| /* -*- c++ -*- */ |
| /* |
| * @file |
| * @author (C) 2009 Piotr Krysik <ptrkrysik@gmail.com> |
| * @section LICENSE |
| * |
| * Gr-gsm 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. |
| * |
| * Gr-gsm 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 gr-gsm; see the file COPYING. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, |
| * Boston, MA 02110-1301, USA. |
| */ |
| |
| /* |
| * viterbi_detector: |
| * This part does the detection of received sequnece. |
| * Employed algorithm is viterbi Maximum Likehood Sequence Estimation. |
| * At this moment it gives hard decisions on the output, but |
| * it was designed with soft decisions in mind. |
| * |
| * SYNTAX: 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) |
| * |
| * INPUT: input: Complex received signal afted matched filtering. |
| * samples_num: Number of samples in the input table. |
| * rhh: The autocorrelation of the estimated channel |
| * impulse response. |
| * start_state: Number of the start point. In GSM each burst |
| * starts with sequence of three bits (0,0,0) which |
| * indicates start point of the algorithm. |
| * stop_states: Table with numbers of possible stop states. |
| * stops_num: Number of possible stop states |
| * |
| * |
| * OUTPUT: output: Differentially decoded hard output of the algorithm: |
| * -1 for logical "0" and 1 for logical "1" |
| * |
| * SUB_FUNC: none |
| * |
| * TEST(S): Tested with real world normal burst. |
| */ |
| |
| #ifndef INCLUDED_VITERBI_DETECTOR_H |
| #define INCLUDED_VITERBI_DETECTOR_H |
| |
| 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); |
| |
| #endif /* INCLUDED_VITERBI_DETECTOR_H */ |