#!/usr/bin/env python
#
# Copyright 2004,2005,2006 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
from optparse import OptionParser
from ofdm_receiver import ofdm_receiver
class ofdm_mod(gr.hier_block):
def __init__(self, fg, options):
self.fg = fg
self._occupied_tones = options.occupied_tones
self._fft_length = options.fft_length
self._cp_length = options.cp_length
self._mtu = options.mtu
symbol_length = self._fft_length + self._cp_length
if self._fft_length < self._occupied_tones:
sys.stderr.write("occupied tones must be less than FFT length\n")
raise SystemExit
if self._fft_length < self._cp_length:
sys.stderr.write("cyclic prefix length must be less than FFT length\n")
raise SystemExit
win = [] #[1 for i in range(self._fft_length)]
# hard-coded known symbol
#ks = self._occupied_tones*[1,]
ks1 = known_symbols_200_1
ks2 = known_symbols_200_2
self.ofdm = gr.ofdm_bpsk_mapper(self._mtu, self._occupied_tones, self._fft_length, ks1, ks2)
self.ifft = gr.fft_vcc(self._fft_length, False, win, True)
self.cp_adder = gr.ofdm_cyclic_prefixer(self._fft_length, symbol_length)
if options.verbose:
self._print_verbage()
self.fg.connect(self.ofdm, self.ifft, self.cp_adder)
gr.hier_block.__init__(self, self.fg, self.ofdm, self.cp_adder)
def samples_per_symbol(self):
return 2
def mtu(self):
return self._mtu
def bits_per_symbol(self=None): # staticmethod that's also callable on an instance
return 1
bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. RTFM
def add_options(normal, expert):
"""
Adds OFDM-specific options to the Options Parser
"""
expert.add_option("", "--mtu", type="int", default=1500,
help="set maximum transmit unit [default=%default]")
expert.add_option("", "--fft-length", type="intx", default=512,
help="set the number of FFT bins [default=%default]")
expert.add_option("", "--occupied-tones", type="intx", default=200,
help="set the number of occupied FFT bins [default=%default]")
expert.add_option("", "--cp-length", type="intx", default=128,
help="set the number of bits in the cyclic prefix [default=%default]")
# Make a static method to call before instantiation
add_options = staticmethod(add_options)
def _print_verbage(self):
"""
Prints information about the OFDM modulator
"""
print "\nOFDM Modulator:"
print "FFT length: %3d" % (self._fft_length)
print "Occupied Tones: %3d" % (self._occupied_tones)
print "CP length: %3d" % (self._cp_length)
class ofdm_demod(gr.hier_block):
def __init__(self, fg, options):
self.fg = fg
self._occupied_tones = options.occupied_tones
self._fft_length = options.fft_length
self._cp_length = options.cp_length
self._snr = options.snr
symbol_length = self._fft_length + self._cp_length
win = [1 for i in range(self._fft_length)]
# hard-coded known symbol
ks1 = known_symbols_200_1
ks2 = known_symbols_200_2
# ML Sync
self.ofdm_sync = ofdm_receiver(self.fg, self._fft_length, symbol_length, self._snr)
# OFDM Demod
self.fft_demod = gr.fft_vcc(self._fft_length, True, win, True)
self.ofdm_corr = gr.ofdm_correlator(self._occupied_tones, self._fft_length,
self._cp_length, ks1, ks2)
self.ofdm_demod = gr.ofdm_bpsk_demapper(self._occupied_tones)
if options.verbose:
self._print_verbage()
self.fg.connect(self.ofdm_sync, self.fft_demod, self.ofdm_corr, self.ofdm_demod)
gr.hier_block.__init__(self, self.fg, self.ofdm_sync, self.ofdm_demod)
def bits_per_symbol(self=None): # staticmethod that's also callable on an instance
return 1
bits_per_symbol = staticmethod(bits_per_symbol) # make it a static method. RTFM
def add_options(normal, expert):
"""
Adds OFDM-specific options to the Options Parser
"""
expert.add_option("", "--fft-length", type="intx", default=512,
help="set the number of FFT bins [default=%default]")
expert.add_option("", "--occupied-tones", type="intx", default=200,
help="set the number of occupied FFT bins [default=%default]")
expert.add_option("", "--cp-length", type="intx", default=128,
help="set the number of bits in the cyclic prefix [default=%default]")
# Make a static method to call before instantiation
add_options = staticmethod(add_options)
def _print_verbage(self):
"""
Prints information about the OFDM demodulator
"""
print "\nOFDM Demodulator:"
print "FFT length: %3d" % (self._fft_length)
print "Occupied Tones: %3d" % (self._occupied_tones)
print "CP length: %3d" % (self._cp_length)
# generated in python using:
# import random
# pn = [2.0*random.randint(0,1)-1.0 for i in range(self._occupied_tones)]
known_symbols_200_1 = [1.0, 1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0]
known_symbols_200_2 = [-1.0, -1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, 1.0]