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/* -*- c++ -*- */
/*
* Copyright 2004 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 2, 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <float.h>
#include <stdexcept>
#include "trellis_calc_metric.h"
// soft decisions (Eucledean distance squared)
void calc_metric_f(const int O, const int D, const std::vector<float> &TABLE, const float *in, float *metric, trellis_metric_type_t type)
{
float minm = FLT_MAX;
int minmi = 0;
switch (type){
case TRELLIS_EUCLIDEAN:
for(int o=0;o<O;o++) {
metric[o]=0.0;
for (int m=0;m<D;m++) {
float s=in[m]-TABLE[o*D+m];
metric[o]+=s*s;
}
}
break;
case TRELLIS_HARD_SYMBOL:
for(int o=0;o<O;o++) {
metric[o]=0.0;
for (int m=0;m<D;m++) {
float s=in[m]-TABLE[o*D+m];
metric[o]+=s*s;
}
if(metric[o]<minm) {
minm=metric[o];
minmi=o;
}
}
for(int o=0;o<O;o++) {
metric[o] = (o==minmi?0.0:1.0);
}
break;
case TRELLIS_HARD_BIT:
throw std::runtime_error ("Invalid metric type (not yet implemented).");
break;
default:
throw std::runtime_error ("Invalid metric type.");
}
}
// soft decisions (Eucledean distance squared)
void calc_metric_c(const int O, const int D, const std::vector<gr_complex> &TABLE, const gr_complex *in, float *metric, trellis_metric_type_t type)
{
float minm = FLT_MAX;
int minmi = 0;
switch (type){
case TRELLIS_EUCLIDEAN:
for(int o=0;o<O;o++) {
metric[o]=0.0;
for (int m=0;m<D;m++) {
gr_complex s=in[m]-TABLE[o*D+m];
metric[o]+=s.real()*s.real()+s.imag()*s.imag();
}
}
case TRELLIS_HARD_SYMBOL:
throw std::runtime_error ("Invalid metric type (not yet implemented).");
break;
case TRELLIS_HARD_BIT:
throw std::runtime_error ("Invalid metric type (not yet implemented).");
break;
default:
throw std::runtime_error ("Invalid metric type.");
}
}
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