[Commit-gnuradio] gnuradio-core/src/python/gnuradio/blksimpl Make...

[Johnathan Corgan]

CVSROOT:        /sources/gnuradio
Module name:    gnuradio-core
Changes by:     Johnathan Corgan <jcorgan>      06/07/02 18:31:23

Modified files:
        src/python/gnuradio/blksimpl: Makefile.am 
Added files:
        src/python/gnuradio/blksimpl: am_demod.py 

Log message:
        Added AM demodulation block hierarchy.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am?cvsroot=gnuradio&r1=1.13&r2=1.14
http://cvs.savannah.gnu.org/viewcvs/gnuradio-core/src/python/gnuradio/blksimpl/am_demod.py?cvsroot=gnuradio&rev=1.1

Patches:
Index: Makefile.am
===================================================================
RCS file: 
/sources/gnuradio/gnuradio-core/src/python/gnuradio/blksimpl/Makefile.am,v
retrieving revision 1.13
retrieving revision 1.14
diff -u -b -r1.13 -r1.14
--- Makefile.am 2 Jul 2006 18:17:22 -0000       1.13
+++ Makefile.am 2 Jul 2006 18:31:23 -0000       1.14
@@ -28,6 +28,7 @@
 
 grblkspython_PYTHON =          \
        __init__.py             \
+       am_demod.py             \
        filterbank.py           \
        fm_demod.py             \
        fm_emph.py              \

Index: am_demod.py
===================================================================
RCS file: am_demod.py
diff -N am_demod.py
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ am_demod.py 2 Jul 2006 18:31:23 -0000       1.1
@@ -0,0 +1,75 @@
+#
+# Copyright 2006 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., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+# 
+
+from gnuradio import gr, optfir
+
+class am_demod_cf(gr.hier_block):
+    """
+    Generalized AM demodulation block with audio filtering.
+
+    This block demodulates a band-limited, complex down-converted AM 
+    channel into the the original baseband signal, applying low pass 
+    filtering to the audio output. It produces a float stream in the
+    range [-1.0, +1.0].
+
+    @param fg: flowgraph
+    @param channel_rate:  incoming sample rate of the AM baseband
+    @type sample_rate: integer
+    @param audio_decim: input to output decimation rate
+    @type audio_decim: integer
+    @param audio_pass: audio low pass filter passband frequency 
+    @type audio_pass: float
+    @param audio_stop: audio low pass filter stop frequency
+    @type audio_stop: float
+    """ 
+    def __init__(self, fg, channel_rate, audio_decim, audio_pass, audio_stop):
+       MAG = gr.complex_to_mag()
+       DCR = gr.add_const_ff(-1.0)
+
+       audio_taps = optfir.low_pass(0.5,          # Filter gain
+                                    channel_rate, # Sample rate
+                                    audio_pass,   # Audio passband
+                                    audio_stop,   # Audio stopband
+                                    0.1,          # Passband ripple
+                                    60)           # Stopband attenuation
+       LPF = gr.fir_filter_fff(audio_decim, audio_taps)
+
+       fg.connect(MAG, DCR, LPF)
+       gr.hier_block.__init__(self, fg, MAG, LPF)
+
+class demod_10k0a3e_cf(am_demod_cf):
+    """
+    AM demodulation block, 10 KHz channel.
+    
+    This block demodulates an AM channel conformant to 10K0A3E emission
+    standards, such as broadcast band AM transmissions.
+
+    @param fg: flowgraph
+    @param channel_rate:  incoming sample rate of the AM baseband
+    @type sample_rate: integer
+    @param audio_decim: input to output decimation rate
+    @type audio_decim: integer
+    """
+    def __init__(self, fg, channel_rate, audio_decim):
+       am_demod_cf.__init__(self, fg, channel_rate, audio_decim, 
+                            5000, # Audio passband
+                            5500) # Audio stopband
+       
\ No newline at end of file