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Diffstat (limited to 'gnuradio-examples/python/gmsk2/dqpsk.py')
| -rw-r--r-- | gnuradio-examples/python/gmsk2/dqpsk.py | 280 |
1 files changed, 0 insertions, 280 deletions
diff --git a/gnuradio-examples/python/gmsk2/dqpsk.py b/gnuradio-examples/python/gmsk2/dqpsk.py deleted file mode 100644 index a18f28b75..000000000 --- a/gnuradio-examples/python/gmsk2/dqpsk.py +++ /dev/null @@ -1,280 +0,0 @@ -# -# 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 2, 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/gmsk2 for examples - -""" -differential QPSK modulation and demodulation. -""" - -from gnuradio import gr, gru -from math import pi, sqrt -import cmath -import Numeric -from pprint import pprint - -_use_gray_code = True - -def make_constellation(m): - return [cmath.exp(i * 2 * pi / m * 1j) for i in range(m)] - -# Common definition of constellations for Tx and Rx -constellation = { - 2 : make_constellation(2), # BPSK - 4 : make_constellation(4), # QPSK - 8 : make_constellation(8) # 8PSK - } - -if 0: - print "const(2) =" - pprint(constellation[2]) - print "const(4) =" - pprint(constellation[4]) - print "const(8) =" - pprint(constellation[8]) - - -if _use_gray_code: - # ----------------------- - # Do Gray code - # ----------------------- - # binary to gray coding - binary_to_gray = { - 2 : (0, 1), - 4 : (0, 1, 3, 2), - 8 : (0, 1, 3, 2, 7, 6, 4, 5) - } - - # gray to binary - gray_to_binary = { - 2 : (0, 1), - 4 : (0, 1, 3, 2), - 8 : (0, 1, 3, 2, 6, 7, 5, 4) - } -else: - # ----------------------- - # Don't Gray code - # ----------------------- - # identity mapping - binary_to_gray = { - 2 : (0, 1), - 4 : (0, 1, 2, 3), - 8 : (0, 1, 2, 3, 4, 5, 6, 7) - } - - # identity mapping - gray_to_binary = { - 2 : (0, 1), - 4 : (0, 1, 2, 3), - 8 : (0, 1, 2, 3, 4, 5, 6, 7) - } - - -# ///////////////////////////////////////////////////////////////////////////// -# QPSK mod/demod with steams of bytes as data i/o -# ///////////////////////////////////////////////////////////////////////////// - - -class dqpsk_mod(gr.hier_block): - - def __init__(self, fg, spb, excess_bw): - """ - 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 fg: flow graph - @type fg: flow graph - @param spb: samples per baud >= 2 - @type spb: integer - @param excess_bw: Root-raised cosine filter excess bandwidth - @type excess_bw: float - """ - if not isinstance(spb, int) or spb < 2: - raise TypeError, "sbp must be an integer >= 2" - self.spb = spb - - ntaps = 11 * spb - - bits_per_symbol = self.bits_per_baud() - arity = pow(2,bits_per_symbol) - print "bits_per_symbol =", bits_per_symbol - - # turn bytes into k-bit vectors - self.bytes2chunks = \ - gr.packed_to_unpacked_bb(bits_per_symbol, gr.GR_MSB_FIRST) - - if True: - self.gray_coder = gr.map_bb(binary_to_gray[arity]) - else: - self.gray_coder = None - - self.diffenc = gr.diff_encoder_bb(arity) - - self.chunks2symbols = gr.chunks_to_symbols_bc(constellation[arity]) - - # pulse shaping filter - self.rrc_taps = gr.firdes.root_raised_cosine( - spb, # gain (spb since we're interpolating by spb) - spb, # sampling rate - 1.0, # symbol rate - excess_bw, # excess bandwidth (roll-off factor) - ntaps) - - self.rrc_filter = gr.interp_fir_filter_ccf(spb, self.rrc_taps) - - # Connect - if self.gray_coder: - fg.connect(self.bytes2chunks, self.gray_coder) - t = self.gray_coder - else: - t = self.bytes2chunks - - fg.connect(t, self.diffenc, self.chunks2symbols, self.rrc_filter) - - if 1: - fg.connect(self.gray_coder, - gr.file_sink(gr.sizeof_char, "graycoder.dat")) - fg.connect(self.diffenc, - gr.file_sink(gr.sizeof_char, "diffenc.dat")) - - # Initialize base class - gr.hier_block.__init__(self, fg, self.bytes2chunks, self.rrc_filter) - - def samples_per_baud(self): - return self.spb - - def bits_per_baud(self=None): # staticmethod that's also callable on an instance - return 2 - bits_per_baud = staticmethod(bits_per_baud) # make it a static method. RTFM - - - -class dqpsk_demod__coherent_detection_of_differentially_encoded_psk(gr.hier_block): - def __init__(self, fg, spb, excess_bw, costas_alpha=0.005, gain_mu=0.05): - """ - Hierarchical block for RRC-filtered QPSK demodulation - - The input is the complex modulated signal at baseband. - The output is a stream of bits packed 1 bit per byte (LSB) - - @param fg: flow graph - @type fg: flow graph - @param spb: samples per baud >= 2 - @type spb: 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: - @type gain_mu: float - """ - if spb < 2: - raise TypeError, "sbp must be >= 2" - self.spb = spb - - bits_per_symbol = self.bits_per_baud() - arity = pow(2,bits_per_symbol) - print "bits_per_symbol =", bits_per_symbol - - # Automatic gain control - self.preamp = gr.multiply_const_cc(10e-5) - self.agc = gr.agc_cc(1e-3, 1, 1) - - # Costas loop (carrier tracking) - # FIXME: need to decide how to handle this more generally; do we pull it from higher layer? - costas_order = 4 - beta = .25 * costas_alpha * costas_alpha - self.costas_loop = gr.costas_loop_cc(costas_alpha, beta, 0.05, -0.05, costas_order) - - # RRC data filter - ntaps = 11 * spb - self.rrc_taps = gr.firdes.root_raised_cosine( - 1.0, # gain - spb, # sampling rate - 1.0, # symbol rate - excess_bw, # excess bandwidth (roll-off factor) - ntaps) - - self.rrc_filter=gr.fir_filter_ccf(1, self.rrc_taps) - - # symbol clock recovery - omega = spb - gain_omega = .25 * gain_mu * gain_mu - omega_rel_limit = 0.5 - mu = 0.05 - gain_mu = 0.1 - self.clock_recovery=gr.clock_recovery_mm_cc(omega, gain_omega, - mu, gain_mu, omega_rel_limit) - - # find closest constellation point - #rot = .707 + .707j - rot = 1 - rotated_const = map(lambda pt: pt * rot, constellation[arity]) - print "rotated_const =", rotated_const - - self.diffdec = gr.diff_phasor_cc() - #self.diffdec = gr.diff_decoder_bb(arity) - - self.slicer = gr.constellation_decoder_cb(rotated_const, range(arity)) - self.gray_decoder = gr.map_bb(gray_to_binary[arity]) - - # unpack the k bit vector into a stream of bits - self.unpack = gr.unpack_k_bits_bb(bits_per_symbol) - - fg.connect(self.preamp, self.agc, self.costas_loop, self.rrc_filter, self.clock_recovery, - self.diffdec, self.slicer, self.gray_decoder, self.unpack) - #fg.connect(self.preamp, self.agc, self.costas_loop, self.rrc_filter, self.clock_recovery, - # self.slicer, self.diffdec, self.gray_decoder, self.unpack) - - # Debug sinks - if 1: - fg.connect(self.agc, - gr.file_sink(gr.sizeof_gr_complex, "agc.dat")) - fg.connect(self.costas_loop, - gr.file_sink(gr.sizeof_gr_complex, "costas_loop.dat")) - fg.connect(self.rrc_filter, - gr.file_sink(gr.sizeof_gr_complex, "rrc.dat")) - fg.connect(self.clock_recovery, - gr.file_sink(gr.sizeof_gr_complex, "clock_recovery.dat")) - fg.connect(self.slicer, - gr.file_sink(gr.sizeof_char, "slicer.dat")) - fg.connect(self.diffdec, - gr.file_sink(gr.sizeof_gr_complex, "diffdec.dat")) - #fg.connect(self.diffdec, - # gr.file_sink(gr.sizeof_char, "diffdec.dat")) - fg.connect(self.unpack, - gr.file_sink(gr.sizeof_char, "unpack.dat")) - - # Initialize base class - gr.hier_block.__init__(self, fg, self.preamp, self.unpack) - - def samples_per_baud(self): - return self.spb - - def bits_per_baud(self=None): # staticmethod that's also callable on an instance - return 2 - bits_per_baud = staticmethod(bits_per_baud) # make it a static method. RTFM - - -dqpsk_demod = dqpsk_demod__coherent_detection_of_differentially_encoded_psk - |