1 /* -*- c++ -*- */
2 /*
3  * Copyright 2015 Free Software Foundation, Inc.
4  *
5  * This file is part of GNU Radio
6  *
7  * GNU Radio is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 3, or (at your option)
10  * any later version.
11  *
12  * GNU Radio is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with GNU Radio; see the file COPYING.  If not, write to
19  * the Free Software Foundation, Inc., 51 Franklin Street,
20  * Boston, MA 02110-1301, USA.
21  */
22 
23 #ifndef INCLUDED_TPC_DECODER_H
24 #define INCLUDED_TPC_DECODER_H
25 
26 typedef float INPUT_DATATYPE;
27 typedef unsigned char OUTPUT_DATATYPE;
28 
29 #include <gnuradio/fec/decoder.h>
30 #include <map>
31 #include <string>
32 #include <vector>
33 
34 namespace gr {
35 namespace fec {
36 
37 
38 #define MAXLOG 1e7
39 
40 class FEC_API tpc_decoder : public generic_decoder
41 {
42     // private constructor
43     tpc_decoder(std::vector<int> row_polys,
44                 std::vector<int> col_polys,
45                 int krow,
46                 int kcol,
47                 int bval,
48                 int qval,
49                 int max_iter,
50                 int decoder_type);
51 
52     // plug into the generic fec api
53     int get_history();
54     float get_shift();
55     int get_input_item_size();
56     int get_output_item_size();
57     const char* get_conversion();
58     void generic_work(void* inBuffer, void* outbuffer);
59     int get_output_size();
60     int get_input_size();
61 
62     std::vector<int> d_rowpolys;
63     std::vector<int> d_colpolys;
64 
65     unsigned int d_krow;
66     unsigned int d_kcol;
67 
68     int d_bval;
69     int d_qval;
70 
71     int d_max_iter;
72     int d_decoder_type;
73 
74     // store the state transitions & outputs
75     int rowNumStates;
76     std::vector<std::vector<int>> rowOutputs;
77     std::vector<std::vector<int>> rowNextStates;
78     int colNumStates;
79     std::vector<std::vector<int>> colOutputs;
80     std::vector<std::vector<int>> colNextStates;
81 
82     int rowEncoder_K;
83     int rowEncoder_n;
84     int rowEncoder_m;
85     int colEncoder_K;
86     int colEncoder_n;
87     int colEncoder_m;
88     int outputSize;
89     int inputSize;
90 
91     uint32_t codeword_M;
92     uint32_t codeword_N;
93 
94     int mInit, nInit;
95 
96     // memory allocated for processing
97     int inputSizeWithPad;
98 
99     std::vector<std::vector<float>> channel_llr;
100     std::vector<std::vector<float>> Z;
101     std::vector<float> extrinsic_info;
102     std::vector<float> input_u_rows;
103     std::vector<float> input_u_cols;
104     std::vector<float> input_c_rows;
105     std::vector<float> input_c_cols;
106     std::vector<float> output_u_rows;
107     std::vector<float> output_u_cols;
108     std::vector<float> output_c_rows;
109     std::vector<float> output_c_cols;
110 
111     uint32_t numInitLoadIter;
112     int numInitRemaining;
113     int output_c_col_idx;
114 
115     bool earlyExit;
116 
117     FILE* fp;
118 
119     // soft input soft output decoding
120     int mm_row, max_states_row, num_symbols_row;
121     std::vector<std::vector<float>> beta_row;
122     std::vector<float> alpha_prime_row;
123     std::vector<float> alpha_row;
124     std::vector<float> metric_c_row;
125     std::vector<float> rec_array_row;
126     std::vector<float> num_llr_c_row;
127     std::vector<float> den_llr_c_row;
128     void siso_decode_row();
129 
130     int mm_col, max_states_col, num_symbols_col;
131     std::vector<std::vector<float>> beta_col;
132     std::vector<float> alpha_prime_col;
133     std::vector<float> alpha_col;
134     std::vector<float> metric_c_col;
135     std::vector<float> rec_array_col;
136     std::vector<float> num_llr_c_col;
137     std::vector<float> den_llr_c_col;
138     void siso_decode_col();
139 
140     // Computes the branch metric used for decoding, returning a metric between the
141     // hypothetical symbol and received vector
142     float gamma(const std::vector<float> rec_array, const int symbol);
143 
144     float (tpc_decoder::*max_star)(const float, const float);
145 
146     float linear_log_map(const float delta1, const float delta2);
147     float max_log_map(const float delta1, const float delta2);
148     float constant_log_map(const float delta1, const float delta2);
149     float log_map_lut_correction(const float delta1, const float delta2);
150     float log_map_cfunction_correction(const float delta1, const float delta2);
151 
152     template <typename T>
153     static int sgn(T val);
154 
155 public:
156     static generic_decoder::sptr make(std::vector<int> row_poly,
157                                       std::vector<int> col_poly,
158                                       int krow,
159                                       int kcol,
160                                       int bval,
161                                       int qval,
162                                       int max_iter,
163                                       int decoder_type);
164     ~tpc_decoder();
rate()165     double rate() { return (1.0 * get_output_size() / get_input_size()); }
set_frame_size(unsigned int frame_size)166     bool set_frame_size(unsigned int frame_size) { return false; }
167 };
168 
169 } // namespace fec
170 } // namespace gr
171 
172 #endif /* INCLUDED_TPC_DECODER_H */
173