#!/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]