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/* -*- c++ -*- */
/*
* Copyright 2013 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "ofdm_sync_sc_cfb_impl.h"
#include <gnuradio/io_signature.h>
#include <gnuradio/blocks/complex_to_arg.h>
#include <gnuradio/blocks/complex_to_mag_squared.h>
#include <gnuradio/blocks/conjugate_cc.h>
#include <gnuradio/blocks/delay.h>
#include <gnuradio/blocks/divide.h>
#include <gnuradio/blocks/multiply.h>
#include <gnuradio/blocks/sample_and_hold.h>
#include <gnuradio/filter/fir_filter_blk.h>
namespace gr {
namespace digital {
ofdm_sync_sc_cfb::sptr
ofdm_sync_sc_cfb::make(int fft_len, int cp_len, bool use_even_carriers, float threshold)
{
return gnuradio::get_initial_sptr(
new ofdm_sync_sc_cfb_impl(fft_len, cp_len, use_even_carriers, threshold));
}
ofdm_sync_sc_cfb_impl::ofdm_sync_sc_cfb_impl(int fft_len,
int cp_len,
bool use_even_carriers,
float threshold)
: hier_block2("ofdm_sync_sc_cfb",
io_signature::make(1, 1, sizeof(gr_complex)),
#ifndef SYNC_ADD_DEBUG_OUTPUT
io_signature::make2(2, 2, sizeof(float), sizeof(unsigned char)))
#else
io_signature::make3(
3, 3, sizeof(float), sizeof(unsigned char), sizeof(float)))
#endif
{
std::vector<float> ma_taps(fft_len / 2, 1.0);
gr::blocks::delay::sptr delay(
gr::blocks::delay::make(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, use_even_carriers ? 1.0 : -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::blocks::sample_and_hold_ff::sptr sample_and_hold(
gr::blocks::sample_and_hold_ff::make());
gr::blocks::plateau_detector_fb::sptr plateau_detector(
gr::blocks::plateau_detector_fb::make(cp_len, threshold));
// store plateau detector for use in callback setting threshold
d_plateau_detector = plateau_detector;
// 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
}
ofdm_sync_sc_cfb_impl::~ofdm_sync_sc_cfb_impl() {}
void ofdm_sync_sc_cfb_impl::set_threshold(float threshold)
{
d_plateau_detector->set_threshold(threshold);
}
float ofdm_sync_sc_cfb_impl::threshold() const { return d_plateau_detector->threshold(); }
} /* namespace digital */
} /* namespace gr */
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