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matrix-based-channel-model.h
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1/*
2 * Copyright (c) 2020 SIGNET Lab, Department of Information Engineering,
3 * University of Padova
4 * Copyright (c) 2020 Institute for the Wireless Internet of Things,
5 * Northeastern University
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation;
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#ifndef MATRIX_BASED_CHANNEL_H
22#define MATRIX_BASED_CHANNEL_H
23
24// #include <complex>
25#include <ns3/matrix-array.h>
26#include <ns3/nstime.h>
27#include <ns3/object.h>
28#include <ns3/phased-array-model.h>
29#include <ns3/vector.h>
30
31#include <tuple>
32
33namespace ns3
34{
35
36class MobilityModel;
37
38/**
39 * \ingroup spectrum
40 *
41 * This is an interface for a channel model that can be described
42 * by a channel matrix, e.g., the 3GPP Spatial Channel Models,
43 * which is generally used in combination with antenna arrays
44 */
46{
47 public:
48 /**
49 * Destructor for MatrixBasedChannelModel
50 */
51 ~MatrixBasedChannelModel() override;
52
53 /// Type definition for vectors of doubles
54 using DoubleVector = std::vector<double>;
55
56 /// Type definition for matrices of doubles
57 using Double2DVector = std::vector<DoubleVector>;
58
59 /// Type definition for 3D matrices of doubles
60 using Double3DVector = std::vector<Double2DVector>;
61
62 using Complex2DVector = ComplexMatrixArray; //!< Create an alias for 2D complex vectors
63 using Complex3DVector = ComplexMatrixArray; //!< Create an alias for 3D complex vectors
64
65 /**
66 * Data structure that stores a channel realization
67 */
68 struct ChannelMatrix : public SimpleRefCount<ChannelMatrix>
69 {
70 /**
71 * Channel matrix H[u][s][n].
72 */
74
75 /**
76 * Generation time.
77 */
79
80 /**
81 * The first element is the ID of the antenna of the s-node (the
82 * antenna of the transmitter when the channel was generated), the
83 * second element is ID of the antenna of the u-node antenna (the
84 * antenna of the receiver when the channel was generated).
85 */
86 std::pair<uint32_t, uint32_t> m_antennaPair;
87
88 /**
89 * The first element is the s-node ID (the transmitter when the channel was
90 * generated), the second element is the u-node ID (the receiver when the
91 * channel was generated).
92 */
93 std::pair<uint32_t, uint32_t> m_nodeIds;
94
95 /**
96 * Returns true if the ChannelMatrix object was generated
97 * considering node b as transmitter and node a as receiver.
98 * \param aAntennaId the ID of the antenna array of the a node
99 * \param bAntennaId the ID of the antenna array of the b node
100 * \return true if b is the rx and a is the tx, false otherwise
101 */
102 bool IsReverse(uint32_t aAntennaId, uint32_t bAntennaId) const
103 {
104 uint32_t sAntennaId;
105 uint32_t uAntennaId;
106 std::tie(sAntennaId, uAntennaId) = m_antennaPair;
107 NS_ASSERT_MSG((sAntennaId == aAntennaId && uAntennaId == bAntennaId) ||
108 (sAntennaId == bAntennaId && uAntennaId == aAntennaId),
109 "This channel matrix does not represent the channel among the antenna "
110 "arrays for which are provided IDs.");
111 return (sAntennaId == bAntennaId && uAntennaId == aAntennaId);
112 }
113 };
114
115 /**
116 * Data structure that stores channel parameters
117 */
118 struct ChannelParams : public SimpleRefCount<ChannelParams>
119 {
120 /**
121 * Generation time.
122 */
124
125 /**
126 * Cluster delay in nanoseconds.
127 */
129
130 /**
131 * Cluster angle angle[direction][n], where direction = 0(AOA), 1(ZOA), 2(AOD), 3(ZOD)
132 * in degree.
133 */
135
136 /**
137 * Sin/cos of cluster angle angle[direction][n], where direction = 0(AOA), 1(ZOA), 2(AOD),
138 * 3(ZOD) in degree.
139 */
140 std::vector<std::vector<std::pair<double, double>>> m_cachedAngleSincos;
141
142 /**
143 * Alpha term per cluster as described in 3GPP TR 37.885 v15.3.0, Sec. 6.2.3
144 * for calculating doppler.
145 */
147
148 /**
149 * D term per cluster as described in 3GPP TR 37.885 v15.3.0, Sec. 6.2.3
150 * for calculating doppler.
151 */
153
154 /**
155 * The first element is the s-node ID (the transmitter when the channel params were
156 * generated), the second element is the u-node ID (the receiver when the channel params
157 * were generated generated).
158 */
159 std::pair<uint32_t, uint32_t> m_nodeIds;
160
161 /**
162 * Auxiliary variable to m_cachedDelaySincos
163 *
164 * It is used to determine RB width (12*SCS) changes due to numerology,
165 * in case the number of the RBs in the channel remains constant.
166 */
167 mutable double m_cachedRbWidth = 0.0;
168
169 /**
170 * Matrix array that holds the precomputed delay sincos
171 */
173
174 /**
175 * Destructor for ChannelParams
176 */
177 virtual ~ChannelParams() = default;
178 };
179
180 /**
181 * Returns a matrix with a realization of the channel between
182 * the nodes with mobility objects passed as input parameters.
183 *
184 * We assume channel reciprocity between each node pair (i.e., H_ab = H_ba^T),
185 * therefore GetChannel (a, b) and GetChannel (b, a) will return the same
186 * ChannelMatrix object.
187 * To understand if the channel matrix corresponds to H_ab or H_ba, we provide
188 * the method ChannelMatrix::IsReverse. For instance, if the channel
189 * matrix corresponds to H_ab, a call to IsReverse (idA, idB) will return
190 * false, conversely, IsReverse (idB, idA) will return true.
191 *
192 * \param aMob mobility model of the a device
193 * \param bMob mobility model of the b device
194 * \param aAntenna antenna of the a device
195 * \param bAntenna antenna of the b device
196 * \return the channel matrix
197 */
201 Ptr<const PhasedArrayModel> bAntenna) = 0;
202
203 /**
204 * Returns a channel parameters structure used to obtain the channel between
205 * the nodes with mobility objects passed as input parameters.
206 *
207 * \param aMob mobility model of the a device
208 * \param bMob mobility model of the b device
209 * \return the channel matrix
210 */
212 Ptr<const MobilityModel> bMob) const = 0;
213
214 /**
215 * Generate a unique value for the pair of unsigned integer of 32 bits,
216 * where the order does not matter, i.e., the same value will be returned for (a,b) and (b,a).
217 * \param a the first value
218 * \param b the second value
219 * \return return an integer representing a unique value for the pair of values
220 */
221 static uint64_t GetKey(uint32_t a, uint32_t b)
222 {
223 return (uint64_t)std::min(a, b) << 32 | std::max(a, b);
224 }
225
226 static const uint8_t AOA_INDEX = 0; //!< index of the AOA value in the m_angle array
227 static const uint8_t ZOA_INDEX = 1; //!< index of the ZOA value in the m_angle array
228 static const uint8_t AOD_INDEX = 2; //!< index of the AOD value in the m_angle array
229 static const uint8_t ZOD_INDEX = 3; //!< index of the ZOD value in the m_angle array
230};
231
232}; // namespace ns3
233
234#endif // MATRIX_BASED_CHANNEL_H
This is an interface for a channel model that can be described by a channel matrix,...
std::vector< double > DoubleVector
Type definition for vectors of doubles.
static const uint8_t AOA_INDEX
index of the AOA value in the m_angle array
static const uint8_t ZOD_INDEX
index of the ZOD value in the m_angle array
static const uint8_t AOD_INDEX
index of the AOD value in the m_angle array
virtual Ptr< const ChannelParams > GetParams(Ptr< const MobilityModel > aMob, Ptr< const MobilityModel > bMob) const =0
Returns a channel parameters structure used to obtain the channel between the nodes with mobility obj...
~MatrixBasedChannelModel() override
Destructor for MatrixBasedChannelModel.
static const uint8_t ZOA_INDEX
index of the ZOA value in the m_angle array
std::vector< Double2DVector > Double3DVector
Type definition for 3D matrices of doubles.
std::vector< DoubleVector > Double2DVector
Type definition for matrices of doubles.
static uint64_t GetKey(uint32_t a, uint32_t b)
Generate a unique value for the pair of unsigned integer of 32 bits, where the order does not matter,...
virtual Ptr< const ChannelMatrix > GetChannel(Ptr< const MobilityModel > aMob, Ptr< const MobilityModel > bMob, Ptr< const PhasedArrayModel > aAntenna, Ptr< const PhasedArrayModel > bAntenna)=0
Returns a matrix with a realization of the channel between the nodes with mobility objects passed as ...
A base class which provides memory management and object aggregation.
Definition: object.h:89
Smart pointer class similar to boost::intrusive_ptr.
Definition: ptr.h:77
A template-based reference counting class.
Simulation virtual time values and global simulation resolution.
Definition: nstime.h:105
#define NS_ASSERT_MSG(condition, message)
At runtime, in debugging builds, if this condition is not true, the program prints the message to out...
Definition: assert.h:86
Every class exported by the ns3 library is enclosed in the ns3 namespace.
MatrixArray< std::complex< double > > ComplexMatrixArray
Create an alias for MatrixArray using complex type.
Definition: matrix-array.h:291
Data structure that stores a channel realization.
Complex3DVector m_channel
Channel matrix H[u][s][n].
bool IsReverse(uint32_t aAntennaId, uint32_t bAntennaId) const
Returns true if the ChannelMatrix object was generated considering node b as transmitter and node a a...
std::pair< uint32_t, uint32_t > m_antennaPair
The first element is the ID of the antenna of the s-node (the antenna of the transmitter when the cha...
std::pair< uint32_t, uint32_t > m_nodeIds
The first element is the s-node ID (the transmitter when the channel was generated),...
Data structure that stores channel parameters.
DoubleVector m_delay
Cluster delay in nanoseconds.
Double2DVector m_angle
Cluster angle angle[direction][n], where direction = 0(AOA), 1(ZOA), 2(AOD), 3(ZOD) in degree.
ComplexMatrixArray m_cachedDelaySincos
Matrix array that holds the precomputed delay sincos.
virtual ~ChannelParams()=default
Destructor for ChannelParams.
double m_cachedRbWidth
Auxiliary variable to m_cachedDelaySincos.
DoubleVector m_alpha
Alpha term per cluster as described in 3GPP TR 37.885 v15.3.0, Sec.
std::vector< std::vector< std::pair< double, double > > > m_cachedAngleSincos
Sin/cos of cluster angle angle[direction][n], where direction = 0(AOA), 1(ZOA), 2(AOD),...
DoubleVector m_D
D term per cluster as described in 3GPP TR 37.885 v15.3.0, Sec.
std::pair< uint32_t, uint32_t > m_nodeIds
The first element is the s-node ID (the transmitter when the channel params were generated),...