Cognitive Radio Networks

Professor Kwang-Cheng Chen National Taiwan University, Taiwan

Professor Ramjee Prasad Aalborg University, Denmark

©WILEY A John Wiley and Sons, Ltd, Publication

Contents

Preface xi

1 Wireless Communications 1 1.1 Wireless Communications Systems 1 1.2 Orthogonal Frequency Division Multiplexing (OFDM) 3

1.2.1 OFDM Concepts 4 1.2.2 Mathematical Model of OFDM System 5 1.2.3 OFDM Design Issues 9 1.2.4 OFDMA 21

1.3 MIMO 24 1.3.1 Space-Time Codes 24 1.3.2 Spatial Multiplexing Using Adaptive Multiple Antenna Techniques 27 1.3.3 Open-loop MIMO Solutions 27 1.3.4 Closed-loop MIMO Solutions 29 7.5.5 MIMO Receiver Structure 31

1.4 Multi-user Detection (MUD) 34 1.4.1 Multi-user (CDMA) Receiver 34 1.4.2 Suboptimum DS/CDMA Receivers 37

References 40

2 Software Defined Radio 41 2.1 Software Defined Radio Architecture 41 2.2 Digital Signal Processor and SDR Baseband Architecture 43 2.3 Reconfigurable Wireless Communication Systems 46

2.3.1 Unified Communication Algorithm 46 2.3.2 Reconfigurable OFDM Implementation 47 2.3.3 Reconfigurable OFDM and CDMA 47

2.4 Digital Radio Processing 48 2.4.1 Conventional RF 48 2.4.2 Digital Radio Processing (DRP) Based System Architecture 52

References 58

3 Wireless Networks 59 3.1 Multiple Access Communications and ALOHA 60

3.1.1 ALOHA Systems and Slotted Multiple Access 61 3.1.2 Slotted ALOHA 61

VI Contents

3.1.3 Stabilised Slotted ALOHA 64 3.1.4 Approximate Delay Analysis 65 3.1.5 Unslotted ALOHA 66

3.2 Splitting Algorithms 66 3.2.1 Tree Algorithms 61 3.2.2 FCFS Splitting Algorithm 68 3.2.3 Analysis of FCFS Splitting Algorithm 69

3.3 Carrier Sensing 71 3.3.1 CSMA Slotted ALOHA 71 3.3.2 Slotted CSMA 76 3.3.3 Carrier Sense Multiple Access with Collision Detection (CSMA/CD) 79

3.4 Routing 82 3.4.1 Flooding and Broadcasting 83 3.4.2 Shortest Path Routing 83 3.4.3 Optimal Routing 83 3.4.4 Hot Potato (Reflection) Routing 84 3.4.5 Cut-through Routing 84 3.4.6 Interconnected Network Routing 84 3.4.7 Shortest Path Routing Algorithms 84

3.5 Flow Control 89 3.5.1 Window Flow Control 89 3.5.2 Rate Control Schemes 91 3.5.3 Queuing Analysis of the Leaky Bucket Scheme 92

References 93

Cooperative Communications and Networks 95 4.1 Information Theory for Cooperative Communications 96

4.1.1 Fundamental Network Information Theory 96 4.1.2 Multiple-access Channel with Cooperative Diversity 101

4.2 Cooperative Communications 102 4.2.1 Three-Node Cooperative Communications 103 4.2.2 Multiple-Node Relay Network 109

4.3 Cooperative Wireless Networks 113 4.3.1 Benefits of Cooperation in Wireless Networks 114 4.3.2 Cooperation in Cluster-Based Ad-hoc Networks 116

References 118

Cognitive Radio Communications 121 5.1 Cognitive Radios and Dynamic Spectrum Access 121

5.1.1 The Capability of Cognitive Radios 122 5.1.2 Spectrum Sharing Models of DSA 124 5.1.3 Opportunistic Spectrum Access: Basic Components 126 5.1.4 Networking The Cognitive Radios 126

5.2 Analytical Approach and Algorithms for Dynamic Spectrum Access 126 5.2.1 Dynamic Spectrum Access in Open Spectrum 128 5.2.2 Opportunistic Spectrum Access 130 5.2.3 Opportunistic Power Control 131

5.3 Fundamental Limits of Cognitive Radios 132

Contents Vll

5.4 Mathematical Models Toward Networking Cognitive Radios 136 5.4.1 CR Link Model 136 5.4.2 Overlay CR Systems 137 5.4.3 Rate-Distance Nature 140

References 142

Cognitive Radio Networks 145 6.1 Network Coding for Cognitive Radio Relay Networks 146

6.1.1 System Model \A1 6.1.2 Network Capacity Analysis on Fundamental CRRN Topologies 150 6.1.3 Link Allocation 154 6.1.4 Numerical Results 156

6.2 Cognitive Radio Networks Architecture 159 6.2.7 Network Architecture 159 6.2.2 Links in CRN 161 6.2.3 IP Mobility Management in CRN 163

6.3 Terminal Architecture of CRN 165 6.3.1 Cognitive Radio Device Architecture 165 6.3.2 Re-configurable MAC 168 6.3.3 Radio Access Network Selection 169

6.4 QoS Provisional Diversity Radio Access Networks 171 6.4.1 Cooperative/Collaborative Diversity and Efficient Protocols 172 6.4.2 Statistical QoS Guarantees over Wireless Asymmetry

Collaborative Relay Networks 174 6.5 Scaling Laws of Ad-hoc and Cognitive Radio Networks 177

6.5.7 Network and Channel Models 111 6.5.2 Ad-hoc Networks 178 6.5.3 Cognitive Radio Networks 179

References 180

Spectrum Sensing 183 7.1 Spectrum Sensing to Detect Specific Primary System 183

7.7.7 Conventional Spectrum Sensing 183 7.7.2 Power Control 187 7.1.3 Power-Scaling Power Control 188 7.1.4 Cooperative Spectrum Sensing 190

7.2 Spectrum Sensing for Cognitive OFDMA Systems 194 7.2.7 Cognitive Cycle 195 7.2.2 Discrimination of States of the Primary System 197 7.2.3 Spectrum Sensing Procedure 203

7.3 Spectrum Sensing for Cognitive Multi-Radio Networks 206 7.5.7 Multiple System Sensing 207 7.3.2 Radio Resource Sensing 216

References 228

8 Medium Access Control 8.1 MAC for Cognitive Radios

231 231

viii Contents

8.2 Multichannel MAC 232 8.2.1 General Description of Multichannel MAC 235 8.2.2 Multichannel MAC: Collision Avoidance/Resolution 238 8.2.3 Multichannel MAC: Access Negotiation 242

8.3 Slotted-ALOHA with Rate-Distance Adaptability 251 8.3.1 System Model 252

8.4 CSMA with AMC 259 8.4.1 Carrier Sense Multiple Access with Spatial-Reuse

Transmissions 261 8.4.2 Analysis of CSMA-ST 263 8.4.3 A Cross-Layer Power-Rate Control Scheme 268 8.4.4 Performance Evaluations 270

References 272

9 Network Layer Design 275 9.1 Routing in Mobile Ad-hoc Networks 275

9.1.1 Routing in Mobile Ad-hoc Networks 275 9.1.2 Features of Routing in CRN 276 9.1.3 Dynamic Source Routing in MANET 278 9.1.4 Ad-hoc On-demand Distance Vector (AODV) 283

9.2 Routing in Cognitive Radio Networks 286 9.2.1 Trusted Cognitive Radio Networking 286 9.2.2 Routing of Dynamic and Unidirectional CR Links in CRN 288

9.3 Control of CRN 291 9.3.1 Flow Control of CRN 291 9.3.2 End-to-End Error Control in CRN 292 9.3.3 Numerical Examples 292

9.4 Network Tomography 296 9.5 Self-organisation in Mobile Communication Networks 298

9.5.1 Self-organised Networks 298 9.5.2 Self-organised Cooperative and Cognitive Networks 299

References 304

10 Trusted Cognitive Radio Networks 307 10.1 Framework of Trust in CRN 308

10.1.1 Mathematical Structure of Trust 308 10.1.2 Trust Model 311

10.2 Trusted Association and Routing 311 10.2.1 Trusted Association 312 10.2.2 Trusted Routing 317

10.3 Trust with Learning 319 10.3.1 Modified Bayesian Learning 319 10.3.2 Learning Experiments for CRN 322

10.4 Security in CRN 328 10.4.1 Security Properties in Cellular Data Networks 328 10.4.2 Dilemma of CRN Security 330

Contents ix

10.4.3 Requirements and Challenges for Preserving User Privacy in CRNs 331

10.4.4 Implementation of CRN Security 332 References 334

11 Spectrum Management of Cognitive Radio Networks 335 11.1 Spectrum Sharing 337 11.2 Spectrum Pricing 339 11.3 Mobility Management of Heterogeneous Wireless Networks 347 11.4 Regulatory Issues and International Standards 350

11.4.1 Regulatory Issues 351 11.4.2 International Standards 354

References 355

Index 357