- 學位論文
全球衛星定位系統軟體接收機之設計
Design of a Software-Based Receiver for Global Positioning System
摘要
由美國所建造的全球定位系統(GPS)為全球衛星導航系統(GNSS)中的一種，也是目前全球唯一系統完整運作的，主要免費提供在地球上任何地方與任何人做為導航使用。另外，GPS系統也提供精確的時間，使用在許多的應用上，例如科學上地震的研究與網路協定上資料的同步等等。因此GPS系統越來越普及於一般日常生活中所使用。 在本論文中，以軟體GPS接收機的實做為主，主要理由是軟體接收機的靈活度比硬體接收機來的好，容易調整應用於各方面的需求。除此之外軟體接收機有相當大的潛在效能增進的空間，例如資料的讀取與處理方式可以是以分區塊來實現，這在硬體接收機上是無法做到的。為了實現軟體GPS接收機可以處理微弱訊號，我們使用一些技巧來增進接收機本身的訊號擷取和訊號追蹤的能力。最後由實際錄製的GPS訊號來測試我們的軟體GPS接收機。從測試的結果，我們的軟體GPS接收機可同時適用於靜態與高速動態的情況。本論文將探討軟體GPS接收機實做的細節。
並列摘要
The Global Positioning System (GPS) is a global navigation satellite system (GNSS) developed by the United States. It is the only fully functional GNSS in the world, can be used freely by anyone, anywhere, and is often used by civilians for navigation purposes. Also, the precise time reference is used in many applications including the scientific study of earthquakes and as a required time synchronization method for network protocols. In this thesis, a software-based GPS receiver is implemented because of its flexibility. Software-based receivers are quite valuable in evaluating potential improvements. In addition, software-based receivers can use block data processing that are not available in hardware implementations. In implementing such a software-based receiver, we use several techniques to impove the capabilities of acquisition and tracking for weak signals. Finally, the real GPS signals are recored by RF front-end instruments and used to test our software-based receiver. From the results, our software-based receiver is compatible with static and mobile situations. Here we will discuss our complete details of software-based GPS receiver.