diff options
Diffstat (limited to 'gr-digital/python/generic_mod_demod.py')
| -rw-r--r-- | gr-digital/python/generic_mod_demod.py | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/gr-digital/python/generic_mod_demod.py b/gr-digital/python/generic_mod_demod.py index a6c4f3445a..105c6fe8ff 100644 --- a/gr-digital/python/generic_mod_demod.py +++ b/gr-digital/python/generic_mod_demod.py @@ -76,10 +76,10 @@ def add_common_options(parser): class generic_mod(gr.hier_block2): def __init__(self, constellation, - samples_per_symbol=_def_samples_per_symbol, differential=_def_differential, + samples_per_symbol=_def_samples_per_symbol, + pre_diff_code=True, excess_bw=_def_excess_bw, - gray_coded=True, verbose=_def_verbose, log=_def_log): """ @@ -92,10 +92,12 @@ class generic_mod(gr.hier_block2): @type constellation: gnuradio.digital.gr_constellation @param samples_per_symbol: samples per baud >= 2 @type samples_per_symbol: float + @param differential: whether to use differential encoding + @type differential: boolean + @param pre_diff_code: whether to use apply a pre-differential mapping + @type pre_diff_code: boolean @param excess_bw: Root-raised cosine filter excess bandwidth @type excess_bw: float - @param gray_coded: turn gray coding on/off - @type gray_coded: bool @param verbose: Print information about modulator? @type verbose: bool @param log: Log modulation data to files? @@ -110,6 +112,8 @@ class generic_mod(gr.hier_block2): self._samples_per_symbol = samples_per_symbol self._excess_bw = excess_bw self._differential = differential + # 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() if self._samples_per_symbol < 2: raise TypeError, ("sbp must be >= 2, is %f" % self._samples_per_symbol) @@ -120,7 +124,7 @@ class generic_mod(gr.hier_block2): self.bytes2chunks = \ gr.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST) - if gray_coded == True: + if self.pre_diff_code: self.symbol_mapper = digital.map_bb(self._constellation.pre_diff_code()) if differential: @@ -142,7 +146,7 @@ class generic_mod(gr.hier_block2): # Connect blocks = [self, self.bytes2chunks] - if gray_coded == True: + if self.pre_diff_code: blocks.append(self.symbol_mapper) if differential: blocks.append(self.diffenc) @@ -186,7 +190,7 @@ class generic_mod(gr.hier_block2): print "Modulation logging turned on." self.connect(self.bytes2chunks, gr.file_sink(gr.sizeof_char, "tx_bytes2chunks.8b")) - if self._constellation.apply_pre_diff_code(): + if self.pre_diff_code: self.connect(self.symbol_mapper, gr.file_sink(gr.sizeof_char, "tx_symbol_mapper.8b")) if self._differential: @@ -208,10 +212,10 @@ class generic_mod(gr.hier_block2): class generic_demod(gr.hier_block2): def __init__(self, constellation, - samples_per_symbol=_def_samples_per_symbol, differential=_def_differential, + samples_per_symbol=_def_samples_per_symbol, + pre_diff_code=True, excess_bw=_def_excess_bw, - gray_coded=True, freq_bw=_def_freq_bw, timing_bw=_def_timing_bw, phase_bw=_def_phase_bw, @@ -227,10 +231,12 @@ class generic_demod(gr.hier_block2): @type constellation: gnuradio.digital.gr_constellation @param samples_per_symbol: samples per symbol >= 2 @type samples_per_symbol: float + @param differential: whether to use differential encoding + @type differential: boolean + @param pre_diff_code: whether to use apply a pre-differential mapping + @type pre_diff_code: boolean @param excess_bw: Root-raised cosine filter excess bandwidth @type excess_bw: float - @param gray_coded: turn gray coding on/off - @type gray_coded: bool @param freq_bw: loop filter lock-in bandwidth @type freq_bw: float @param timing_bw: timing recovery loop lock-in bandwidth @@ -259,6 +265,9 @@ class generic_demod(gr.hier_block2): if self._samples_per_symbol < 2: raise TypeError, ("sbp 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()) nfilts = 32 @@ -289,7 +298,7 @@ class generic_demod(gr.hier_block2): if differential: self.diffdec = digital.diff_decoder_bb(arity) - if gray_coded: + if self.pre_diff_code: self.symbol_mapper = digital.map_bb( mod_codes.invert_code(self._constellation.pre_diff_code())) @@ -307,7 +316,7 @@ class generic_demod(gr.hier_block2): self.time_recov, self.receiver] if differential: blocks.append(self.diffdec) - if self._constellation.apply_pre_diff_code(): + if self.pre_diff_code: blocks.append(self.symbol_mapper) blocks += [self.unpack, self] self.connect(*blocks) @@ -357,7 +366,7 @@ class generic_demod(gr.hier_block2): if self._differential: self.connect(self.diffdec, gr.file_sink(gr.sizeof_char, "rx_diffdec.8b")) - if self._constellation.apply_pre_diff_code(): + if self.pre_diff_code: self.connect(self.symbol_mapper, gr.file_sink(gr.sizeof_char, "rx_symbol_mapper.8b")) self.connect(self.unpack, |