[Commit-gnuradio] r4442 - gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect

[jcorgan]

Author: jcorgan
Date: 2007-02-11 02:30:44 -0700 (Sun, 11 Feb 2007)
New Revision: 4442

Added:
   
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/gmsk2.py
Modified:
   
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/README
   
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/dect_receiver.py
   
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/usrp_dect.py
Log:
Work in progress.  Added GMSK demodulator and option to log to file.

Modified: 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/README
===================================================================
--- 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/README  
    2007-02-11 07:44:21 UTC (rev 4441)
+++ 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/README  
    2007-02-11 09:30:44 UTC (rev 4442)
@@ -5,12 +5,15 @@
 Status
 ------
 
+2007 Feb 11 - Added GMSK demodulation and option to log to file
 2007 Feb 10 - Able to tune and log filtered baseband to file
 
 
 Files
 -----
 
+usrp_dect.py     - DECT receiver application
+
 dect_receiver.py - Top-level hierarchical block (new type) implementing 
                    receiver
 
@@ -18,9 +21,10 @@
                    complex source, with convenience functions for tuning, 
                    gain, decimation, etc.
 
-usrp_dect.py     - DECT receiver application
+gmsk2.py         - Hierarchical block (new type) implementing GMSK
+                   modulation and demodulation.  This will eventually go
+                   into the core blksimpl directory
 
-
 DECT Modulation Details
 -----------------------
 

Modified: 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/dect_receiver.py
===================================================================
--- 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/dect_receiver.py
    2007-02-11 07:44:21 UTC (rev 4441)
+++ 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/dect_receiver.py
    2007-02-11 09:30:44 UTC (rev 4442)
@@ -22,7 +22,10 @@
 
 from gnuradio import gr, optfir
 from usrp_source import usrp_source_c
+from gmsk2 import gmsk2_demod
 
+_dect_symbol_rate = 1.152e6
+
 # Top-level hierarchical block that implements DECT demodulation and
 # decoding.
 class dect_receiver(gr.hier_block2):
@@ -33,8 +36,9 @@
                                gr.io_signature(0,0,0)) # Output signature
         self._options = options
 
-        # Get 2 MHz swath at channel frequency
-        if_rate = 2e6
+        # Need greater than 2 samples per symbol. This makes a decimation
+        # rate of 26 and a samples per symbol of 2.136752
+        if_rate = 2.461538e6
         self._usrp = usrp_source_c(self,
                                    which=0,
                                    subdev_spec=options.rx_subdev_spec,
@@ -56,19 +60,30 @@
         self._channel_filter = gr.freq_xlating_fir_filter_ccf(1,         # 
Decimation rate
                                                               chan_taps, # 
Filter taps
                                                               0.0,       # 
Offset frequency
-                                                              2e6)       # 
Sample rate
+                                                              if_rate)   # 
Sample rate
 
+        self._demod = gmsk2_demod(samples_per_symbol=if_rate/_dect_symbol_rate,
+                                  verbose=options.verbose)
+
+        # Define and connect components
+        self.define_component("usrp", self._usrp)
+        self.define_component("channel", self._channel_filter)
+        self.define_component("demod", self._demod)
+        self.define_component("sink", gr.null_sink(gr.sizeof_char))
+        self.connect("usrp", 0, "channel", 0)
+        self.connect("channel", 0, "demod", 0)
+        self.connect("demod", 0, "sink", 0)
+
         # Log baseband to file if requested
         if options.log_baseband is not None:
-            self._sink = gr.file_sink(gr.sizeof_gr_complex, 
options.log_baseband)
             if options.verbose:
                 print "Logging baseband to file", options.log_baseband
-        else:
-            self._sink = gr.null_sink(gr.sizeof_gr_complex)
+            self.define_component("baseband_log", 
gr.file_sink(gr.sizeof_gr_complex, options.log_baseband))
+            self.connect("channel", 0, "baseband_log", 0)
 
-        self.define_component("usrp", self._usrp)
-        self.define_component("channel", self._channel_filter)
-        self.define_component("sink", self._sink)
-
-        self.connect("usrp", 0, "channel", 0)
-        self.connect("channel", 0, "sink", 0)
+        # Log demodulator output to file if requested
+        if options.log_demod is not None:
+            if options.verbose:
+                print "Logging demodulator to file", options.log_demod
+            self.define_component("demod_log", gr.file_sink(gr.sizeof_char, 
options.log_demod))
+            self.connect("demod", 0, "demod_log", 0)

Copied: 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/gmsk2.py
 (from rev 4429, 
gnuradio/branches/developers/jcorgan/dect/gnuradio-core/src/python/gnuradio/blksimpl/gmsk.py)
===================================================================
--- 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/gmsk2.py
                            (rev 0)
+++ 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/gmsk2.py
    2007-02-11 09:30:44 UTC (rev 4442)
@@ -0,0 +1,300 @@
+#
+# GMSK modulation and demodulation.  
+#
+#
+# Copyright 2005,2006,2007 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
+
+from gnuradio import gr
+from gnuradio import modulation_utils
+from math import pi
+import Numeric
+from pprint import pprint
+import inspect
+
+# default values (used in __init__ and add_options)
+_def_samples_per_symbol = 2
+_def_bt = 0.35
+_def_verbose = False
+_def_log = False
+
+_def_gain_mu = 0.05
+_def_mu = 0.5
+_def_freq_error = 0.0
+_def_omega_relative_limit = 0.005
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                              GMSK modulator
+# /////////////////////////////////////////////////////////////////////////////
+
+class gmsk2_mod(gr.hier_block2):
+
+    def __init__(self,
+                 samples_per_symbol=_def_samples_per_symbol,
+                 bt=_def_bt,
+                 verbose=_def_verbose,
+                 log=_def_log):
+        """
+       Hierarchical block for Gaussian Minimum Shift Key (GMSK)
+       modulation.
+
+       The input is a byte stream (unsigned char) and the
+       output is the complex modulated signal at baseband.
+
+       @param samples_per_symbol: samples per baud >= 2
+       @type samples_per_symbol: integer
+       @param bt: Gaussian filter bandwidth * symbol time
+       @type bt: float
+        @param verbose: Print information about modulator?
+        @type verbose: bool
+        @param debug: Print modualtion data to files?
+        @type debug: bool       
+       """
+        gr.hier_block2.__init__(self,
+                                "gmsk2_mod",                               # 
Block typename
+                                gr.io_signature(1,1,gr.sizeof_char),       # 
Input signature
+                                gr.io_signature(1,1,gr.sizeof_gr_complex)) # 
Output signature
+
+        self._samples_per_symbol = samples_per_symbol
+        self._bt = bt
+
+        if not isinstance(samples_per_symbol, int) or samples_per_symbol < 2:
+            raise TypeError, ("samples_per_symbol must be an integer >= 2, is 
%r" % (samples_per_symbol,))
+
+       ntaps = 4 * samples_per_symbol                  # up to 3 bits in 
filter at once
+       sensitivity = (pi / 2) / samples_per_symbol     # phase change per bit 
= pi / 2
+
+       # Turn it into NRZ data.
+       self.nrz = gr.bytes_to_syms()
+
+       # Form Gaussian filter
+        # Generate Gaussian response (Needs to be convolved with window below).
+       self.gaussian_taps = gr.firdes.gaussian(
+               1,                     # gain
+               samples_per_symbol,    # symbol_rate
+               bt,                    # bandwidth * symbol time
+               ntaps                  # number of taps
+               )
+
+       self.sqwave = (1,) * samples_per_symbol       # rectangular window
+       self.taps = 
Numeric.convolve(Numeric.array(self.gaussian_taps),Numeric.array(self.sqwave))
+       self.gaussian_filter = gr.interp_fir_filter_fff(samples_per_symbol, 
self.taps)
+
+       # FM modulation
+       self.fmmod = gr.frequency_modulator_fc(sensitivity)
+               
+        if verbose:
+            self._print_verbage()
+         
+       # Define and connect components
+        self.define_component("nrz", self.nrz)
+        self.define_component("filter", self.gaussian_filter)
+        self.define_component("fmmod", self.fmmod)
+        self.connect("self", 0, "nrz", 0)
+        self.connect("nrz", 0, "filter", 0)
+        self.connect("filter", 0, "fmmod", 0)
+        self.connect("fmmod", 0, "self", 0)
+
+        if log:
+            self._setup_logging()
+
+    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 1
+    bits_per_symbol = staticmethod(bits_per_symbol)      # make it a static 
method.
+
+
+    def _print_verbage(self):
+        print "bits per symbol = %d" % self.bits_per_symbol()
+        print "Gaussian filter bt = %.2f" % self._bt
+
+
+    def _setup_logging(self):
+        print "Modulation logging turned on."
+        self.define_component("nrz_log", gr.file_sink(gr.sizeof_float, 
"nrz.dat"))
+        self.define_component("filter_log", gr.file_sink(gr.sizeof_float, 
"gaussian_filter.dat"))
+        self.define_component("fmmod_log", gr.file_sink(gr.sizeof_gr_complex, 
"fmmod.dat"))
+        self.connect("nrz", 0, "nrz_log", 0)
+        self.connect("filter", 0, "filter_log", 0)
+        self.connect("fmmod", 0, "fmmod_log", 0)
+
+    def add_options(parser):
+        """
+        Adds GMSK modulation-specific options to the standard parser
+        """
+        parser.add_option("", "--bt", type="float", default=_def_bt,
+                          help="set bandwidth-time product [default=%default] 
(GMSK)")
+    add_options=staticmethod(add_options)
+
+    # FIXME: figure out what has to change for gr.hier_block2 version
+    #def extract_kwargs_from_options(options):
+    #    """
+    #    Given command line options, create dictionary suitable for passing to 
__init__
+    #    """
+    #    return modulation_utils.extract_kwargs_from_options(gmsk_mod.__init__,
+    #                                                        ('self', 'fg'), 
options)
+    #extract_kwargs_from_options=staticmethod(extract_kwargs_from_options)
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                            GMSK demodulator
+# /////////////////////////////////////////////////////////////////////////////
+
+class gmsk2_demod(gr.hier_block2):
+
+    def __init__(self,
+                 samples_per_symbol=_def_samples_per_symbol,
+                 gain_mu=_def_gain_mu,
+                 mu=_def_mu,
+                 omega_relative_limit=_def_omega_relative_limit,
+                 freq_error=_def_freq_error,
+                 verbose=_def_verbose,
+                 log=_def_log):
+        """
+       Hierarchical block for Gaussian Minimum Shift Key (GMSK)
+       demodulation.
+
+       The input is the complex modulated signal at baseband.
+       The output is a stream of bits packed 1 bit per byte (the LSB)
+
+       @param samples_per_symbol: samples per baud
+       @type samples_per_symbol: integer
+        @param verbose: Print information about modulator?
+        @type verbose: bool
+        @param log: Print modualtion data to files?
+        @type log: bool 
+
+        Clock recovery parameters.  These all have reasonble defaults.
+        
+        @param gain_mu: controls rate of mu adjustment
+        @type gain_mu: float
+        @param mu: fractional delay [0.0, 1.0]
+        @type mu: float
+        @param omega_relative_limit: sets max variation in omega
+        @type omega_relative_limit: float, typically 0.000200 (200 ppm)
+        @param freq_error: bit rate error as a fraction
+        @param float
+       """
+
+        gr.hier_block2.__init__(self,
+                                "gmsk2_demod",                             # 
Block typename
+                                gr.io_signature(1,1,gr.sizeof_gr_complex), # 
Input signature
+                                gr.io_signature(1,1,gr.sizeof_char))       # 
Output signature
+                                
+        self._samples_per_symbol = samples_per_symbol
+        self._gain_mu = gain_mu
+        self._mu = mu
+        self._omega_relative_limit = omega_relative_limit
+        self._freq_error = freq_error
+        
+        if samples_per_symbol < 2:
+            raise TypeError, "samples_per_symbol >= 2, is %f" % 
samples_per_symbol
+
+        self._omega = samples_per_symbol*(1+self._freq_error)
+
+       self._gain_omega = .25 * self._gain_mu * self._gain_mu        # 
critically damped
+
+       # Demodulate FM
+       sensitivity = (pi / 2) / samples_per_symbol
+       self.fmdemod = gr.quadrature_demod_cf(1.0 / sensitivity)
+
+       # the clock recovery block tracks the symbol clock and resamples as 
needed.
+       # the output of the block is a stream of soft symbols (float)
+       self.clock_recovery = gr.clock_recovery_mm_ff(self._omega, 
self._gain_omega,
+                                                      self._mu, self._gain_mu,
+                                                      
self._omega_relative_limit)
+
+        # slice the floats at 0, outputting 1 bit (the LSB of the output byte) 
per sample
+        self.slicer = gr.binary_slicer_fb()
+
+        if verbose:
+            self._print_verbage()
+
+        # Define and connect components
+        self.define_component("fmdemod", self.fmdemod)
+        self.define_component("clock_recovery", self.clock_recovery)
+        self.define_component("slicer", self.slicer)
+        self.connect("self", 0, "fmdemod", 0)
+        self.connect("fmdemod", 0, "clock_recovery", 0)
+        self.connect("clock_recovery", 0, "slicer", 0)
+        self.connect("slicer", 0, "self", 0)
+
+        if log:
+            self._setup_logging()
+
+    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 1
+    bits_per_symbol = staticmethod(bits_per_symbol)      # make it a static 
method.
+
+
+    def _print_verbage(self):
+        print "bits per symbol = %d" % self.bits_per_symbol()
+        print "M&M clock recovery omega = %f" % self._omega
+        print "M&M clock recovery gain mu = %f" % self._gain_mu
+        print "M&M clock recovery mu = %f" % self._mu
+        print "M&M clock recovery omega rel. limit = %f" % 
self._omega_relative_limit
+        print "frequency error = %f" % self._freq_error
+
+
+    def _setup_logging(self):
+        print "Demodulation logging turned on."
+        self.define_component("fmdemod_log", gr.file_sink(gr.sizeof_float, 
"fmdemod.dat"))
+        self.define_component("clock_recovery_log", 
gr.file_sink(gr.sizeof_float, "clock_recovery.dat"))
+        self.define_component("slicer_log", gr.file_sink(gr.sizeof_char, 
"slicer.dat"))
+        self.connect("fmdemod", 0, "fmdemod_log", 0)
+        self.connect("clock_recovery", 0, "clock_recovery_log", 0)
+        self.connect("slicer", 0, "slicer_log", 0)
+
+    def add_options(parser):
+        """
+        Adds GMSK demodulation-specific options to the standard parser
+        """
+        parser.add_option("", "--gain-mu", type="float", default=_def_gain_mu,
+                          help="M&M clock recovery gain mu [default=%default] 
(GMSK/PSK)")
+        parser.add_option("", "--mu", type="float", default=_def_mu,
+                          help="M&M clock recovery mu [default=%default] 
(GMSK/PSK)")
+        parser.add_option("", "--omega-relative-limit", type="float", 
default=_def_omega_relative_limit,
+                          help="M&M clock recovery omega relative limit 
[default=%default] (GMSK/PSK)")
+        parser.add_option("", "--freq-error", type="float", 
default=_def_freq_error,
+                          help="M&M clock recovery frequency error 
[default=%default] (GMSK)")
+    add_options=staticmethod(add_options)
+
+    # FIXME: figure out what this is for gr.hier_block2 version
+    #def extract_kwargs_from_options(options):
+    #    """
+    #    Given command line options, create dictionary suitable for passing to 
__init__
+    #    """
+    #    return 
modulation_utils.extract_kwargs_from_options(gmsk_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('gmsk2', gmsk2_mod)
+modulation_utils.add_type_1_demod('gmsk2', gmsk2_demod)

Modified: 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/usrp_dect.py
===================================================================
--- 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/usrp_dect.py
        2007-02-11 07:44:21 UTC (rev 4441)
+++ 
gnuradio/branches/developers/jcorgan/dect/gnuradio-examples/python/dect/usrp_dect.py
        2007-02-11 09:30:44 UTC (rev 4442)
@@ -39,7 +39,9 @@
        parser.add_option("-v", "--verbose", action="store_true", default=False,
                          help="print extra debugging info")
         parser.add_option("", "--log-baseband", default=None,
-                          help="log filtered basedband to file")
+                          help="log filtered baseband to file")
+        parser.add_option("", "--log-demod", default=None,
+                          help="log demodulator output to file")
         (options, args) = parser.parse_args()
 
        if len(sys.argv) == 1 or len(args) != 0: