piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 1 | /* -*- c++ -*- */ |
| 2 | /* |
| 3 | * @file |
Piotr Krysik | a6268a5 | 2017-08-23 16:02:19 +0200 | [diff] [blame] | 4 | * @author (C) 2009 Piotr Krysik <ptrkrysik@gmail.com> |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 5 | * @section LICENSE |
| 6 | * |
ptrkrysik | 529895b | 2014-12-02 18:07:38 +0100 | [diff] [blame] | 7 | * Gr-gsm is free software; you can redistribute it and/or modify |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 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 | * |
ptrkrysik | 529895b | 2014-12-02 18:07:38 +0100 | [diff] [blame] | 12 | * Gr-gsm is distributed in the hope that it will be useful, |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 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 |
ptrkrysik | 529895b | 2014-12-02 18:07:38 +0100 | [diff] [blame] | 18 | * along with gr-gsm; see the file COPYING. If not, write to |
piotr | 437f546 | 2014-02-04 17:57:25 +0100 | [diff] [blame] | 19 | * the Free Software Foundation, Inc., 51 Franklin Street, |
| 20 | * Boston, MA 02110-1301, USA. |
| 21 | */ |
| 22 | |
| 23 | /* |
| 24 | * viterbi_detector: |
| 25 | * This part does the detection of received sequnece. |
| 26 | * Employed algorithm is viterbi Maximum Likehood Sequence Estimation. |
| 27 | * At this moment it gives hard decisions on the output, but |
| 28 | * it was designed with soft decisions in mind. |
| 29 | * |
| 30 | * SYNTAX: void viterbi_detector( |
| 31 | * const gr_complex * input, |
| 32 | * unsigned int samples_num, |
| 33 | * gr_complex * rhh, |
| 34 | * unsigned int start_state, |
| 35 | * const unsigned int * stop_states, |
| 36 | * unsigned int stops_num, |
| 37 | * float * output) |
| 38 | * |
| 39 | * INPUT: input: Complex received signal afted matched filtering. |
| 40 | * samples_num: Number of samples in the input table. |
| 41 | * rhh: The autocorrelation of the estimated channel |
| 42 | * impulse response. |
| 43 | * start_state: Number of the start point. In GSM each burst |
| 44 | * starts with sequence of three bits (0,0,0) which |
| 45 | * indicates start point of the algorithm. |
| 46 | * stop_states: Table with numbers of possible stop states. |
| 47 | * stops_num: Number of possible stop states |
| 48 | * |
| 49 | * |
| 50 | * OUTPUT: output: Differentially decoded hard output of the algorithm: |
| 51 | * -1 for logical "0" and 1 for logical "1" |
| 52 | * |
| 53 | * SUB_FUNC: none |
| 54 | * |
| 55 | * TEST(S): Tested with real world normal burst. |
| 56 | */ |
| 57 | |
| 58 | #ifndef INCLUDED_VITERBI_DETECTOR_H |
| 59 | #define INCLUDED_VITERBI_DETECTOR_H |
| 60 | |
| 61 | void viterbi_detector(const gr_complex * input, unsigned int samples_num, gr_complex * rhh, unsigned int start_state, const unsigned int * stop_states, unsigned int stops_num, float * output); |
| 62 | |
| 63 | #endif /* INCLUDED_VITERBI_DETECTOR_H */ |