本 研 究 旨 在 探 討 在 多 用 戶 和 多 竊 聽 者 環 境 下， 利 用 可 重 構 智 慧 表 面(Reconfigurable Intelligent Surface, RIS) 和複合衛星地面中繼網路 (Hybrid Satellite-Terrestrial Relay Network, HSTRN) 實現實體層安全性 (Physical Layer Security, PLS)的方法。分析衛星與地面之間的陰影萊斯 (Shadowed-Rician) 衰落通道。本研究比較了不同中繼模式，包括增幅轉發 (Amplify and Forward, AF) 與解碼轉發 (Decodeand Forward, DF) 之間的運作模式，並研究 AF 與 DF 對模擬結果的影響。研究目標為最大化最小保密速率，並透過最佳化預編碼技術與量化反射相位來達成，為此，我們使用了啟發式元件相位選擇和傳輸速率界限最佳化方法。本論文使用的技術方案有助於提升通訊系統在面對潛在竊聽者時的保密性能，同時在多用戶環境中維持良好的資料傳輸。該研究結果對於未來物聯網 (IoT) 和 5G/6G 通訊系統
具有重要的理論和實務價值。

This thesis aims to investigate methods for achieving physical layer security (PLS) using reconfigurable intelligent surface (RIS) in hybrid satellite-terrestrial relay networks (HSTRNs) where multiple users and multiple eavesdroppers are present.It analyzes the Shadowed-Rician fading channels between satellites and terrestrial stations.This thesis compares different relay modes, including Amplify and Forward (AF) and Decode and Forward (DF), and examines the impact of AF and DF on simulation results. The research objective is to maximize the minimum secrecy rate through optimization of precoding techniques and quantized reflection phases.The used technique enhances the security performance of communication systems against potential eavesdroppers while maintaining efficient data transmission in multi-user environments. The findings in this thesis have significant theoretical and practical implications for future Internet of Things (IoT) and 5G/6G communication systems.

[1] K. An, J. Ouyang, M. Lin and T. Liang,“Outage analysis of multi-antenna cognitivehybrid satellite-terrestrial relay networks with beamforming,＂IEEE CommunicationsLetters, vol. 19, no. 7, pp. 1157-1160, Jul. 2015.
[2] W. Cao, Y. Zou, Z. Yang and J. Zhu, “Relay selection for improving physical-layersecurity in hybrid satellite-terrestrial relay networks,＂IEEE Access, vol. 6, pp. 65275-65285, Jan 2018.
[3] W. Cao et al., “Secrecy outage analysis of relay-user pairing for secure hybridsatellite-terrestrial networks,＂IEEE Transactions on Vehicular Technology, vol. 71,no. 8, pp. 8906-8918, Aug. 2022.
[4] R. Xu, D. Guo, B. Zhang, K. Guo and C. Li, “Secrecy performance analysis forhybrid satellite terrestrial relay networks with multiple eavesdroppers,＂in: Proceed-ings of the 2019 28th Wireless and Optical Communications Conference (WOCC),Beijing, China, 2019, pp. 1-5.
[5] P. K. Upadhyay and P. K. Sharma, “Max-max user-relay selection scheme in mul-tiuser and multirelay hybrid satellite-terrestrial relay systems,＂IEEE Communica-tions Letters, vol. 20, no. 2, pp. 268-271, Feb. 2016.
[6] L. Han, W. -P. Zhu and M. Lin,“Outage analysis of multi-relay NOMA-based hybridsatellite-terrestrial relay networks,＂IEEE Transactions on Vehicular Technology, vol.71, no. 6, pp. 6469-6487, June 2022.
[7] K. Guo et al., “Performance analysis of hybrid satellite-terrestrial cooperative net-works with relay selection,＂IEEE Transactions on Vehicular Technology, vol. 69,no. 8, pp. 9053-9067, Aug. 2020.
[8] L. Han, W. -P. Zhu and M. Lin, “Outage analysis of noma-based multiple-antennahybrid satellite-terrestrial relay networks,＂IEEE Communications Letters, vol. 25,no. 4, pp. 1109-1113, April 2021.
[9] H. Yu, H. D. Tuan, E. Dutkiewicz, H. V. Poor and L. Hanzo, “Maximizing thegeometric mean of user-rates to improve rate-fairness: proper vs. Improper gaussiansignaling,＂IEEE Transactions on Wireless Communications, vol. 21, no. 1, pp. 295-309, Jan. 2022.
[10] M. Gao, J. Yang, H. Li and Y. Wang, “Robust beamforming optimization designfor RIS-aided MIMO systems with practical phase shift model and imperfect CSI,＂IEEE Internet of Things Journal, vol. 11, no. 1, pp. 958-973, Jan. 2024.
[11] A. A. Nasir, H. D. Tuan, E. Dutkiewicz, H. V. Poor and L. Hanzo,“Low-resolutionRIS-aided multiuser MIMO signaling,＂IEEE Transactions on Communications, vol.70, no. 10, pp. 6517-6531, Oct. 2022.
[12] H. D. Tuan, A. A. Nasir, H. Q. Ngo, E. Dutkiewicz and H. V. Poor,“Scalable user rateand energy-efficiency optimization in cell-free massive MIMO,＂IEEE Transactionson Communications, vol. 70, no. 9, pp. 6050-6065, Sept. 2022.
[13] X. Yu, J. Xu, N. Zhao, X. Wang and D. Niyato, “Secure integrated sensing andcommunication aided by IRS-UAV,＂in: Proceedings of the GLOBECOM 2023 -2023 IEEE Global Communications Conference, Kuala Lumpur, Malaysia, 2023,pp. 1735-1740.
[14] Q. -U. -A. Nadeem, A. Kammoun, A. Chaaban, M. Debbah and M. -S. Alouini,“Asymptotic max-min sinr analysis of reconfigurable intelligent surface assistedMISO systems,＂IEEE Transactions on Wireless Communications, vol. 19, no. 12,pp. 7748-7764, Dec. 2020.
[15] H. H. M. Tam, H. D. Tuan and D. T. Ngo, “Successive convex quadratic program-ming for quality-of-service management in full-duplex MU-MIMO multicell net-works,＂IEEE Transactions on Communications, vol. 64, no. 6, pp. 2340-2353, Jun.2016.
[16] A. A. Nasir, H. D. Tuan, T. Q. Duong and H. V. Poor, “Secrecy rate beamformingfor multicell networks with information and energy harvesting,＂IEEE Transactionson Signal Processing, vol. 65, no. 3, pp. 677-689, Feb. 2017.
[17] Chun Loo,“A statistical model for a land mobile satellite link,＂IEEE Transactionson Vehicular Technology, vol. 34, no. 3, pp. 122-127, Aug. 1985.
[18] A. Abdi, W. C. Lau, M. . -S. Alouini and M. Kaveh, “A new simple model for landmobile satellite channels,＂in: Proceedings of the IEEE International Conferenceon Communications. Conference Record (Cat. No.01CH37240), Helsinki, Finland,2001, pp. 2630-2634 vol.9.
[19] A. Abdi, W. C. Lau, M. . -S. Alouini and M. Kaveh, “A new simple model for landmobile satellite channels: first- and second-order statistics,＂IEEE Transactions onWireless Communications, vol. 2, no. 3, pp. 519-528, May 2003.
[20] H. Stefanovic, V. Stefanovic, A. Cvetkovic, J. Anastasov and D. Stefanovic,“Somestatistical characteristics of a new shadowed Rician fading channel model,＂in: Pro-ceedings of the Fourth International Conference on Wireless and Mobile Communi-cations, Athens, Greece, 2008, pp. 235-240.
[21] A. Abdi, W. C. Lau, M. . -S. Alouini and M. Kaveh,“On the second-order statisticsof a new simple model for land mobile satellite channels,＂in: Proceedings of the Ve-hicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211),Atlantic City, NJ, USA, 2001, pp. 301-304.
[22] A. Abdi and M. Kaveh, “On the utility of gamma PDF in modeling shadow fad-ing (slow fading),＂in: Proceedings of the Vehicular Technology Conference (Cat.No.99CH36363), Houston, TX, USA, 1999, pp. 2308-2312.
[23] S. W. Ellingson, “Path loss in reconfigurable intelligent surface-enabled channels,＂in: Proceedings of the Annual International Symposium on Personal, Indoor andMobile Radio Communications (PIMRC), Helsinki, Finland, 2021, pp. 829-835.
[24] W. Tang et al., “Wireless communications with reconfigurable intelligent surface:path loss modeling and experimental measurement,＂IEEE Transactions on WirelessCommunications, vol. 20, no. 1, pp. 421-439, Jan. 2021.
[25] F. Bohagen, P. Orten and G. E. Oien, “On spherical vs. plane wave modeling ofline-of-sight MIMO channels,＂IEEE Transactions on Communications, vol. 57, no.3, pp. 841-849, Mar. 2009.
[26] Y. Han, S. Zhang, L. Duan and R. Zhang,“Double-irs aided MIMO communicationunder LoS channels: capacity maximization and scaling,＂IEEE Transactions onCommunications, vol. 70, no. 4, pp. 2820-2837, Apr. 2022.
[27] J.-C. Lin and H. V. Poor,“Optimum combiner for spatially correlated Nakagami-mfading channels,＂IEEE Trans. Wirel. Commun., vol. 20, no. 2, pp. 771–784, Feb.2021.
[28] J.-C. Lin and H. V. Poor, “A systematic approach to deriving the covariance matrixof correlated Nakagami-m fading channels,＂IEEE Trans. Veh. Technol., vol. 69, no.2, pp. 1612–1625, Feb. 2020.
[29] J.-C. Lin, H.-K. Chang, M.-L. Ku and H. V. Poor,“Impact of imperfect source-torelayCSI in amplify-and-forward relay networks,＂IEEE Trans. Veh. Technol., vol. 66, no.6, pp. 5056–5069, Jun. 2017.
[30] K.-P. Chou, J.-C. Lin and H. V. Poor,“Disintegrated channel estimation in filterand-forward relay networks,＂IEEE Trans. Commun., vol. 64, no. 7, pp. 2835–2847, Jul.2016.
[31] W. Magnus, F. Oberhettinger and R. P. Soni, Formulas and Theorems for the SpecialFunctions of Mathematical Physics, New York:Springer, 1966.
[32] A. Subhash, A. Kammoun, A. Elzanaty, S. Kalyani, Y. H. Al-Badarneh and M. -S.Alouini, “Max-min SINR optimization for RIS-aided uplink communications withgreen constraints,＂IEEE Wireless Communications Letters, vol. 12, no. 6, pp. 942-946, June 2023.
[33] H. D. Tuan, A. A. Nasir, Y. Chen, E. Dutkiewicz and H. V. Poor, “Quantized RIS-aided multi-user secure beamforming against multiple eavesdroppers,＂IEEE Trans-actions on Information Forensics and Security, vol. 18, pp. 4695-4706, 2023.