RandomFrequencyOnlyModel.cc

#include "RandomFrequencyOnlyModel.h"


void RandomFrequencyOnlyModel::filterSignal(Signal& s){


  /* At first get a new instance of the default Mapping implementation
   * which is able to represent our attenuation mapping.
   * the first parameter of "createMapping" gets the DimensionSet the
   * Mapping should use as domain and the second parameter gets the
   * interpolation method to be used to calculate the values between
   * two Mapping entries.
   *
   * Note 1: At the moment only LINEAR interpolation is implemented.
   *
   * Note 2: For now the same interpolation method is used for
   * interpolation in every dimension. Later it might be possible
   * to define different interpolation methods for different
   * dimensions. For example: While linear interpolation of time
   * makes sence in most cases, using NEAREST whould make more sense
   * for frequency.
   */
  Mapping* attMapping = MappingUtils::createMapping(1.0, dimensions, Mapping::LINEAR);

  /* Get start and end of the signal to avoid unnecessary calculation
   * of attenuation.*/
  simtime_t sStart = s.getSignalStart();

  // Since this mapping does not depend on time, we just set values for
  // the first entry in time-dimension (start of the Signal)
  /*
  simtime_t sEnd = sStart + s.getSignalLength();

  simtime_t interval = 0.01; //lets use constant intervals for entries in time
  */

  Argument pos(dimensions); //create an Argument which we will use as parameter
                //to set the values inside the mapping

  pos.setTime(sStart); // set arguments position in time dimension

  for(double freq = 2.412; freq < 2.465; freq += 0.01){

    pos.setArgValue(frequency, freq*1.e9); // update arguments position in frequency dimension

    /*
    //create time entries for this frequency
    for(simtime_t t = sStart; t <= sEnd; t+=interval){


      pos.setTime(t); // update arguments position in time dimension
    */
      /* Create random attenuation between 0.1 and 1.0.
       * Since the attenuation value is multiplied to the transmission power mapping
       * it should be between 0.0 and 1.0, otherwise it whouldn't be a real
       * attenuation.*/
      double att = (double)rand() / (double)RAND_MAX * 0.9 + 0.1;

      attMapping->setValue(pos, att); //put the attenuation at the current position into the mapping
    /*
    }
    */
  }
  //asure attenuation is set at end of freq range
  pos.setArgValue(frequency, 2.472e9); // update arguments position in frequency dimension
  double att = (double)rand() / (double)RAND_MAX * 0.9 + 0.1;
  attMapping->setValue(pos, att); //put the attenuation at the current position into the mapping

  //at last add the created attenuation mapping to the signal
  s.addAttenuation(attMapping);
}