3 * Copyright 2004 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
27 #include <trellis_viterbi_combined_i.h>
28 #include <gr_io_signature.h>
32 static const float INF = 1.0e9;
34 trellis_viterbi_combined_i_sptr
35 trellis_make_viterbi_combined_i (
38 const std::vector<float> &TABLE,
42 const trellis_metric_type_t TYPE)
44 return trellis_viterbi_combined_i_sptr (new trellis_viterbi_combined_i (FSM,D,TABLE,K,S0,SK,TYPE));
47 trellis_viterbi_combined_i::trellis_viterbi_combined_i (
50 const std::vector<float> &TABLE,
54 const trellis_metric_type_t TYPE)
55 : gr_block ("viterbi_combined_i",
56 gr_make_io_signature (1, -1, sizeof (float)),
57 gr_make_io_signature (1, -1, sizeof (int))),
67 set_relative_rate (1.0 / ((double) d_D));
68 set_output_multiple (d_K);
73 trellis_viterbi_combined_i::forecast (int noutput_items, gr_vector_int &ninput_items_required)
75 assert (noutput_items % d_K == 0);
76 int input_required = d_D * noutput_items ;
77 unsigned ninputs = ninput_items_required.size();
78 for (unsigned int i = 0; i < ninputs; i++) {
79 ninput_items_required[i] = input_required;
86 void viterbi_algorithm_combined(const int I, const int S, const int O,
87 const std::vector<int> &NS,
88 const std::vector<int> &OS,
89 const std::vector<int> &PS,
90 const std::vector<int> &PI,
92 const std::vector<float> &TABLE,
94 const int S0,const int SK,
95 const trellis_metric_type_t TYPE,
96 const float *in, int *out,
97 std::vector<int> &trace)
99 std::vector<float> alpha(S*2);
100 float *metric = new float[O];
106 if(S0<0) { // initial state not specified
107 for(int i=0;i<S;i++) alpha[0*S+i]=0;
110 for(int i=0;i<S;i++) alpha[0*S+i]=INF;
115 for(int k=0;k<K;k++) {
116 calc_metric_f(O, D, TABLE, &(in[k*D]), metric,TYPE); // calc metrics
118 for(int j=0;j<S;j++) { // for each next state do ACS
121 for(int i=0;i<I;i++) {
123 if((mm=alpha[alphai*S+PS[i0]]+metric[OS[PS[i0]*I+PI[i0]]])<minm)
127 alpha[((alphai+1)%2)*S+j]=minm;
128 if(minm<norm) norm=minm;
131 alpha[((alphai+1)%2)*S+j]-=norm; // normalize total metrics so they do not explode
135 if(SK<0) { // final state not specified
139 if((mm=alpha[alphai*S+i])<minm) minm=mm,minmi=i;
146 for(int k=K-1;k>=0;k--) { // traceback
147 int i0=st*I+trace[k*S+st];
148 out[k]= (int) PI[i0];
162 trellis_viterbi_combined_i::general_work (int noutput_items,
163 gr_vector_int &ninput_items,
164 gr_vector_const_void_star &input_items,
165 gr_vector_void_star &output_items)
167 assert (input_items.size() == output_items.size());
168 int nstreams = input_items.size();
169 assert (noutput_items % d_K == 0);
170 int nblocks = noutput_items / d_K;
172 for (int m=0;m<nstreams;m++) {
173 const float *in = (const float *) input_items[m];
174 int *out = (int *) output_items[m];
175 for (int n=0;n<nblocks;n++) {
176 viterbi_algorithm_combined(d_FSM.I(),d_FSM.S(),d_FSM.O(),d_FSM.NS(),d_FSM.OS(),d_FSM.PS(),d_FSM.PI(),d_D,d_TABLE,d_K,d_S0,d_SK,d_TYPE,&(in[n*d_K*d_D]),&(out[n*d_K]),d_trace);
180 consume_each (d_D * noutput_items );
181 return noutput_items;