From 28e086141aead2e43f958f0ae14d58cac557fa2d Mon Sep 17 00:00:00 2001
From: trondeau <trondeau@221aa14e-8319-0410-a670-987f0aec2ac5>
Date: Wed, 7 Mar 2007 04:31:19 +0000
Subject: merged trondeau/digital-wip2 r4193:4730 into trunk - improves digital
receiver and fixes ticket:72
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@4731 221aa14e-8319-0410-a670-987f0aec2ac5
---
.../python/hier/digital/transmit_path.py | 239 +++++++++++++++++++++
1 file changed, 239 insertions(+)
create mode 100644 gnuradio-examples/python/hier/digital/transmit_path.py
(limited to 'gnuradio-examples/python/hier/digital/transmit_path.py')
diff --git a/gnuradio-examples/python/hier/digital/transmit_path.py b/gnuradio-examples/python/hier/digital/transmit_path.py
new file mode 100644
index 0000000000..c517210aef
--- /dev/null
+++ b/gnuradio-examples/python/hier/digital/transmit_path.py
@@ -0,0 +1,239 @@
+#
+# 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, blks2
+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_block2):
+ def __init__(self, modulator_class, options):
+ '''
+ See below for what options should hold
+ '''
+
+ gr.hier_block2.__init__(self, "transmit_path",
+ gr.io_signature(0,0,0), # 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._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._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 = \
+ blks2.mod_pkts(self._modulator_class(**mod_kwargs),
+ access_code=None,
+ msgq_limit=4,
+ pad_for_usrp=True)
+
+ # Set the USRP for maximum transmit gain
+ # (Note that on the RFX cards this is a nop.)
+ self.set_gain(self.subdev.gain_range()[0])
+
+ 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()
+
+ # Define the components
+ self.define_component("packet_transmitter", self.packet_transmitter)
+ self.define_component("amp", self.amp)
+ self.define_component("usrp", self.u)
+
+ # Connect components in the flowgraph; set amp component to the output of this block
+ self.connect("packet_transmitter", 0, "amp", 0)
+ self.connect("amp", 0, "usrp", 0)
+
+ 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)")
+
+ # 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")
--
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