[Commit-gnuradio] r5975 - gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2

[jcorgan]

Author: jcorgan
Date: 2007-07-15 22:25:54 -0600 (Sun, 15 Jul 2007)
New Revision: 5975

Added:
   
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/filterbank.py
Modified:
   
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
Log:
Added hier_block2 version of filterbank block.

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 03:52:05 UTC (rev 5974)
+++ 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/Makefile.am
    2007-07-16 04:25:54 UTC (rev 5975)
@@ -31,6 +31,7 @@
        dbpsk.py                \
        dqpsk.py                \
        d8psk.py                \
+       filterbank.py           \
        gmsk.py                 \
        pkt.py                  \
        psk.py                  \

Copied: 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/filterbank.py
 (from rev 5969, 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl/filterbank.py)
===================================================================
--- 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/filterbank.py
                          (rev 0)
+++ 
gnuradio/branches/features/pager/gnuradio-core/src/python/gnuradio/blksimpl2/filterbank.py
  2007-07-16 04:25:54 UTC (rev 5975)
@@ -0,0 +1,174 @@
+#
+# Copyright 2005 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.
+# 
+
+import sys
+from gnuradio import gr, gru
+
+def _generate_synthesis_taps(mpoints):
+    return []   # FIXME
+
+
+def _split_taps(taps, mpoints):
+    assert (len(taps) % mpoints) == 0
+    result = [list() for x in range(mpoints)]
+    for i in xrange(len(taps)):
+        (result[i % mpoints]).append(taps[i])
+    return [tuple(x) for x in result]
+
+
+class synthesis_filterbank(gr.hier_block2):
+    """
+    Uniformly modulated polyphase DFT filter bank: synthesis
+
+    See http://cnx.rice.edu/content/m10424/latest
+    """
+    def __init__(self, mpoints, taps=None):
+        """
+        Takes M complex streams in, produces single complex stream out
+        that runs at M times the input sample rate
+
+        @param fg:      flow_graph
+        @param mpoints: number of freq bins/interpolation factor/subbands
+        @param taps:    filter taps for subband filter
+
+        The channel spacing is equal to the input sample rate.
+        The total bandwidth and output sample rate are equal the input
+        sample rate * nchannels.
+
+        Output stream to frequency mapping:
+        
+          channel zero is at zero frequency.
+
+          if mpoints is odd:
+            
+            Channels with increasing positive frequencies come from
+            channels 1 through (N-1)/2.
+
+            Channel (N+1)/2 is the maximum negative frequency, and
+            frequency increases through N-1 which is one channel lower
+            than the zero frequency.
+
+          if mpoints is even:
+
+            Channels with increasing positive frequencies come from
+            channels 1 through (N/2)-1.
+
+            Channel (N/2) is evenly split between the max positive and
+            negative bins.
+
+            Channel (N/2)+1 is the maximum negative frequency, and
+            frequency increases through N-1 which is one channel lower
+            than the zero frequency.
+
+            Channels near the frequency extremes end up getting cut
+            off by subsequent filters and therefore have diminished
+            utility.
+        """
+        item_size = gr.sizeof_gr_complex
+       gr.hier_block2.__init__(self, "synthesis_filterbank",
+                               gr.io_signature(mpoints, mpoints, item_size),
+                               gr.io_signature(1, 1, item_size))
+
+        if taps is None:
+            taps = _generate_synthesis_taps(mpoints)
+
+        # pad taps to multiple of mpoints
+        r = len(taps) % mpoints
+        if r != 0:
+            taps = taps + (mpoints - r) * (0,)
+
+        # split in mpoints separate set of taps
+        sub_taps = _split_taps(taps, mpoints)
+
+        self.ss2v = gr.streams_to_vector(item_size, mpoints)
+        self.ifft = gr.fft_vcc(mpoints, False, [])
+        self.v2ss = gr.vector_to_streams(item_size, mpoints)
+        # mpoints filters go in here...
+        self.ss2s = gr.streams_to_stream(item_size, mpoints)
+
+       for i in range(mpoints):
+           self.connect((self, i), (self.ss2v, i))
+
+        self.connect(self.ss2v, self.ifft, self.v2ss, self)
+
+        # build mpoints fir filters...
+        for i in range(mpoints):
+            f = gr.fft_filter_ccc(1, sub_taps[i])
+            self.connect((self.v2ss, i), f)
+            self.connect(f, (self.ss2s, i))
+
+
+class analysis_filterbank(gr.hier_block2):
+    """
+    Uniformly modulated polyphase DFT filter bank: analysis
+
+    See http://cnx.rice.edu/content/m10424/latest
+    """
+    def __init__(self, mpoints, taps=None):
+        """
+        Takes 1 complex stream in, produces M complex streams out
+        that runs at 1/M times the input sample rate
+
+        @param fg:      flow_graph
+        @param mpoints: number of freq bins/interpolation factor/subbands
+        @param taps:    filter taps for subband filter
+
+        Same channel to frequency mapping as described above.
+        """
+        item_size = gr.sizeof_gr_complex
+       gr.hier_block2.__init__(self, "analysis_filterbank",
+                               gr.io_signature(1, 1, item_size),
+                               gr.io_signature(mpoints, mpoints, item_size))
+
+        if taps is None:
+            taps = _generate_synthesis_taps(mpoints)
+
+        # pad taps to multiple of mpoints
+        r = len(taps) % mpoints
+        if r != 0:
+            taps = taps + (mpoints - r) * (0,)
+        
+        # split in mpoints separate set of taps
+        sub_taps = _split_taps(taps, mpoints)
+
+        # print >> sys.stderr, "mpoints =", mpoints, "len(sub_taps) =", 
len(sub_taps) 
+        
+        self.s2ss = gr.stream_to_streams(item_size, mpoints)
+        # filters here
+        self.ss2v = gr.streams_to_vector(item_size, mpoints)
+        self.fft = gr.fft_vcc(mpoints, True, [])
+        self.v2ss = gr.vector_to_streams(item_size, mpoints)
+
+       self.connect(self, self.s2ss)
+
+        # build mpoints fir filters...
+        for i in range(mpoints):
+            f = gr.fft_filter_ccc(1, sub_taps[mpoints-i-1])
+            self.connect((self.s2ss, i), f)
+            self.connect(f, (self.ss2v, i))
+
+        self.connect(self.ss2v, self.fft, self.v2ss)
+
+       for i in range(mpoints):
+           self.connect((self.v2ss, i), (self, i))
+
+
+