Ultra-Wideband Wireless Communications and Networks

List of Contributors xi

Preface xiii

1 Introduction 1
Robert Caiming Qiu, Xuemin (Sherman) Shen, Mohsen Guizani and Tho Le-Ngoc

1.1 Fundamentals 1

1.1.1 Overview of UWB 1

1.1.2 History 2

1.1.3 Regulatory 2

1.1.4 Applications 2

1.1.5 Pulse- or Multicarrier-Based UWB 3

1.2 Issues Unique to UWB 4

1.2.1 Antennas 4

1.2.2 Propagation and Channel Model 4

1.2.3 Modulations 5

1.2.4 A/D Sampling 6

1.2.5 Timing Acquisition 7

1.2.6 Receiver Structures 7

1.2.7 Multiple Access 8

1.3 Emerging Technologies 8

1.3.1 Low-Complexity Noncoherent Receivers 8

1.3.2 Location-Based Sensor Networks 9

1.3.3 Time Reversal 9

1.3.4 MAC 10

1.3.5 Future Directions 12

References 13

2 Modulation and Signal Detection in UWB 15
Uzoma A. Onunkwo and Ye (Geoffrey) Li

2.1 Overview 15

2.1.1 Evolution and Definition 15

2.1.2 Major Differences from Narrowband and CDMA Systems 16

2.1.3 Types of UWB Modulation 16

2.1.4 UWB Applications 16

2.2 Single-Carrier–Based Modulation 17

2.2.1 Time-Hopping PPM 17

2.2.2 Other Types of Modulations 21

2.2.3 Channel Estimation 23

2.2.4 Signal Detection 27

2.3 OFDM-Based Modulation 29

2.3.1 Basic OFDM for UWB 29

2.3.2 Channel Estimation 30

2.3.3 Interference Suppression 31

2.4 Conclusion and Further Reading 34

References 34

3 UWB Pulse Propagation and Detection 37
Robert Caiming Qiu

3.1 Introduction 37

3.2 UWB Pulse Propagation 37

3.2.1 Generalized Multipath Model 37

3.2.2 IEEE 802.15.4a Channel Model 39

3.3 UWB Pulse Signal Detection 39

3.3.1 Optimum Receiver 39

3.3.2 Generalized RAKE Receiver 41

3.3.3 Optimum Receiver with Intersymbol Interference 44

3.3.4 Receiver with Time-Reversal Channel Impulse Response 47

3.3.5 Optimum Receiver with Multiuser Detection 48

References 51

4 Timing Synchronization for UWB Impulse Radios 53
Zhi Tian and Georgios B. Giannakis

4.1 Introduction 53

4.2 Signal Model 55

4.3 Signal Detection and Symbol-Level Acquisition 57

4.3.1 Analog Energy Detectors 57

4.3.2 Discrete-Time Energy Detectors 57

4.4 SAT and MAT: Templates with and without Timing 59

4.5 Coarse Synchronization Using Symbol-Rate Samples 60

4.5.1 Discrete-Time Correlator Output Model under Mistiming 61

4.5.2 CML Timing Synchronization 62

4.5.3 Analytic and Simulated Performance 62

4.6 Synchronization with Flexible Timing Resolution 64

4.6.1 Timing-Offset Search via Sample Mean Square 64

4.6.2 Timing-Offset Search via Cross-Correlation Mean Square 66

4.6.3 Comparative Study and Implementation Aspects 68

4.7 Timing Acquisition for Ad Hoc Multiple Access 70

4.7.1 Training-Based Multiuser TOE 70

4.7.2 Blind Synchronization for Multiuser Ad Hoc Access 71

4.7.3 TOE Performance Analysis 75

4.8 Demodulation and BER Sensitivity to Mistiming 76

4.9 Concluding Summary 78

References 79

5 Error Performance of Pulsed Ultra-wideband Systems in Indoor Environments 83
Huaping Liu

5.1 Introduction 83

5.2 System Model 85

5.3 Error Performance in Indoor Environments 89

5.3.1 Pulse Amplitude Modulation and Pulse Position Modulation 90

5.3.2 Receiver with Self-Derived Template Waveforms 92

5.3.3 System with Multiple Antennas 95

References 101

6 Mixed-Signal Ultra-wideband Communications Receivers 103
Sebastian Hoyos and Brian M. Sadler

6.1 Introduction 103

6.2 Analog-to-Digital Conversion via Signal Expansion 105

6.3 Mixed-Signal Communication Receivers Based on A/D Conversion via Signal Expansion 107

6.3.1 Transmitted Signal and Channel Model 107

6.3.2 Digital Linear Receivers Based on ADC via Signal Expansion 107

6.4 Analog-to-Digital Conversion in the Frequency Domain 109

6.5 Frequency-Domain Mixed-Signal Receivers 111

6.5.1 Multicarrier Communication Systems Based on A/D Conversion in the Frequency Domain 111

6.5.2 Relationship to the Fourier Series Coefficients 117

6.5.3 Mixed-Signal Transmitted-Reference Receiver 118

6.6 Conclusions 124

References 125

7 Trends in Ultra-wideband Transceiver Design 127
Zhengyuan Xu

7.1 Introduction 127

7.2 Status of UWB Transceiver Design 128

7.3 Digital UWB Receivers 130

7.3.1 PPM-Based TH-UWB System Model 131

7.3.2 Channel Estimation Techniques 132

7.3.3 Design of Linear Receivers 133

7.3.4 Some Thoughts about Complexity Reduction 134

7.3.5 Finite Resolution Digital Receivers 135

7.4 Analog/Digital UWB Transceivers 136

7.4.1 Near Full-Rate TR Transceivers 136

7.4.2 Full-Rate TR Transceivers 144

7.5 Conclusions 149

Acknowledgments 149

References 149

8 UWB MAC and Ad Hoc Networks 155
Zihua Guo and Richard Yao

8.1 Introduction 155

8.1.1 Overview of IEEE 802.15.3 MAC 155

8.1.2 Overview of MBOA MAC 157

8.2 QoS Scheduling in PNC 158

8.2.1 Problem Definition 159

8.2.2 Deadline-Aware Scheduling Algorithm 160

8.2.3 Calculation of the Reserved CTA 161

8.2.4 Simulation Results 161

8.3 Power Management in IEEE 802.15.3 163

8.3.1 Problem Definition 164

8.3.2 Proposed Approach 165

8.3.3 Simulation Results 167

8.4 Adaptive Dly-ACK 168

8.4.1 Problem Definition 170

8.4.2 Adaptive Dly-ACK 172

8.4.3 Simulation Results 177

8.5 Ad Hoc Networks 183

8.5.1 Child Piconet 183

8.5.2 Independent Piconets 184

8.6 Summary 187

References 187

9 Radio Resource Management for Ultra-wideband Communications 189
Xuemin (Sherman) Shen, Weihua Zhuang, Hai Jiang and Jun Cai

9.1 Introduction 189

9.2 Radio Resource Management 191

9.2.1 Pulse-Based UWB Physical Layer Characteristics 191

9.2.2 Challenges and Opportunities 192

9.3 Multiple Access 193

9.3.1 Exclusive versus Concurrent Transmissions 193

9.3.2 Code Assignment 194

9.3.3 Interference Mitigation in TH-UWB 196

9.4 Overhead Reduction 197

9.4.1 ACK Mechanisms 198

9.4.2 Long Acquisition Time 199

9.5 Power/Rate Allocation 200

9.5.1 Power Allocation 200

9.5.2 Rate Guarantee 202

9.5.3 Rate Control 203

9.5.4 Cross-Layer Design 205

9.6 Conclusions 206

References 207

10 Pulsed UWB Interference to Narrowband Receivers 211
Jay E. Padgett

10.1 Introduction 211

10.2 Pulsed UWB Signal Model 212

10.3 Narrowband Receiver Model 216

10.4 Equivalent Receiver Model and Response to a Pulse 218

10.5 Response to a Pulse Sequence 220

10.6 Simulating the Response to a Pulse Sequence 223

10.6.1 I/Q Component Formulation 223

10.6.2 Simulation Parameters 224

10.6.3 Normalization 224

10.6.4 Example Filter Response: The n-Pole Filter 225

10.7 General Properties of the IF Output 227

10.7.1 Case 1: Pulse Rate Less than IF Bandwidth 227

10.7.2 Case 2: Pulse Rate Greater than IF Bandwidth 228

10.8 Power Spectral Density 230

10.9 Discrete PDF PSD Example: Equally Spaced, Equally Likely Time Offsets 233

10.10 Continuous PDF PSD Examples 239

10.10.1 The Poisson Process 239

10.10.2 Continuous PDF Uniform Random Pulse Position 240

10.11 Comparison of PSD and Simulation Results 242

10.12 Statistical Properties of the Output Envelope 247

10.13 Summary 249

References 250

11 Digital-Carrier Spreading Codes for Baseband UWB Multiaccess 251
Liuqing Yang and Georgios B. Giannakis

11.1 Introduction 251

11.2 Digital-Carrier Multiband User Codes 252

11.2.1 Baseband Single-Carrier UWB 252

11.2.2 Baseband Multicarrier UWB 254

11.3 Low Duty-Cycle Access in the Presence of NBI 255

11.3.1 General Rake Reception Model 255

11.3.2 SINR Analysis 259

11.3.3 Simulations and Numerical Results 260

11.4 Improved Rate Access in the Presence of Multipath 263

11.4.1 Rake Reception Model with IFI 263

11.4.2 Performance Comparisons 266

11.4.3 Simulated Examples 271

11.5 Multiuser Interference Mitigation 273

11.6 Summary 276

References 276

12 Localization 279
Kegen Yu, Harri Saarnisaari, Jean-Philippe Montillet, Alberto Rabbachin, Ian Oppermann and Giuseppe Thadeu Freitas de Abreu

12.1 Introduction 279

12.2 Time-of-Arrival Estimation 279

12.2.1 Estimation Accuracy 280

12.2.2 Energy-Collection–Based TOA Estimation 281

12.2.3 Two-Stage TOA Estimation 282

12.2.4 Simulation Results 286

12.3 Location and Tracking 286

12.3.1 Position Estimation 287

12.3.2 Tracking 292

12.3.3 Simulation Results 292

12.4 Location in Distributed Architectures 294

12.4.1 Overview 294

12.4.2 Proposed Algorithm 295

12.4.3 Simulation Results 296

12.5 Theoretical Positioning Accuracy 297

12.5.1 Analysis Tool 298

12.5.2 Hyperbolic Location Accuracy 299

12.6 Conclusions 301

Acknowledgment 301

References 301

Index 305