傳統GPS接收器雖然可以提供精確位置解與導航功能，但由於不易改變其硬體架構，對於不同的環境下，無法提供適應性的應用。由於數位訊號處理與類比轉數位技術的發展，提供了軟體接收器的發展。相較於傳統接收器，軟體接收器的可程式化的優點，具有能改變處理GPS訊號所用的架構程式與內部的參數設定，可以依不同的需求而設定。因此相較於傳統接收器更有彈性。

本篇論文的目的在於研發單頻GNSS軟體接收器測試平台。 此測試平台包含了對於輸入的GNSS訊號的分析、擷取、追蹤與定位等處理。 使用者在進行訊號處理過程中，可以根據不同的需求考量，並透過此平台的使用者介面進行相關參數的變更。 由於軟體接收器具有可程式化的優點，可以將不同的訊號擷取或追蹤演算法加入此平台，並可進一步利用此平台來評估此演算法的效能。 另一方面，由於伽利略衛星導航系統於E1頻段所傳送的訊號與全球定位系統L1頻段所傳送的訊號的中心頻率是相同的，因此可以使用相同的一套天線與前端同時接收伽利略衛星導航系統與全球定位系統的E1/L1 頻段的訊號。 因此，本篇論文將著重在於伽利略衛星導航系統的E1頻段與全球定位系統的L1頻段訊號的研究。

在此篇論文中，將介紹伽利略GIOVE-A測試衛星訊號於E1頻段的訊號擷取方法，並進而利用此平台實行伽利略E1頻段訊號的擷取。 而本篇論文主要會著重在於探討不同環境下，所接收到的不同強度訊號，對於執行追蹤迴路時所需考慮的影響，並針對不同訊號強度，對追蹤迴路部分參數做補償。 本論文主要利用Nordnav R30軟體接收器與SIGE前端儲存實際中頻訊號的功能，儲存不同環境的實際中頻訊號，探討在不同環境下的GPS訊號品質對於追蹤迴路可能產生的影響，並針對不同訊號強度，利用改變追蹤迴路架構與內部參數設定，達到追蹤的目的。 因此，利用此平台的特點就可以針對不同環境下，所接收到的不同強度訊號，找出一套最合適的訊號處理方法。

The modern standard GPS receivers, the hardware-based receivers, can provide accurate positioning and navigation services to users. However, the standard GPS receivers consist of hardware, the framework, and algorithm are difficult to modify for different environments. Recent advancement in digital signal processing and analog-to-digital conversion techniques has motivated the development of software defined receiver. In comparison with standard approaches, one advantage of the software defined receiver is the programmable algorithm. With the programmable algorithm, it is easy to change the parameters of the algorithm for all purposes. Therefore, the software defined receiver is more flexible than traditional approaches.

This thesis will develop a GNSS Software Defined Receiver Test Bed on single frequency. This test bed consists of GNSS signal analysis, acquisition, tracking, and positioning processes. Users can change the parameters of these signal process algorithms for all purposes by the Graphical User Interface (GUI) of this test bed. In order to take advantages of software defined receiver, various GPS signal acquisition and tracking algorithms are included and evaluated by this test bed. Only the Galileo E1 band and GPS L1 band signals are broadcasted at the same center frequency (1575.42 MHz). The Galileo E1 band and GPS L1 band signals can be received by using the same antenna and front end. Consequently, this thesis will focus on the study of Galileo E1 band and GPS L1 band signals.

In this thesis, the acquisition of Galileo GIOVE-A E1 band signal will be introduced and implemented by this testbed. This thesis will focus on the tracking GPS signals of different strength received by a GPS receiver under different environments. The parameters of tracking loop are compensated according to different strength signals. This thesis uses NordNav R30 software receiver and SiGe front end to collect the GPS signals under different environments and store the real intermediate frequency data for after processes. According to the different signal strengths, reach the purposes of signal tracking by changing the tracking algorithm and parameters. Finally, we use these different tracking loop algorithms to position and to evaluate their positioning results. By this test bed, it is possible to obtain the suitable signal processing algorithm under the different receiving strength by a GPS receiver under different environments.

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