/* -*- 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 (Euclidean distance squared) void calc_metric_s(const int O, const int D, const std::vector<short> &TABLE, const short *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 (Euclidean distance squared) void calc_metric_i(const int O, const int D, const std::vector<int> &TABLE, const int *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 (Euclidean 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 (Euclidean 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."); } }