Stephen Wolfe
528536e3f2
Add a viterbi decoder base class that viterbi decoder implementations can inherit from.
71 lines
2.1 KiB
C++
71 lines
2.1 KiB
C++
/*
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* Copyright (C) 2016 Bastian Bloessl <bloessl@ccs-labs.org>
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*
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* This program 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 of the License, or
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* (at your option) any later version.
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*
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* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef INCLUDED_IEEE802_11_VITERBI_DECODER_BASE_H
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#define INCLUDED_IEEE802_11_VITERBI_DECODER_BASE_H
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#include "utils.h"
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namespace gr {
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namespace ieee802_11 {
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// Maximum number of traceback bytes
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#define TRACEBACK_MAX 24
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/* This Viterbi decoder was taken from the gr-dvbt module of
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* GNU Radio. It is an SSE2 version of the Viterbi Decoder
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* created by Phil Karn. The SSE2 version was made by Bogdan
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* Diaconescu. For more info see: gr-dvbt/lib/d_viterbi.h
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*/
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class base
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{
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public:
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base();
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~base();
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virtual uint8_t* decode(ofdm_param *ofdm, frame_param *frame, uint8_t *in) = 0;
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protected:
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// Position in circular buffer where the current decoded byte is stored
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int d_store_pos;
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// Metrics for each state
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unsigned char d_mmresult[64] __attribute__((aligned(16)));
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// Paths for each state
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unsigned char d_ppresult[TRACEBACK_MAX][64] __attribute__((aligned(16)));
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int d_ntraceback;
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int d_k;
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ofdm_param *d_ofdm;
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frame_param *d_frame;
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const unsigned char *d_depuncture_pattern;
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uint8_t d_depunctured[MAX_ENCODED_BITS];
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uint8_t d_decoded[MAX_ENCODED_BITS * 3 / 4];
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static const unsigned char PARTAB[256];
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static const unsigned char PUNCTURE_1_2[2];
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static const unsigned char PUNCTURE_2_3[4];
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static const unsigned char PUNCTURE_3_4[6];
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virtual void reset() = 0;
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uint8_t* depuncture(uint8_t *in);
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};
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} // namespace ieee802_11
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} // namespace gr
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#endif /* INCLUDED_IEEE802_11_VITERBI_DECODER_BASE_H */
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