interference-helper.h

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2005,2006 INRIA
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 */

#ifndef INTERFERENCE_HELPER_H
#define INTERFERENCE_HELPER_H

#include "ns3/nstime.h"
#include "ns3/wifi-spectrum-value-helper.h"
#include "wifi-tx-vector.h"
#include <map>

namespace ns3 {

class WifiPpdu;
class WifiPsdu;
class ErrorRateModel;

typedef std::map <WifiSpectrumBand, double> RxPowerWattPerChannelBand;

class Event : public SimpleRefCount<Event>
{
public:
  Event (Ptr<const WifiPpdu> ppdu, WifiTxVector txVector, Time duration, RxPowerWattPerChannelBand rxPower);
  ~Event ();

  Ptr<const WifiPpdu> GetPpdu (void) const;
  Time GetStartTime (void) const;
  Time GetEndTime (void) const;
  Time GetDuration (void) const;
  double GetRxPowerW (void) const;
  double GetRxPowerW (WifiSpectrumBand band) const;
  RxPowerWattPerChannelBand GetRxPowerWPerBand (void) const;
  WifiTxVector GetTxVector (void) const;


private:
  Ptr<const WifiPpdu> m_ppdu;           
  WifiTxVector m_txVector;              
  Time m_startTime;                     
  Time m_endTime;                       
  RxPowerWattPerChannelBand m_rxPowerW; 
};

std::ostream& operator<< (std::ostream& os, const Event &event);


class InterferenceHelper
{
public:
  struct SnrPer
  {
    double snr; 
    double per; 
  };

  InterferenceHelper ();
  ~InterferenceHelper ();

  void AddBand (WifiSpectrumBand band);

  void RemoveBands (void);

  void SetNoiseFigure (double value);
  void SetErrorRateModel (const Ptr<ErrorRateModel> rate);

  Ptr<ErrorRateModel> GetErrorRateModel (void) const;
  void SetNumberOfReceiveAntennas (uint8_t rx);

  Time GetEnergyDuration (double energyW, WifiSpectrumBand band) const;

  Ptr<Event> Add (Ptr<const WifiPpdu> ppdu, WifiTxVector txVector, Time duration, RxPowerWattPerChannelBand rxPower);

  void AddForeignSignal (Time duration, RxPowerWattPerChannelBand rxPower);
  struct InterferenceHelper::SnrPer CalculatePayloadSnrPer (Ptr<Event> event, uint16_t channelWidth, WifiSpectrumBand band,
                                                            uint16_t staId, std::pair<Time, Time> relativeMpduStartStop) const;
  double CalculateSnr (Ptr<Event> event, uint16_t channelWidth, uint8_t nss, WifiSpectrumBand band) const;
  struct InterferenceHelper::SnrPer CalculateNonHtPhyHeaderSnrPer (Ptr<Event> event, WifiSpectrumBand band) const;
  struct InterferenceHelper::SnrPer CalculateHtPhyHeaderSnrPer (Ptr<Event> event, WifiSpectrumBand band) const;

  void NotifyRxStart ();
  void NotifyRxEnd ();
  void EraseEvents (void);


protected:
  double CalculateSnr (double signal, double noiseInterference, uint16_t channelWidth, uint8_t nss) const;
  double CalculateChunkSuccessRate (double snir, Time duration, WifiMode mode, WifiTxVector txVector) const;


private:
  class NiChange
  {
public:
    NiChange (double power, Ptr<Event> event);
    double GetPower (void) const;
    void AddPower (double power);
    Ptr<Event> GetEvent (void) const;


private:
    double m_power; 
    Ptr<Event> m_event; 
  };

  typedef std::multimap<Time, NiChange> NiChanges;

  typedef std::map <WifiSpectrumBand, NiChanges> NiChangesPerBand;

  void AppendEvent (Ptr<Event> event);
  double CalculateNoiseInterferenceW (Ptr<Event> event, NiChangesPerBand *nis, WifiSpectrumBand band) const;
  double CalculatePayloadChunkSuccessRate (double snir, Time duration, WifiTxVector txVector, uint16_t staId) const;
  double CalculatePayloadPer (Ptr<const Event> event, uint16_t channelWidth, NiChangesPerBand *nis, WifiSpectrumBand band,
                              uint16_t staId, std::pair<Time, Time> window) const;
  double CalculateNonHtPhyHeaderPer (Ptr<const Event> event, NiChangesPerBand *nis, WifiSpectrumBand band) const;
  double CalculateHtPhyHeaderPer (Ptr<const Event> event, NiChangesPerBand *nis, WifiSpectrumBand band) const;

  double m_noiseFigure;                                    
  Ptr<ErrorRateModel> m_errorRateModel;                    
  uint8_t m_numRxAntennas;                                 
  NiChangesPerBand m_niChangesPerBand;                     
  std::map <WifiSpectrumBand, double> m_firstPowerPerBand; 
  bool m_rxing;                                            

  NiChanges::const_iterator GetNextPosition (Time moment, WifiSpectrumBand band) const;
  NiChanges::const_iterator GetPreviousPosition (Time moment, WifiSpectrumBand band) const;

  NiChanges::iterator AddNiChangeEvent (Time moment, NiChange change, WifiSpectrumBand band);
};

} //namespace ns3

#endif /* INTERFERENCE_HELPER_H */