welch_pdgm.cpp

this is the simulation model for wireless communication

//
//  File = welch_pdgm.cpp
//

#include <stdlib.h>
#include <fstream>
#include "parmfile.h"
#include "model_graph.h"
#include "welch_pdgm.h"
#include "trianglr.h"
#include "hamming.h"
#include "hann.h"
#include "fft_T.h"
#include "dump_spect.h"

#ifdef _DEBUG
  extern ofstream *DebugFile;
#endif
#define _NO_ZERO_ENDS 0
#define _ZERO_ENDS 1

extern ParmFile *ParmInput;
extern int PassNumber;

//======================================================

template <class T>
WelchPeriodogram<T>::WelchPeriodogram( char* instance_name,
                                  PracSimModel* outer_model,
                                  Signal<T>* in_sig )
                :PracSimModel( instance_name,
                                outer_model )
{
  MODEL_NAME(WelchPeriodogram);
  OPEN_PARM_BLOCK;
  int is;
  GET_INT_PARM(Seg_Len);
  GET_INT_PARM(Fft_Len);
  GET_INT_PARM(Hold_Off);
  GET_INT_PARM(Shift_Between_Segs);
  GET_INT_PARM(Num_Segs_To_Avg);

  Psd_File_Name = new char[64];
  strcpy(Psd_File_Name, "\0");
  GET_STRING_PARM(Psd_File_Name);
  //GET_DOUBLE_PARM(Norm_Factor);
  GET_DOUBLE_PARM(Freq_Norm_Factor);
  GET_BOOL_PARM(Output_In_Decibels);
  GET_BOOL_PARM(Plot_Two_Sided);
  GET_BOOL_PARM(Halt_When_Completed);
  GET_BOOL_PARM(Using_Window);
  if(Using_Window)
  {
      Window_Shape = GetWindowShapeParm("Window_Shape\0");
      switch(Window_Shape)
      {
      case WINDOW_SHAPE_TRIANGULAR:
        Data_Window = new TriangularWindow( Seg_Len, _NO_ZERO_ENDS );
        break;
      case WINDOW_SHAPE_HAMMING:
        Data_Window = new HammingWindow( Seg_Len );
        break;
      case WINDOW_SHAPE_HANN:
        Data_Window = new HannWindow( Seg_Len, _NO_ZERO_ENDS );
        break;
      default:
        break;
      }
      ofstream* lag_win_file = new ofstream("lag_win.txt\0", ios::out);
//      Data_Window->DumpHalfLagWindow(lag_win_file);
      Window_Taps = Data_Window->GetDataWindow();
      Window_Power = 0.0;
      for(is=0; is<Seg_Len; is++)
      {
         Window_Power += Window_Taps[is]*Window_Taps[is];
      }
      Window_Power /= double(Seg_Len);
      double window_scale = sqrt(Window_Power);
      for(is=0; is<Seg_Len; is++)
      {
         Window_Taps[is] /= window_scale;
      }
   }

  In_Sig = in_sig;
  MAKE_INPUT(In_Sig);


  Time_Seg = new T[Seg_Len];
  Overlap_Len = Seg_Len - Shift_Between_Segs;
  Overlap_Seg = Time_Seg + Shift_Between_Segs;
  Win_Time_Seg = new T[Seg_Len];
  Sample_Spectrum = new double[Fft_Len];
  Freq_Seg = new std::complex<double>[Fft_Len];

  for(is=0; is<Fft_Len; is++)
    {
    Sample_Spectrum[is] = 0.0;
    }

  Psd_File = new ofstream(Psd_File_Name, ios::out);
  Processing_Completed = false;


}
template <class T>
WelchPeriodogram<T>::~WelchPeriodogram( void ){ };

template <class T>
void WelchPeriodogram<T>::Initialize(void)
{
  Segs_In_Est = 0;
  Samps_Needed = Seg_Len;
  Block_Size = In_Sig->GetBlockSize();
  Samp_Intvl = In_Sig->GetSampIntvl();
  Delta_F = 1.0/(Samp_Intvl*Fft_Len);

};

template <class T>
int WelchPeriodogram<T>::Execute()
{
   int i,is;
   #ifdef _DEBUG
      *DebugFile << "In WelchPeriodogram::Execute\0" << endl;
   #endif


   if(Processing_Completed) return(_MES_AOK);
   if(PassNumber < Hold_Off) return (_MES_AOK);
   //--------------------------------
   //  Get pointers for buffers

   T *in_sig_ptr = GET_INPUT_PTR(In_Sig);

   int samps_avail = Block_Size;

   while(Samps_Needed <= samps_avail)
   {
      //  The new input block has enough samples to finish a segment.

      //  Fill up FFT buffer by getting Samps_Needed input samples.
      for(is=Samps_Needed; is>0; is--)
      {
         Time_Seg[Seg_Len - is] = *in_sig_ptr++;
      }
      samps_avail -= Samps_Needed;

      if(Using_Window)
      {
         for(is=0; is<Seg_Len; is++)
         {
            Win_Time_Seg[is] = Window_Taps[is]*Time_Seg[is];
         }
      }
      else
      {
         for(is=0; is<Seg_Len; is++)
         {
            Win_Time_Seg[is] = Time_Seg[is];
         }
      }

      //  Perform FFT
      FFT<double>(   Win_Time_Seg,
                     Freq_Seg,
                     Seg_Len,
                     Fft_Len);

      for(i=0; i<Seg_Len; i++)
      {
         //Sample_Spectrum[i] += Samp_Intvl * std::norm(Freq_Seg[i])/(Window_Power*Seg_Len);
         Sample_Spectrum[i] += Samp_Intvl * std::norm(Freq_Seg[i])/Seg_Len;
      }

      //for(is=0; is<Seg_Len; is++)
      //{
      //   Time_Seg[is] = 0.0;
      //}
      // copy overlap samples down to start of buffer
      //memmove( Time_Seg, Overlap_Seg, 
      //        (sizeof(T)/sizeof(char))*Overlap_Len);
      for(i=0; i<Overlap_Len; i++)
      {
         Time_Seg[i] = Overlap_Seg[i];
      }
      Samps_Needed = Shift_Between_Segs;

      Segs_In_Est++;

      // is it time to dump the results?
      if(Segs_In_Est == Num_Segs_To_Avg)
      {
         for(i=0; i<Seg_Len; i++)
         {
            Sample_Spectrum[i] /= double(Num_Segs_To_Avg);
         }
         DumpSpectrum(  Sample_Spectrum,
                        Fft_Len,
                        Delta_F,
                        Freq_Norm_Factor,
                        Output_In_Decibels,
                        Plot_Two_Sided,
                        Psd_File);

         Processing_Completed = true;
         Psd_File->close();
         if(Halt_When_Completed)
         {
            #ifdef _DEBUG
               *DebugFile << "Execution halted by " << GetModelName() << endl;
            #endif
            exit(0);
         }
      }

   }// end of while
  //  The number of avail new samples is not sufficient to finish a segment.
  //  Copy the avaialble samples and then wait for the next pass
  //  to get some more.

   for(is=0; is<samps_avail; is++)
   {
      Time_Seg[Seg_Len - Samps_Needed + is] = *in_sig_ptr++;
   }
   Samps_Needed -= samps_avail;

   return(_MES_AOK);

}
template WelchPeriodogram<float>;