diff -r 28dfd0c7510d -r 22aa62a108ed src/devices/wifi/jakes-propagation-loss-model.cc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/devices/wifi/jakes-propagation-loss-model.cc Fri Mar 21 04:51:36 2008 +0100 @@ -0,0 +1,235 @@ +/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */ +/* + * Copyright (c) 2005,2006,2007 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: Federico Maguolo + */ + +#include "ns3/simulator.h" +#include "ns3/uinteger.h" +#include "ns3/double.h" +#include "ns3/random-variable.h" +#include "ns3/default-value.h" +#include "ns3/mobility-model.h" +#include "ns3/log.h" +#include "jakes-propagation-loss-model.h" +#include + +NS_LOG_COMPONENT_DEFINE ("Jakes"); + +namespace ns3 { + + + +class JakesPropagationLossModel::PathCoefficients { +public: + PathCoefficients (Ptr jakes, + Ptr receiver, + uint8_t nRays, + uint8_t nOscillators); + ~PathCoefficients (); + double GetLoss (void); + Ptr GetReceiver (void); +private: + void DoConstruct (void); + Ptr m_receiver; + uint8_t m_nOscillators; + uint8_t m_nRays; + double **m_phases; + Time m_lastUpdate; + Ptr m_jakes; +}; + + +JakesPropagationLossModel::PathCoefficients::PathCoefficients (Ptr jakes, + Ptr receiver, + uint8_t nRays, + uint8_t nOscillators) + : m_receiver (receiver), + m_nOscillators (nOscillators), + m_nRays (nRays), + m_jakes(jakes) +{ + DoConstruct (); +} + +JakesPropagationLossModel::PathCoefficients::~PathCoefficients () +{ + for (uint8_t i = 0; i < m_nRays; i++) { + delete [] m_phases[i]; + } + delete [] m_phases; +} + +void +JakesPropagationLossModel::PathCoefficients::DoConstruct () +{ + m_phases = new double*[m_nRays]; + for (uint8_t i = 0; i < m_nRays; i++) { + m_phases[i] = new double[m_nOscillators + 1]; + for (uint8_t j = 0; j <= m_nOscillators; j++) { + m_phases[i][j] = 2.0 * JakesPropagationLossModel::PI * m_jakes->m_variable.GetValue (); + } + } + m_lastUpdate = Simulator::Now (); +} + +Ptr +JakesPropagationLossModel::PathCoefficients::GetReceiver () +{ + return m_receiver; +} + +double +JakesPropagationLossModel::PathCoefficients::GetLoss (void) +{ + uint16_t N = 4 * m_nOscillators + 2; + Time interval = Simulator::Now () - m_lastUpdate; + ComplexNumber coef= {0.0, 0.0}; + ComplexNumber fading; + double norm = 0.0; + for (uint8_t i = 0; i < m_nRays; i++) { + fading.real = 0.0; + fading.imag = 0.0; + for (uint8_t j = 0; j <= m_nOscillators; j++) { + m_phases[i][j] += 2.0 * JakesPropagationLossModel::PI * cos (2.0 * JakesPropagationLossModel::PI * j / N) * m_jakes->m_fd * interval.GetSeconds (); + m_phases[i][j] -= 2.0 * JakesPropagationLossModel::PI * floor (m_phases[i][j] / 2.0 / JakesPropagationLossModel::PI); + fading.real += m_jakes->m_amp[j].real * cos (m_phases[i][j]); + fading.imag += m_jakes->m_amp[j].imag * cos (m_phases[i][j]); + norm += sqrt(pow (m_jakes->m_amp[j].real, 2) + pow(m_jakes->m_amp[j].imag, 2)); + } + coef.real += fading.real; + coef.imag += fading.imag; + } + m_lastUpdate = Simulator::Now (); + double k = sqrt (pow (coef.real, 2) + pow (coef.imag, 2)) / norm; + NS_LOG_DEBUG ("Jakes coef "<< k << " (" << 10 * log10 (k) << "dB)"); + return 10 * log10 (k); +} + +NS_OBJECT_ENSURE_REGISTERED (JakesPropagationLossModel); + +const double JakesPropagationLossModel::PI = 3.1415; + +TypeId +JakesPropagationLossModel::GetTypeId (void) +{ + static TypeId tid = TypeId ("ns3::JakesPropagationLossModel") + .SetParent () + .AddConstructor () + .AddAttribute ("NumberOfRaysPerPath", + "The number of rays to use by default for compute the fading coeficent for a given path (default is 1)", + Uinteger (1), + MakeUintegerAccessor (&JakesPropagationLossModel::m_nRays), + MakeUintegerChecker ()) + .AddAttribute ("NumberOfOscillatorsPerRay", + "The number of oscillators to use by default for compute the coeficent for a given ray of a given path (default is 4)", + Uinteger (4), + MakeUintegerAccessor (&JakesPropagationLossModel::m_nOscillators), + MakeUintegerChecker ()) + .AddAttribute ("DopplerFreq", + "The doppler frequency in Hz (f_d = v / lambda = v * f / c, the defualt is 0)", + Double(0.0), + MakeDoubleAccessor (&JakesPropagationLossModel::m_fd), + MakeDoubleChecker ()) + .AddAttribute ("Distribution", + "The distribution to choose the initial phases.", + ConstantVariable (1.0), + MakeRandomVariableAccessor (&JakesPropagationLossModel::m_variable), + MakeRandomVariableChecker ()) + ; + return tid; +} + +JakesPropagationLossModel::JakesPropagationLossModel () +{ + DoConstruct (); +} + +JakesPropagationLossModel::~JakesPropagationLossModel () +{ + delete [] m_amp; + for (PathsList::iterator i = m_paths.end (); i != m_paths.begin (); i--) { + PathsSet *ps = *i; + for (DestinationList::iterator r = ps->receivers.begin (); r != ps->receivers.end (); r++) { + PathCoefficients *pc = *r; + delete pc; + } + delete ps; + } +} + +void +JakesPropagationLossModel::DoConstruct () +{ + uint16_t N = 4 * m_nOscillators + 2; + m_amp = new ComplexNumber[m_nOscillators + 1]; + m_amp[0].real = 2.0 * sqrt(2.0 / N) * cos (PI / 4.0); + m_amp[0].imag = 2.0 * sqrt(2.0 / N) * sin (PI / 4.0); + for (uint8_t i = 1; i <= m_nOscillators; i++) { + double beta = PI * (double)i / m_nOscillators; + m_amp[i].real = 4.0 * cos (beta) / sqrt(N); + m_amp[i].imag = 4.0 * sin (beta) / sqrt(N); + } +} + +void +JakesPropagationLossModel::SetNRays (uint8_t nRays) +{ + m_nRays = nRays; +} + +void +JakesPropagationLossModel::SetNOscillators (uint8_t nOscillators) +{ + m_nOscillators = nOscillators; +} + +double +JakesPropagationLossModel::GetLoss (Ptr a, + Ptr b) const +{ + PathsList::iterator i = m_paths.end (); + while (i != m_paths.begin ()) { + i--; + PathsSet *ps = *i; + if (PeekPointer (ps->sender) == PeekPointer(a)) { + m_paths.erase (i); + m_paths.push_back (ps); + for (DestinationList::iterator r = ps->receivers.begin (); r != ps->receivers.end (); r++) { + PathCoefficients *pc = *r; + if (PeekPointer (pc->GetReceiver ()) == PeekPointer (b)) { + ps->receivers.erase (r); + ps->receivers.push_back (pc); + return pc->GetLoss (); + } + } + PathCoefficients *pc = new PathCoefficients (this, b, m_nRays, m_nOscillators); + ps->receivers.push_back (pc); + return pc->GetLoss (); + } + } + PathsSet *ps = new PathsSet; + ps->sender = a; + PathCoefficients *pc = new PathCoefficients (this, b, m_nRays, m_nOscillators); + ps->receivers.push_back (pc); + m_paths.push_back (ps); + return pc->GetLoss (); +} + + +} // namespace ns3 +