全球衛星定位導航系統已被廣泛應用於各種產品，因此穩定且可靠的定位表現是必要的。傳統的單頻定位僅能使用單一頻段之訊號進行定位，系統的效能會被限制，因此本篇論文目的為發展一可接收L1及L2訊號之雙頻接收機以提升定位精度以及穩定度。在訊號處理方面，由於L1及L2訊號之電碼速率與週期皆不相同，在軟硬體實現上必須在特定時間內分別完成L1及L2訊號之處理，因此接收機之軟體時序與架構之設計就顯得非常重要。在定位效能方面，本論文所提出之雙頻接收機可同時解算出利用L1與L2所計算出虛擬距離，並透過線性組合以消除虛擬距離內之電離層誤差，最後再利用此虛擬距離求解使用者位置，以獲得更好的精確度。除此之外，本論文使用之架構在訊號擷取與導航解算方面皆會透過L1與L2二頻段訊號間資料的共享以增強系統的穩定度。最後，本論文也會介紹所提出之接收機於空曠無遮蔽與部分遮蔽環境之定位表現，並透過實驗結果驗證所提出之接收機架構於空曠無遮蔽與部分遮蔽環境皆可達成高精度與穩定的表現。

Global Navigation Satellite System (GNSS) has been widely used in a variety of appli-cations, so a stable and reliable positioning performance is necessary. The traditional sin-gle-frequency positioning method can only use a single band signal to perform positioning, so the performance may be limited. The purpose of this thesis is to develop an L1/L2 du-al-frequency receiver to improve the accuracy and stability of the system. In the aspect of signal processing, the code rate and code period in L1 and L2 signals are different. Therefore, the hardware-software integration receiver has to provide the signal processing procedure in L1 and L2 bands within a particular time, which makes the architecture and software se-quence of the receiver critical. In the aspect of positioning performance, the L1 and L2 pseudoranges can be resolved simultaneously. And accordingly, combined with the pseu-dorange by the linear combination to eliminate the ionospheric error. Finally, the iono-sphere-free pseudorange can be used to resolve the user position and improve the positioning accuracy. Furthermore, the information in the L1 and L2 signals are shared in the signal ac-quisition and navigation task to improve the stability of the system. Lastly, the performance of the proposed receiver in the open-sky and partially-blocked environment is also discussed. Through the experimental result, it is demonstrated that the proposed receiver can achieve a high accuracy and stability performance.

[1] 莊智清, 衛星導航. 全華圖書, 2012.
[2] C. Hegarty and E. Chatre, "Evolution of the Global Navigation SatelliteSystem (GNSS)," Proceedings of the IEEE, vol. 96, pp. 1902-1917, 01/01 2009.
[3] G. P. S. Association, "Trend of Multi-GNSS receiver," Journal of the Japan society of photogrammetry and remote sensing, vol. 52, p. 165, 09/01 2014.
[4] K. Borre, D. Akos, N. Bertelsen, P. Rinder, and S. Jensen, A Software-Defined GPS and Galileo Receiver: A Single-Frequency Approach. 2007.
[5] K. W. Park, S. Jae-Won, S. Bo-Seok, M. J. Lee, and C. Park, "Design of signal acquisition and tracking process based on multi-thread for real-time GNSS software receiver," in 2016 International Conference on Localization and GNSS (ICL-GNSS), 2016, pp. 1-4.
[6] Y. Pei, H. Chen, and B. Pei, "Implementation of GPS Software Receiver Based on GNU Radio," in 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC), 2018, pp. 1-3.
[7] S. Minghui and Z. Ming, "Beidou receiver based on DSP embedded software reliability testing scheme," in 2013 International Workshop on Microwave and Millimeter Wave Circuits and System Technology, 2013, pp. 415-418.
[8] J. P. Wang, X. Han, and M. Gao, "Implementation of Acquisition Algorithm for Multi-system Software-based BD/GPS Receiver," in 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC), 2018, pp. 1-4.
[9] R. L. L. Valle, J. G. Garcia, P. A. Roncagliolo, and C. H. Muravchik, "An Experimental L1/L2 GNSS Receiver for High Precision Applications," IEEE Latin America Transactions, vol. 11, no. 1, pp. 48-53, 2013.
[10] K. W. Park, B. Seo, J. Suh, and C. Park, "A Method of Channel Selection for Multi-GNSS Receiver," in 2019 International Conference on Electronics, Information, and Communication (ICEIC), 2019, pp. 1-3.
[11] J. T. Curran, M. Petovello, and G. Lachapelle, "Design Paradigms for Multi-Constellation Multi-Frequency Software GNSS Receivers," in China Satellite Navigation Conference, China, 2013, vol. 243.
[12] I. Mallika, V. Ratnam, S. Raman, and S. Gampala, "A New Ionospheric Model for Single Frequency GNSS User Applications using Klobuchar model driven by Auto Regressive Moving Average (SAKARMA) Method over Indian Region," IEEE Access, vol. PP, pp. 1-1, 03/17 2020.
[13] D. Skournetou and E. S. Lohan, Comparison of Single and Dual Frequency GNSS Receivers in the Presence of Ionospheric and Multipath Errors. 2011, pp. 402-410.
[14] J. Liu, M. Lu, and Z. Feng, "An advanced dual-frequency positioning algorithm for satellite navigation receivers," Journal of Electronics (china), vol. 26, pp. 466-472, 07/01 2009.
[15] S. Cui, X. Yao, and J. Fang, "An optimized acquisition algorithm in GPS software receiver," Journal of Computer Research and Development, vol. 51, pp. 1794-1801, 08/01 2014.
[16] B. Kim and S.-H. Kong, "Ultra-Fast L2-CL Code Acquisition for a Dual Band GPS Receiver," Journal of Positioning, Navigation, and Timing, vol. 4, pp. 151-160, 12/15 2015.
[17] D. W. Lim, S. W. Moon, C. Park, and S. Lee, "L1/L2CS GPS Receiver Implementation with Fast Acquisition Scheme," in Position, Location, And Navigation Symposium, 2006 IEEE/ION, San Diego, CA, 2006: Proceedings of IEEE/ION PLANS 2006, pp. 840-844.
[18] K.-C. Kwon and D.-S. Shim, "Fast acquisition method for GPS L1/L2C software receivers," 01/01 2011.
[19] S. Peng, Y. Morton, and R. Di, "A multiple-frequency GPS software receiver design based on a Vector tracking loop," pp. 495-505, 04/01 2012.
[20] C. Kim, S. Jeon, M. Park, S. Beomju, and C. Kee, "Optimal GNSS Signal Tracking Loop Design Based on Plant Modeling," International Journal of Aeronautical and Space Sciences, vol. 20, 02/09 2019.
[21] P. Roncagliolo, J. Garcia, and C. Muravchik, "Optimized Carrier Tracking Loop Design for Real-Time High-Dynamics GNSS Receivers," International Journal of Navigation and Observation, vol. 2012, pp. 1-18, 03/21 2012.
[22] 吳政廷, "多頻多星系GNSS訊號接收軟硬體整合即時處理架構之研究," 碩士, 電機工程學系, 國立成功大學, 台南市, 2018.
[23] E. D. K. a. C. J. Hegarty, "Understanding GPS: Principles and Applications," 2005.
[24] I. Maxim Integrated Products, "MAX2769 Universal GPS Receiver," 2012.
[25] I. Maxim Integrated Products, "MAX2112 Datasheet," 2019.
[26] Xilinx, "Mercury ZX1 User Manual," 2019.
[27] (2022). OEM7720 Technical Specifications [Online]. Available: https://hexagondownloads.blob.core.windows.net/public/Novatel/assets/Documents/Papers/OEM7720-Product-Sheet/OEM7720-Product-Sheet.pdf.
[28] J. Christos, Ed. Trends in Telecommunications Technologies. 2010.
[29] 交通部中央氣象局太空天氣作業辦公室 [Online]. Available: https://swoo.cwb.gov.tw/V2/page/Observation/IonoTECmap.html.
[30] "Global Positioning System Standard Positioning Service Performance Standard," (in English), Tech Report 2008.
[31] (2015). ZC706 Evaluation Board User Guide UG954 [Online]. Available: https://www.xilinx.com.