From 43819f0f33498239970b4479684f12aa080859e6 Mon Sep 17 00:00:00 2001 From: jcorgan Date: Thu, 26 Apr 2007 22:51:48 +0000 Subject: Merged r4518:5130 from developer branch n4hy/ofdm into trunk, passes distcheck. Adds incomplete OFDM implementation, further work to be completed in the features/ofdm branch. git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@5131 221aa14e-8319-0410-a670-987f0aec2ac5 --- gnuradio-examples/python/ofdm/ofdm.py | 161 ++++++++++++++++++++++++++++++++++ 1 file changed, 161 insertions(+) create mode 100644 gnuradio-examples/python/ofdm/ofdm.py (limited to 'gnuradio-examples/python/ofdm/ofdm.py') diff --git a/gnuradio-examples/python/ofdm/ofdm.py b/gnuradio-examples/python/ofdm/ofdm.py new file mode 100644 index 000000000..8b1e616f9 --- /dev/null +++ b/gnuradio-examples/python/ofdm/ofdm.py @@ -0,0 +1,161 @@ +#!/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] -- cgit