diff options
Diffstat (limited to 'gr-digital/python/digital/generic_mod_demod.py')
| -rw-r--r-- | gr-digital/python/digital/generic_mod_demod.py | 66 |
1 files changed, 38 insertions, 28 deletions
diff --git a/gr-digital/python/digital/generic_mod_demod.py b/gr-digital/python/digital/generic_mod_demod.py index a40a7fda5f..2db9e4482a 100644 --- a/gr-digital/python/digital/generic_mod_demod.py +++ b/gr-digital/python/digital/generic_mod_demod.py @@ -29,17 +29,18 @@ _def_log = False _def_truncate = False # Frequency correction -_def_freq_bw = 2*math.pi/100.0 +_def_freq_bw = 2 * math.pi / 100.0 # Symbol timing recovery -_def_timing_bw = 2*math.pi/100.0 +_def_timing_bw = 2 * math.pi / 100.0 _def_timing_max_dev = 1.5 # Fine frequency / Phase correction -_def_phase_bw = 2*math.pi/100.0 +_def_phase_bw = 2 * math.pi / 100.0 # Number of points in constellation _def_constellation_points = 16 # Whether differential coding is used. _def_differential = False + def add_common_options(parser): """ Sets options common to both modulator and demodulator. @@ -55,7 +56,7 @@ def add_common_options(parser): parser.add_option("", "--mod-code", type="choice", choices=mod_codes.codes, default=mod_codes.NO_CODE, help="Select modulation code from: %s [default=%%default]" - % (', '.join(mod_codes.codes),)) + % (', '.join(mod_codes.codes),)) parser.add_option("", "--excess-bw", type="float", default=_def_excess_bw, help="set RRC excess bandwidth factor [default=%default]") @@ -92,8 +93,9 @@ class generic_mod(gr.hier_block2): truncate=_def_truncate): gr.hier_block2.__init__(self, "generic_mod", - gr.io_signature(1, 1, gr.sizeof_char), # Input signature - gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature + # Input signature + gr.io_signature(1, 1, gr.sizeof_char), + gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature self._constellation = constellation self._samples_per_symbol = samples_per_symbol @@ -103,31 +105,36 @@ class generic_mod(gr.hier_block2): self.pre_diff_code = pre_diff_code and self._constellation.apply_pre_diff_code() if self._samples_per_symbol < 2: - raise TypeError("sps must be >= 2, is %f" % self._samples_per_symbol) + raise TypeError("sps must be >= 2, is %f" % + self._samples_per_symbol) - arity = pow(2,self.bits_per_symbol()) + arity = pow(2, self.bits_per_symbol()) # turn bytes into k-bit vectors self.bytes2chunks = \ - blocks.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST) + blocks.packed_to_unpacked_bb( + self.bits_per_symbol(), gr.GR_MSB_FIRST) if self.pre_diff_code: - self.symbol_mapper = digital.map_bb(self._constellation.pre_diff_code()) + self.symbol_mapper = digital.map_bb( + self._constellation.pre_diff_code()) if differential: self.diffenc = digital.diff_encoder_bb(arity) - self.chunks2symbols = digital.chunks_to_symbols_bc(self._constellation.points()) + self.chunks2symbols = digital.chunks_to_symbols_bc( + self._constellation.points()) # pulse shaping filter nfilts = 32 ntaps_per_filt = 11 - ntaps = nfilts * ntaps_per_filt * int(self._samples_per_symbol) # make nfilts filters of ntaps each + # make nfilts filters of ntaps each + ntaps = nfilts * ntaps_per_filt * int(self._samples_per_symbol) self.rrc_taps = filter.firdes.root_raised_cosine( nfilts, # gain nfilts, # sampling rate based on 32 filters in resampler 1.0, # symbol rate - self._excess_bw, # excess bandwidth (roll-off factor) + self._excess_bw, # excess bandwidth (roll-off factor) ntaps) self.rrc_filter = filter.pfb_arb_resampler_ccf(self._samples_per_symbol, self.rrc_taps) @@ -135,8 +142,10 @@ class generic_mod(gr.hier_block2): # Remove the filter transient at the beginning of the transmission if truncate: fsps = float(self._samples_per_symbol) - len_filt_delay = int((ntaps_per_filt*fsps*fsps-fsps)/2.0) # Length of delay through rrc filter - self.skiphead = blocks.skiphead(gr.sizeof_gr_complex*1, len_filt_delay) + # Length of delay through rrc filter + len_filt_delay = int((ntaps_per_filt * fsps * fsps - fsps) / 2.0) + self.skiphead = blocks.skiphead( + gr.sizeof_gr_complex * 1, len_filt_delay) # Connect self._blocks = [self, self.bytes2chunks] @@ -145,7 +154,7 @@ class generic_mod(gr.hier_block2): if differential: self._blocks.append(self.diffenc) self._blocks += [self.chunks2symbols, self.rrc_filter] - + if truncate: self._blocks.append(self.skiphead) self._blocks.append(self) @@ -157,7 +166,6 @@ class generic_mod(gr.hier_block2): if log: self._setup_logging() - def samples_per_symbol(self): return self._samples_per_symbol @@ -176,8 +184,7 @@ class generic_mod(gr.hier_block2): Given command line options, create dictionary suitable for passing to __init__ """ return extract_kwargs_from_options_for_class(cls, options) - extract_kwargs_from_options=classmethod(extract_kwargs_from_options) - + extract_kwargs_from_options = classmethod(extract_kwargs_from_options) def _print_verbage(self): print("\nModulator:") @@ -239,7 +246,8 @@ class generic_demod(gr.hier_block2): log=_def_log): gr.hier_block2.__init__(self, "generic_demod", - gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature + # Input signature + gr.io_signature(1, 1, gr.sizeof_gr_complex), gr.io_signature(1, 1, gr.sizeof_char)) # Output signature self._constellation = constellation @@ -248,19 +256,20 @@ class generic_demod(gr.hier_block2): self._phase_bw = phase_bw self._freq_bw = freq_bw self._timing_bw = timing_bw - self._timing_max_dev= _def_timing_max_dev + self._timing_max_dev = _def_timing_max_dev self._differential = differential if self._samples_per_symbol < 2: - raise TypeError("sps must be >= 2, is %d" % self._samples_per_symbol) + raise TypeError("sps must be >= 2, is %d" % + self._samples_per_symbol) # Only apply a predifferential coding if the constellation also supports it. self.pre_diff_code = pre_diff_code and self._constellation.apply_pre_diff_code() - arity = pow(2,self.bits_per_symbol()) + arity = pow(2, self.bits_per_symbol()) nfilts = 32 - ntaps = 11 * int(self._samples_per_symbol*nfilts) + ntaps = 11 * int(self._samples_per_symbol * nfilts) # Automatic gain control self.agc = analog.agc2_cc(0.6e-1, 1e-3, 1, 1) @@ -271,11 +280,11 @@ class generic_demod(gr.hier_block2): fll_ntaps, self._freq_bw) # symbol timing recovery with RRC data filter - taps = filter.firdes.root_raised_cosine(nfilts, nfilts*self._samples_per_symbol, + taps = filter.firdes.root_raised_cosine(nfilts, nfilts * self._samples_per_symbol, 1.0, self._excess_bw, ntaps) self.time_recov = digital.pfb_clock_sync_ccf(self._samples_per_symbol, self._timing_bw, taps, - nfilts, nfilts//2, self._timing_max_dev) + nfilts, nfilts // 2, self._timing_max_dev) fmin = -0.25 fmax = 0.25 @@ -318,7 +327,7 @@ class generic_demod(gr.hier_block2): def _print_verbage(self): print("\nDemodulator:") - print("bits per symbol: %d" % self.bits_per_symbol()) + print("bits per symbol: %d" % self.bits_per_symbol()) print("RRC roll-off factor: %.2f" % self._excess_bw) print("FLL bandwidth: %.2e" % self._freq_bw) print("Timing bandwidth: %.2e" % self._timing_bw) @@ -381,7 +390,8 @@ class generic_demod(gr.hier_block2): Given command line options, create dictionary suitable for passing to __init__ """ return extract_kwargs_from_options_for_class(cls, options) - extract_kwargs_from_options=classmethod(extract_kwargs_from_options) + extract_kwargs_from_options = classmethod(extract_kwargs_from_options) + shared_demod_args = """ samples_per_symbol: samples per baud >= 2 (float) excess_bw: Root-raised cosine filter excess bandwidth (float) |