trellis_calc_metric.cc

这是用python语言写的一个数字广播的信号处理工具包。利用它

/* -*- 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 3, 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., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include <float.h>
#include <stdexcept>
#include "trellis_calc_metric.h"



template <class T> 
void calc_metric(int O, int D, const std::vector<T> &TABLE, const T *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++) {
        T s=in[m]-TABLE[o*D+m];
        //gr_complex sc(1.0*s,0);
        //metric[o]+=(sc*conj(sc)).real();
        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++) {
        T s=in[m]-TABLE[o*D+m];
        //gr_complex sc(1.0*s,0);
        //metric[o]+=(sc*conj(sc)).real();
        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.");
  }
}



template
void calc_metric<short>(int O, int D, const std::vector<short> &TABLE, const short *in, float *metric, trellis_metric_type_t type);

template
void calc_metric<int>(int O, int D, const std::vector<int> &TABLE, const int *in, float *metric, trellis_metric_type_t type);

template
void calc_metric<float>(int O, int D, const std::vector<float> &TABLE, const float *in, float *metric, trellis_metric_type_t type);


/*
void calc_metric(int O, 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.");
  }
}


void calc_metric(int O, 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.");
  }
}



void calc_metric(int O, 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.");
  }
}
*/





void calc_metric(int O, 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:
    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();
      }
      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.");
  }
}