Cover

Contents

Contributors

Preface

Acknowledgments

Notation

1 The concept of cognitive radio

1.1 Motivation for cognitive radios: spectrum is underutilized

1.2 What is cognitive radio?

1.2.1 Agile radios and dynamic spectrum access

1.2.2 User hierarchy in cognitive radio networks

1.2.3 Usage scenarios for cognitive radio

1.2.4 Cognitive radio bands

1.3 Spectrum policy: present and future

1.3.1 Role of spectrum policy

1.4 Data explosion: future spectrum implications

1.5 Applications of cognitive radio

1.5.1 Dynamic spectrum access in cellular systems

1.5.2 Cellular data boost

1.5.3 Machine-to-machine communications

1.5.4 Distribution and backhaul

1.5.5 Cognitive digital home

1.5.6 Long range vehicle-to-vehicle network

1.6 Cognitive radio network design

1.6.1 Global control plane

1.6.2 Spectrum servers, spectrum brokers, and network information servers

1.6.3 Security aspects of cognitive radio

1.7 Hardware and system design considerations

1.7.1 Design tradeoffs in usage scenarios

1.7.2 Antenna design in cognitive radio systems

1.7.3 Analog-to-digital converters

1.7.4 Wideband channels and noncontiguous transmission

1.8 Spectrum coexistence in cognitive radio networks

1.8.1 Spectrum pooling and bandwidth exchange

1.8.2 Cross-layer scheduling in cognitive radio networks

1.9 Prototyping

1.10 Standardization activity in cognitive radio

1.11 Organization of this book

References

2 Capacity of cognitive radio networks

2.1 Introduction

2.2 Cognitive radio network paradigms

2.2.1 Underlay paradigm

2.2.2 Overlay paradigm

2.2.3 Interweave paradigm

2.2.4 Comparison of cognitive radio paradigms

2.3 Fundamental performance limits of wireless networks

2.3.1 Performance metrics

2.3.2 Mathematical definition of capacity

2.3.3 Capacity region of wireless networks

2.4 Interference channels without cognition

2.4.1 K-user interference channels

2.4.2 Two-user interference channel capacity

2.4.3 Interference channel techniques for cognitive radios

2.5 Underlay cognitive radio networks

2.5.1 Underlay capacity region

2.5.2 Capacity results for specific scenarios

2.6 Interweave cognitive radio networks

2.6.1 Shannon capacity

2.6.2 Random switch model for secondary channels

2.6.3 Scaling laws for interweave networks

2.7 Overlay cognitive radio networks

2.7.1 Cognitive encoder for the two-user overlay channel

2.7.2 Capacity results

2.7.3 K-user overlay networks

2.8 Summary

2.9 Further reading

References

3 Propagation issues for cognitive radio

3.1 Introduction

3.1.1 Propagation in the cognitive radio bands

3.1.2 Impact of propagation on sensing

3.1.3 Impact of propagation on transmission

3.1.4 Outline of the chapter

3.2 Generic channel response

3.3 Introduction to path loss

3.3.1 Free-space path loss

3.3.2 Path loss in CR scenarios

3.4 Path loss models for wireless channels

3.4.1 General formulation

3.4.2 Shadow fading, S

3.4.3 Median path loss, PLmed

3.4.4 Antenna gain and the gain reduction factor

3.5 Path loss models for tower-based scenarios

3.5.1 Transmissions from TV towers

3.5.2 Tower-to-tower paths at low-to-moderate heights

3.6 Small-scale fading and the Ricean K-factor

3.6.1 Spatial variation of field strength

3.6.2 Temporal fading on mobile radio links

3.6.3 Temporal fading on fixed wireless links

3.7 Small-scale fading and the Doppler spectrum

3.7.1 Doppler frequency

3.7.2 The angle-of-arrival and Doppler spectra

3.7.3 The autocorrelation function, A((Δt)

3.7.4 The Doppler spectrum for fixed terminals

3.7.5 Dispersion

3.8 Delay dispersion

3.8.1 ``Narrowband" vs. ``wideband"

3.8.2 Wideband channels

3.8.3 Time-variant impulse response

3.8.4 The power delay profile, P(τ)

3.8.5 The frequency correlation function, F(Δf)

3.8.6 A model and values for the delay spread

3.8.7 Ultra-wideband (UWB) channels

3.9 Angle dispersion

3.9.1 Directions of arrival and departure

3.9.2 Models for the APS shape and angular spread

3.9.3 Joint dispersions

3.10 Polarization

3.11 Special environments

3.11.1 Vehicle-to-vehicle (V2V) propagation

3.11.2 Wireless sensor networks (WSNs)

3.12 Summary of key model parameters

3.12.1 Path loss models

3.12.2 Ricean K-factor models

3.12.3 Delay dispersion models

3.12.4 Frequency dispersion models

3.12.5 Comprehensive models

3.12.6 Usage of models

3.13 Summary

3.14 Further reading

References

4 Spectrum sensing

4.1 Introduction

4.2 Interference temperature for cognitive underlaying

4.3 White-space detection for cognitive interweaving

4.3.1 Energy sensing

4.3.2 Coherent detection

4.3.3 Cyclostationarity-based detection

4.3.4 Autocorrelation-based detection

4.4 An application: spectrum sensing with OFDM

4.4.1 Neyman–Pearson detection

4.4.2 Detection based on second-order statistics

4.5 Effects of imperfect knowledge of noise power

4.5.1 Energy sensing

4.5.2 Pilot-tone-aided coherent sensing

4.5.3 Cyclostationarity-based detection

4.6 Effects of an inaccurate model of interference

4.6.1 Basics of moment-bound theory

4.6.2 Energy sensing

4.6.3 Pilot-tone-aided coherent sensing

4.7 Summary

4.8 Further reading

References

5 Spectrum exploration and exploitation

5.1 Introduction

5.1.1 Chapter motivation

5.1.2 Preview of the chapter

5.2 Advanced spectrum sensing techniques

5.2.1 Distributed detection in spectrum sensing

5.2.2 Sequential and quickest detection

5.3 Optimized spectrum exploration and exploitation: sensing and access policy design

5.3.1 Optimization techniques

5.3.2 Bandit problems

5.3.3 Reinforcement learning

5.3.4 Game-theoretic approaches

5.3.5 Location awareness and geolocation

5.4 Summary

5.5 Further reading

References

Bibliography

Index