._samples_per_symbol, self.rrc_taps) + + if verbose: + self._print_verbage() + + if log: + self._setup_logging() + + # Connect & Initialize base class + 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 + + @staticmethod + def bits_per_symbol(): + return 2 + + def _print_verbage(self): + print "\nModulator:" + 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, "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")) + + @staticmethod + def add_options(parser): + """ + Adds QPSK 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)") + + @staticmethod + def extract_kwargs_from_options(options): + """ + Given command line options, create dictionary suitable for passing to __init__ + """ + return modulation_utils.extract_kwargs_from_options(dqpsk_mod.__init__, + ('self',), options) + + +# ///////////////////////////////////////////////////////////////////////////// +# CQPSK demodulator +# +# ///////////////////////////////////////////////////////////////////////////// + +class cqpsk_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): + """ + Hierarchical block for RRC-filtered CQPSK demodulation + + The input is the complex modulated signal at baseband. + The output is a stream of floats in [ -3 / -1 / +1 / +3 ] + + @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_alphas: float + @param gain_mu: for M&M block + @type gain_mu: float + @param mu: for M&M block + @type mu: float + @param omega_relative_limit: for M&M block + @type omega_relative_limit: 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, "cqpsk_demod", + gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature + gr.io_signature(1, 1, gr.sizeof_float)) # Output signature + + self._samples_per_symbol = samples_per_symbol + self._excess_bw = excess_bw + self._costas_alpha = costas_alpha + self._mm_gain_mu = gain_mu + self._mm_mu = mu + self._mm_omega_relative_limit = omega_relative_limit + self._gray_code = gray_code + + if samples_per_symbol < 2: + raise TypeError, "sbp must be >= 2, is %d" % samples_per_symbol + + arity = pow(2,self.bits_per_symbol()) + + # Automatic gain control + scale = (1.0/16384.0) + self.pre_scaler = blocks.multiply_const_cc(scale) # scale the signal from full-range to +-1 + #self.agc = analog.agc2_cc(0.6e-1, 1e-3, 1, 1, 100) + self.agc = analog.feedforward_agc_cc(16, 2.0) + + # RRC data filter + ntaps = 11 * samples_per_symbol + self.rrc_taps = filter.firdes.root_raised_cosine( + 1.0, # gain + self._samples_per_symbol, # sampling rate + 1.0, # symbol rate + self._excess_bw, # excess bandwidth (roll-off factor) + ntaps) + self.rrc_filter=filter.interp_fir_filter_ccf(1, self.rrc_taps) + + if not self._mm_gain_mu: + sbs_to_mm = {2: 0.050, 3: 0.075, 4: 0.11, 5: 0.125, 6: 0.15, 7: 0.15} + self._mm_gain_mu = sbs_to_mm[samples_per_symbol] + + self._mm_omega = self._samples_per_symbol + self._mm_gain_omega = .25 * self._mm_gain_mu * self._mm_gain_mu + self._costas_beta = 0.25 * self._costas_alpha * self._costas_alpha + fmin = -0.025 + fmax = 0.025 + + self.receiver=digital.mpsk_receiver_cc( + arity, pi/4.0, + 2*pi/150, + fmin, fmax, + self._mm_mu, self._mm_gain_mu, + self._mm_omega, self._mm_gain_omega, + self._mm_omega_relative_limit + ) + + self.receiver.set_alpha(self._costas_alpha) + self.receiver.set_beta(self._costas_beta) + + # Perform Differential decoding on the constellation + self.diffdec = digital.diff_phasor_cc() + + # take angle of the difference (in radians) + self.to_float = blocks.complex_to_arg() + + # convert from radians such that signal is in -3/-1/+1/+3 + self.rescale = blocks.multiply_const_ff( 1 / (pi / 4) ) + + if verbose: + self._print_verbage() + + if log: + self._setup_logging() + + # Connect & Initialize base class + self.connect(self, self.pre_scaler, self.agc, self.rrc_filter, self.receiver, + self.diffdec, self.to_float, self.rescale, self) + + def samples_per_symbol(self): + return self._samples_per_symbol + + @staticmethod + def bits_per_symbol(): + return 2 + + 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: %.2e" % self._costas_alpha + print "Costas Loop beta: %.2e" % self._costas_beta + print "M&M mu: %.2f" % self._mm_mu + print "M&M mu gain: %.2e" % self._mm_gain_mu + print "M&M omega: %.2f" % self._mm_omega + print "M&M omega gain: %.2e" % self._mm_gain_omega + print "M&M omega limit: %.2f" % self._mm_omega_relative_limit + + 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.receiver, + gr.file_sink(gr.sizeof_gr_complex, "rx_receiver.dat")) + self.connect(self.diffdec, + gr.file_sink(gr.sizeof_gr_complex, "rx_diffdec.dat")) + self.connect(self.to_float, + gr.file_sink(gr.sizeof_float, "rx_to_float.dat")) + self.connect(self.rescale, + gr.file_sink(gr.sizeof_float, "rx_rescale.dat")) + + @staticmethod + def add_options(parser): + """ + Adds 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)") + parser.add_option("", "--costas-alpha", type="float", default=_def_costas_alpha, + help="set Costas loop alpha value [default=%default] (PSK)") + parser.add_option("", "--gain-mu", type="float", default=_def_gain_mu, + help="set M&M symbol sync loop gain mu value [default=%default] (PSK)") + parser.add_option("", "--mu", type="float", default=_def_mu, + help="set M&M symbol sync loop mu value [default=%default] (PSK)") + + @staticmethod + def extract_kwargs_from_options(options): + """ + Given command line options, create dictionary suitable for passing to __init__ + """ + return modulation_utils.extract_kwargs_from_options( + cqpsk_demod.__init__, ('self',), options) diff --git a/src/demod/osmosdr-tetra_demod_fft.py b/src/demod/osmosdr-tetra_demod_fft.py new file mode 100755 index 0000000..81fbe9d --- /dev/null +++ b/src/demod/osmosdr-tetra_demod_fft.py @@ -0,0 +1,255 @@ +#!/usr/bin/env python + +# Copyright 2012 Dimitri Stolnikov <horiz0n@gmx.net> + +# Usage: +# src$ ./demod/python/osmosdr-tetra_demod_fft.py -o /dev/stdout | ./float_to_bits /dev/stdin /dev/stdout | ./tetra-rx /dev/stdin +# +# Adjust the center frequency (-f) and gain (-g) according to your needs. +# Use left click in Wideband Spectrum window to roughly select a TETRA carrier. +# In Wideband Spectrum you can also tune by 1/4 of the bandwidth by clicking on the rightmost/leftmost spectrum side. +# Use left click in Channel Spectrum windows to fine tune the carrier by clicking on the left or right side of the spectrum. + + +import sys +import math +from gnuradio import gr, gru, eng_notation, blocks, filter +from gnuradio.filter import pfb +from gnuradio.eng_option import eng_option +from gnuradio.wxgui import fftsink2, scopesink2, forms, TRIG_MODE_AUTO +from grc_gnuradio import wxgui as grc_wxgui +from optparse import OptionParser +import osmosdr +import wx + +try: + import cqpsk +except: + from tetra_demod import cqpsk + +# applies frequency translation, resampling and demodulation + +class top_block(grc_wxgui.top_block_gui): + def __init__(self): + grc_wxgui.top_block_gui.__init__(self, title="Top Block") + + options = get_options() + + self.ifreq = options.frequency + self.rfgain = options.gain + + self.src = osmosdr.source(options.args) + self.src.set_center_freq(self.ifreq) + self.src.set_sample_rate(int(options.sample_rate)) + + if self.rfgain is None: + self.src.set_gain_mode(1) + self.iagc = 1 + self.rfgain = 0 + else: + self.iagc = 0 + self.src.set_gain_mode(0) + self.src.set_gain(self.rfgain) + + # may differ from the requested rate + sample_rate = self.src.get_sample_rate() + sys.stderr.write("sample rate: %d\n" % (sample_rate)) + + symbol_rate = 18000 + sps = 2 # output rate will be 36,000 + out_sample_rate = symbol_rate * sps + + options.low_pass = options.low_pass / 2.0 + + if sample_rate == 96000: # FunCube Dongle + first_decim = 2 + else: + first_decim = 10 + + self.offset = 0 + + taps = filter.firdes.low_pass(1.0, sample_rate, options.low_pass, options.low_pass * 0.2, filter.firdes.WIN_HANN) + self.tuner = filter.freq_xlating_fir_filter_ccf(first_decim, taps, self.offset, sample_rate) + + self.demod = cqpsk.cqpsk_demod( + samples_per_symbol = sps, + excess_bw=0.35, + costas_alpha=0.03, + gain_mu=0.05, + mu=0.05, + omega_relative_limit=0.05, + log=options.log, + verbose=options.verbose) + + self.output = blocks.file_sink(gr.sizeof_float, options.output_file) + + rerate = float(sample_rate / float(first_decim)) / float(out_sample_rate) + sys.stderr.write("resampling factor: %f\n" % rerate) + + if rerate.is_integer(): + sys.stderr.write("using pfb decimator\n") + self.resamp = pfb.decimator_ccf(int(rerate)) + else: + sys.stderr.write("using pfb resampler\n") + self.resamp = pfb.arb_resampler_ccf(1 / rerate) + + self.connect(self.src, self.tuner, self.resamp, self.demod, self.output) + + self.Main = wx.Notebook(self.GetWin(), style=wx.NB_TOP) + self.Main.AddPage(grc_wxgui.Panel(self.Main), "Wideband Spectrum") + self.Main.AddPage(grc_wxgui.Panel(self.Main), "Channel Spectrum") + self.Main.AddPage(grc_wxgui.Panel(self.Main), "Soft Bits") + + def set_ifreq(ifreq): + self.ifreq = ifreq + self._ifreq_text_box.set_value(self.ifreq) + self.src.set_center_freq(self.ifreq) + + self._ifreq_text_box = forms.text_box( + parent=self.GetWin(), + value=self.ifreq, + callback=set_ifreq, + label="Center Frequency", + converter=forms.float_converter(), + ) + self.Add(self._ifreq_text_box) + + def set_iagc(iagc): + self.iagc = iagc + self._agc_check_box.set_value(self.iagc) + self.src.set_gain_mode(self.iagc, 0) + self.src.set_gain(0 if self.iagc == 1 else self.rfgain, 0) + + self._agc_check_box = forms.check_box( + parent=self.GetWin(), + value=self.iagc, + callback=set_iagc, + label="Automatic Gain", + true=1, + false=0, + ) + + self.Add(self._agc_check_box) + + def set_rfgain(rfgain): + self.rfgain = rfgain + self._rfgain_slider.set_value(self.rfgain) + self._rfgain_text_box.set_value(self.rfgain) + self.src.set_gain(0 if self.iagc == 1 else self.rfgain, 0) + + _rfgain_sizer = wx.BoxSizer(wx.VERTICAL) + self._rfgain_text_box = forms.text_box( + parent=self.GetWin(), + sizer=_rfgain_sizer, + value=self.rfgain, + callback=set_rfgain, + label="RF Gain", + converter=forms.float_converter(), + proportion=0, + ) + self._rfgain_slider = forms.slider( + parent=self.GetWin(), + sizer=_rfgain_sizer, + value=self.rfgain, + callback=set_rfgain, + minimum=0, + maximum=50, + num_steps=200, + style=wx.SL_HORIZONTAL, + cast=float, + proportion=1, + ) + + self.Add(_rfgain_sizer) + + self.Add(self.Main) + + def fftsink2_callback(x, y): + if abs(x / (sample_rate / 2)) > 0.9: + set_ifreq(self.ifreq + x / 2) + else: + sys.stderr.write("coarse tuned to: %d Hz\n" % x) + self.offset = x + self.tuner.set_center_freq(self.offset) + + self.scope = fftsink2.fft_sink_c(self.Main.GetPage(0).GetWin(), + title="Wideband Spectrum (click to coarse tune)", + fft_size=1024, + sample_rate=sample_rate, + ref_scale=2.0, + ref_level=0, + y_divs=10, + fft_rate=10, + average=False, + avg_alpha=0.6) + + self.Main.GetPage(0).Add(self.scope.win) + self.scope.set_callback(fftsink2_callback) + + self.connect(self.src, self.scope) + + def fftsink2_callback2(x, y): + self.offset = self.offset - (x / 10) + sys.stderr.write("fine tuned to: %d Hz\n" % self.offset) + self.tuner.set_center_freq(self.offset) + + self.scope2 = fftsink2.fft_sink_c(self.Main.GetPage(1).GetWin(), + title="Channel Spectrum (click to fine tune)", + fft_size=1024, + sample_rate=out_sample_rate, + ref_scale=2.0, + ref_level=-20, + y_divs=10, + fft_rate=10, + average=False, + avg_alpha=0.6) + + self.Main.GetPage(1).Add(self.scope2.win) + self.scope2.set_callback(fftsink2_callback2) + + self.connect(self.resamp, self.scope2) + + self.scope3 = scopesink2.scope_sink_f( + self.Main.GetPage(2).GetWin(), + title="Soft Bits", + sample_rate=out_sample_rate, + v_scale=0, + v_offset=0, + t_scale=0.001, + ac_couple=False, + xy_mode=False, + num_inputs=1, + trig_mode=TRIG_MODE_AUTO, + y_axis_label="Counts", + ) + self.Main.GetPage(2).Add(self.scope3.win) + + self.connect(self.demod, self.scope3) + +def get_options(): + parser = OptionParser(option_class=eng_option) + + parser.add_option("-a", "--args", type="string", default="", + help="gr-osmosdr device arguments") + parser.add_option("-s", "--sample-rate", type="eng_float", default=1800000, + help="set receiver sample rate (default 1800000)") + parser.add_option("-f", "--frequency", type="eng_float", default=394.4e6, + help="set receiver center frequency") + parser.add_option("-g", "--gain", type="eng_float", default=None, + help="set receiver gain") + + # demodulator related settings + parser.add_option("-l", "--log", action="store_true", default=False, help="dump debug .dat files") + parser.add_option("-L", "--low-pass", type="eng_float", default=25e3, help="low pass cut-off", metavar="Hz") + parser.add_option("-o", "--output-file", type="string", default="out.float", help="specify the bit output file") + parser.add_option("-v", "--verbose", action="store_true", default=False, help="dump demodulation data") + (options, args) = parser.parse_args() + if len(args) != 0: + parser.print_help() + raise SystemExit, 1 + + return (options) + +if __name__ == '__main__': + tb = top_block() + tb.Run(True) |