gr-air-modes/python/rx_path.py
Johnathan Corgan 62304ff59e Refactor flowgraph into hierarchical block
This commit creates air_modes.rx_path, which is the common portion
of the flowgraph once the sample source and possible resampler are
created.  It takes baseband I/Q and emits Mode-S packets into the
supplied message queue.
2012-10-15 09:27:22 -07:00

51 lines
1.8 KiB
Python

#
# Copyright 2012 Corgan Labs
#
# This file is part of gr-air-modes
#
# gr-air-modes 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.
#
# gr-air-modes 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 gr-air-modes; 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
import air_modes_swig
class rx_path(gr.hier_block2):
def __init__(self, rate, threshold, queue):
gr.hier_block2.__init__(self, "modes_rx_path",
gr.io_signature(1, 1, gr.sizeof_gr_complex),
gr.io_signature(0,0,0))
self._rate = int(rate)
self._threshold = threshold
self._queue = queue
# Convert incoming I/Q baseband to amplitude
self._demod = gr.complex_to_mag()
# Establish baseline amplitude (noise, interference)
self._avg = gr.moving_average_ff(100, 1.0/100, 400) # FIXME
# Synchronize to Mode-S preamble
self._sync = air_modes_swig.modes_preamble(self._rate, self._threshold)
# Slice Mode-S bits and send to message queue
self._slicer = air_modes_swig.modes_slicer(self._rate, self._queue)
self.connect(self, self._demod, (self._sync, 0))
self.connect(self._demod, self._avg, (self._sync, 1))
self.connect(self._sync, self._slicer)