Contents
List of Acronyms X
List of Symbols XIV
List of Figures XVII
List of Tables XXI
1 Introduction 1
1.1 Internet-of-Things (IoT) . . . . 1
1.2 Bluetooth Low Energy (BLE) technology . . . . 2
1.2.1 Channels and packet structure . . . . 2
1.2.2 Frequency Hopping Spread Spectrum (FHSS) . . . . 3
1.2.3 Gaussian Frequency Shift Keying (GFSK) modulation . . . . 3
1.3 Indoor positioning . . . . 4
1.3.1 Range parameters . . . . 6
1.3.1.1 Received Signal Strength (RSS) . . . . 6
1.3.1.2 Time-of-Arrival (ToA) . . . . 6
1.3.1.3 Time Difference-of-Arrival (TDoA) . . . . 7
1.3.1.4 Angle-of-Arrival (AoA) . . . . 7
1.3.2 Position estimation methods . . . . 8
1.3.2.1 Fingerprinting . . . . 8
1.3.2.2 Geometry-based . . . . 8
1.4 System model . . . . 10
1.5 Prototyping . . . . 13
1.6 Motivation and contribution . . . . 16
1.7 Outline . . . . 20
2 Impact of hardware imperfections on AoA estimation 23 2.1 Introduction and Contribution . . . . 23
2.2 Outline . . . . 24
2.3 Multiple Signal Classification (MUSIC) algorithm . . . . 24
2.4 Analysis of the impact of hardware imperfections on MUSIC . . . . . 25
VIII Contents
2.5 Experimental setup . . . . 27
2.5.1 Setup description . . . . 27
2.5.2 Calibration method . . . . 28
2.6 Experimental results . . . . 33
2.6.1 AoA estimation uncertainty with calibration errors . . . . 33
2.6.2 AoA estimation under a perfect calibration . . . . 33
2.7 Conclusion . . . . 37
3 Iterative AoA-based positioning 39 3.1 Introduction and contribution . . . . 39
3.2 Outline . . . . 40
3.3 Iterative algorithm . . . . 40
3.3.1 Angle estimation step . . . . 41
3.3.1.1 Data-Aided Maximum a Posteriori (DA-MAP) . . . 42
3.3.1.2 Non-Data-Aided Maximum a Posteriori (NDA-MAP) 43 3.3.2 Position estimation step . . . . 46
3.3.3 Coordinates to AoA translation . . . . 49
3.4 Complexity analysis . . . . 49
3.5 Simulation results . . . . 51
3.5.1 AoA performance . . . . 52
3.5.2 Positioning performance . . . . 54
3.5.3 Impact of multipath and Non-Line-of-Sight (NLOS) propagation 60 3.5.4 Impact of precomputed autocorrelation function . . . . 62
3.5.5 Complexity analysis . . . . 63
3.6 Experimental Validation . . . . 65
3.7 Conclusion . . . . 67
4 Anchor selection against NLOS propagation 69 4.1 Introduction and contribution . . . . 69
4.2 Outline . . . . 70
4.3 Iterative algorithm with anchor selection . . . . 70
4.3.1 Angle estimation step . . . . 71
4.3.2 Position estimation step . . . . 72
4.3.3 Coordinates to AoA translation . . . . 74
4.4 Simulation results . . . . 75
4.5 Conclusion . . . . 77
5 Conclusion and future work 81 5.1 Conclusion . . . . 81
5.2 Future work . . . . 82
Publications and scientific activities 85
Contents IX
Bibliography 87
