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Diffstat (limited to 'gsm-receiver/src/lib/viterbi_detector.h')
| -rw-r--r-- | gsm-receiver/src/lib/viterbi_detector.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/gsm-receiver/src/lib/viterbi_detector.h b/gsm-receiver/src/lib/viterbi_detector.h new file mode 100644 index 0000000..0360f83 --- /dev/null +++ b/gsm-receiver/src/lib/viterbi_detector.h @@ -0,0 +1,63 @@ +/* -*- c++ -*- */ +/* + * @file + * @author Piotr Krysik <pkrysik@stud.elka.pw.edu.pl> + * @section LICENSE + * + * This program 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. + * + * This program 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 this program; 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 */ |