2 * Copyright 2008 Free Software Foundation, Inc.
4 * This file is part of GNU Radio
6 * GNU Radio is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 3, or (at your option)
11 * GNU Radio is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with GNU Radio; see the file COPYING. If not, write to
18 * the Free Software Foundation, Inc., 51 Franklin Street,
19 * Boston, MA 02110-1301, USA.
22 /* The path memory for each state is 32 bits. This is slightly shorter
23 * than we'd like for K=7, especially since we chain back every 8 bits.
24 * But it fits so nicely into a 32-bit machine word...
26 struct viterbi_state {
27 unsigned long path; /* Decoded path to this state */
28 long metric; /* Cumulative metric to this state */
31 int gen_met(int mettab[2][256], /* Metric table */
32 int amp, /* Signal amplitude */
33 double esn0, /* Es/N0 ratio in dB */
34 double bias, /* Metric bias */
35 int scale); /* Scale factor */
38 encode(unsigned char *symbols, unsigned char *data,
39 unsigned int nbytes,unsigned char encstate);
42 viterbi_chunks_init(struct viterbi_state* state);
45 viterbi_butterfly2(unsigned char *symbols, int mettab[2][256],
46 struct viterbi_state *state0, struct viterbi_state *state1);
49 viterbi_get_output(struct viterbi_state *state, unsigned char *outbuf);