gr-digital: API-CHANGE. Tidying bpsk, qpsk and generic_mod_demod.

author: Ben Reynwar <ben@reynwar.net> 2012-04-26 21:41:11 -0700
committer: Ben Reynwar <ben@reynwar.net> 2012-04-26 21:41:11 -0700
commit: 93940233c63b1e889a502dc0558de2bc03bab414 (patch)
tree: 604e286bf13689f2af939e04b395a17da5587111
parent: e7f45e3c513242706a9e4aa36e99e33e79e66d4f (diff)
3 files changed, 75 insertions, 98 deletions
diff --git a/gr-digital/python/bpsk.py b/gr-digital/python/bpsk.py
index 0d8f05c4c1..09dc856cf5 100644
--- a/gr-digital/python/bpsk.py
+++ b/gr-digital/python/bpsk.py
@@ -31,18 +31,11 @@ from gnuradio.digital.generic_mod_demod import generic_mod, generic_demod
 import digital_swig
 import modulation_utils
 
-# Default number of points in constellation.
-_def_constellation_points = 2
-# Whether differential coding is used.
-_def_differential = False
-
 # /////////////////////////////////////////////////////////////////////////////
 #                           BPSK constellation
 # /////////////////////////////////////////////////////////////////////////////
 
-def bpsk_constellation(m=_def_constellation_points):
-    if m != _def_constellation_points:
-        raise ValueError("BPSK can only have 2 constellation points.")
+def bpsk_constellation():
     return digital_swig.constellation_bpsk()
 
 # /////////////////////////////////////////////////////////////////////////////
@@ -51,8 +44,7 @@ def bpsk_constellation(m=_def_constellation_points):
 
 class bpsk_mod(generic_mod):
 
-    def __init__(self, constellation_points=_def_constellation_points,
-                 differential=False, *args, **kwargs):
+    def __init__(self, differential=False, *args, **kwargs):
 
         """
 	Hierarchical block for RRC-filtered BPSK modulation.
@@ -63,10 +55,7 @@ class bpsk_mod(generic_mod):
         See generic_mod block for list of parameters.
 	"""
 
-        constellation_points = _def_constellation_points
         constellation = digital_swig.constellation_bpsk()
-        if constellation_points != 2:
-            raise ValueError('Number of constellation points must be 2 for BPSK.')
         super(bpsk_mod, self).__init__(constellation=constellation,
                                        differential=differential, *args, **kwargs)
         
@@ -77,8 +66,7 @@ class bpsk_mod(generic_mod):
 
 class bpsk_demod(generic_demod):
 
-    def __init__(self, constellation_points=_def_constellation_points,
-                 differential=False, *args, **kwargs):
+    def __init__(self, differential=False, *args, **kwargs):
 
         """
 	Hierarchical block for RRC-filtered BPSK modulation.
@@ -89,10 +77,7 @@ class bpsk_demod(generic_demod):
         See generic_demod block for list of parameters.
         """
 
-        constellation_points = _def_constellation_points
         constellation = digital_swig.constellation_bpsk()
-        if constellation_points != 2:
-            raise ValueError('Number of constellation points must be 2 for BPSK.')
         super(bpsk_demod, self).__init__(constellation=constellation,
                                          differential=differential, *args, **kwargs)
 
@@ -102,19 +87,16 @@ class bpsk_demod(generic_demod):
 #                           DBPSK constellation
 # /////////////////////////////////////////////////////////////////////////////
 
-def dbpsk_constellation(m=_def_constellation_points):
-    if m != _def_constellation_points:
-        raise ValueError("DBPSK can only have 2 constellation points.")
+def dbpsk_constellation():
     return digital_swig.constellation_dbpsk()
 
 # /////////////////////////////////////////////////////////////////////////////
 #                           DBPSK modulator
 # /////////////////////////////////////////////////////////////////////////////
 
-class dbpsk_mod(generic_mod):
+class dbpsk_mod(bpsk_mod):
 
-    def __init__(self, constellation_points=_def_constellation_points,
-                 differential=True, *args, **kwargs):
+    def __init__(self, *args, **kwargs):
 
         """
 	Hierarchical block for RRC-filtered DBPSK modulation.
@@ -125,12 +107,7 @@ class dbpsk_mod(generic_mod):
         See generic_mod block for list of parameters.
 	"""
 
-        constellation_points = _def_constellation_points
-        constellation = digital_swig.constellation_bpsk()
-        if constellation_points != 2:
-            raise ValueError('Number of constellation points must be 2 for DBPSK.')
-        super(dbpsk_mod, self).__init__(constellation=constellation,
-                                        differential=True,
+        super(dbpsk_mod, self).__init__(differential=True,
                                         *args, **kwargs)
 
 # /////////////////////////////////////////////////////////////////////////////
@@ -138,10 +115,9 @@ class dbpsk_mod(generic_mod):
 #
 # /////////////////////////////////////////////////////////////////////////////
 
-class dbpsk_demod(generic_demod):
+class dbpsk_demod(bpsk_demod):
 
-    def __init__(self, constellation_points=_def_constellation_points,
-                 differential=True, *args, **kwargs):
+    def __init__(self, *args, **kwargs):
 
         """
 	Hierarchical block for RRC-filtered DBPSK modulation.
@@ -152,12 +128,7 @@ class dbpsk_demod(generic_demod):
         See generic_demod block for list of parameters.
         """
 
-        constellation_points = _def_constellation_points
-        constellation = digital_swig.constellation_bpsk()
-        if constellation_points != 2:
-            raise ValueError('Number of constellation points must be 2 for DBPSK.')
-        super(dbpsk_demod, self).__init__(constellation=constellation,
-                                          differential=True,
+        super(dbpsk_demod, self).__init__(differential=True,
                                           *args, **kwargs)
 
 #
diff --git a/gr-digital/python/generic_mod_demod.py b/gr-digital/python/generic_mod_demod.py
index ae876e1086..49a5f5ac6c 100644
--- a/gr-digital/python/generic_mod_demod.py
+++ b/gr-digital/python/generic_mod_demod.py
@@ -78,8 +78,8 @@ class generic_mod(gr.hier_block2):
     def __init__(self, constellation,
                  samples_per_symbol=_def_samples_per_symbol,
                  differential=_def_differential,
+                 pre_diff_code=True,
                  excess_bw=_def_excess_bw,
-                 gray_coded=True,
                  verbose=_def_verbose,
                  log=_def_log):
         """
@@ -92,10 +92,12 @@ class generic_mod(gr.hier_block2):
 	@type constellation: gnuradio.digital.gr_constellation
 	@param samples_per_symbol: samples per baud >= 2
 	@type samples_per_symbol: float
+	@param differential: whether to use differential encoding
+	@type differential: boolean
+	@param pre_diff_code: whether to use apply a pre-differential mapping
+	@type pre_diff_code: boolean
 	@param excess_bw: Root-raised cosine filter excess bandwidth
 	@type excess_bw: float
-        @param gray_coded: turn gray coding on/off
-        @type gray_coded: bool
         @param verbose: Print information about modulator?
         @type verbose: bool
         @param log: Log modulation data to files?
@@ -110,6 +112,8 @@ class generic_mod(gr.hier_block2):
         self._samples_per_symbol = samples_per_symbol
         self._excess_bw = excess_bw
         self._differential = differential
+        # Only apply a predifferential coding if the constellation also supports it.
+        self.pre_diff_code = pre_diff_code and self._constellation.apply_pre_diff_code()
 
         if self._samples_per_symbol < 2:
             raise TypeError, ("sbp must be >= 2, is %f" % self._samples_per_symbol)
@@ -120,7 +124,7 @@ class generic_mod(gr.hier_block2):
         self.bytes2chunks = \
           gr.packed_to_unpacked_bb(self.bits_per_symbol(), gr.GR_MSB_FIRST)
 
-        if gray_coded == True:
+        if self.pre_diff_code:
             self.symbol_mapper = gr.map_bb(self._constellation.pre_diff_code())
 
         if differential:
@@ -142,7 +146,7 @@ class generic_mod(gr.hier_block2):
 
 	# Connect
         blocks = [self, self.bytes2chunks]
-        if gray_coded == True:
+        if self.pre_diff_code:
             blocks.append(self.symbol_mapper)
         if differential:
             blocks.append(self.diffenc)
@@ -186,7 +190,7 @@ class generic_mod(gr.hier_block2):
         print "Modulation logging turned on."
         self.connect(self.bytes2chunks,
                      gr.file_sink(gr.sizeof_char, "tx_bytes2chunks.8b"))
-        if self._constellation.apply_pre_diff_code():
+        if self.pre_diff_code:
             self.connect(self.symbol_mapper,
                          gr.file_sink(gr.sizeof_char, "tx_symbol_mapper.8b"))
         if self._differential:
@@ -210,8 +214,8 @@ class generic_demod(gr.hier_block2):
     def __init__(self, constellation,
                  samples_per_symbol=_def_samples_per_symbol,
                  differential=_def_differential,
+                 pre_diff_code=True,
                  excess_bw=_def_excess_bw,
-                 gray_coded=True,
                  freq_bw=_def_freq_bw,
                  timing_bw=_def_timing_bw,
                  phase_bw=_def_phase_bw,
@@ -227,10 +231,12 @@ class generic_demod(gr.hier_block2):
 	@type constellation: gnuradio.digital.gr_constellation
 	@param samples_per_symbol: samples per symbol >= 2
 	@type samples_per_symbol: float
+	@param differential: whether to use differential encoding
+	@type differential: boolean
+	@param pre_diff_code: whether to use apply a pre-differential mapping
+	@type pre_diff_code: boolean
 	@param excess_bw: Root-raised cosine filter excess bandwidth
 	@type excess_bw: float
-        @param gray_coded: turn gray coding on/off
-        @type gray_coded: bool
         @param freq_bw: loop filter lock-in bandwidth
         @type freq_bw: float
         @param timing_bw: timing recovery loop lock-in bandwidth
@@ -259,6 +265,9 @@ class generic_demod(gr.hier_block2):
         if self._samples_per_symbol < 2:
             raise TypeError, ("sbp must be >= 2, is %d" % self._samples_per_symbol)
 
+        # Only apply a predifferential coding if the constellation also supports it.
+        self.pre_diff_code = pre_diff_code and self._constellation.apply_pre_diff_code()
+
         arity = pow(2,self.bits_per_symbol())
 
         nfilts = 32
@@ -289,7 +298,7 @@ class generic_demod(gr.hier_block2):
         if differential:
             self.diffdec = gr.diff_decoder_bb(arity)
 
-        if gray_coded:
+        if self.pre_diff_code:
             self.symbol_mapper = gr.map_bb(
                 mod_codes.invert_code(self._constellation.pre_diff_code()))
 
@@ -307,7 +316,7 @@ class generic_demod(gr.hier_block2):
                   self.time_recov, self.receiver]
         if differential:
             blocks.append(self.diffdec)
-        if self._constellation.apply_pre_diff_code():
+        if self.pre_diff_code:
             blocks.append(self.symbol_mapper)
         blocks += [self.unpack, self]
         self.connect(*blocks)
@@ -357,7 +366,7 @@ class generic_demod(gr.hier_block2):
         if self._differential:
             self.connect(self.diffdec,
                          gr.file_sink(gr.sizeof_char, "rx_diffdec.8b"))
-        if self._constellation.apply_pre_diff_code():
+        if self.pre_diff_code:
             self.connect(self.symbol_mapper,
                          gr.file_sink(gr.sizeof_char, "rx_symbol_mapper.8b"))
         self.connect(self.unpack,
diff --git a/gr-digital/python/qpsk.py b/gr-digital/python/qpsk.py
index be21fd76f1..2fdeabd40f 100644
--- a/gr-digital/python/qpsk.py
+++ b/gr-digital/python/qpsk.py
@@ -27,21 +27,20 @@ Demodulation is not included since the generic_mod_demod
 
 from gnuradio import gr
 from gnuradio.digital.generic_mod_demod import generic_mod, generic_demod
+from utils import mod_codes
 import digital_swig
 import modulation_utils
 
-# Default number of points in constellation.
-_def_constellation_points = 4
-# Whether gray coding is used.
-_def_gray_coded = True
+# The default encoding (e.g. gray-code, set-partition)
+_def_mod_code = mod_codes.GRAY_CODE
 
 # /////////////////////////////////////////////////////////////////////////////
 #                           QPSK constellation
 # /////////////////////////////////////////////////////////////////////////////
 
-def qpsk_constellation(m=_def_constellation_points): 
-    if m != _def_constellation_points:
-        raise ValueError("QPSK can only have 4 constellation points.")
+def qpsk_constellation(mod_code=_def_mod_code): 
+    if mod_code != mod_codes.GRAY_CODE:
+        raise ValueError("This QPSK mod/demod works only for gray-coded constellations.")
     return digital_swig.constellation_qpsk()
 
 # /////////////////////////////////////////////////////////////////////////////
@@ -50,9 +49,7 @@ def qpsk_constellation(m=_def_constellation_points):
 
 class qpsk_mod(generic_mod):
 
-    def __init__(self, constellation_points=_def_constellation_points,
-                 gray_coded=_def_gray_coded,
-                 *args, **kwargs):
+    def __init__(self, mod_code=_def_mod_code, differential=False, *args, **kwargs):
 
         """
 	Hierarchical block for RRC-filtered QPSK modulation.
@@ -62,15 +59,21 @@ class qpsk_mod(generic_mod):
 
         See generic_mod block for list of parameters.
 	"""
-
-        constellation_points = _def_constellation_points
-        constellation = digital_swig.constellation_qpsk()
-        if constellation_points != 4:
-            raise ValueError("QPSK can only have 4 constellation points.")
-        if not gray_coded:
-            raise ValueError("This QPSK mod/demod works only for gray-coded constellations.")
+        
+        pre_diff_code = True
+        if not differential:
+            constellation = digital_swig.constellation_qpsk()
+            if mod_code != mod_codes.GRAY_CODE:
+                raise ValueError("This QPSK mod/demod works only for gray-coded constellations.")
+        else:
+            constellation = digital_swig.constellation_dqpsk()
+            if mod_code not in (mod_codes.GRAY_CODE or mod_codes.NO_CODE):
+                raise ValueError("That mod_code is not supported for DQPSK mod/demod.")
+            if mod_code == mod_codes.NO_CODE:
+                pre_diff_code = False
+                
         super(qpsk_mod, self).__init__(constellation=constellation,
-                                       gray_coded=gray_coded, 
+                                       pre_diff_code=pre_diff_code,
                                        *args, **kwargs)
 
 
@@ -81,7 +84,7 @@ class qpsk_mod(generic_mod):
 
 class qpsk_demod(generic_demod):
 
-    def __init__(self, constellation_points=_def_constellation_points,
+    def __init__(self, mod_code=_def_mod_code, differential=False,
                  *args, **kwargs):
 
         """
@@ -93,11 +96,20 @@ class qpsk_demod(generic_demod):
         See generic_demod block for list of parameters.
         """
 
-        constellation_points = _def_constellation_points
-        constellation = digital_swig.constellation_qpsk()
-        if constellation_points != 4:
-            raise ValueError('Number of constellation points must be 4 for QPSK.')
+        pre_diff_code = True
+        if not differential:
+            constellation = digital_swig.constellation_qpsk()
+            if mod_code != mod_codes.GRAY_CODE:
+                raise ValueError("This QPSK mod/demod works only for gray-coded constellations.")
+        else:
+            constellation = digital_swig.constellation_dqpsk()
+            if mod_code not in (mod_codes.GRAY_CODE or mod_codes.NO_CODE):
+                raise ValueError("That mod_code is not supported for DQPSK mod/demod.")
+            if mod_code == mod_codes.NO_CODE:
+                pre_diff_code = False
+
         super(qpsk_demod, self).__init__(constellation=constellation,
+                                         pre_diff_code=pre_diff_code,
                                          *args, **kwargs)
 
 
@@ -106,20 +118,18 @@ class qpsk_demod(generic_demod):
 #                           DQPSK constellation
 # /////////////////////////////////////////////////////////////////////////////
 
-def dqpsk_constellation(m=_def_constellation_points):
-    if m != _def_constellation_points:
-        raise ValueError("DQPSK can only have 4 constellation points.")
+def dqpsk_constellation(mod_code=_def_mod_code):
+    if mod_code != mod_codes.GRAY_CODE:
+        raise ValueError("The DQPSK constellation is only generated for gray_coding.  But it can be used for non-grayed coded modulation if one doesn't use the pre-differential code.")
     return digital_swig.constellation_dqpsk()
 
 # /////////////////////////////////////////////////////////////////////////////
 #                           DQPSK modulator
 # /////////////////////////////////////////////////////////////////////////////
 
-class dqpsk_mod(generic_mod):
+class dqpsk_mod(qpsk_mod):
 
-    def __init__(self, constellation_points=_def_constellation_points,
-                 gray_coded=_def_gray_coded,
-                 differential=True, *args, **kwargs):
+    def __init__(self, mod_code=_def_mod_code, *args, **kwargs):
         """
 	Hierarchical block for RRC-filtered DQPSK modulation.
 
@@ -128,14 +138,7 @@ class dqpsk_mod(generic_mod):
 
         See generic_mod block for list of parameters.
 	"""
-
-        constellation_points = _def_constellation_points
-        constellation = digital_swig.constellation_dqpsk()
-        if constellation_points != 4:
-            raise ValueError('Number of constellation points must be 4 for DQPSK.')
-        super(dqpsk_mod, self).__init__(constellation=constellation,
-                                        gray_coded=gray_coded,
-                                        differential=True,
+        super(dqpsk_mod, self).__init__(mod_code, differential=True,
                                         *args, **kwargs)
 
 # /////////////////////////////////////////////////////////////////////////////
@@ -143,10 +146,9 @@ class dqpsk_mod(generic_mod):
 #
 # /////////////////////////////////////////////////////////////////////////////
 
-class dqpsk_demod(generic_demod):
+class dqpsk_demod(qpsk_demod):
 
-    def __init__(self, constellation_points=_def_constellation_points,
-                 differential=True, *args, **kwargs):
+    def __init__(self, mod_code=_def_mod_code, *args, **kwargs):
 
         """
 	Hierarchical block for RRC-filtered DQPSK modulation.
@@ -156,12 +158,7 @@ class dqpsk_demod(generic_demod):
 
         See generic_demod block for list of parameters.
         """
-        constellation_points = _def_constellation_points
-        constellation = digital_swig.constellation_dqpsk()
-        if constellation_points != 4:
-            raise ValueError('Number of constellation points must be 4 for DQPSK.')
-        super(dqpsk_demod, self).__init__(constellation=constellation,
-                                          differential=True,
+        super(dqpsk_demod, self).__init__(mod_code, differential=True,
                                           *args, **kwargs)
 
 #
author	Ben Reynwar <ben@reynwar.net>	2012-04-26 21:41:11 -0700
committer	Ben Reynwar <ben@reynwar.net>	2012-04-26 21:41:11 -0700
commit	93940233c63b1e889a502dc0558de2bc03bab414 (patch)
tree	604e286bf13689f2af939e04b395a17da5587111
parent	e7f45e3c513242706a9e4aa36e99e33e79e66d4f (diff)