臺灣博碩士論文加值系統

　　本論文探討多相關器降低多路徑效應於GNSS所產生的量測誤差。GNSS為一發展成熟的系統，但仍有許多的外在因素影響其定位的精準性，例如：受電離層、對流層影響傳送速度以及接收器時鐘漂移等均構成誤差的來源。本文針對多路徑效應產生的定位誤差，提供一個利用多相關器的概念來降低誤差的產生，且對於以往文獻中降低多路徑影響的各種方法提供模擬並比較。另外本論文也描述新型導航訊號和目前GPS上訊號在多路徑效應上所呈現的差異性。

　The thesis is concerned with the use of multicorrelator technique in reducing multipath effect in GNSS application. Although GNSS has been widely used in navigation and survey, its performance is subject to several errors such as ionosphere delay, troposphere delay and multipath. Among which, the multipath effect constitutes one of the most unpredictable error sources. The multicorrelator techniques is analyzed in the thesis to assess its effectiveness in multipath mitigation. Both BPSK and BOC modulations are considered.

摘 要 I
ABSTRACT II
誌謝 III
表目錄 VI
圖目錄 VII
第一章 緒論 1
1.1 前言 1
1.2 研究動機 1
1.3 文獻探討 2
1.4 論文架構 3
第二章 衛星導航系統訊號介紹 4
2.1 C/A碼介紹 4
2.2 相關函數（CORRELATION FUNCTION） 8
2.3 追蹤迴路 14
2.4 多路徑效應 18
2.5 非同調性時延迴路與同調性時延迴路之比較 23
2.6 頻寬的影響 26
2.7 BOC簡介 27
第三章 軟體無線電實驗平台 31
3.1 軟體無線電 31
3.2 NORDNAV R30 33
3.3 多相關器於R30上之應用 35
第四章 訊號處理之模擬 37
4.1 解決多路徑效應的方法 37
4.2 多路徑於追蹤迴路模擬 51
4.2.1 Narrow Correlator 60
4.2.2 Strobe Correlator 63
4.2.3 Early1/Early2 Correlator 70
4.3 雜訊於追蹤迴路之模擬 72
4.4 利用多相關器降低多路徑效應 87
4.4.1 多相關器的概念 87
4.4.2 以多相關器描述訊號組成 88
4.4.3 以多相關器估測直接訊號 90
第五章 結論 95
5.1 結論 95
5.2 未來工作 95
參考文獻 97

參考文獻
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