[Commit-gnuradio] r5974 - gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2

[jcorgan]

Author: jcorgan
Date: 2007-07-15 21:52:05 -0600 (Sun, 15 Jul 2007)
New Revision: 5974

Added:
   
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/rational_resampler.py
Modified:
   
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
Log:
Re-add hier_block2 version of rational resampler while preserving history.

Modified: 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
===================================================================
--- 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
    2007-07-16 03:50:34 UTC (rev 5973)
+++ 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
    2007-07-16 03:52:05 UTC (rev 5974)
@@ -33,7 +33,8 @@
        d8psk.py                \
        gmsk.py                 \
        pkt.py                  \
-       psk.py
+       psk.py                  \
+       rational_resampler.py
 
 noinst_PYTHON =                
 

Copied: 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/rational_resampler.py
 (from rev 5969, 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl/rational_resampler.py)
===================================================================
--- 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/rational_resampler.py
                          (rev 0)
+++ 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/rational_resampler.py
  2007-07-16 03:52:05 UTC (rev 5974)
@@ -0,0 +1,131 @@
+#
+# Copyright 2005,2007 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.
+# 
+
+from gnuradio import gr, gru
+
+_plot = None
+
+def design_filter(interpolation, decimation, fractional_bw):
+    """
+    Given the interpolation rate, decimation rate and a fractional bandwidth,
+    design a set of taps.
+
+    @param interpolation: interpolation factor
+    @type  interpolation: integer > 0
+    @param decimation: decimation factor
+    @type  decimation: integer > 0
+    @param fractional_bw: fractional bandwidth in (0, 0.5)  0.4 works well.
+    @type  fractional_bw: float
+    @returns: sequence of numbers
+    """
+
+    if fractional_bw >= 0.5 or fractional_bw <= 0:
+        raise ValueError, "Invalid fractional_bandwidth, must be in (0, 0.5)"
+
+    beta = 5.0
+    trans_width = 0.5 - fractional_bw
+    mid_transition_band = 0.5 - trans_width/2
+
+    taps = gr.firdes.low_pass(interpolation,                     # gain
+                              1,                                 # Fs
+                              mid_transition_band/interpolation, # trans mid 
point
+                              trans_width/interpolation,         # transition 
width
+                              gr.firdes.WIN_KAISER,
+                              beta                               # beta
+                              )
+
+    return taps
+
+
+
+class _rational_resampler_base(gr.hier_block2):
+    """
+    base class for all rational resampler variants.
+    """
+    def __init__(self, resampler_base,
+                 interpolation, decimation, taps=None, fractional_bw=None):
+        """
+        Rational resampling polyphase FIR filter.
+
+        Either taps or fractional_bw may be specified, but not both.
+        If neither is specified, a reasonable default, 0.4, is used as
+        the fractional_bw.
+
+        @param interpolation: interpolation factor
+        @type  interpolation: integer > 0
+        @param decimation: decimation factor
+        @type  decimation: integer > 0
+        @param taps: optional filter coefficients
+        @type  taps: sequence
+        @param fractional_bw: fractional bandwidth in (0, 0.5), measured at 
final freq (use 0.4)
+        @type  fractional_bw: float
+        """
+
+        if not isinstance(interpolation, int) or interpolation < 1:
+            raise ValueError, "interpolation must be an integer >= 1"
+
+        if not isinstance(decimation, int) or decimation < 1:
+            raise ValueError, "decimation must be an integer >= 1"
+
+        if taps is None and fractional_bw is None:
+            fractional_bw = 0.4
+
+        d = gru.gcd(interpolation, decimation)
+        interpolation = interpolation // d
+        decimation = decimation // d
+        
+        if taps is None:
+            taps = design_filter(interpolation, decimation, fractional_bw)
+
+        resampler = resampler_base(interpolation, decimation, taps)
+       gr.hier_block2.__init__(self, resampler.name(),
+                               gr.io_signature(1, 1, 
resampler.input_signature().sizeof_stream_item(0)),
+                               gr.io_signature(1, 1, 
resampler.output_signature().sizeof_stream_item(1)))
+
+       self.connect(self, resampler, self)
+
+
+class rational_resampler_fff(_rational_resampler_base):
+    def __init__(self, interpolation, decimation, taps=None, 
fractional_bw=None):
+        """
+        Rational resampling polyphase FIR filter with
+        float input, float output and float taps.
+        """
+        _rational_resampler_base.__init__(self, gr.rational_resampler_base_fff,
+                                         interpolation, decimation, taps, 
fractional_bw)
+
+class rational_resampler_ccf(_rational_resampler_base):
+    def __init__(self, interpolation, decimation, taps=None, 
fractional_bw=None):
+        """
+        Rational resampling polyphase FIR filter with
+        complex input, complex output and float taps.
+        """
+        _rational_resampler_base.__init__(self, 
gr.rational_resampler_base_ccf, 
+                                          interpolation, decimation, taps, 
fractional_bw)
+
+class rational_resampler_ccc(_rational_resampler_base):
+    def __init__(self, interpolation, decimation, taps=None, 
fractional_bw=None):
+        """
+        Rational resampling polyphase FIR filter with
+        complex input, complex output and complex taps.
+        """
+        _rational_resampler_base.__init__(self, 
gr.rational_resampler_base_ccc, 
+                                          interpolation, decimation, taps, 
fractional_bw)