_def_verbose = False
_def_log = False
-_def_costas_alpha = 0.05
+_def_costas_alpha = None
_def_gain_mu = 0.03
_def_mu = 0.05
_def_omega_relative_limit = 0.005
# Costas loop (carrier tracking)
- # FIXME: need to decide how to handle this more generally; do we pull it from higher layer?
- costas_order = 2
- beta = .25 * self._costas_alpha * self._costas_alpha
- self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.002, -0.002, costas_order)
+ # The Costas loop is not needed for BPSK, though it can help. Turn the Costas loop on
+ # by setting an alpha value not None.
+ if self._costas_alpha is not None:
+ costas_order = 2
+ beta = .25 * self._costas_alpha * self._costas_alpha
+ self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.002, -0.002, costas_order)
# RRC data filter
ntaps = 11 * self._samples_per_symbol
self._setup_logging()
# Connect and 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)
+ if self._costas_alpha is not None: # With Costas Loop
+ 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)
+ else: # Without Costas Loop
+ self._fg.connect(self.pre_scaler, self.agc,
+ self.rrc_filter, self.clock_recovery, self.diffdec,
+ self.slicer, self.symbol_mapper, self.unpack)
gr.hier_block.__init__(self, self._fg, self.pre_scaler, self.unpack)
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
+ if self._costas_alpha is not None:
+ print "Costas Loop alpha = %.5f" % self._costas_alpha
+ else:
+ print "Costas Loop is turned off"
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
gr.file_sink(gr.sizeof_gr_complex, "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"))
+ if self._costas_alpha is not None:
+ 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"))
self._fg.connect(self.rrc_filter,
gr.file_sink(gr.sizeof_gr_complex, "rrc_filter.dat"))
self._fg.connect(self.clock_recovery,