Imported Upstream version 3.2.2

[debian/gnuradio] / gnuradio-core / src / python / gnuradio / blks2impl / am_demod.py

diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/am_demod.py b/gnuradio-core/src/python/gnuradio/blks2impl/am_demod.py
new file mode 100644 (file)
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@@ -0,0 +1,76 @@
+#
+# Copyright 2006,2007 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 3, 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, optfir
+
+class am_demod_cf(gr.hier_block2):
+    """
+    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 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, channel_rate, audio_decim, audio_pass, audio_stop):
+       gr.hier_block2.__init__(self, "am_demod_cf",
+                               gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
+                               gr.io_signature(1, 1, gr.sizeof_float))      # Input signature
+
+       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)
+
+       self.connect(self, MAG, DCR, LPF, self)
+
+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 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, channel_rate, audio_decim):
+       am_demod_cf.__init__(self, channel_rate, audio_decim, 
+                            5000, # Audio passband
+                            5500) # Audio stopband
+       
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