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Diffstat (limited to 'gnuradio-examples/python/ofdm/receive_path.py')
| -rw-r--r-- | gnuradio-examples/python/ofdm/receive_path.py | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/gnuradio-examples/python/ofdm/receive_path.py b/gnuradio-examples/python/ofdm/receive_path.py new file mode 100644 index 000000000..1c9c23844 --- /dev/null +++ b/gnuradio-examples/python/ofdm/receive_path.py @@ -0,0 +1,125 @@ +#!/usr/bin/env python +# +# Copyright 2005,2006 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., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +from gnuradio import gr, gru, blks +from gnuradio import usrp +from gnuradio import eng_notation +import copy +import sys + +# from current dir +from pick_bitrate import pick_rx_bitrate +import ofdm + +# ///////////////////////////////////////////////////////////////////////////// +# receive path +# ///////////////////////////////////////////////////////////////////////////// + +class receive_path(gr.hier_block): + def __init__(self, fg, rx_callback, options): + + options = copy.copy(options) # make a copy so we can destructively modify + + self._verbose = options.verbose + self._log = options.log + self._rx_callback = rx_callback # this callback is fired when there's a packet available + + if 0: + + chan_coeffs = gr.firdes.low_pass (1.0, # gain + 2.0, # sampling rate + bw, # midpoint of trans. band + 1*bw, # width of trans. band + gr.firdes.WIN_KAISER) # filter type + else: + chan_coeffs = [ 1.0, 0.0, 0 ] + self.chan_filt = gr.fft_filter_ccc(1, chan_coeffs) + + self.ofdm_demod = ofdm.ofdm_demod(fg, options) + + # receiver + self.packet_receiver = \ + blks.demod_ofdm_pkts(fg, + self.ofdm_demod, + access_code=None, + callback=self._rx_callback, + threshold=-1) + + # Carrier Sensing Blocks + alpha = 0.001 + thresh = 30 # in dB, will have to adjust + self.probe = gr.probe_avg_mag_sqrd_c(thresh,alpha) + fg.connect(self.chan_filt, self.probe) + + # Display some information about the setup + if self._verbose: + self._print_verbage() + + fg.connect(self.chan_filt, self.packet_receiver) + #fg.connect(self.chan_filt, gr.file_sink(gr.sizeof_gr_complex, "ofdmrx_chflt.dat")) + gr.hier_block.__init__(self, fg, self.chan_filt, None) + + def carrier_sensed(self): + """ + Return True if we think carrier is present. + """ + #return self.probe.level() > X + return self.probe.unmuted() + + def carrier_threshold(self): + """ + Return current setting in dB. + """ + return self.probe.threshold() + + def set_carrier_threshold(self, threshold_in_db): + """ + Set carrier threshold. + + @param threshold_in_db: set detection threshold + @type threshold_in_db: float (dB) + """ + self.probe.set_threshold(threshold_in_db) + + + def add_options(normal, expert): + """ + Adds receiver-specific options to the Options Parser + """ + normal.add_option("-v", "--verbose", action="store_true", default=False) + expert.add_option("", "--log", action="store_true", default=False, + help="Log all parts of flow graph to files (CAUTION: lots of data)") + + # Make a static method to call before instantiation + add_options = staticmethod(add_options) + + + def _print_verbage(self): + """ + Prints information about the receive path + """ + print "Using RX d'board %s" % (self.subdev.side_and_name(),) + print "Rx gain: %g" % (self.gain,) + print "modulation: %s" % (self._demod_class.__name__) + print "bitrate: %sb/s" % (eng_notation.num_to_str(self._bitrate)) + print "samples/symbol: %3d" % (self._samples_per_symbol) + print "decim: %3d" % (self._decim) |