#!/usr/bin/env python
#
# Copyright 2014,2019 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
#
"""
TXs a waveform (either from a file, or a sinusoid) in a frequency-hopping manner.
"""
import argparse
import numpy
import pmt
from gnuradio import gr
from gnuradio import blocks
from gnuradio import uhd
def setup_parser():
""" Setup the parser for the frequency hopper. """
parser = argparse.ArgumentParser(
description="Transmit a signal in a frequency-hopping manner, using tx_freq tags."
)
parser.add_argument(
'-i', '--input-file',
help="File with samples to transmit. If left out, will transmit a sinusoid.")
parser.add_argument(
"-a", "--args", default="",
help="UHD device address args.")
parser.add_argument(
"--spec", default="",
help="UHD subdev spec.")
parser.add_argument(
"--antenna", default="",
help="UHD antenna settings.")
parser.add_argument(
"--gain", default=None, type=float,
help="USRP gain (defaults to mid-point in dB).")
parser.add_argument(
"-r", "--rate", type=float, default=1e6,
help="Sampling rate")
parser.add_argument(
"-N", "--samp-per-burst", type=int, default=10000,
help="Samples per burst")
parser.add_argument(
"-t", "--hop-time", type=float, default=1000,
help="Time between hops in milliseconds. This must be larger than or "
"equal to the burst duration as set by --samp-per-burst")
parser.add_argument(
"-f", "--freq", type=float, default=2.45e9,
help="Base frequency. This is the middle channel frequency at which "
"the USRP will Tx.")
parser.add_argument(
"--dsp", action='store_true',
help="DSP tuning only.")
parser.add_argument(
"-d", "--freq-delta", type=float, default=1e6,
help="Channel spacing.")
parser.add_argument(
"-c", "--num-channels", type=int, default=5,
help="Number of channels.")
parser.add_argument(
"-B", "--num-bursts", type=int, default=30,
help="Number of bursts to transmit before terminating.")
parser.add_argument(
"-p", "--post-tuning", action='count',
help="Tune after transmitting. Default is to tune immediately before "
"transmitting.")
parser.add_argument(
"-v", "--verbose", action='count',
help="Print more information. The morer the printier.")
return parser
class FrequencyHopperSrc(gr.hier_block2):
""" Provides tags for frequency hopping """
def __init__(
self,
n_bursts, n_channels,
freq_delta, base_freq, dsp_tuning,
burst_length, base_time, hop_time,
post_tuning=False,
tx_gain=0,
verbose=False
):
gr.hier_block2.__init__(
self, "FrequencyHopperSrc",
gr.io_signature(1, 1, gr.sizeof_gr_complex),
gr.io_signature(1, 1, gr.sizeof_gr_complex),
)
n_samples_total = n_bursts * burst_length
lowest_frequency = base_freq - numpy.floor(n_channels / 2) * freq_delta
self.hop_sequence = [lowest_frequency + n *
freq_delta for n in range(n_channels)]
numpy.random.shuffle(self.hop_sequence)
# Repeat that:
self.hop_sequence = [self.hop_sequence[x % n_channels]
for x in range(n_bursts)]
if verbose:
print("Hop Frequencies | Hop Pattern")
print("=================|================================")
for f in self.hop_sequence:
print("{:6.3f} MHz | ".format(f / 1e6), end='')
if n_channels < 50:
print(" " * int((f - base_freq) / freq_delta) + "#")
else:
print("\n")
print("=================|================================")
# There's no real point in setting the gain via tag for this application,
# but this is an example to show you how to do it.
gain_tag = gr.tag_t()
gain_tag.offset = 0
gain_tag.key = pmt.string_to_symbol('tx_command')
gain_tag.value = pmt.to_pmt({'gain': tx_gain})
tag_list = [gain_tag, ]
for i in range(len(self.hop_sequence)):
time = pmt.cons(
pmt.from_uint64(int(base_time + i * hop_time + 0.01)),
pmt.from_double((base_time + i * hop_time + 0.01) % 1),
)
tune_tag = gr.tag_t()
tune_tag.offset = i * burst_length
# TODO dsp_tuning should also be able to do post_tuning
if i > 0 and post_tuning and not dsp_tuning:
tune_tag.offset -= 1 # Move it to last sample of previous burst
if dsp_tuning:
tune_tag.key = pmt.string_to_symbol('tx_command')
tune_tag.value = pmt.to_pmt(
{'lo_freq': base_freq, 'dsp_freq': base_freq - self.hop_sequence[i]})
tune_tag.value = pmt.dict_add(
tune_tag.value, pmt.intern("time"), time)
else:
tune_tag.key = pmt.string_to_symbol('tx_command')
tune_tag.value = pmt.to_pmt({'freq': self.hop_sequence[i]})
tune_tag.value = pmt.dict_add(
tune_tag.value, pmt.intern('time'), time)
tag_list.append(tune_tag)
length_tag = gr.tag_t()
length_tag.offset = i * burst_length
length_tag.key = pmt.string_to_symbol('packet_len')
length_tag.value = pmt.from_long(burst_length)
tag_list.append(length_tag)
time_tag = gr.tag_t()
time_tag.offset = i * burst_length
time_tag.key = pmt.string_to_symbol('tx_time')
time_tag.value = pmt.make_tuple(
pmt.car(time),
pmt.cdr(time)
)
tag_list.append(time_tag)
tag_source = blocks.vector_source_c(
(1.0,) * n_samples_total, repeat=False, tags=tag_list)
mult = blocks.multiply_cc()
self.connect(self, mult, self)
self.connect(tag_source, (mult, 1))
class FlowGraph(gr.top_block):
""" Flow graph that does the frequency hopping. """
def __init__(self, args):
gr.top_block.__init__(self)
if args.input_file is not None:
src = blocks.file_source(
gr.sizeof_gr_complex, args.input_file, repeat=True)
else:
src = blocks.vector_source_c((.5,) * int(1e6) * 2, repeat=True)
# Setup USRP
self.usrp = uhd.usrp_sink(
args.args,
uhd.stream_args('fc32'),
"packet_len"
)
if args.spec:
self.usrp.set_subdev_spec(args.spec, 0)
if args.antenna:
self.usrp.set_antenna(args.antenna, 0)
self.usrp.set_samp_rate(args.rate)
# Gain is set in the hopper block
if not args.gain:
gain_range = self.usrp.get_gain_range()
args.gain = float(gain_range.start() + gain_range.stop()) / 2.0
print("-- Setting gain to {} dB".format(args.gain))
if not self.usrp.set_center_freq(args.freq):
print('[ERROR] Failed to set base frequency.')
exit(1)
hopper_block = FrequencyHopperSrc(
args.num_bursts, args.num_channels,
args.freq_delta, args.freq, args.dsp,
args.samp_per_burst, 1.0, args.hop_time / 1000.,
args.post_tuning,
args.gain,
args.verbose,
)
self.connect(src, hopper_block, self.usrp)
def print_hopper_stats(args):
""" Nothing to do with Grace Hopper """
print("""
Parameter | Value
===================+=========================
Hop Interval | {hop_time} ms
Burst duration | {hop_duration} ms
Lowest Frequency | {lowest_freq:6.3f} MHz
Highest Frequency | {highest_freq:6.3f} MHz
Frequency spacing | {freq_delta:6.4f} MHz
Number of channels | {num_channels}
Sampling rate | {rate} Msps
Transmit Gain | {gain} dB
===================+=========================
""".format(
hop_time=args.hop_time,
hop_duration=1000.0 / args.rate * args.samp_per_burst,
gain=args.gain if args.gain else "(midpoint)",
lowest_freq=args.freq / 1e6,
highest_freq=(args.freq + (args.num_channels - 1) *
args.freq_delta) / 1e6,
freq_delta=args.freq_delta / 1e6,
num_channels=args.num_channels,
rate=args.rate / 1e6,
))
def main():
""" Go, go, go! """
args = setup_parser().parse_args()
if (1.0 * args.samp_per_burst / args.rate) > args.hop_time * 1e-3:
print("Burst duration must be smaller than hop time.")
exit(1)
if args.verbose:
print_hopper_stats(args)
top_block = FlowGraph(args)
print("Starting to hop, skip and jump... press Ctrl+C to exit.")
top_block.usrp.set_time_now(uhd.time_spec(0.0))
top_block.run()
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass