/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2010 TELEMATICS LAB, DEE - Politecnico di Bari

 *

 * 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: Giuseppe Piro  <g.piro@poliba.it>

 * Author: Marco Miozzo <marco.miozzo@cttc.es>

 */

#include "trace-fading-loss-model.h"

#include <ns3/mobility-model.h>

#include <ns3/spectrum-value.h>

#include <ns3/log.h>

NS_LOG_COMPONENT_DEFINE ("TraceFadingLossModel");

namespace ns3 {

  NS_OBJECT_ENSURE_REGISTERED (TraceFadingLossModel);

TraceFadingLossModel::TraceFadingLossModel ()

{

  SetNext (NULL);

}

TraceFadingLossModel::~TraceFadingLossModel ()

{

}

TypeId

TraceFadingLossModel::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::TraceFadingLossModel")

    .SetParent<SpectrumPropagationLossModel> ()

  ;

  return tid;

}

Ptr<SpectrumValue>

TraceFadingLossModel::DoCalcRxPowerSpectralDensity (

  Ptr<const SpectrumValue> txPsd,

  Ptr<const MobilityModel> a,

  Ptr<const MobilityModel> b) const

{

  NS_LOG_FUNCTION (this << *txPsd << a << b);

  Ptr<JakesFadingLossModel> c = GetFadingChannelRealization (a,b);

  Ptr<SpectrumValue> rxPsd = Copy<SpectrumValue> (txPsd);

  Values::iterator vit = rxPsd->ValuesBegin ();

  Vector aSpeedVector = a->GetVelocity ();

  Vector bSpeedVector = b->GetVelocity ();

  double speed = sqrt (pow (aSpeedVector.x-bSpeedVector.x,2) +  pow (aSpeedVector.y-bSpeedVector.y,2));

  NS_LOG_FUNCTION (this << *rxPsd);

  int subChannel = 0;

  while (vit != rxPsd->ValuesEnd ())

    {

      NS_ASSERT (subChannel < 100);

      if (*vit != 0.)

        {

          double fading = c->GetValue (subChannel, speed);

          double power = *vit; // in Watt/Hz

          power = 10 * log10 (180000 * power); // in dB

          NS_LOG_FUNCTION (this << subChannel << *vit  << power << fading);

          *vit = pow (10., ((power + fading) / 10)) / 180000; // in Watt

          NS_LOG_FUNCTION (this << subChannel << *vit);

        }

      ++vit;

      ++subChannel;

    }

  NS_LOG_FUNCTION (this << *rxPsd);

  return rxPsd;

}

void

TraceFadingLossModel::CreateFadingChannelRealization (Ptr<const MobilityModel> enbMobility, Ptr<const MobilityModel> ueMobility)

{

  NS_LOG_FUNCTION (this << enbMobility << ueMobility);

  Ptr<JakesFadingLossModel> c = CreateObject<JakesFadingLossModel> ();

  ChannelRealizationId_t mobilities = std::make_pair (enbMobility, ueMobility);

  NS_LOG_FUNCTION (this <<

                   "insert new channel realization, m_channelRealizationMap.size () = "

                        << m_channelRealizationMap.size ());

  m_channelRealizationMap.insert ( std::pair<ChannelRealizationId_t,Ptr<JakesFadingLossModel> > (mobilities, c) );

  NS_LOG_FUNCTION (this <<

                   "m_channelRealizationMap.size () = "

                        << m_channelRealizationMap.size ());

}

Ptr<JakesFadingLossModel>

TraceFadingLossModel::GetFadingChannelRealization (Ptr<const MobilityModel> a, Ptr<const MobilityModel> b) const

{

  NS_LOG_FUNCTION (this << a << b);

  std::map <ChannelRealizationId_t, Ptr<JakesFadingLossModel> >::const_iterator it;

  ChannelRealizationId_t mobilities = std::make_pair (a,b);

  it = m_channelRealizationMap.find (mobilities);

  return it->second;

}

} // namespace ns3