# # 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 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, gru, blks from gnuradio import usrp from gnuradio import eng_notation import copy import sys # from current dir from pick_bitrate import pick_tx_bitrate # ///////////////////////////////////////////////////////////////////////////// # transmit path # ///////////////////////////////////////////////////////////////////////////// class transmit_path(gr.hier_block): def __init__(self, fg, modulator_class, options): ''' See below for what options should hold ''' options = copy.copy(options) # make a copy so we can destructively modify self._verbose = options.verbose self._tx_freq = options.tx_freq # tranmitter's center frequency self._tx_amplitude = options.tx_amplitude # digital amplitude sent to USRP self._tx_subdev_spec = options.tx_subdev_spec # daughterboard to use self._bitrate = options.bitrate # desired bit rate self._interp = options.interp # interpolating rate for the USRP (prelim) self._samples_per_symbol = options.samples_per_symbol # desired samples/baud self._fusb_block_size = options.fusb_block_size # usb info for USRP self._fusb_nblocks = options.fusb_nblocks # usb info for USRP self._use_whitener_offset = options.use_whitener_offset # increment start of whitener XOR data self._modulator_class = modulator_class # the modulator_class we are using if self._tx_freq is None: sys.stderr.write("-f FREQ or --freq FREQ or --tx-freq FREQ must be specified\n") raise SystemExit # Set up USRP sink; also adjusts interp, samples_per_symbol, and bitrate self._setup_usrp_sink() # copy the final answers back into options for use by modulator options.samples_per_symbol = self._samples_per_symbol options.bitrate = self._bitrate options.interp = self._interp # Get mod_kwargs mod_kwargs = self._modulator_class.extract_kwargs_from_options(options) # Set center frequency of USRP ok = self.set_freq(self._tx_freq) if not ok: print "Failed to set Tx frequency to %s" % (eng_notation.num_to_str(self._tx_freq),) raise ValueError # transmitter self.packet_transmitter = \ blks.mod_pkts(fg, self._modulator_class(fg, **mod_kwargs), access_code=None, msgq_limit=4, pad_for_usrp=True, use_whitener_offset=options.use_whitener_offset) # Set the USRP for maximum transmit gain # (Note that on the RFX cards this is a nop.) self.set_gain(self.subdev.gain_range()[1]) self.amp = gr.multiply_const_cc(1) self.set_tx_amplitude(self._tx_amplitude) # enable Auto Transmit/Receive switching self.set_auto_tr(True) # Display some information about the setup if self._verbose: self._print_verbage() # Create and setup transmit path flow graph fg.connect(self.packet_transmitter, self.amp, self.u) gr.hier_block.__init__(self, fg, None, None) def _setup_usrp_sink(self): """ Creates a USRP sink, determines the settings for best bitrate, and attaches to the transmitter's subdevice. """ self.u = usrp.sink_c(fusb_block_size=self._fusb_block_size, fusb_nblocks=self._fusb_nblocks) dac_rate = self.u.dac_rate(); # derive values of bitrate, samples_per_symbol, and interp from desired info (self._bitrate, self._samples_per_symbol, self._interp) = \ pick_tx_bitrate(self._bitrate, self._modulator_class.bits_per_symbol(), self._samples_per_symbol, self._interp, dac_rate) self.u.set_interp_rate(self._interp) # determine the daughterboard subdevice we're using if self._tx_subdev_spec is None: self._tx_subdev_spec = usrp.pick_tx_subdevice(self.u) self.u.set_mux(usrp.determine_tx_mux_value(self.u, self._tx_subdev_spec)) self.subdev = usrp.selected_subdev(self.u, self._tx_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(self.subdev._which, self.subdev, target_freq) if r: return True return False def set_gain(self, gain): """ Sets the analog gain in the USRP """ self.gain = gain self.subdev.set_gain(gain) def set_tx_amplitude(self, ampl): """ Sets the transmit amplitude sent to the USRP @param: ampl 0 <= ampl < 32768. Try 8000 """ self._tx_amplitude = max(0.0, min(ampl, 32767.0)) self.amp.set_k(self._tx_amplitude) def set_auto_tr(self, enable): """ Turns on auto transmit/receive of USRP daughterboard (if exits; else ignored) """ return self.subdev.set_auto_tr(enable) def send_pkt(self, payload='', eof=False): """ Calls the transmitter method to send a packet """ return self.packet_transmitter.send_pkt(payload, eof) def bitrate(self): return self._bitrate def samples_per_symbol(self): return self._samples_per_symbol def interp(self): return self._interp def add_options(normal, expert): """ Adds transmitter-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("-T", "--tx-subdev-spec", type="subdev", default=None, help="select USRP Tx side A or B") normal.add_option("", "--tx-amplitude", type="eng_float", default=12000, metavar="AMPL", help="set transmitter digital amplitude: 0 <= AMPL < 32768 [default=%default]") normal.add_option("-v", "--verbose", action="store_true", default=False) expert.add_option("-S", "--samples-per-symbol", type="int", default=None, help="set samples/symbol [default=%default]") expert.add_option("", "--tx-freq", type="eng_float", default=None, help="set transmit frequency to FREQ [default=%default]", metavar="FREQ") expert.add_option("-i", "--interp", type="intx", default=None, help="set fpga interpolation rate to INTERP [default=%default]") expert.add_option("", "--log", action="store_true", default=False, help="Log all parts of flow graph to file (CAUTION: lots of data)") expert.add_option("","--use-whitener-offset", action="store_true", default=False, help="make sequential packets use different whitening") # Make a static method to call before instantiation add_options = staticmethod(add_options) def _print_verbage(self): """ Prints information about the transmit path """ print "Using TX d'board %s" % (self.subdev.side_and_name(),) print "Tx amplitude %s" % (self._tx_amplitude) print "modulation: %s" % (self._modulator_class.__name__) print "bitrate: %sb/s" % (eng_notation.num_to_str(self._bitrate)) print "samples/symbol: %3d" % (self._samples_per_symbol) print "interp: %3d" % (self._interp) print "Tx Frequency: %s" % (eng_notation.num_to_str(self._tx_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")