diff options
Diffstat (limited to 'gr-digital/lib/digital_ofdm_sync_sc_cfb.cc')
| -rw-r--r-- | gr-digital/lib/digital_ofdm_sync_sc_cfb.cc | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/gr-digital/lib/digital_ofdm_sync_sc_cfb.cc b/gr-digital/lib/digital_ofdm_sync_sc_cfb.cc new file mode 100644 index 0000000000..a3ebd549cb --- /dev/null +++ b/gr-digital/lib/digital_ofdm_sync_sc_cfb.cc @@ -0,0 +1,109 @@ +/* -*- c++ -*- */ +/* Copyright 2012 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 3, 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. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <gr_io_signature.h> +#include "digital_ofdm_sync_sc_cfb.h" + +#include <gr_delay.h> +#include <blocks/conjugate_cc.h> +#include <blocks/multiply_cc.h> +#include <filter/fir_filter_ccf.h> +#include <blocks/complex_to_mag_squared.h> +#include <filter/fir_filter_fff.h> +#include <blocks/multiply_ff.h> +#include <blocks/divide_ff.h> +#include <blocks/complex_to_arg.h> +#include <analog/plateau_detector_fb.h> +#include <gr_sample_and_hold_ff.h> + +// Define this to add a third output for debugging +//#define SYNC_ADD_DEBUG_OUTPUT + +digital_ofdm_sync_sc_cfb_sptr +digital_make_ofdm_sync_sc_cfb (int fft_len, int cp_len) +{ + return gnuradio::get_initial_sptr (new digital_ofdm_sync_sc_cfb(fft_len, cp_len)); +} + + +digital_ofdm_sync_sc_cfb::digital_ofdm_sync_sc_cfb (int fft_len, int cp_len) + : gr_hier_block2 ("ofdm_sync_sc_cfb", + gr_make_io_signature(1, 1, sizeof (gr_complex)), +#ifndef SYNC_ADD_DEBUG_OUTPUT + gr_make_io_signature2(2, 2, sizeof (float), sizeof (unsigned char))) +#else + gr_make_io_signature3(3, 3, sizeof (float), sizeof (unsigned char), sizeof (float))) +#endif +{ + std::vector<float> ma_taps(fft_len/2, 1.0); + gr_delay_sptr delay(gr_make_delay(sizeof(gr_complex), fft_len/2)); + gr::blocks::conjugate_cc::sptr delay_conjugate(gr::blocks::conjugate_cc::make()); + gr::blocks::multiply_cc::sptr delay_corr(gr::blocks::multiply_cc::make()); + gr::filter::fir_filter_ccf::sptr delay_ma(gr::filter::fir_filter_ccf::make(1, std::vector<float>(fft_len/2, 1.0))); + gr::blocks::complex_to_mag_squared::sptr delay_magsquare(gr::blocks::complex_to_mag_squared::make()); + gr::blocks::divide_ff::sptr delay_normalize(gr::blocks::divide_ff::make()); + + gr::blocks::complex_to_mag_squared::sptr normalizer_magsquare(gr::blocks::complex_to_mag_squared::make()); + gr::filter::fir_filter_fff::sptr normalizer_ma(gr::filter::fir_filter_fff::make(1, std::vector<float>(fft_len, 0.5))); + gr::blocks::multiply_ff::sptr normalizer_square(gr::blocks::multiply_ff::make()); + + gr::blocks::complex_to_arg::sptr peak_to_angle(gr::blocks::complex_to_arg::make()); + gr_sample_and_hold_ff_sptr sample_and_hold(gr_make_sample_and_hold_ff()); + + gr::analog::plateau_detector_fb::sptr plateau_detector(gr::analog::plateau_detector_fb::make(cp_len)); + + // Delay Path + connect(self(), 0, delay, 0); + connect(delay, 0, delay_conjugate, 0); + connect(delay_conjugate, 0, delay_corr, 1); + connect(self(), 0, delay_corr, 0); + connect(delay_corr, 0, delay_ma, 0); + connect(delay_ma, 0, delay_magsquare, 0); + connect(delay_magsquare, 0, delay_normalize, 0); + // Energy Path + connect(self(), 0, normalizer_magsquare, 0); + connect(normalizer_magsquare, 0, normalizer_ma, 0); + connect(normalizer_ma, 0, normalizer_square, 0); + connect(normalizer_ma, 0, normalizer_square, 1); + connect(normalizer_square, 0, delay_normalize, 1); + // Fine frequency estimate (output 0) + connect(delay_ma, 0, peak_to_angle, 0); + connect(peak_to_angle, 0, sample_and_hold, 0); + connect(sample_and_hold, 0, self(), 0); + // Peak detect (output 1) + connect(delay_normalize, 0, plateau_detector, 0); + connect(plateau_detector, 0, sample_and_hold, 1); + connect(plateau_detector, 0, self(), 1); +#ifdef SYNC_ADD_DEBUG_OUTPUT + // Debugging: timing metric (output 2) + connect(delay_normalize, 0, self(), 2); +#endif +} + + +digital_ofdm_sync_sc_cfb::~digital_ofdm_sync_sc_cfb() +{ +} + |