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/* -*- c++ -*- */
/*
* Copyright 2015 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 <gnuradio/io_signature.h>
#include <gnuradio/fec/polar_decoder_sc_list.h>
#include <volk/volk.h>
#include <scl_list.h>
#include <cmath>
#include <algorithm>
namespace gr
{
namespace fec
{
generic_decoder::sptr
polar_decoder_sc_list::make(int max_list_size, int block_size, int num_info_bits,
std::vector<int> frozen_bit_positions,
std::vector<char> frozen_bit_values, bool is_packed)
{
return generic_decoder::sptr(
new polar_decoder_sc_list(max_list_size, block_size, num_info_bits, frozen_bit_positions,
frozen_bit_values, is_packed));
}
polar_decoder_sc_list::polar_decoder_sc_list(int max_list_size, int block_size,
int num_info_bits,
std::vector<int> frozen_bit_positions,
std::vector<char> frozen_bit_values,
bool is_packed) :
polar_decoder_common(block_size, num_info_bits, frozen_bit_positions, frozen_bit_values,
is_packed), d_max_list_size(max_list_size), d_frozen_bit_counter(0)
{
d_scl = new polar::scl_list(max_list_size, block_size, block_power());
}
polar_decoder_sc_list::~polar_decoder_sc_list()
{
delete d_scl;
}
void
polar_decoder_sc_list::generic_work(void* in_buffer, void* out_buffer)
{
const float *in = (const float*) in_buffer;
unsigned char *out = (unsigned char*) out_buffer;
polar::path* init_path = d_scl->initial_path();
initialize_llr_vector(init_path->llr_vec, in);
memset(init_path->u_vec, 0, sizeof(unsigned char) * block_size() * (block_power() + 1));
decode_list();
const polar::path* temp = d_scl->optimal_path();
extract_info_bits(out, temp->u_vec);
}
void
polar_decoder_sc_list::decode_list()
{
d_frozen_bit_counter = 0;
for(int i = 0; i < block_size(); i++){
calculate_next_llr_in_paths(i);
}
}
void
polar_decoder_sc_list::calculate_next_llr_in_paths(int u_num)
{
for(unsigned int i = 0; i < d_scl->active_size(); i++){
polar::path* current_path = d_scl->next_active_path();
calculate_next_llr(current_path, u_num);
}
// 1. if frozen bit, update with known value
if(d_frozen_bit_counter < d_frozen_bit_positions.size() && u_num == d_frozen_bit_positions.at(d_frozen_bit_counter)){
update_with_frozenbit(u_num);
}
// 2. info bit
else{
d_scl->set_info_bit(u_num);
}
}
void
polar_decoder_sc_list::update_with_frozenbit(const int u_num)
{
unsigned char frozen_bit = d_frozen_bit_values[d_frozen_bit_counter];
d_scl->set_frozen_bit(frozen_bit, u_num);
d_frozen_bit_counter++;
}
void
polar_decoder_sc_list::calculate_next_llr(polar::path* current_path, int u_num)
{
butterfly(current_path->llr_vec, current_path->u_vec, 0, u_num, u_num);
}
} /* namespace fec */
} /* namespace gr */
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