A Discrete-Event Network Simulator
API
jakes-process.cc
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2012 Telum (www.telum.ru)
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation;
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  *
18  * Author: Kirill Andreev <andreev@telum.ru>, Alexander Sofronov <sofronov@telum.ru>
19  */
20 
21 #include "jakes-process.h"
22 #include "ns3/simulator.h"
23 #include "ns3/double.h"
24 #include "ns3/log.h"
25 #include "ns3/uinteger.h"
26 #include "propagation-loss-model.h"
28 
29 namespace ns3 {
30 
31 NS_LOG_COMPONENT_DEFINE ("JakesProcess");
32 
34 JakesProcess::Oscillator::Oscillator (std::complex<double> amplitude, double initialPhase, double omega) :
35  m_amplitude (amplitude),
36  m_phase (initialPhase),
37  m_omega (omega)
38 {}
39 
40 std::complex<double>
42 {
43  return (m_amplitude * std::cos (at.GetSeconds () * m_omega + m_phase));
44 }
45 
47 
48 TypeId
50 {
51  static TypeId tid = TypeId ("ns3::JakesProcess")
52  .SetParent<Object> ()
53  .SetGroupName ("Propagation")
54  .AddConstructor<JakesProcess> ()
55  .AddAttribute ("DopplerFrequencyHz", "Corresponding doppler frequency[Hz]",
56  DoubleValue (80),
58  MakeDoubleChecker<double> (0.0, 1e4))
59  .AddAttribute ("NumberOfOscillators", "The number of oscillators",
60  UintegerValue (20),
62  MakeUintegerChecker<unsigned int> (4, 1000))
63  ;
64  return tid;
65 }
66 
67 void
69 {
70  Ptr<const JakesPropagationLossModel> jakes = propagationModel->GetObject<JakesPropagationLossModel> ();
71  NS_ASSERT_MSG (jakes != 0, "Jakes Process can work only with JakesPropagationLossModel!");
72  m_jakes = jakes;
73 
76 
78 }
79 
80 void
81 JakesProcess::SetNOscillators (unsigned int nOscillators)
82 {
83  m_nOscillators = nOscillators;
84 }
85 
86 void
87 JakesProcess::SetDopplerFrequencyHz (double dopplerFrequencyHz)
88 {
89  m_omegaDopplerMax = 2 * dopplerFrequencyHz * M_PI;
90 }
91 
92 void
94 {
96  // Initial phase is common for all oscillators:
97  double phi = m_jakes->GetUniformRandomVariable ()->GetValue ();
98  // Theta is common for all oscillators:
99  double theta = m_jakes->GetUniformRandomVariable ()->GetValue ();
100  for (unsigned int i = 0; i < m_nOscillators; i++)
101  {
102  unsigned int n = i + 1;
105  double alpha = (2.0 * M_PI * n - M_PI + theta) / (4.0 * m_nOscillators);
107  double omega = m_omegaDopplerMax * std::cos (alpha);
109  double psi = m_jakes->GetUniformRandomVariable ()->GetValue ();
110  std::complex<double> amplitude = std::complex<double> (std::cos (psi), std::sin (psi)) * 2.0 / std::sqrt (m_nOscillators);
112  m_oscillators.push_back (Oscillator (amplitude, phi, omega));
113  }
114 }
115 
117  m_omegaDopplerMax (0),
118  m_nOscillators (0)
119 {
120 }
121 
123 {
124  m_oscillators.clear ();
125 }
126 
127 void
129 {
130  m_jakes = 0;
131 }
132 
133 std::complex<double>
135 {
136  std::complex<double> sumAplitude = std::complex<double> (0, 0);
137  for (unsigned int i = 0; i < m_oscillators.size (); i++)
138  {
139  sumAplitude += m_oscillators[i].GetValueAt (Now ());
140  }
141  return sumAplitude;
142 }
143 
144 double
146 {
147  std::complex<double> complexGain = GetComplexGain ();
148  return (10 * std::log10 ((std::pow (complexGain.real (), 2) + std::pow (complexGain.imag (), 2)) / 2));
149 }
150 
151 } // namespace ns3
Simulation virtual time values and global simulation resolution.
Definition: nstime.h:102
virtual ~JakesProcess()
Smart pointer class similar to boost::intrusive_ptr.
Definition: ptr.h:73
#define NS_OBJECT_ENSURE_REGISTERED(type)
Register an Object subclass with the TypeId system.
Definition: object-base.h:45
NS_ASSERT_MSG(false, "Ipv4AddressGenerator::MaskToIndex(): Impossible")
double GetSeconds(void) const
Get an approximation of the time stored in this instance in the indicated unit.
Definition: nstime.h:355
std::complex< double > GetValueAt(Time t) const
Get the complex amplitude at a given moment.
#define NS_ASSERT(condition)
At runtime, in debugging builds, if this condition is not true, the program prints the source file...
Definition: assert.h:67
#define NS_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
Definition: log.h:202
void SetPropagationLossModel(Ptr< const PropagationLossModel > model)
Set the propagation model using this class.
std::vector< Oscillator > m_oscillators
Vector of oscillators.
virtual void DoDispose()
Destructor implementation.
This class Represents a single oscillator.
Definition: jakes-process.h:87
Oscillator(std::complex< double > amplitude, double initialPhase, double omega)
Initiate oscillator with complex amplitude, initial phase and rotation speed.
Hold an unsigned integer type.
Definition: uinteger.h:44
std::complex< double > GetComplexGain() const
Get the channel complex gain.
double m_omegaDopplerMax
max rotation speed Doppler frequency
Every class exported by the ns3 library is enclosed in the ns3 namespace.
void SetDopplerFrequencyHz(double dopplerFrequencyHz)
Set the Doppler frequency.
double GetChannelGainDb() const
Get the channel gain in dB.
unsigned int m_nOscillators
number of oscillators
Ptr< const AttributeAccessor > MakeDoubleAccessor(T1 a1)
Create an AttributeAccessor for a class data member, or a lone class get functor or set method...
Definition: double.h:42
static TypeId GetTypeId(void)
Get the type ID.
void ConstructOscillators()
Time Now(void)
create an ns3::Time instance which contains the current simulation time.
Definition: simulator.cc:365
A base class which provides memory management and object aggregation.
Definition: object.h:87
Ptr< const JakesPropagationLossModel > m_jakes
pointer to the propagation loss model
This class can be used to hold variables of floating point type such as &#39;double&#39; or &#39;float&#39;...
Definition: double.h:41
a Jakes narrowband propagation model.
Ptr< const AttributeAccessor > MakeUintegerAccessor(T1 a1)
Create an AttributeAccessor for a class data member, or a lone class get functor or set method...
Definition: uinteger.h:45
a unique identifier for an interface.
Definition: type-id.h:58
TypeId SetParent(TypeId tid)
Set the parent TypeId.
Definition: type-id.cc:915
void SetNOscillators(unsigned int nOscillators)
Set the number of Oscillators to use.
Implementation for a single path Stationary Jakes propagation loss model.
Definition: jakes-process.h:55