A Discrete-Event Network Simulator
API
cosine-antenna-model.cc
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2011 CTTC
4  *
5  * This program is free software; you can redistribute it and/or modify
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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.
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16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  *
18  * Author: Nicola Baldo <nbaldo@cttc.es>
19  */
20 
21 
22 #include <ns3/log.h>
23 #include <ns3/double.h>
24 #include <cmath>
25 
26 #include "antenna-model.h"
27 #include "cosine-antenna-model.h"
28 
29 
30 namespace ns3 {
31 
32 NS_LOG_COMPONENT_DEFINE ("CosineAntennaModel");
33 
34 NS_OBJECT_ENSURE_REGISTERED (CosineAntennaModel);
35 
36 
37 TypeId
39 {
40  static TypeId tid = TypeId ("ns3::CosineAntennaModel")
42  .SetGroupName ("Antenna")
43  .AddConstructor<CosineAntennaModel> ()
44  .AddAttribute ("VerticalBeamwidth",
45  "The 3 dB vertical beamwidth (degrees). A beamwidth of 360 deg corresponds to constant gain",
46  DoubleValue (360),
49  MakeDoubleChecker<double> (0, 360))
50  .AddAttribute ("HorizontalBeamwidth",
51  "The 3 dB horizontal beamwidth (degrees). A beamwidth of 360 deg corresponds to constant gain",
52  DoubleValue (120),
55  MakeDoubleChecker<double> (0, 360))
56  .AddAttribute ("Orientation",
57  "The angle (degrees) that expresses the orientation of the antenna on the x-y plane relative to the x axis",
58  DoubleValue (0.0),
61  MakeDoubleChecker<double> (-360, 360))
62  .AddAttribute ("MaxGain",
63  "The gain (dB) at the antenna boresight (the direction of maximum gain)",
64  DoubleValue (0.0),
66  MakeDoubleChecker<double> ())
67  ;
68  return tid;
69 }
70 
71 
72 double
74 {
75  NS_LOG_FUNCTION (beamwidthDegrees);
76 
77  // The formula in obtained by inverting the power pattern P(alpha) in a single direction,
78  // while imposing that P(alpha0/2) = 0.5 = -3 dB, with respect to the exponent
79  // See CosineAntennaModel::GetGainDb for more information.
80  //
81  // The undetermined case of alpha0=360 is treated separately.
82  double exponent;
83  if (beamwidthDegrees == 360.0)
84  {
85  exponent = 0.0;
86  }
87  else
88  {
89  exponent = -3.0 / (20 * std::log10 (std::cos (DegreesToRadians (beamwidthDegrees / 4.0))));
90  }
91 
92  return exponent;
93 }
94 
95 
96 double
98 {
99  NS_LOG_FUNCTION (exponent);
100 
101  // The formula in obtained by inverting the power pattern P(alpha) in a single direction,
102  // while imposing that P(alpha0/2) = 0.5 = -3 dB, with respect to the beamwidth.
103  // See CosineAntennaModel::GetGainDb for more information.
104  double beamwidthRadians = 4 * std::acos (std::pow (0.5, 1 / (2 * exponent)));
105  return RadiansToDegrees (beamwidthRadians);
106 }
107 
108 
109 void
110 CosineAntennaModel::SetVerticalBeamwidth (double verticalBeamwidthDegrees)
111 {
112  NS_LOG_FUNCTION (this << verticalBeamwidthDegrees);
113  m_verticalExponent = GetExponentFromBeamwidth (verticalBeamwidthDegrees);
114 }
115 
116 
117 void
118 CosineAntennaModel::SetHorizontalBeamwidth (double horizontalBeamwidthDegrees)
119 {
120  NS_LOG_FUNCTION (this << horizontalBeamwidthDegrees);
121  m_horizontalExponent = GetExponentFromBeamwidth (horizontalBeamwidthDegrees);
122 }
123 
124 
125 double
127 {
129 }
130 
131 
132 double
134 {
136 }
137 
138 
139 void
140 CosineAntennaModel::SetOrientation (double orientationDegrees)
141 {
142  NS_LOG_FUNCTION (this << orientationDegrees);
143  m_orientationRadians = DegreesToRadians (orientationDegrees);
144 }
145 
146 
147 double
149 {
151 }
152 
153 
154 double
156 {
157  NS_LOG_FUNCTION (this << a);
158 
159  // make sure phi is in (-pi, pi]
161 
162  NS_LOG_LOGIC (a);
163 
164  // The element power gain is computed as a product of cosine functions on the two axis
165  // The power pattern of the element is equal to:
166  // P(az,el) = cos(az/2)^2m * cos(pi/2 - incl/2)^2n,
167  // where az is the azimuth angle, and incl is the inclination angle.
168  double gain = (std::pow (std::cos (a.GetAzimuth () / 2), 2 * m_horizontalExponent)) *
169  (std::pow (std::cos ((M_PI / 2 - a.GetInclination ()) / 2), 2 * m_verticalExponent));
170  double gainDb = 10 * std::log10 (gain);
171 
172  NS_LOG_LOGIC ("gain = " << gainDb << " + " << m_maxGain << " dB");
173  return gainDb + m_maxGain;
174 }
175 
176 
177 }
Class holding the azimuth and inclination angles of spherical coordinates.
Definition: angles.h:119
double GetInclination(void) const
Getter for inclination angle.
Definition: angles.cc:231
double GetAzimuth(void) const
Getter for azimuth angle.
Definition: angles.cc:224
void SetAzimuth(double azimuth)
Setter for azimuth angle.
Definition: angles.cc:208
interface for antenna radiation pattern models
Definition: antenna-model.h:56
Cosine Antenna Model.
double m_maxGain
antenna gain in dB towards the main orientation
void SetHorizontalBeamwidth(double horizontalBeamwidthDegrees)
Set the horizontal 3 dB beamwidth (bilateral) of the cosine antenna model.
double GetOrientation(void) const
Get the horizontal orientation of the antenna element.
virtual double GetGainDb(Angles a)
this method is expected to be re-implemented by each antenna model
static double GetBeamwidthFromExponent(double exponent)
Compute the beamwidth of the cosine antenna model from the exponent.
static double GetExponentFromBeamwidth(double beamwidthDegrees)
Compute the exponent of the cosine antenna model from the beamwidth.
static TypeId GetTypeId()
Get the type ID.
double GetVerticalBeamwidth(void) const
Get the vertical 3 dB beamwidth of the cosine antenna model.
double GetHorizontalBeamwidth(void) const
Get the horizontal 3 dB beamwidth of the cosine antenna model.
double m_verticalExponent
exponent of the vertical direction
void SetVerticalBeamwidth(double verticalBeamwidthDegrees)
Set the vertical 3 dB beamwidth (bilateral) of the cosine antenna model.
void SetOrientation(double orientationDegrees)
Set the horizontal orientation of the antenna element.
double m_orientationRadians
orientation in radians in the horizontal direction (bearing)
double m_horizontalExponent
exponent of the horizontal direction
This class can be used to hold variables of floating point type such as 'double' or 'float'.
Definition: double.h:41
a unique identifier for an interface.
Definition: type-id.h:59
TypeId SetParent(TypeId tid)
Set the parent TypeId.
Definition: type-id.cc:922
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
#define NS_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
Definition: log.h:205
#define NS_LOG_LOGIC(msg)
Use NS_LOG to output a message of level LOG_LOGIC.
Definition: log.h:289
#define NS_LOG_FUNCTION(parameters)
If log level LOG_FUNCTION is enabled, this macro will output all input parameters separated by ",...
#define NS_OBJECT_ENSURE_REGISTERED(type)
Register an Object subclass with the TypeId system.
Definition: object-base.h:45
Every class exported by the ns3 library is enclosed in the ns3 namespace.
double DegreesToRadians(double degrees)
converts degrees to radians
Definition: angles.cc:40
double RadiansToDegrees(double radians)
converts radians to degrees
Definition: angles.cc:47