PAM_Demodulator_impl.h

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/* -*- c++ -*- */
/* gr-owc OOT module for optical wireless communications. 
 *
 * Copyright 2021 Arsalan Ahmed from The Ubiquitous Communications and Networking (UCAN) Lab, University of Massachusetts, Boston.
 *
 * This 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.
 *
 * This software 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 this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef INCLUDED_OWC_PAM_DEMODULATOR_IMPL_H
#define INCLUDED_OWC_PAM_DEMODULATOR_IMPL_H

#include <owc/PAM_Demodulator.h>

namespace gr {
  namespace owc {

    class PAM_Demodulator_impl : public PAM_Demodulator
    {
     private:
     int d_modulation_order;
     float d_max_magnitude;
     float d_min_magnitude;
     int d_samples_per_symbol;
     
     std::vector<int> d_symbol_array;
     std::vector<float> d_level_array;

     public:
      PAM_Demodulator_impl(int modulation_order, float max_magnitude, float min_magnitude, int samples_per_symbol);
      ~PAM_Demodulator_impl();
      
      void set_modulation_order(int modulation_order) { d_modulation_order = modulation_order; }
      int modulation_order() { return d_modulation_order; }

      void set_max_magnitude(float max_magnitude) { d_max_magnitude = max_magnitude; }
      float max_magnitude() { return d_max_magnitude; }
      
      void set_min_magnitude(float min_magnitude) { d_min_magnitude = min_magnitude; }
      float min_magnitude() { return d_min_magnitude; }

      void set_samples_per_symbol(int samples_per_symbol) { d_samples_per_symbol = samples_per_symbol; }
      int samples_per_symbol() { return d_samples_per_symbol; }
      
      void set_symbol_array(int modulation_order)
      {
        int num_bits = floor(log2(modulation_order));
        int max_symbol = pow(2,num_bits);
        
        for (int i = 0; i < max_symbol; i++)
        {
                d_symbol_array.push_back(i);
        }
        
      }
      std::vector<int> symbol_array() {return d_symbol_array;}
      
      
      void set_level_array(int modulation_order, float max_magnitude, float min_magnitude)
      {
        d_level_array.clear();
      
        int num_bits = floor(log2(modulation_order));
        int max_symbol = pow(2,num_bits);
        float range = max_magnitude - min_magnitude;
        float single_level_magnitude = range/(modulation_order-1);
        
        float levels = min_magnitude;
                
        for (int i = 0; i < max_symbol; i++)
        {
                d_level_array.push_back(levels);
                levels += single_level_magnitude;
        }
        
      }
      std::vector<float> level_array() {return d_level_array;}
      
      float samples_average_value(std::vector<float> samples_array, int num_incoming_samples)
      {
        float sum = 0;
        
        for (int i = 0; i < num_incoming_samples; i++)
        {
                sum += samples_array[i];
        }
        
        return (sum/num_incoming_samples);
      }
      

      // Where all the action really happens
      int work(
              int noutput_items,
              gr_vector_const_void_star &input_items,
              gr_vector_void_star &output_items
      );
    };

  } // namespace owc
} // namespace gr

#endif /* INCLUDED_OWC_PAM_DEMODULATOR_IMPL_H */