Changeset 4072

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Timestamp:
12/12/06 14:51:12
Author:
jcorgan
Message:

Merged trunk version r4071 of dqpsk.py and dbpsk.py into release branch.

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  • gnuradio/branches/releases/3.0/gnuradio-core/src/python/gnuradio/blksimpl/dbpsk.py

    r3696 r4072  
    4040_def_log = False 
    4141 
    42 _def_costas_alpha = 0.05 
     42_def_costas_alpha = None 
    4343_def_gain_mu = 0.03 
    4444_def_mu = 0.05 
    …… 
    242242         
    243243        # Costas loop (carrier tracking) 
    244         # FIXME: need to decide how to handle this more generally; do we pull it from higher layer? 
    245         costas_order = 2 
    246         beta = .25 * self._costas_alpha * self._costas_alpha 
    247         self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.002, -0.002, costas_order) 
     244        # The Costas loop is not needed for BPSK, though it can help. Turn the Costas loop on 
     245        # by setting an alpha value not None. 
     246        if self._costas_alpha is not None: 
     247            costas_order = 2 
     248            beta = .25 * self._costas_alpha * self._costas_alpha 
     249            self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.002, -0.002, costas_order) 
    248250 
    249251        # RRC data filter 
    …… 
    290292 
    291293        # Connect and Initialize base class 
    292         self._fg.connect(self.pre_scaler, self.agc, self.costas_loop, 
    293                          self.rrc_filter, self.clock_recovery, self.diffdec, 
    294                          self.slicer, self.symbol_mapper, self.unpack) 
     294        if self._costas_alpha is not None:   # With Costas Loop 
     295            self._fg.connect(self.pre_scaler, self.agc, self.costas_loop, 
     296                             self.rrc_filter, self.clock_recovery, self.diffdec, 
     297                             self.slicer, self.symbol_mapper, self.unpack) 
     298        else: # Without Costas Loop 
     299            self._fg.connect(self.pre_scaler, self.agc, 
     300                             self.rrc_filter, self.clock_recovery, self.diffdec, 
     301                             self.slicer, self.symbol_mapper, self.unpack) 
    295302 
    296303        gr.hier_block.__init__(self, self._fg, self.pre_scaler, self.unpack) 
    …… 
    307314        print "Gray code = %s"               % self._gray_code 
    308315        print "RRC roll-off factor = %.2f"   % self._excess_bw 
    309         print "Costas Loop alpha = %.5f"     % self._costas_alpha 
     316        if self._costas_alpha is not None: 
     317            print "Costas Loop alpha = %.5f"     % self._costas_alpha 
     318        else: 
     319            print "Costas Loop is turned off" 
    310320        print "M&M symbol sync gain = %.5f"  % self._gain_mu 
    311321        print "M&M symbol sync mu = %.5f"    % self._mu 
    …… 
    318328        self._fg.connect(self.agc, 
    319329                         gr.file_sink(gr.sizeof_gr_complex, "agc.dat")) 
    320         self._fg.connect(self.costas_loop, 
    321                          gr.file_sink(gr.sizeof_gr_complex, "costas_loop.dat")) 
    322         self._fg.connect((self.costas_loop,1), 
    323                          gr.file_sink(gr.sizeof_gr_complex, "costas_error.dat")) 
     330        if self._costas_alpha is not None: 
     331            self._fg.connect(self.costas_loop, 
     332                             gr.file_sink(gr.sizeof_gr_complex, "costas_loop.dat")) 
     333            self._fg.connect((self.costas_loop,1), 
     334                             gr.file_sink(gr.sizeof_gr_complex, "costas_error.dat")) 
    324335        self._fg.connect(self.rrc_filter, 
    325336                         gr.file_sink(gr.sizeof_gr_complex, "rrc_filter.dat")) 

  • gnuradio/branches/releases/3.0/gnuradio-core/src/python/gnuradio/blksimpl/dqpsk.py

    r3662 r4072  
    4040_def_log = False 
    4141 
    42 _def_costas_alpha = 0.10 
     42_def_costas_alpha = None 
    4343_def_gain_mu = 0.03 
    4444_def_mu = 0.05 
    …… 
    239239        
    240240        # Costas loop (carrier tracking) 
    241         # FIXME: need to decide how to handle this more generally; do we pull it from higher layer? 
    242         costas_order = 4 
    243         beta = .25 * self._costas_alpha * self._costas_alpha 
    244         #self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.1, -0.1, costas_order) 
    245         self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.002, -0.002, costas_order) 
     241        if self._costas_alpha is None:   # If no alpha value was specified by the user 
     242            alpha_dir = {2:0.075, 3:0.09, 4:0.09, 5:0.095, 6:0.10, 7:0.105} 
     243            self._costas_alpha = alpha_dir[self._samples_per_symbol] 
     244         
     245        costas_order = 4         
     246        # The value of beta is now set to be underdamped; this value can have a huge impact on the 
     247        # performance of QPSK. Set to 0.25 for critically damped or higher for underdamped responses. 
     248        beta = .35 * self._costas_alpha * self._costas_alpha 
     249        self.costas_loop = gr.costas_loop_cc(self._costas_alpha, beta, 0.02, -0.02, costas_order) 
    246250 
    247251        # RRC data filter