| 摘要: | 本論文旨在設計並建置一個基於實務GPS衛星廣播星曆資料的即時通道效應模擬架構，提供相關參數給相應硬體系統以實現即時GPS訊號擬真器。研究首先探討了GPS系統的基本架構，包括太空部分、地面控制部分和使用者部分，並闡述了GPS定位原理及常用座標系統。接著，深入分析了GPS訊號結構，包括載波、C/A碼和導航電文等組成部分。
在此基礎上，本研究利用實務GPS衛星廣播星曆資料，完成了在給定時刻的GPS衛星位置、速度和加速度的精確計算，以及可見衛星的判定。進一步地，本論文模擬了GPS訊號傳播過程中的各種即時通道效應，包括各種訊號延遲和Doppler頻移等。最後，利用MATLAB App Designer設計了一個直觀易用的圖形化使用者介面(GUI)，實現了多顆GPS衛星訊號組合的即時通道效應與視覺化呈現，GUI不僅提供即時模擬結果顯示，更具備數據收集功能，可將各種即時通道效應等重要數據以時間序列形式保存，為後續的硬體實現與驗證提供重要依據，進而推動實現完整的即時GPS訊號擬真器。;This thesis aims to design and establish a framework for simulating real-time channel effects of GPS signals based on practical broadcast ephemeris data, providing relevant parameters for corresponding hardware systems to realize a real-time GPS signal simulator. The research first explores the basic architecture of the GPS system, including the space segment, ground control segment, and user segment, and elucidates GPS positioning principles and commonly used coordinate systems. Subsequently, it delves into a detailed analysis of GPS signal structure, including carrier waves, C/A codes, and navigation messages.
Building on this foundation, this study utilizes practical GPS satellite broadcast ephemeris data to accurately calculate satellite positions, velocities, and accelerations at given time points, as well as determine visible satellites. Furthermore, this thesis simulates various real-time channel effects in GPS signal propagation, including various signal delays and Doppler shifts. Finally, an intuitive and user-friendly Graphical User Interface (GUI) is designed using MATLAB App Designer, realizing real-time channel effect simulation and visualization for multiple GPS satellite signal combinations. The GUI not only provides real-time simulation result display but also features data collection functionality, capable of storing important data such as real-time channel effects in time series format, providing crucial references for subsequent hardware implementation and verification, thereby promoting the realization of a comprehensive real-time GPS signal simulator. |
