臺灣博碩士論文加值系統

最近，有研究者提出一種高準度定位演算法，此法使用正交分頻多工 (orthogonal frequency division multiplexing ，OFDM)系統的直流相位，雖然此方法有好的準度，但其考慮的環境是直視性 (line of sight, LOS)，並且，此方法在室外需要非常高的計算複雜度。本篇論文主要是針對這些問題提出解決的方法。首先，我們使用一個考慮觀測到達時間差(observed time of arrival, OTDOA)、入射角度（angle of arrival, AOA）以及發射角度（angle of departure, AOD）的演算法來得到目標的初始估計值，再來，我們提出可用於非直視性 (non LOS,NLOS) 環境的延伸版直流相位方法來優化定位估計，最後我們提出低複雜度的方法減少其計算量，本論文提出的方法可在直視性與非直視性的環境得到令人滿意的結果。

Recently, a high-precision localization method has been proposed using the DC-phase in OFDM systems. Although this method is effective, it only considers the line-of-sight (LOS) scenario. Also, its computational complexity will be very high when used in outdoor environments. This thesis is aimed to solve these problems. First, a hybrid OTDOA and AOA/AOD method is used to obtain an initial estimate of the location. Then, the extended DC-phase method is proposed such that it can be used to refine the estimation in NLOS channel environments. Finally, a low complexity method is proposed to reduce computational requirement. Simulations show that the proposed method can greatly improve the accuracy of the localization in both LOS and NLOS environments.

摘要 II
Abstract III
Acknowledgement IV
List of tables V
List of figures VI
CHAPTER 1 Introduction 1
1.1 Motivation 1
1.2 Review 1
1.3 Proposed algorithm 4
1.4 Outlines 5
CHAPTER 2 Localization with OTDOA, AOA and AOD 6
2.1 Single-bounce model 6
2.2 Single-bound geometric method 9
2.3 Linearized iterative method 11
2.4 AOA and AOD estimation 16
2.5 Localization for multiple-path model 20
CHAPTER 3 Localization with phase-difference method 24
3.1 Formulation 24
3.2 Measurement of time of arrival 24
3.3 Elimination packet detection delay 28
3.4 LOS multiple-path channel 30
3.5 Localization algorithm 34
CHAPTER 4 Proposed Localization using OTDOA, AOA, AOD and DC-phase 36
4.1 Formulation 36
4.2 Proposed algorithm in LOS environment 37
4.3 Proposed algorithm in NLOS environment 39
4.4 Low complexity method 44
4.5 Consideration 45
CHAPTER 5 Simulation results 46
5.1 Environmental setup 46
5.2 Simulation results 47
CHAPTER 6 Conclusions 61
APPENDIX A 62
APPENDIX B 66

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