82 lines
2.8 KiB
Python
82 lines
2.8 KiB
Python
#
|
|
# Copyright 2012, 2013 Corgan Labs, Nick Foster
|
|
#
|
|
# 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, blocks
|
|
import air_modes_swig
|
|
|
|
class rx_path(gr.hier_block2):
|
|
|
|
def __init__(self, rate, threshold, queue, use_pmf=False):
|
|
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
|
|
self._spc = int(rate/2e6)
|
|
|
|
# Convert incoming I/Q baseband to amplitude
|
|
self._demod = blocks.complex_to_mag_squared()
|
|
self._bb = self._demod
|
|
|
|
# Pulse matched filter for 0.5us pulses
|
|
if use_pmf:
|
|
self._pmf = blocks.moving_average_ff(self._spc, 1.0/self._spc)#, self._rate)
|
|
self.connect(self._demod, self._pmf)
|
|
self._bb = self._pmf
|
|
|
|
# Establish baseline amplitude (noise, interference)
|
|
self._avg = blocks.moving_average_ff(48*self._spc, 1.0/(48*self._spc))#, self._rate) # 3 preambles
|
|
|
|
# Synchronize to Mode-S preamble
|
|
self._sync = air_modes_swig.preamble(self._rate, self._threshold)
|
|
|
|
# Slice Mode-S bits and send to message queue
|
|
self._slicer = air_modes_swig.slicer(self._queue)
|
|
|
|
# Wire up the flowgraph
|
|
self.connect(self, self._demod)
|
|
self.connect(self._bb, (self._sync, 0))
|
|
self.connect(self._bb, self._avg, (self._sync, 1))
|
|
self.connect(self._sync, self._slicer)
|
|
|
|
def set_rate(self, rate):
|
|
self._sync.set_rate(rate)
|
|
self._spc = int(rate/2e6)
|
|
self._avg.set_length_and_scale(48*self._spc, 1.0/(48*self._spc))
|
|
if self._bb != self._demod:
|
|
self._pmf.set_length_and_scale(self._spc, 1.0/self._spc)
|
|
|
|
def set_threshold(self, threshold):
|
|
self._sync.set_threshold(threshold)
|
|
|
|
def set_pmf(self, pmf):
|
|
#TODO must be done when top block is stopped
|
|
pass
|
|
|
|
def get_pmf(self, pmf):
|
|
return not (self._bb == self._demod)
|
|
|
|
def get_threshold(self, threshold):
|
|
return self._sync.get_threshold()
|
|
|