[Commit-gnuradio] r4060 - gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl

[trondeau]

Author: trondeau
Date: 2006-12-11 10:20:41 -0700 (Mon, 11 Dec 2006)
New Revision: 4060

Added:
   
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/d8psk.py
Log:
modulator for differential 8PSK (no demod yet)

Added: 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/d8psk.py
===================================================================
--- 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/d8psk.py
                               (rev 0)
+++ 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/d8psk.py
       2006-12-11 17:20:41 UTC (rev 4060)
@@ -0,0 +1,375 @@
+#
+# Copyright 2005,2006 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+# 
+
+# See gnuradio-examples/python/digital for examples
+
+"""
+differential 8PSK modulation and demodulation.
+"""
+
+from gnuradio import gr, gru, modulation_utils
+from math import pi, sqrt
+import psk
+import cmath
+import Numeric
+from pprint import pprint
+
+# default values (used in __init__ and add_options)
+_def_samples_per_symbol = 3
+_def_excess_bw = 0.35
+_def_gray_code = True
+_def_verbose = False
+_def_log = False
+
+_def_costas_alpha = None
+_def_gain_mu = 0.03
+_def_mu = 0.05
+_def_omega_relative_limit = 0.005
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                           DQPSK modulator
+# /////////////////////////////////////////////////////////////////////////////
+
+class d8psk_mod(gr.hier_block):
+
+    def __init__(self, fg,
+                 samples_per_symbol=_def_samples_per_symbol,
+                 excess_bw=_def_excess_bw,
+                 gray_code=_def_gray_code,
+                 verbose=_def_verbose,
+                 log=_def_log):
+        """
+       Hierarchical block for RRC-filtered QPSK modulation.
+
+       The input is a byte stream (unsigned char) and the
+       output is the complex modulated signal at baseband.
+
+       @param fg: flow graph
+       @type fg: flow graph
+       @param samples_per_symbol: samples per symbol >= 2
+       @type samples_per_symbol: integer
+       @param excess_bw: Root-raised cosine filter excess bandwidth
+       @type excess_bw: float
+        @param gray_code: Tell modulator to Gray code the bits
+        @type gray_code: bool
+        @param verbose: Print information about modulator?
+        @type verbose: bool
+        @param debug: Print modualtion data to files?
+        @type debug: bool
+       """
+
+        self._fg = fg
+        self._samples_per_symbol = samples_per_symbol
+        self._excess_bw = excess_bw
+        self._gray_code = gray_code
+
+        if not isinstance(samples_per_symbol, int) or samples_per_symbol < 2:
+            raise TypeError, ("sbp must be an integer >= 2, is %d" % 
samples_per_symbol)
+
+       ntaps = 11 * samples_per_symbol
+ 
+        arity = pow(2,self.bits_per_symbol())
+
+        # turn bytes into k-bit vectors
+        self.bytes2chunks = \
+          gr.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST)
+
+        if self._gray_code:
+            self.symbol_mapper = gr.map_bb(psk.binary_to_gray[arity])
+        else:
+            self.symbol_mapper = gr.map_bb(psk.binary_to_ungray[arity])
+            
+        self.diffenc = gr.diff_encoder_bb(arity)
+
+        #rot = .707 + .707j
+        rot = 1.0
+        rotated_const = map(lambda pt: pt * rot, psk.constellation[arity])
+        self.chunks2symbols = gr.chunks_to_symbols_bc(rotated_const)
+
+        # pulse shaping filter
+       self.rrc_taps = gr.firdes.root_raised_cosine(
+           self._samples_per_symbol, # gain  (sps since we're interpolating by 
sps)
+            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(self._samples_per_symbol, 
self.rrc_taps)
+
+        if verbose:
+            self._print_verbage()
+        
+        if log:
+            self._setup_logging()
+            
+       # Connect & Initialize base class
+        self._fg.connect(self.bytes2chunks, self.symbol_mapper, self.diffenc,
+                         self.chunks2symbols, self.rrc_filter)
+       gr.hier_block.__init__(self, self._fg, self.bytes2chunks, 
self.rrc_filter)
+
+    def samples_per_symbol(self):
+        return self._samples_per_symbol
+
+    def bits_per_symbol(self=None):   # staticmethod that's also callable on 
an instance
+        return 3
+    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
+
+    def _setup_logging(self):
+        print "Modulation logging turned on."
+        self._fg.connect(self.bytes2chunks,
+                         gr.file_sink(gr.sizeof_char, "bytes2chunks.dat"))
+        self._fg.connect(self.symbol_mapper,
+                         gr.file_sink(gr.sizeof_char, "graycoder.dat"))
+        self._fg.connect(self.diffenc,
+                         gr.file_sink(gr.sizeof_char, "diffenc.dat"))        
+        self._fg.connect(self.chunks2symbols,
+                         gr.file_sink(gr.sizeof_gr_complex, 
"chunks2symbols.dat"))
+        self._fg.connect(self.rrc_filter,
+                         gr.file_sink(gr.sizeof_gr_complex, "rrc_filter.dat"))
+
+    def add_options(parser):
+        """
+        Adds 8PSK modulation-specific options to the standard parser
+        """
+        parser.add_option("", "--excess-bw", type="float", 
default=_def_excess_bw,
+                          help="set RRC excess bandwith factor 
[default=%default] (PSK)")
+        parser.add_option("", "--no-gray-code", dest="gray_code",
+                          action="store_false", default=_def_gray_code,
+                          help="disable gray coding on modulated bits (PSK)")
+    add_options=staticmethod(add_options)
+
+
+    def extract_kwargs_from_options(options):
+        """
+        Given command line options, create dictionary suitable for passing to 
__init__
+        """
+        return modulation_utils.extract_kwargs_from_options(d8psk_mod.__init__,
+                                                            ('self', 'fg'), 
options)
+    extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                           D8PSK demodulator
+#
+# Differentially coherent detection of differentially encoded 8psk
+# /////////////////////////////////////////////////////////////////////////////
+
+class d8psk_demod(gr.hier_block):
+
+    def __init__(self, fg,
+                 samples_per_symbol=_def_samples_per_symbol,
+                 excess_bw=_def_excess_bw,
+                 costas_alpha=_def_costas_alpha,
+                 gain_mu=_def_gain_mu,
+                 mu=_def_mu,
+                 omega_relative_limit=_def_omega_relative_limit,
+                 gray_code=_def_gray_code,
+                 verbose=_def_verbose,
+                 log=_def_log):
+        """
+       Hierarchical block for RRC-filtered DQPSK demodulation
+
+       The input is the complex modulated signal at baseband.
+       The output is a stream of bits packed 1 bit per byte (LSB)
+
+       @param fg: flow graph
+       @type fg: flow graph
+       @param samples_per_symbol: samples per symbol >= 2
+       @type samples_per_symbol: float
+       @param excess_bw: Root-raised cosine filter excess bandwidth
+       @type excess_bw: float
+        @param costas_alpha: loop filter gain
+        @type costas_alphas: float
+        @param gain_mu: for M&M block
+        @type gain_mu: float
+        @param mu: for M&M block
+        @type mu: float
+        @param omega_relative_limit: for M&M block
+        @type omega_relative_limit: float
+        @param gray_code: Tell modulator to Gray code the bits
+        @type gray_code: bool
+        @param verbose: Print information about modulator?
+        @type verbose: bool
+        @param debug: Print modualtion data to files?
+        @type debug: bool
+       """
+
+        self._fg = fg
+        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._gray_code = gray_code
+
+        if samples_per_symbol < 2:
+            raise TypeError, "sbp must be >= 2, is %d" % samples_per_symbol
+
+        arity = pow(2,self.bits_per_symbol())
+ 
+        # Automatic gain control
+        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)
+       
+        # 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
+            self._samples_per_symbol, # sampling rate
+            1.0,                      # symbol rate
+            self._excess_bw,          # excess bandwidth (roll-off factor)
+            ntaps)
+
+        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)
+
+        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())
+
+        if verbose:
+            self._print_verbage()
+        
+        if log:
+            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)
+        gr.hier_block.__init__(self, self._fg, self.pre_scaler, self.unpack)
+
+    def samples_per_symbol(self):
+        return self._samples_per_symbol
+
+    def bits_per_symbol(self=None):   # staticmethod that's also callable on 
an instance
+        return 2
+    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
+        
+
+    def _setup_logging(self):
+        print "Modulation logging turned on."
+        self._fg.connect(self.pre_scaler,
+                         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"))
+        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"))
+        self._fg.connect(self.diffdec,
+                         gr.file_sink(gr.sizeof_gr_complex, "diffdec.dat"))    
    
+        self._fg.connect(self.slicer,
+                         gr.file_sink(gr.sizeof_char, "slicer.dat"))
+        self._fg.connect(self.symbol_mapper,
+                         gr.file_sink(gr.sizeof_char, "gray_decoder.dat"))
+        self._fg.connect(self.unpack,
+                         gr.file_sink(gr.sizeof_char, "unpack.dat"))
+
+    def add_options(parser):
+        """
+        Adds modulation-specific options to the standard parser
+        """
+        parser.add_option("", "--excess-bw", type="float", 
default=_def_excess_bw,
+                          help="set RRC excess bandwith factor 
[default=%default] (PSK)")
+        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,
+                          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)")
+        parser.add_option("", "--mu", type="float", default=_def_mu,
+                          help="set M&M symbol sync loop mu value 
[default=%default] (PSK)")
+    add_options=staticmethod(add_options)
+
+    def extract_kwargs_from_options(options):
+        """
+        Given command line options, create dictionary suitable for passing to 
__init__
+        """
+        return modulation_utils.extract_kwargs_from_options(
+            dqpsk_demod.__init__, ('self', 'fg'), options)
+    extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
+
+
+#
+# Add these to the mod/demod registry
+#
+modulation_utils.add_type_1_mod('d8psk', d8psk_mod)
+#modulation_utils.add_type_1_demod('d8psk', d8psk_demod)