本論文主要目的為研究一個具有列車及平交道防護功能的無線電系統。平交道（列車）的防護功能係當該平交道（列車）上的緊急按鈕被按下時，可利用無線電設備及無線電傳播之機制，傳送信息（數據資料）至車輛，使司機員得以事先了解每個平交道的緊急狀況，達到列車及平交道即時性的防護效果。
訂定各平交道所屬無線電設備靜態與動態量測，可做為日後無線電傳播設備之參考依據。另外，對於台鐵電氣化列車等車輛供電系統，本論文亦進行了電磁干擾研究，並與歐盟和國內相關規範比較，來分析其電磁干擾問題。
在針對無線電傳播距離估測的模擬與分析時，本論文列舉數種無線電傳播模式並使用非等間距數值分析方法估測無線電的傳播距離。

The purpose of this thesis is to investigate radio systems for the protection of vehicles and grade crossings. The protection function used with wireless communication, associated with grade crossings (the vehicles), uses the radio propagation to dispatch message (data) from the radio facilities to the vehicles when the emergency button is pushed to enable the operator to assess the emergency situation in advance.
The rule for static and non-static measurements of the radio system, concerned with the crossing, is able to offer an improved spectrum assignment tool. All measurement data was derived from measurements performed for the trains of The Taiwan Railway Administration. The results are compared with the European Norm and China National Standard. Thus, the electromagnetic interferences due to trains can be analyzed.
In order to estimate the radio propagation distances, we particularize the several modes of radio propagation in detail, and use the Lagrange method to analyze and determine the distance.

總 目 錄
誌謝……………………………………………………………………………...I
中文摘要……………………………………………………………………….IV英文摘要………………………………………….…………………………….V
總目錄………………………………………………………………………….VI
圖目錄…………………………………………………………………….……IX
表目錄…………………………………….…………………………….…..…..X

第一章 緒論……………………………………………….………….…….1
1.1研究背景………………………………………………………….....1
1.2臺灣鐵路管理局業務電子化現況……………………..……….3
1.3研究範圍與限制………………….……….…………………...…..4
1.4研究方法…………………………………..………………………..4
1.5論文架構………………………..………………………...…….…..5

第二章 無線電系統 ……………………..……………………………...7
2.1系統概要說明…….………..…………………………….…….…..7
2.1.1 列車防護無線電之用途…….…………………...….…..……..7
2.1.2無線電主機之特性…….…….…..…………………….……….8
2.2防護無線電系統之實施………..…..………………..…..…..8
2.2.1防護無線電之實施裝置……………………………….…...…..9
2.2.2防護無線電之實施機能………...……………………..……...11
2.2.3無線電之天線裝置…...………….…………………….……...12

第三章 無線電傳播特性之研究……………………….……....16
3.1無線電波傳播之理論背景………….…………..……………….16
3.1.1 對流層……………………………….………..………………16
3.1.2 對流層電波的傳播機制…………………………………16
3.2 電波傳播方式及特性…………….………………….………….17
3.2.1無線電波傳播方式的特點…………………….………….…..17
3.2.2無線電波傳播的特性..………………………………………..17
3.2.3 無線電波的傳播方式………………………………………...19
3.3 數種電波傳播模式認識……………………………..……..…..20

第四章 無線電系統量測………………..…………………...………..22
4.1靜態量測………………….………………………………………..22
4.1.1 靜態量測方法與步驟………….…………….…………..…...22
4.1.2 量測數據校正與規範限制………….……...………………...24
4.2 動態量測……………….………………….….………………..….24
4.2.1 動態量測方法與步驟………………….………..………..…..24
4.3無線電系統電磁干擾之探討…………………….…………….26
4.3.1 無線電頻率干擾的種類和來源……………………………...26
4.3.2 臺鐵電氣化列車電磁干擾………………………………..….26
4.3.3 無線電電磁雜訊量測標準………………………………..….27
4.3.4 臺鐵列車電磁干擾之影響…………………...……………....27

第五章 無線電傳播距離之估測…..…………………….……...33
5.1無線電傳播距離理論……………………………………....33
5.1.1 無線電自由空間傳播損失…………………...………………35
5.1.2 無線電地球表面傳播損失…………………...………………36
5.2 無線電傳播模型之考量……………………………………..…39
5.3無線電傳播模型理論……………………………………...40
5.3.1 Fresnel 模型………………………………...………………...40
5.3.2 無線電傳播模型之場強預測………………………..……….42
5.4利用非等間距法預測無線電傳播距離………………………43
5.4.1非等間距數值分析法…………………………………………43
5.4.2非等間距數值分析法流程……………………….………...…45
5.4.3非等間距數值分析法之比較…………………….………...…47
第六章 結論…………………….……………………………….…..…….49
6.1總結…………………………………………………………………49
6.2系統未來研究架構研討……………………………………..….50
參考文獻……………………………………………………….………………52

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