diff options
| author | trondeau <trondeau@221aa14e-8319-0410-a670-987f0aec2ac5> | 2007-03-07 04:31:19 +0000 |
|---|---|---|
| committer | trondeau <trondeau@221aa14e-8319-0410-a670-987f0aec2ac5> | 2007-03-07 04:31:19 +0000 |
| commit | 28e086141aead2e43f958f0ae14d58cac557fa2d (patch) | |
| tree | 1ae54b3d508506d4ea25c7e8a335c5e2cd56dcef /gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py | |
| parent | 224434889bf564a4456011180c62a58e0ca55c8f (diff) | |
merged trondeau/digital-wip2 r4193:4730 into trunk - improves digital receiver and fixes ticket:72
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@4731 221aa14e-8319-0410-a670-987f0aec2ac5
Diffstat (limited to 'gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py')
| -rw-r--r-- | gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py | 128 |
1 files changed, 59 insertions, 69 deletions
diff --git a/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py b/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py index 4332767bdf..b6701ef9f6 100644 --- a/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py +++ b/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py @@ -39,9 +39,9 @@ _def_gray_code = True _def_verbose = False _def_log = False -_def_costas_alpha = None -_def_gain_mu = 0.03 -_def_mu = 0.05 +_def_costas_alpha = 0.15 +_def_gain_mu = None +_def_mu = 0.5 _def_omega_relative_limit = 0.005 @@ -133,22 +133,23 @@ class dqpsk_mod(gr.hier_block): 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 + 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._fg.connect(self.bytes2chunks, - gr.file_sink(gr.sizeof_char, "bytes2chunks.dat")) + gr.file_sink(gr.sizeof_char, "tx_bytes2chunks.dat")) self._fg.connect(self.symbol_mapper, - gr.file_sink(gr.sizeof_char, "graycoder.dat")) + gr.file_sink(gr.sizeof_char, "tx_graycoder.dat")) self._fg.connect(self.diffenc, - gr.file_sink(gr.sizeof_char, "diffenc.dat")) + gr.file_sink(gr.sizeof_char, "tx_diffenc.dat")) self._fg.connect(self.chunks2symbols, - gr.file_sink(gr.sizeof_gr_complex, "chunks2symbols.dat")) + gr.file_sink(gr.sizeof_gr_complex, "tx_chunks2symbols.dat")) self._fg.connect(self.rrc_filter, - gr.file_sink(gr.sizeof_gr_complex, "rrc_filter.dat")) + gr.file_sink(gr.sizeof_gr_complex, "tx_rrc_filter.dat")) def add_options(parser): """ @@ -221,9 +222,9 @@ class dqpsk_demod(gr.hier_block): self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._costas_alpha = costas_alpha - self._gain_mu = gain_mu - self._mu = mu - self._omega_relative_limit = omega_relative_limit + 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: @@ -235,53 +236,47 @@ class dqpsk_demod(gr.hier_block): scale = (1.0/16384.0) self.pre_scaler = gr.multiply_const_cc(scale) # scale the signal from full-range to +-1 #self.agc = gr.agc2_cc(0.6e-1, 1e-3, 1, 1, 100) - self.agc = gr.feedforward_agc_cc(16, 1.0) + self.agc = gr.feedforward_agc_cc(16, 2.0) - # Costas loop (carrier tracking) - if self._costas_alpha is None: # If no alpha value was specified by the user - alpha_dir = {2:0.075, 3:0.09, 4:0.09, 5:0.095, 6:0.10, 7:0.105} - self._costas_alpha = alpha_dir[self._samples_per_symbol] - - costas_order = 4 - # The value of beta is now set to be underdamped; this value can have a huge impact on the - # performance of QPSK. Set to 0.25 for critically damped or higher for underdamped responses. - beta = .35 * self._costas_alpha * self._costas_alpha - self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.02, -0.02, costas_order) - # RRC data filter ntaps = 11 * samples_per_symbol self.rrc_taps = gr.firdes.root_raised_cosine( - self._samples_per_symbol, # gain + 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=gr.interp_fir_filter_ccf(1, self.rrc_taps) - self.rrc_filter=gr.fir_filter_ccf(1, self.rrc_taps) - - # symbol clock recovery - omega = self._samples_per_symbol - gain_omega = .25 * self._gain_mu * self._gain_mu - self.clock_recovery=gr.clock_recovery_mm_cc(omega, gain_omega, - self._mu, self._gain_mu, - self._omega_relative_limit) + 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=gr.mpsk_receiver_cc(arity, pi/4.0, + self._costas_alpha, self._costas_beta, + fmin, fmax, + self._mm_mu, self._mm_gain_mu, + self._mm_omega, self._mm_gain_omega, + self._mm_omega_relative_limit) + + # Perform Differential decoding on the constellation self.diffdec = gr.diff_phasor_cc() - #self.diffdec = gr.diff_decoder_bb(arity) - + # find closest constellation point rot = 1 - #rot = .707 + .707j rotated_const = map(lambda pt: pt * rot, psk.constellation[arity]) - #print "rotated_const = %s" % rotated_const - 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()) @@ -293,10 +288,8 @@ class dqpsk_demod(gr.hier_block): self._setup_logging() # Connect & Initialize base class - self._fg.connect(self.pre_scaler, self.agc, self.costas_loop, - self.rrc_filter, self.clock_recovery, - self.diffdec, self.slicer, self.symbol_mapper, - self.unpack) + self._fg.connect(self.pre_scaler, self.agc, self.rrc_filter, self.receiver, + self.diffdec, self.slicer, self.symbol_mapper, self.unpack) gr.hier_block.__init__(self, self._fg, self.pre_scaler, self.unpack) def samples_per_symbol(self): @@ -307,39 +300,36 @@ class dqpsk_demod(gr.hier_block): 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 "RRC roll-off factor = %.2f" % self._excess_bw - print "Costas Loop alpha = %.5f" % self._costas_alpha - print "M&M symbol sync gain = %.5f" % self._gain_mu - print "M&M symbol sync mu = %.5f" % self._mu - print "M&M omega relative limit = %.5f" % self._omega_relative_limit - + 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._fg.connect(self.pre_scaler, - gr.file_sink(gr.sizeof_gr_complex, "prescaler.dat")) + gr.file_sink(gr.sizeof_gr_complex, "rx_prescaler.dat")) self._fg.connect(self.agc, - gr.file_sink(gr.sizeof_gr_complex, "agc.dat")) - self._fg.connect(self.costas_loop, - gr.file_sink(gr.sizeof_gr_complex, "costas_loop.dat")) - self._fg.connect((self.costas_loop,1), - gr.file_sink(gr.sizeof_gr_complex, "costas_error.dat")) + gr.file_sink(gr.sizeof_gr_complex, "rx_agc.dat")) self._fg.connect(self.rrc_filter, - gr.file_sink(gr.sizeof_gr_complex, "rrc_filter.dat")) - self._fg.connect(self.clock_recovery, - gr.file_sink(gr.sizeof_gr_complex, "clock_recovery.dat")) - self._fg.connect((self.clock_recovery,1), - gr.file_sink(gr.sizeof_gr_complex, "clock_recovery_error.dat")) + gr.file_sink(gr.sizeof_gr_complex, "rx_rrc_filter.dat")) + self._fg.connect(self.receiver, + gr.file_sink(gr.sizeof_gr_complex, "rx_receiver.dat")) self._fg.connect(self.diffdec, - gr.file_sink(gr.sizeof_gr_complex, "diffdec.dat")) + gr.file_sink(gr.sizeof_gr_complex, "rx_diffdec.dat")) self._fg.connect(self.slicer, - gr.file_sink(gr.sizeof_char, "slicer.dat")) + gr.file_sink(gr.sizeof_char, "rx_slicer.dat")) self._fg.connect(self.symbol_mapper, - gr.file_sink(gr.sizeof_char, "gray_decoder.dat")) + gr.file_sink(gr.sizeof_char, "rx_gray_decoder.dat")) self._fg.connect(self.unpack, - gr.file_sink(gr.sizeof_char, "unpack.dat")) + gr.file_sink(gr.sizeof_char, "rx_unpack.dat")) def add_options(parser): """ @@ -350,7 +340,7 @@ class dqpsk_demod(gr.hier_block): 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, + 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)") |