[Commit-gnuradio] r4061 - gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl

[trondeau]

Author: trondeau
Date: 2006-12-11 10:22:27 -0700 (Mon, 11 Dec 2006)
New Revision: 4061

Added:
   
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam16.py
   
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam256.py
   
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam64.py
Log:
M-QAM modulators (no demod yet) for square constellations ('cept for QAM8, 
which is generally weird)

Added: 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam16.py
===================================================================
--- 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam16.py
                               (rev 0)
+++ 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam16.py
       2006-12-11 17:22:27 UTC (rev 4061)
@@ -0,0 +1,205 @@
+#
+# 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
+
+"""
+QAM16 modulation and demodulation.
+"""
+
+from gnuradio import gr, gru, modulation_utils
+from math import pi, sqrt
+import qam
+import cmath
+import Numeric
+from pprint import pprint
+
+# default values (used in __init__ and add_options)
+_def_samples_per_symbol = 2
+_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
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                           QAM16 modulator
+# /////////////////////////////////////////////////////////////////////////////
+
+class qam16_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(qam.binary_to_gray[arity])
+        else:
+            self.symbol_mapper = gr.map_bb(qam.binary_to_ungray[arity])
+            
+        self.diffenc = gr.diff_encoder_bb(arity)
+
+        rot = 1.0
+        print "constellation with %d arity" % arity
+        rotated_const = map(lambda pt: pt * rot, qam.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 4
+    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 QAM 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(qam16_mod.__init__,
+                                                            ('self', 'fg'), 
options)
+    extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                           QAM16 demodulator
+#
+# /////////////////////////////////////////////////////////////////////////////
+
+class qam16_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):
+
+        # do this
+        pass
+    
+    def bits_per_symbol(self=None):   # staticmethod that's also callable on 
an instance
+        return 4
+    bits_per_symbol = staticmethod(bits_per_symbol)      # make it a static 
method.  RTFM
+
+#
+# Add these to the mod/demod registry
+#
+modulation_utils.add_type_1_mod('qam16', qam16_mod)
+#modulation_utils.add_type_1_demod('qam16', qam16_demod)

Added: 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam256.py
===================================================================
--- 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam256.py
                              (rev 0)
+++ 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam256.py
      2006-12-11 17:22:27 UTC (rev 4061)
@@ -0,0 +1,205 @@
+#
+# 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
+
+"""
+QAM256 modulation and demodulation.
+"""
+
+from gnuradio import gr, gru, modulation_utils
+from math import pi, sqrt
+import qam
+import cmath
+import Numeric
+from pprint import pprint
+
+# default values (used in __init__ and add_options)
+_def_samples_per_symbol = 2
+_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
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                           QAM256 modulator
+# /////////////////////////////////////////////////////////////////////////////
+
+class qam256_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(qam.binary_to_gray[arity])
+        else:
+            self.symbol_mapper = gr.map_bb(qam.binary_to_ungray[arity])
+            
+        self.diffenc = gr.diff_encoder_bb(arity)
+
+        rot = 1.0
+        print "constellation with %d arity" % arity
+        rotated_const = map(lambda pt: pt * rot, qam.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 8
+    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 QAM 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(qam256_mod.__init__,
+                                                            ('self', 'fg'), 
options)
+    extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                           QAM256 demodulator
+#
+# /////////////////////////////////////////////////////////////////////////////
+
+class qam256_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):
+
+        # do this
+        pass
+    
+    def bits_per_symbol(self=None):   # staticmethod that's also callable on 
an instance
+        return 8
+    bits_per_symbol = staticmethod(bits_per_symbol)      # make it a static 
method.  RTFM
+
+#
+# Add these to the mod/demod registry
+#
+modulation_utils.add_type_1_mod('qam256', qam256_mod)
+#modulation_utils.add_type_1_demod('qam256', qam256_demod)

Added: 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam64.py
===================================================================
--- 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam64.py
                               (rev 0)
+++ 
gnuradio/branches/developers/trondeau/digital-wip/gnuradio-core/src/python/gnuradio/blksimpl/qam64.py
       2006-12-11 17:22:27 UTC (rev 4061)
@@ -0,0 +1,205 @@
+#
+# 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 QPSK modulation and demodulation.
+"""
+
+from gnuradio import gr, gru, modulation_utils
+from math import pi, sqrt
+import qam
+import cmath
+import Numeric
+from pprint import pprint
+
+# default values (used in __init__ and add_options)
+_def_samples_per_symbol = 2
+_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
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                           QAM64 modulator
+# /////////////////////////////////////////////////////////////////////////////
+
+class qam64_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(qam.binary_to_gray[arity])
+        else:
+            self.symbol_mapper = gr.map_bb(qam.binary_to_ungray[arity])
+            
+        self.diffenc = gr.diff_encoder_bb(arity)
+
+        rot = 1.0
+        print "constellation with %d arity" % arity
+        rotated_const = map(lambda pt: pt * rot, qam.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 6
+    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 QAM 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(qam64_mod.__init__,
+                                                            ('self', 'fg'), 
options)
+    extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                           QAM16 demodulator
+#
+# /////////////////////////////////////////////////////////////////////////////
+
+class qam64_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):
+
+        # do this
+        pass
+    
+    def bits_per_symbol(self=None):   # staticmethod that's also callable on 
an instance
+        return 6
+    bits_per_symbol = staticmethod(bits_per_symbol)      # make it a static 
method.  RTFM
+
+#
+# Add these to the mod/demod registry
+#
+modulation_utils.add_type_1_mod('qam64', qam64_mod)
+#modulation_utils.add_type_1_demod('qam16', qam16_demod)