#!/usr/bin/env python
#
-# Copyright 2005,2006 Free Software Foundation, Inc.
+# Copyright 2005,2006,2007 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# Boston, MA 02110-1301, USA.
#
-from gnuradio import gr, gru, blks
-from gnuradio import usrp
+from gnuradio import gr, gru, blks2
from gnuradio import eng_notation
import copy
import sys
-# from current dir
-from pick_bitrate import pick_rx_bitrate
-
# /////////////////////////////////////////////////////////////////////////////
# receive path
# /////////////////////////////////////////////////////////////////////////////
-class receive_path(gr.hier_block):
- def __init__(self, fg, demod_class, rx_callback, options):
+class receive_path(gr.hier_block2):
+ def __init__(self, demod_class, rx_callback, options):
+ gr.hier_block2.__init__(self, "receive_path",
+ gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
+ gr.io_signature(0, 0, 0)) # Output signature
+
options = copy.copy(options) # make a copy so we can destructively modify
self._verbose = options.verbose
- self._rx_freq = options.rx_freq # receiver's center frequency
- self._rx_gain = options.rx_gain # receiver's gain
- self._rx_subdev_spec = options.rx_subdev_spec # daughterboard to use
self._bitrate = options.bitrate # desired bit rate
- self._decim = options.decim # Decimating rate for the USRP (prelim)
self._samples_per_symbol = options.samples_per_symbol # desired samples/symbol
- self._fusb_block_size = options.fusb_block_size # usb info for USRP
- self._fusb_nblocks = options.fusb_nblocks # usb info for USRP
self._rx_callback = rx_callback # this callback is fired when there's a packet available
self._demod_class = demod_class # the demodulator_class we're using
- if self._rx_freq is None:
- sys.stderr.write("-f FREQ or --freq FREQ or --rx-freq FREQ must be specified\n")
- raise SystemExit
-
- # Set up USRP source; also adjusts decim, samples_per_symbol, and bitrate
- self._setup_usrp_source()
-
- # copy the final answers back into options for use by demodulator
- options.samples_per_symbol = self._samples_per_symbol
- options.bitrate = self._bitrate
- options.decim = self._decim
-
# Get demod_kwargs
demod_kwargs = self._demod_class.extract_kwargs_from_options(options)
chan_coeffs = gr.firdes.low_pass (1.0, # gain
sw_decim * self._samples_per_symbol, # sampling rate
1.0, # midpoint of trans. band
- 0.1, # width of trans. band
- gr.firdes.WIN_HANN) # filter type
-
- # Decimating channel filter
- # complex in and out, float taps
- self.chan_filt = gr.fft_filter_ccc(sw_decim, chan_coeffs)
- #self.chan_filt = gr.fir_filter_ccf(sw_decim, chan_coeffs)
-
+ 0.5, # width of trans. band
+ gr.firdes.WIN_HANN) # filter type
+ self.channel_filter = gr.fft_filter_ccc(sw_decim, chan_coeffs)
+
# receiver
self.packet_receiver = \
- blks.demod_pkts(fg,
- self._demod_class(fg, **demod_kwargs),
- access_code=None,
- callback=self._rx_callback,
- threshold=-1)
-
- ok = self.set_freq(self._rx_freq)
- if not ok:
- print "Failed to set Rx frequency to %s" % (eng_notation.num_to_str(self._rx_freq))
- raise ValueError, eng_notation.num_to_str(self._rx_freq)
-
- g = self.subdev.gain_range()
- if options.show_rx_gain_range:
- print "Rx Gain Range: minimum = %g, maximum = %g, step size = %g" \
- % (g[0], g[1], g[2])
-
- self.set_gain(options.rx_gain)
-
- self.set_auto_tr(True) # enable Auto Transmit/Receive switching
+ blks2.demod_pkts(self._demod_class(**demod_kwargs),
+ 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.u, self.chan_filt, self.packet_receiver)
- gr.hier_block.__init__(self, fg, None, None)
-
- def _setup_usrp_source(self):
- self.u = usrp.source_c (fusb_block_size=self._fusb_block_size,
- fusb_nblocks=self._fusb_nblocks)
- adc_rate = self.u.adc_rate()
- # derive values of bitrate, samples_per_symbol, and decim from desired info
- (self._bitrate, self._samples_per_symbol, self._decim) = \
- pick_rx_bitrate(self._bitrate, self._demod_class.bits_per_symbol(), \
- self._samples_per_symbol, self._decim, adc_rate)
+ # connect block input to channel filter
+ self.connect(self, self.channel_filter)
- self.u.set_decim_rate(self._decim)
+ # connect the channel input filter to the carrier power detector
+ self.connect(self.channel_filter, self.probe)
- # determine the daughterboard subdevice we're using
- if self._rx_subdev_spec is None:
- self._rx_subdev_spec = usrp.pick_rx_subdevice(self.u)
- self.subdev = usrp.selected_subdev(self.u, self._rx_subdev_spec)
+ # connect channel filter to the packet receiver
+ self.connect(self.channel_filter, self.packet_receiver)
- self.u.set_mux(usrp.determine_rx_mux_value(self.u, self._rx_subdev_spec))
-
- def set_freq(self, target_freq):
- """
- Set the center frequency we're interested in.
-
- @param target_freq: frequency in Hz
- @rypte: bool
-
- Tuning is a two step process. First we ask the front-end to
- tune as close to the desired frequency as it can. Then we use
- the result of that operation and our target_frequency to
- determine the value for the digital up converter.
- """
- r = self.u.tune(0, self.subdev, target_freq)
- if r:
- return True
-
- return False
-
- def set_gain(self, gain):
- """
- Sets the analog gain in the USRP
- """
- if gain is None:
- r = self.subdev.gain_range()
- gain = (r[0] + r[1])/2 # set gain to midpoint
- self.gain = gain
- return self.subdev.set_gain(gain)
-
- def set_auto_tr(self, enable):
- return self.subdev.set_auto_tr(enable)
-
def bitrate(self):
return self._bitrate
def samples_per_symbol(self):
return self._samples_per_symbol
- def decim(self):
- return self._decim
-
def carrier_sensed(self):
"""
Return True if we think carrier is present.
"""
Adds receiver-specific options to the Options Parser
"""
- add_freq_option(normal)
if not normal.has_option("--bitrate"):
- normal.add_option("-r", "--bitrate", type="eng_float", default=None,
- help="specify bitrate. samples-per-symbol and interp/decim will be derived.")
- normal.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
- help="select USRP Rx side A or B")
- normal.add_option("", "--rx-gain", type="eng_float", default=None, metavar="GAIN",
- help="set receiver gain in dB [default=midpoint]. See also --show-rx-gain-range")
- normal.add_option("", "--show-rx-gain-range", action="store_true", default=False,
- help="print min and max Rx gain available on selected daughterboard")
+ normal.add_option("-r", "--bitrate", type="eng_float", default=100e3,
+ help="specify bitrate [default=%default].")
normal.add_option("-v", "--verbose", action="store_true", default=False)
- expert.add_option("-S", "--samples-per-symbol", type="int", default=None,
+ expert.add_option("-S", "--samples-per-symbol", type="int", default=2,
help="set samples/symbol [default=%default]")
- expert.add_option("", "--rx-freq", type="eng_float", default=None,
- help="set Rx frequency to FREQ [default=%default]", metavar="FREQ")
- expert.add_option("-d", "--decim", type="intx", default=None,
- help="set fpga decimation rate to DECIM [default=%default]")
expert.add_option("", "--log", action="store_true", default=False,
help="Log all parts of flow graph to files (CAUTION: lots of data)")
"""
Prints information about the receive path
"""
- print "Using RX d'board %s" % (self.subdev.side_and_name(),)
- print "Rx gain: %g" % (self.gain,)
+ print "\nReceive Path:"
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)
- print "Rx Frequency: %s" % (eng_notation.num_to_str(self._rx_freq))
- # print "Rx Frequency: %f" % (self._rx_freq)
-
-def add_freq_option(parser):
- """
- Hackery that has the -f / --freq option set both tx_freq and rx_freq
- """
- def freq_callback(option, opt_str, value, parser):
- parser.values.rx_freq = value
- parser.values.tx_freq = value
-
- if not parser.has_option('--freq'):
- parser.add_option('-f', '--freq', type="eng_float",
- action="callback", callback=freq_callback,
- help="set Tx and/or Rx frequency to FREQ [default=%default]",
- metavar="FREQ")