65 lines
2.8 KiB
C++
65 lines
2.8 KiB
C++
/* -*- c++ -*- */
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/*
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* @file
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* @author (C) 2009 Piotr Krysik <ptrkrysik@gmail.com>
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* @section LICENSE
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*
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* Gr-gsm is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* any later version.
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*
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* Gr-gsm is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with gr-gsm; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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/*
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* viterbi_detector:
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* This part does the detection of received sequnece.
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* Employed algorithm is viterbi Maximum Likehood Sequence Estimation.
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* At this moment it gives hard decisions on the output, but
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* it was designed with soft decisions in mind.
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*
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* SYNTAX: void viterbi_detector(
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* const gr_complex * input,
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* unsigned int samples_num,
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* gr_complex * rhh,
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* unsigned int start_state,
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* const unsigned int * stop_states,
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* unsigned int stops_num,
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* float * output)
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*
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* INPUT: input: Complex received signal afted matched filtering.
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* samples_num: Number of samples in the input table.
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* rhh: The autocorrelation of the estimated channel
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* impulse response.
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* start_state: Number of the start point. In GSM each burst
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* starts with sequence of three bits (0,0,0) which
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* indicates start point of the algorithm.
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* stop_states: Table with numbers of possible stop states.
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* stops_num: Number of possible stop states
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*
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*
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* OUTPUT: output: Differentially decoded hard output of the algorithm:
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* -1 for logical "0" and 1 for logical "1"
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*
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* SUB_FUNC: none
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*
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* TEST(S): Tested with real world normal burst.
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*/
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#ifndef INCLUDED_VITERBI_DETECTOR_H
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#define INCLUDED_VITERBI_DETECTOR_H
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#include "constants.h"
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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);
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#endif /* INCLUDED_VITERBI_DETECTOR_H */
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