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
|
/* -*- 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.h>
#include <volk/volk.h>
#include <cmath>
#include <cstdio>
namespace gr
{
namespace fec
{
generic_decoder::sptr
polar_decoder_sc::make(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(block_size, num_info_bits, frozen_bit_positions, frozen_bit_values));
}
polar_decoder_sc::polar_decoder_sc(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_llr_vec = (float*) volk_malloc(sizeof(float) * block_size * (block_power() + 1), volk_get_alignment());
memset(d_llr_vec, 0, sizeof(float) * block_size * (block_power() + 1));
d_u_hat_vec = (unsigned char*) volk_malloc(block_size * (block_power() + 1), volk_get_alignment());
memset(d_u_hat_vec, 0, sizeof(unsigned char) * block_size * (block_power() + 1));
}
polar_decoder_sc::~polar_decoder_sc()
{
volk_free(d_llr_vec);
volk_free(d_u_hat_vec);
}
void
polar_decoder_sc::generic_work(void* in_buffer, void* out_buffer)
{
const float *in = (const float*) in_buffer;
unsigned char *out = (unsigned char*) out_buffer;
initialize_decoder(d_u_hat_vec, d_llr_vec, in);
sc_decode(d_llr_vec, d_u_hat_vec);
extract_info_bits(out, d_u_hat_vec);
}
void
polar_decoder_sc::sc_decode(float* llrs, unsigned char* u)
{
for(int i = 0; i < block_size(); i++){
butterfly(llrs, u, 0, i, i);
u[i] = retrieve_bit_from_llr(llrs[i], i);
}
}
unsigned char
polar_decoder_sc::retrieve_bit_from_llr(float llr, const int pos)
{
if(is_frozen_bit(pos)){
return next_frozen_bit();
}
return llr_bit_decision(llr);
}
} /* namespace fec */
} /* namespace gr */
|
