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/*
* Copyright 2008 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
/* The path memory for each state is 32 bits. This is slightly shorter
* than we'd like for K=7, especially since we chain back every 8 bits.
* But it fits so nicely into a 32-bit machine word...
*/
#include <gr_core_api.h>
struct GR_CORE_API viterbi_state {
unsigned long path; /* Decoded path to this state */
long metric; /* Cumulative metric to this state */
};
GR_CORE_API
int gen_met(int mettab[2][256], /* Metric table */
int amp, /* Signal amplitude */
double esn0, /* Es/N0 ratio in dB */
double bias, /* Metric bias */
int scale); /* Scale factor */
GR_CORE_API unsigned char
encode(unsigned char *symbols, unsigned char *data,
unsigned int nbytes,unsigned char encstate);
GR_CORE_API void
viterbi_chunks_init(struct viterbi_state* state);
GR_CORE_API void
viterbi_butterfly2(unsigned char *symbols, int mettab[2][256],
struct viterbi_state *state0, struct viterbi_state *state1);
GR_CORE_API unsigned char
viterbi_get_output(struct viterbi_state *state, unsigned char *outbuf);
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