江簡富臺灣大學：電信工程學研究所朱如瓏Chu, Ju-LungJu-LungChu2007-11-272018-07-052007-11-272018-07-052005http://ntur.lib.ntu.edu.tw//handle/246246/58777一直以來，在描述傳輸通道特性時，通常使用一系列的統計參數搭配複雜的公式來表達通道的特徵。然而，在推導這些參數和公式的過程中，許多有關現實狀況的資訊被捨去，只留下比較抽象的統計參數。因此如果只從統計參數出發對通道特性做討論，將只能獲得有關通道的片面資訊。本篇論文中，建立出一套有效的電磁全波分析流程來處理有關大型金屬物體的散射場分析。由於目標是分析車輛與路側基地台的無線傳輸通道，在這篇文章中的散射體是以日常的轎車做為分析的例子。在分析的概念上，我們利用不同的方法取得散射體的表面等效電流分布，再藉由這些資訊進一步計算物體的散射場。除了理論分析的部份，也進行了相關的散射體建模與量測。而量測的結果和理論模擬十分吻合，因此我們可以斷定這種分析方式是可行的且具備相當的可信度。In the past works, wireless communication channels are usually described with a series of statistical parameters. The parameters and the sophisticate formulas which were derived from measurement results can describe the channel in a well manner. However, the physical situation can hardly be extracted from formulas because real physical scenarios are often over-simpli ed during the derivation and much information is disappeared. In this work, a hybrid full wave analyze procedure is developed by applying the information of surface equivalent currents. These equivalent currents are derived with hybrid methods, and then, used to further calculate the scattering fields. Besides of the theoretical formulas, a physical model is also accomplished for the purpose of the experiments. Since the results of simulation and measurement match quite well to each other, this full-wave approach is practicable and reliable.Abstract Table of Contents iii List of Figures v 1 Introduction 1 1.1 Parameters Characterizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Channel Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.3 VehicularAntenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.4 Scattering Analysis Techniques . . . . . . . . . . . . . . . . . . . . . . . . . 8 2 Deterministic Channel Model for DSRC 10 2.1 Line-of-Sight Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Ground-Reflected Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 Scattering from NearbyVehicles . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.4 ScatteringMechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3 Results and Discussions 31 3.1 Model Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.2 Scattered Fields from Nearby Vehicles . . . . . . . . . . . . . . . . . . . . . 35 3.3 Scattered Fields from Platform . . . . . . . . . . . . . . . . . . . . . . . . . 36 3.4 Practical Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 4 Conclusions 43en-US電磁全波分析通道分析散射車輛通訊channel analysisequivalent currentlarge objectmetallic bodiesscattering analysisvehicular communicationhybrid methodthesis