Ground-Based Wireless Positioning

Dr Kegen Yu received a BEng degree from Jilin University, China, a MEng degree from the Australian National University, Australia, and a PhD degree from the University of Sydney, Australia, in 1983, 1999 and 2003 respectively. From 1983 to 1997 he worked as a practicing engineer and later a lecturer at Nanchang University, China. From 2003 to 2005 he was employed as a Postdoctoral Fellow at the Centre for Wireless Communications, University of Oulu, Finland, researching on wireless positioning and communications theory. Since November 2005 he has served as a Research Scientist at CSIRO working on ad hoc wireless positioning systems, wireless sensor networks and reconfigurable radio. Kegen has published three book chapters, and over 40 refereed journal and conference papers. Ian Sharp is a Senior Consultant on wireless positioning systems. He has over 30 years of engineering experience in radio systems. His initial involvement in positioning technology was in aviation and later, in the 1980s, with the Interscan microwave landing system (MLS). In the later 1980s to the early 1990s, Ian was the R&D manager for the Quiktrak covert vehicle tracking system. This system is now commercially operating worldwide. From the mid 1990s to 2007 Ian worked at the CSIROmainly on developing experimental radio systems. Hewas the inventor and architect designer of CSIRO’s precision location system (PLS) for sports applications. The PLS has been successfully trialed in Australia and the USA. Ian holds a number of patents relating to positioning technology. Professor Y Jay Guo is the Director of the Wireless Technologies Laboratory and Theme Leader of Broadband for Australia in the CSIRO ICT Centre, Australia. Prior to this appointment in August 2005, Jay held various senior positions in the European wireless industry managing the development of advanced technologies for the third-generation (3G) mobile communications systems. Jay has over 20 years of industrial and academic experience in antennas, signal processing and wireless networks. He has published three technical books and over 100 scientific papers in top-tier research journals and at international conferences. He holds 12 patents in wireless technologies. He is a Fellow of IET, Adjunct Professor at Macquarie University, Australia, and Guest Professor at the Chinese Academy of Science (CAS).

About the Authors xiii

Preface xv

Acknowledgments xvii

1 Introduction 1

1.1 Introduction to Radio Positioning 3

1.2 Short and Medium-range Radiolocation Technologies 5

1.3 Overview of the Book 10

2 Radio Propagation 15

2.1 Statistical Multipath Theory 16

2.2 Radio Propagation Characteristics at Different Distance Scales 29

2.3 Measurements 39

2.4 Excess Delays in Radio Propagation 44

2.5 Antenna Effects 51

3 Signal Detection by Correlation 55

3.1 Transmitter Signal 55

3.2 Receiver Signal Processing 58

4 Bandlimited Time-of-Arrival Measurements 77

4.1 Wideband Multipath Theorem 78

4.2 Bandlimited Correlogram Characteristics 80

4.3 Model of Bandlimited Correlogram 83

4.4 Peak-Tracking Algorithm Performance 86

4.5 Leading-edge Projection Tracking Algorithm 95

4.6 Leading-edge Ratio Algorithm 101

4.7 Multipath Phase 108

4.8 Performance Summary of Tracking Algorithms 110

5 Fundamentals of Positioning Systems 115

5.1 Navigation Systems and Tracking Systems 116

5.2 System Architecture 118

5.3 Overview of Position Determination 132

5.4 Indoor Performance Issues 139

6 Noniterative Position Determination 147

6.1 Basic Positioning Methods 147

6.2 Linearization-Based Least-Squares Methods 157

6.3 Spherical Interpolation Approach 159

6.4 Quasi-Least-Squares Solution 164

6.5 Linear-Correction Least-Squares Approach 168

7 Iterative Position Determination 173

7.1 Iterative Algorithms 173

7.2 Filtering-Based Methods 184

7.3 Data Smoothing 191

8 Positioning Accuracy Evaluation 199

8.1 Accuracy Measures 199

8.2 Cramer--Rao Lower Bound in Line-of-Sight Conditions 201

8.3 Derivation of Cramer--Rao Lower Bound in Non-Line-of-Sight Conditions 207

8.4 Approximate Variance of Linear Least-Squares Algorithm 210

8.5 Accuracy Comparison 215

9 Geometric Dilution of Precision Analysis 223

9.1 Geometric Error Analysis 223

9.2 Statistical Error Analysis 226

9.3 Calculation of Geometric Dilution of Precision 228

9.4 Accuracy Probabilities 230

9.5 Special Cases: Analytical Solutions to Geometric Dilution of Precision 232

9.6 Geometric Dilution of Precision Performance 244

10 Multipath Mitigation 249

10.1 Residual-Weighting-based Method 249

10.2 Filtering-based Method 250

10.3 Constrained Optimization 253

10.4 Scatterer-based Method 266

10.5 Error Statistics 270

10.6 Propagation-Model-based Method 274

10.7 Pattern Matching 276

10.8 Performance Analysis 280

11 Anchor-based Localization for Wireless Sensor Networks 289

11.1 Characteristics of Wireless Sensor Networks 290

11.2 Coarse Localization Methods 291

11.3 Global Localization Methods 294

11.4 Localization with Unknown Internal Delays and Clock Offsets 298

12 Anchor Position Accuracy Enhancement 321

12.1 Impact of Anchor Location Accuracy on Sensor Node Localization 322

12.2 Line-of-Sight and Non-Line-of-Sight Propagation Models 324

12.3 Anchor Position Accuracy Bound 326

12.4 Accuracy Improvement Based on Distance and Angle Estimates 330

12.5 Accuracy Improvement Based on Distance Estimates 335

13 Anchor-Free Localization 343

13.1 Robust Quads 344

13.2 Multidimensional Scaling Method 344

13.3 Mass--Spring Model 348

13.4 Hybrid Approach 349

13.5 Graphical Model 352

13.6 Clustering and Stitching 353

13.7 Referent Coordinate System Establishment 355

13.8 Cramer--Rao Lower Bound 356

13.9 Accuracy of Location Estimates 359

13.10 Distance-Error-based Accuracy Measure 363

13.11 Accuracy Evaluation 364

14 Non-Line-of-Sight Identification 371

14.1 Data Smoothing 372

14.2 Distribution Tests 373

14.3 Calculating Level Crossing Rate and Fade Duration 379

14.4 Estimating the Rician Factor 381

14.5 Generalized Likelihood Ratio Test 381

14.6 Nonparametric Method 383

14.7 Using Intermediate Location Estimation 385

14.8 Neyman--Pearson Test 387

14.9 Joint Time-of-Arrival and Received Signal Strength-based Approaches 390

14.10 Angle-of-Arrival-based Methods 395

Appendix A: Hyperbolic Navigation 409

A.1 Analytical Equations of a Hyperbola 409

A.2 Solution to Hyperbolic Navigation 412

A.3 Solution to Example Problem 414

Appendix B: Radio Propagation Measurement Techniques 417

B.1 Measurements with a Network Analyzer 417

B.2 Time-Domain Measurements 421

Index