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/* -*- c++ -*- */
/*
* Copyright 2007,2009,2010 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 "dpll_bb_impl.h"
#include <gnuradio/io_signature.h>
#include <cstdio>
namespace gr {
namespace analog {
dpll_bb::sptr dpll_bb::make(float period, float gain)
{
return gnuradio::get_initial_sptr(new dpll_bb_impl(period, gain));
}
dpll_bb_impl::dpll_bb_impl(float period, float gain)
: sync_block("dpll_bb",
io_signature::make(1, 1, sizeof(char)),
io_signature::make(1, 1, sizeof(char))),
d_restart(0),
d_pulse_phase(0)
{
d_pulse_frequency = 1.0 / period;
d_gain = gain;
d_decision_threshold = 1.0 - 0.5 * d_pulse_frequency;
#if 0
fprintf(stderr,"frequency = %f period = %f gain = %f threshold = %f\n",
d_pulse_frequency,
period,
d_gain,
d_decision_threshold);
#endif
}
dpll_bb_impl::~dpll_bb_impl() {}
int dpll_bb_impl::work(int noutput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items)
{
const char* iptr = (const char*)input_items[0];
char* optr = (char*)output_items[0];
for (int i = 0; i < noutput_items; i++) {
optr[i] = 0;
if (iptr[i] == 1) {
if (d_restart == 0) {
d_pulse_phase = 1;
} else {
if (d_pulse_phase > 0.5)
d_pulse_phase += d_gain * (1.0 - d_pulse_phase);
else
d_pulse_phase -= d_gain * d_pulse_phase;
}
d_restart = 3;
}
if (d_pulse_phase > d_decision_threshold) {
d_pulse_phase -= 1.0;
if (d_restart > 0) {
d_restart -= 1;
optr[i] = 1;
}
}
d_pulse_phase += d_pulse_frequency;
}
return noutput_items;
}
} /* namespace analog */
} /* namespace gr */
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