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 3, 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., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
30 #include <gr_io_signature.h>
34 static const float INF = 1.0e9;
37 trellis_make_@BASE_NAME@ (
43 return @SPTR_NAME@ (new @NAME@ (FSM,K,S0,SK));
51 : gr_block ("@BASE_NAME@",
52 gr_make_io_signature (1, -1, sizeof (float)),
53 gr_make_io_signature (1, -1, sizeof (@TYPE@))),
60 set_relative_rate (1.0 / ((double) d_FSM.O()));
61 set_output_multiple (d_K);
66 @NAME@::forecast (int noutput_items, gr_vector_int &ninput_items_required)
68 assert (noutput_items % d_K == 0);
69 int input_required = d_FSM.O() * noutput_items ;
70 unsigned ninputs = ninput_items_required.size();
71 for (unsigned int i = 0; i < ninputs; i++) {
72 ninput_items_required[i] = input_required;
79 void viterbi_algorithm(int I, int S, int O,
80 const std::vector<int> &NS,
81 const std::vector<int> &OS,
82 const std::vector< std::vector<int> > &PS,
83 const std::vector< std::vector<int> > &PI,
86 const float *in, @TYPE@ *out)//,
87 //std::vector<int> &trace)
89 std::vector<int> trace(S*K);
90 std::vector<float> alpha(S*2);
97 if(S0<0) { // initial state not specified
98 for(int i=0;i<S;i++) alpha[0*S+i]=0;
101 for(int i=0;i<S;i++) alpha[0*S+i]=INF;
106 for(int k=0;k<K;k++) {
108 for(int j=0;j<S;j++) { // for each next state do ACS
111 for(unsigned int i=0;i<PS[j].size();i++) {
113 if((mm=alpha[alphai*S+PS[j][i]]+in[k*O+OS[PS[j][i]*I+PI[j][i]]])<minm)
117 alpha[((alphai+1)%2)*S+j]=minm;
118 if(minm<norm) norm=minm;
121 alpha[((alphai+1)%2)*S+j]-=norm; // normalize total metrics so they do not explode
125 if(SK<0) { // final state not specified
129 if((mm=alpha[alphai*S+i])<minm) minm=mm,minmi=i;
136 for(int k=K-1;k>=0;k--) { // traceback
137 int i0=trace[k*S+st];
138 out[k]= (@TYPE@) PI[st][i0];
150 @NAME@::general_work (int noutput_items,
151 gr_vector_int &ninput_items,
152 gr_vector_const_void_star &input_items,
153 gr_vector_void_star &output_items)
155 assert (input_items.size() == output_items.size());
156 int nstreams = input_items.size();
157 assert (noutput_items % d_K == 0);
158 int nblocks = noutput_items / d_K;
160 for (int m=0;m<nstreams;m++) {
161 const float *in = (const float *) input_items[m];
162 @TYPE@ *out = (@TYPE@ *) output_items[m];
163 for (int n=0;n<nblocks;n++) {
164 viterbi_algorithm(d_FSM.I(),d_FSM.S(),d_FSM.O(),d_FSM.NS(),d_FSM.OS(),d_FSM.PS(),d_FSM.PI(),d_K,d_S0,d_SK,&(in[n*d_K*d_FSM.O()]),&(out[n*d_K]));//,d_trace);
168 consume_each (d_FSM.O() * noutput_items );
169 return noutput_items;