1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
/* -*- 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)
{
return generic_decoder::sptr(
new polar_decoder_sc_list(max_list_size, block_size, num_info_bits, frozen_bit_positions,
frozen_bit_values));
}
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) :
polar_decoder_common(block_size, num_info_bits, frozen_bit_positions, frozen_bit_values)
{
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;
initialize_list(in);
const unsigned char* temp = decode_list();
extract_info_bits(out, temp);
}
void
polar_decoder_sc_list::initialize_list(const float* in_buf)
{
polar::path* init_path = d_scl->initial_path();
initialize_decoder(init_path->u_vec, init_path->llr_vec, in_buf);
}
const unsigned char*
polar_decoder_sc_list::decode_list()
{
for(int u_num = 0; u_num < block_size(); u_num++){
decode_bit(u_num);
}
return d_scl->optimal_path()->u_vec;
}
void
polar_decoder_sc_list::decode_bit(const int u_num)
{
if(u_num % 2 && is_frozen_bit(u_num)){ // LLR value is obsolete. save some time.
const unsigned char frozen_bit = next_frozen_bit();
d_scl->set_frozen_bit(frozen_bit, u_num);
}
else{
calculate_llrs_for_list(u_num);
set_bit_in_list(u_num);
}
}
void
polar_decoder_sc_list::calculate_llrs_for_list(const int u_num)
{
for(unsigned int i = 0; i < d_scl->active_size(); i++){
polar::path* current_path = d_scl->next_active_path();
butterfly(current_path->llr_vec, current_path->u_vec, 0, u_num, u_num);
}
}
void
polar_decoder_sc_list::set_bit_in_list(const int u_num)
{
// 1. if frozen bit, update with known value
if(is_frozen_bit(u_num)){
const unsigned char frozen_bit = next_frozen_bit();
d_scl->set_frozen_bit(frozen_bit, u_num);
}
// 2. info bit
else{
d_scl->set_info_bit(u_num);
}
}
} /* namespace fec */
} /* namespace gr */
|
