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/* -*- c++ -*- */
/*
* Copyright 2019-2020 Daniel Estevez <daniel@destevez.net>
*
* This file is part of gr-satellites
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "distributed_syncframe_soft_impl.h"
#include <gnuradio/io_signature.h>
namespace gr {
namespace satellites {
distributed_syncframe_soft::sptr
distributed_syncframe_soft::make(int threshold, const std::string& syncword, int step)
{
return gnuradio::make_block_sptr<distributed_syncframe_soft_impl>(
threshold, syncword, step);
}
/*
* The private constructor
*/
distributed_syncframe_soft_impl::distributed_syncframe_soft_impl(
int threshold, const std::string& syncword, int step)
: gr::sync_block("distributed_syncframe_soft",
gr::io_signature::make(1, 1, sizeof(float)),
gr::io_signature::make(0, 0, 0)),
d_threshold(threshold),
d_step(step)
{
// look at LSB only, as in correlate_access_code_bb_impl.cc
for (auto s : syncword)
d_syncword.push_back(s & 1);
set_history(d_syncword.size() * d_step);
message_port_register_out(pmt::mp("out"));
}
/*
* Our virtual destructor.
*/
distributed_syncframe_soft_impl::~distributed_syncframe_soft_impl() {}
int distributed_syncframe_soft_impl::work(int noutput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items)
{
size_t match;
const float* in = (const float*)input_items[0];
for (int i = 0; i < noutput_items; i++) {
match = 0;
for (size_t j = 0; j < d_syncword.size(); ++j) {
match += (in[i + j * d_step] < 0.0) ^ d_syncword[j];
}
if (match >= d_syncword.size() - d_threshold) {
// sync found
message_port_pub(
pmt::mp("out"),
pmt::cons(pmt::PMT_NIL,
pmt::init_f32vector(d_syncword.size() * d_step, in + i)));
}
}
return noutput_items;
}
} /* namespace satellites */
} /* namespace gr */
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