[Commit-gnuradio] r5657 - gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl

[trondeau]

Author: trondeau
Date: 2007-06-03 21:08:40 -0600 (Sun, 03 Jun 2007)
New Revision: 5657

Added:
   
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/channel_model.py
Modified:
   
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am
Log:
adding channel model block for simulations

Modified: 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am
===================================================================
--- 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am
     2007-06-04 02:14:43 UTC (rev 5656)
+++ 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am
     2007-06-04 03:08:40 UTC (rev 5657)
@@ -29,6 +29,7 @@
 grblkspython_PYTHON =          \
        __init__.py             \
        am_demod.py             \
+       channel_model.py        \
        dbpsk.py                \
        dqpsk.py                \
        d8psk.py                \

Added: 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/channel_model.py
===================================================================
--- 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/channel_model.py
                                (rev 0)
+++ 
gnuradio/branches/features/ofdm/receiver/gnuradio-core/src/python/gnuradio/blksimpl/channel_model.py
        2007-06-04 03:08:40 UTC (rev 5657)
@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+#
+# Copyright 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
+
+class channel_model(gr.hier_block):
+    def __init__(self, fg, noise_voltage=0.0, frequency_offset=0.0, 
epsilon=1.0, taps=[1.0,0.0]):
+        ''' Creates a channel model that includes:
+          - AWGN noise power in terms of noise voltage
+          - A frequency offest in the channel in ratio
+          - A timing offset ratio to model clock difference (epsilon)
+          - Multipath taps
+          '''
+
+        print epsilon
+        self.timing_offset = gr.fractional_interpolator_cc(0, epsilon)
+        
+        self.multipath = gr.fir_filter_ccc(1, taps)
+        
+        self.noise_adder = gr.add_cc()
+        self.noise = gr.noise_source_c(gr.GR_GAUSSIAN,noise_voltage)
+        self.freq_offset = gr.sig_source_c(1, gr.GR_SIN_WAVE, 
frequency_offset, 1.0, 0.0)
+        self.mixer_offset = gr.multiply_cc()
+
+        fg.connect(self.timing_offset, self.multipath)
+        fg.connect(self.multipath, (self.mixer_offset,0))
+        fg.connect(self.freq_offset,(self.mixer_offset,1))
+        fg.connect(self.mixer_offset, (self.noise_adder,1))
+        fg.connect(self.noise, (self.noise_adder,0))
+        
+        gr.hier_block.__init__(self, fg, self.timing_offset, self.noise_adder)