Cognitive Radio Technology (eBook)

Front Cover 1
Contents 6
List of Contributors 18
Foreword 22
Chapter 1: History and Background of Cognitive Radio Technology 28
1.1 The Vision of Cognitive Radio 28
1.2 History and Background Leading to Cognitive Radio 29
1.3 A Brief History of SDR 31
1.4 Basic SDR 35
1.4.1 The Hardware Architecture of an SDR 35
1.4.2 Computational Processing Resources in an SDR 38
1.4.3 The Software Architecture of an SDR 40
1.4.4 Java Reflection in a Cognitive Radio 42
1.4.5 Smart Antennas in a Cognitive Radio 42
1.5 Spectrum Management 44
1.5.1 Managing Unlicensed Spectrum 45
1.5.2 Noise Aggregation 46
1.5.3 Aggregating Spectrum Demand and Use of Subleasing Methods 48
1.5.4 Priority Access 49
1.6 US Government Roles in Cognitive Radio 49
1.6.1 DARPA 49
1.6.2 FCC 50
1.6.3 NSF/CSTB Study 50
1.7 How Smart Is Useful? 51
1.8 Organization of this Book 52
Chapter 2: Communications Policy and Spectrum Management 56
2.1 Introduction 56
2.2 Cognitive Radio Technology Enablers 57
2.3 New Opportunities in Spectrum Access 60
2.3.1 Current Spectrum Access Techniques 60
2.3.2 Opportunistic Spectrum Access 66
2.3.3 Dynamic Frequency Selection 69
2.4 Policy Challenges for Cognitive Radios 69
2.4.1 Dynamic Spectrum Access 70
2.4.2 Security 73
2.4.3 Communications Policy before Cognitive Radio 75
2.4.4 Cognitive Radio Impact on Communications Policy 76
2.4.5 US Telecommunications Policy, Beginning with the Titanic 76
2.4.6 US Telecommunications Policy: Keeping Pace with Technology 78
2.5 Telecommunications Policy and Technology Impact on Regulation 80
2.5.1 Basic Geometries 80
2.5.2 Introduction of Dynamic Policies 83
2.5.3 Introduction of Policy-Enabled Devices 85
2.5.4 Interference Avoidance 87
2.5.5 Overarching Impact 88
2.6 Global Policy Interest in Cognitive Radios 88
2.6.1 Global Interest 89
2.6.2 US Reviews of Cognitive Radios for Dynamic Spectrum Access 89
2.7 Summary 96
Chapter 3: The Software Defined Radio as a Platform for Cognitive Radio 100
3.1 Introduction 100
3.2 Hardware Architecture 102
3.2.1 The Block Diagram 103
3.2.2 Baseband Processor Engines 109
3.2.3 Baseband Processing Deployment 114
3.2.4 Multicore Systems and System-on-Chip 116
3.3 Software Architecture 117
3.3.1 Design Philosophies and Patterns 118
3.4 SDR Development and Design 121
3.4.1 GNURadio 121
3.4.2 Software Communications Architecture 122
3.5 Applications 135
3.5.1 Application Software 135
3.6 Development 138
3.6.1 Component Development 139
3.6.2 Waveform Development 140
3.7 Cognitive Waveform Development 141
3.8 Summary 143
Chapter 4: Cognitive Radio: The Technologies Required 146
4.1 Introduction 146
4.2 Radio Flexibility and Capability 147
4.2.1 Continuum of Radio Flexibility and Capability 147
4.2.2 Examples of Software Capable Radios 148
4.2.3 Examples of Software Programmable Radios 153
4.2.4 Examples of SDR 153
4.3 Aware, Adaptive, and CRs 153
4.3.1 Aware Radios 153
4.3.2 Adaptive Radios 158
4.3.3 Cognitive Radios 159
4.4 Comparison of Radio Capabilities and Properties 160
4.5 Available Technologies for CRs 160
4.5.1 Geolocation 162
4.5.2 Spectrum Awareness/Frequency Occupancy 162
4.5.3 Biometrics 163
4.5.4 Time 163
4.5.5 Spatial Awareness or Situational Awareness 165
4.5.6 Software Technology 165
4.5.7 Spectrum Awareness and Potential for Sublease or Borrow 171
4.6 Funding and Research in CRs 171
4.6.1 Cognitive Geolocation Applications 173
4.6.2 Dynamic Spectrum Access and Spectrum Awareness 175
4.6.3 The Rendezvous Problem 180
4.6.4 CR Authentication Applications 182
4.7 Timeline for CRs 183
4.7.1 Decisions, Directions, and Standards 184
4.7.2 Manufacture of New Products 184
4.8 Summary and Conclusions 185
Chapter 5: Spectrum Awareness 190
5.1 Introduction 190
5.2 The Interference Avoidance Problem 191
5.3 Cognitive Radio Role 192
5.4 Spectral Footprint Minimization 193
5.5 Creating Spectrum Awareness 195
5.5.1 Spectrum Usage Reporting 195
5.5.2 Spectrum Sensing 196
5.5.3 Potential Interference Analysis 197
5.5.4 Link Rendezvous 200
5.5.5 Distributed Sensing and Operation 200
5.6 Channel Awareness and Multiple Signals in Space 201
5.7 Spectrally Aware Networking 203
5.8 Overlay and Underlay Techniques 205
5.9 Adaptive Spectrum Implications for Cognitive Radio Hardware 207
5.10 Summary: The Cognitive Radio Toolkit 209
Appendix: Propagation Energy Loss 210
Chapter 6: Cognitive Policy Engines 212
6.1 The Promise of Policy Management for Radios 212
6.2 Background and Definitions 212
6.3 Spectrum Policy 214
6.3.1 Management of Spectrum Policy 215
6.3.2 System Requirements for Spectrum Policy Management 216
6.4 Antecedents for Cognitive Policy Management 216
6.4.1 Defense Advanced Research Projects Agency Policy Management Projects 217
6.4.2 Academic Research in Policy Management 218
6.4.3 Commercial Applications of Policy Management 221
6.4.4 Standardization Efforts for Policy Management 222
6.5 Policy Engine Architectures for Radio 225
6.5.1 Concept for Policy Engine Operations 225
6.5.2 Technical Approaches for Policy Management 227
6.5.3 Enabling Technologies 229
6.6 Integration of Policy Engines into Cognitive Radio 231
6.6.1 Software Communications Architecture Integration 231
6.6.2 Policy Engine Design 233
6.6.3 Integration of the Radio into a Network Policy Management Architecture 236
6.7 The Future of Cognitive Policy Management 238
6.7.1 Military Opportunities for Cognitive Policy Management 238
6.7.2 Commercial Opportunities for Spectrum Management 239
6.7.3 Obstacles to Adoption of Policy Management Architectures 240
6.8 Summary 241
Chapter 7: Cognitive Techniques: Physical and Link Layers 246
7.1 Introduction 246
7.2 Optimizing PHY and Link Layers for Multiple-Objectives Under Current Channel Conditions 247
7.3 Defining the Cognitive Radio 249
7.4 Developing Radio Controls (Knobs) and Performance Measures (Meters) 250
7.4.1 PHY- and Link-Layer Parameters 250
7.4.2 Modeling Outcome as a Primary Objective 254
7.5 MODM Theory and Its Application to Cognitive Radio 257
7.5.1 Definition of MODM and Its Basic Formulation 257
7.5.2 Constraint Modeling 258
7.5.3 The Pareto-Optimal Front: Finding the Nondominated Solutions 258
7.5.4 Why the Radio Environment Is a MODM Problem 259
7.5.5 GA Approach to the MODM 260
7.6 The Multi-objective GA for Cognitive Radios 266
7.6.1 Cognition Loop 266
7.6.2 Representing Radio Parameters as Genes in a Chromosome 271
7.6.3 Multi-dimensional Analysis of the Chromosomes 272
7.6.4 Relative Pooling Tournament Evaluation 276
7.6.5 Example of the WSGA 276
7.7 Advanced GA Techniques 279
7.7.1 Population Initialization 280
7.7.2 Priming the GA with Previously Observed Solutions 281
7.7.3 CBDT Initialization of GAs 282
7.8 Need for a Higher-Layer Intelligence 285
7.8.1 Adjusting Parameters Autonomously to Achieve Goals 285
7.8.2 Rewards for Good Behavior and Punishments for Poor Performance 285
7.9 How the Intelligent Computer Operates 287
7.9.1 Sensing and Environmental Awareness 288
7.9.2 Decision-Making and Optimization 289
7.9.3 Case-Based Learning 289
7.9.4 Weight Values and Objective Functions 290
7.9.5 Distributed Learning 290
7.10 Summary 290
Chapter 8: Cognitive Techniques: Position Awareness 296
8.1 Introduction 296
8.2 Radio Geolocation and Time Services 297
8.2.1 GPS 298
8.2.2 Coordinate System Transformations 302
8.2.3 GPS Geolocation Summary 302
8.3 Network Localization 303
8.3.1 Spatially Variant Network Service Availability 303
8.3.2 Geolocation-Enabled Routing 305
8.3.3 Miscellaneous Functions 305
8.4 Additional Geolocation Approaches 305
8.4.1 Time-Based Approaches 306
8.4.2 AOA Approach 313
8.4.3 RSS Approach 314
8.5 Network-Based Approaches 315
8.6 Boundary Decisions 315
8.6.1 Regulatory Region Selection 315
8.6.2 Policy Servers and Regions 319
8.6.3 Other Uses of Boundary Decisions 320
8.7 Example of Cellular Telephone 911 Geolocation for First Responders 320
8.8 Interfaces to Other Cognitive Technologies 321
8.8.1 Interface to Policy Engines 321
8.8.2 Interface to Networking Functions 322
8.8.3 Interface to Planning Engines 322
8.8.4 Interface to User 322
8.9 Summary 322
Chapter 9: Cognitive Techniques: Network Awareness 326
9.1 Introduction 326
9.2 Applications and their Requirements 327
9.3 Network Solutions to Requirements 329
9.4 Coping with the Complex Trade-Space 331
9.5 Cognition to the Rescue 333
9.6 The DARPA SAPIENT Program 335
9.7 Summary 337
Chapter 10: Cognitive Services for the User 340
10.1 Introduction 340
10.2 Speech and Language Processing 341
10.2.1 Speaker Recognition 341
10.2.2 Language Identification 350
10.2.3 Text-to-Speech Conversion 352
10.2.4 Speech-to-Text Conversion 352
10.2.5 Machine Translation 353
10.2.6 Background Noise Suppression 354
10.2.7 Speech Coding 355
10.2.8 Speaker Stress Characterization 356
10.2.9 Noise Characterization 356
10.3 Concierge Services 357
10.4 Summary 359
Chapter 11: Network Support: The Radio Environment Map 364
11.1 Introduction 364
11.2 Internal and External Network Support 365
11.3 Introduction to the REM 366
11.4 REM Infrastructure Support to Cognitive Radios 368
11.4.1 The Role of the REM in Cognitive Radio 368
11.4.2 REM Design 368
11.4.3 Enabling Techniques for Implementing REM 370
11.5 Obtaining Awareness with the REM 372
11.5.1 Awareness: Prerequisite for Cognitive Radio 372
11.5.2 Classification of Awareness 374
11.5.3 Obtaining SA 376
11.6 Network Support Scenarios and Applications 380
11.6.1 Infrastructure-Based Network and Centralized Global REM 381
11.6.2 Ad hoc Mesh Networks and Distributed Local REMs 382
11.7 Supporting Elements to the REM 384
11.8 Summary and Open Issues 387
Chapter 12: Cognitive Research: Knowledge Representation and Learning 392
12.1 Introduction 392
12.2 Knowledge Representation and Reasoning 396
12.2.1 Symbolic Representation 398
12.2.2 Ontologies and Frame Systems 399
12.2.3 Behavioral Representation 401
12.2.4 Case-Based Reasoning 402
12.2.5 Rule-Based Systems 404
12.2.6 Temporal Knowledge 405
12.2.7 Knowledge Representation Summary 406
12.3 Machine Learning 407
12.3.1 Memorization 408
12.3.2 Classifiers 409
12.3.3 Bayesian Logic 410
12.3.4 Decision Trees 412
12.3.5 Reinforcement-Based Learning 413
12.3.6 Temporal Difference 416
12.3.7 Neural Networks 417
12.3.8 Genetic Algorithms 419
12.3.9 Simulation and Gaming 420
12.4 Implementation Considerations 421
12.4.1 Computational Requirements 421
12.4.2 Brittleness and Edge Conditions 421
12.4.3 Predictable Behavior 422
12.5 Summary 423
Chapter 13: Roles of Ontologies in Cognitive Radios 428
13.1 Introduction to Ontology-Based Radio 428
13.2 Knowledge-Intensive Characteristics of Cognitive Radio 428
13.2.1 Knowledge of Constraints and Requirements 430
13.2.2 Information Collection and Fusion 431
13.2.3 Situation Awareness and Advice 431
13.2.4 Self-awareness 432
13.2.5 Query by User, Self, or Other Radio 432
13.2.6 Query Responsiveness and Command Execution 432
13.2.7 Negotiation for Resources 433
13.2.8 Dynamic Interoperability at Any Stack Layer 433
13.3 Ontologies and Their Roles in Cognitive Radio 434
13.3.1 Introduction 434
13.3.2 Role of Ontology in Knowledge-Intensive Applications 440
13.4 A Layered Ontology and Reference Model 441
13.4.1 Physical Layer Ontology 441
13.4.2 Data Link Layer Ontology 443
13.5 Examples 448
13.5.1 Responding to Delays and Errors 448
13.5.2 Adaptation of Training Sequence Length 450
13.5.3 Data Link Layer Protocol Consistency and Selection 452
13.6 Open Research Issues 454
13.6.1 Ontology Development and Consensus 454
13.6.2 Ontology Mapping 455
13.6.3 Learning 456
13.6.4 Efficiency of Reasoning 457
13.7 Summary 458
Chapter 14: Cognitive Radio Architecture 462
14.1 Introduction 462
14.2 CRA I: Functions, Components, and Design Rules 463
14.2.1 AACR Functional Component Architecture 463
14.2.2 Design Rules Include Functional Component Interfaces 468
14.2.3 Near-Term Implementations 475
14.2.4 The Cognition Components 477
14.2.5 Self-referential Components 482
14.2.6 Flexible Functions of the Component Architecture 485
14.3 CRA II: The Cognition Cycle 487
14.3.1 The Cognition Cycle 487
14.3.2 Observe (Sense and Perceive) 488
14.3.3 Orient 489
14.3.4 Plan 490
14.3.5 Decide 491
14.3.6 Act 491
14.3.7 Learning 491
14.3.8 Self-monitoring 492
14.4 CRA III: The Inference Hierarchy 493
14.4.1 Atomic Stimuli 495
14.4.2 Primitive Sequences: Words and Dead Time 496
14.4.3 Basic Sequences 496
14.4.4 NL in the CRA Inference Hierarchy 497
14.4.5 Observe–Orient Links for Scene Interpretation 499
14.4.6 Observe–Orient Links for Radio Skill Sets 500
14.4.7 General World Knowledge 501
14.5 CRA IV: Architecture Maps 503
14.5.1 CRA Topological Maps 504
14.5.2 CRA Identifies Self, Owner, and Home Network 505
14.5.3 CRA-Reinforced Hierarchical Sequences 505
14.5.4 Behaviors in the CRA 506
14.5.5 From Maps to APIs 508
14.5.6 Industrial-Strength Inference Hierarchy 508
14.6 CRA V: Building the CRA on SDR Architectures 510
14.6.1 Review of SWR and SDR Principles 510
14.6.2 Radio Architecture 513
14.6.3 The SCA 514
14.6.4 Functions-Transforms Model of Radio 517
14.6.5 Architecture Migration: From SDR to AACR 518
14.6.6 Cognitive Electronics 518
14.6.7 When Should a Radio Transition toward Cognition? 519
14.6.8 Radio Evolution toward the CRA 521
14.7 Cognition Architecture Research Topics 521
14.8 Industrial-Strength AACR Design Rules 522
14.9 Summary and Future Directions 524
Chapter 15: Cognitive Radio Performance Analysis 528
15.1 Introduction 528
15.2 The Analysis Problem 532
15.2.1 Mathematical Preliminaries 532
15.2.2 A Formal Model of a Cognitive Radio Network 533
15.2.3 Analysis Objectives 536
15.3 Traditional Engineering Analysis Techniques 540
15.3.1 A Dynamical Systems Approach 540
15.3.2 Contraction Mappings and the General Convergence Theorem 545
15.3.3 Markov Models 551
15.4 Applying Game Theory to the Analysis Problem 556
15.4.1 Basic Elements of Game Theory 557
15.4.2 Mapping the Basic Elements of a Game to the Cognition Cycle 560
15.4.3 Basic Game Models 561
15.4.4 Basic Game Theory Analysis Techniques 565
15.5 Relevant Game Models 571
15.5.1 Potential Games 571
15.5.2 Supermodular Games 581
15.6 Case Studies 590
15.6.1 Distributed Power Control 590
15.6.2 Dynamic Frequency Selection 595
15.6.3 Adaptive Interference Avoidance 596
15.7 Summary and Conclusions 599
15.8 Questions 602
Chapter 16: The Really Hard Problems 608
16.1 Introduction 608
16.2 Review of the Book 608
16.3 Services Offered to Wireless Networks through Infrastructure 614
16.3.1 Stand-Alone Radios with Cognition 615
16.3.2 Cellular Infrastructure Support to Cognition 616
16.3.3 Data Radios 617
16.3.4 Cognitive Services Offered through Infrastructure 618
16.3.5 The Remaining Hard Problems 620
Glossary 622
A 622
B 623
C 623
D 624
E 625
F 625
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O 629
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Q 630
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Index 636
A 636
B 637
C 637
D 638
E 639
F 639
G 639
H 640
I 641
J 641
K 641
L 641
M 642
N 642
O 643
P 643
Q 645
R 645
S 646
T 648
U 648
V 648
W 649
X 649
Y 649
Z 649