第五代行動通訊 (5G) 之大規模機器通訊 (massive machine type communications，mMTC)，預期會有數十億之物聯網 (IoT) 設備需連接上網，由於衛星系統擁有訊號覆蓋範圍大且對於地面基礎設施依賴較小等優勢，因此部屬低軌道 (Low Earth Orbit，LEO) 衛星為未來無線通訊發展之重點項目。當 LEO 數量增加時，其系統與地球同步 (Geosynchronous Equatorial Orbit，GEO) 衛星系統在線干擾 (inline interference) 會是一嚴重之問題，為使 GEO 與 LEO 衛星網路共存，上述兩種衛星網路之頻譜資源分配為必要條件。 目前相關研究大多分是藉由功率控制技術以減輕在線干擾之問題，而頻譜資源分配之機制則是直接分配獨立資源給 GEO 衛星系統，然而，此方法將大幅降低頻譜使用效能。本研究考慮 LEO 衛星系統具有多波束 (multiple beams) 與圓極化 (circular polarization) 之特性，使用波束跳躍 (beam hopping) 降低不同波束間之干擾，藉由統計 LEO 衛星系統使用之頻率，針對 GEO 衛星系統之設備設計八種不同之頻譜資源分配機制，並將八種機制各自建立一跳頻表 (frequency hopping table)，使 GEO 衛星系統之設備根據該表進行跳頻，以降低兩套衛星系統之在線干擾。並使用全頻率複用 (Full Frequency Reuse)，提升衛星系統之傳輸效能。此外，本文將八種頻譜資源分配機制進行模擬，探討各機制之效能以及其對於 LEO、GEO 衛星系統之公平性。;Massive machine type communications (mMTC) of the fifth-generation mobile networks (5G). It will also embody connections to billions of Internet of Things (IoT) objects. Thanks to satellite systems, including larger radio coverage and less reliance on the ground station., so the deployment of Low Earth Orbit (LEO) satellites is a key project for the development of future radio communications. When the number of LEOs increases, inline interference between its system and the Geosynchronous Equatorial Orbit (GEO) satellite system will be a serious problem. In order for GEO and LEO satellite networks to coexist, one of the above two satellite networks. The allocation of spectrum resources becomes a requisite... At present, most of the related researches use power control technology to solve the problem of satellite inline interference, and the spectrum resource allocation mechanism is to directly allocate independent resources to the GEO satellite system. However, this method will greatly reduce the efficiency of spectrum usage. This study considers that the LEO satellite system has the characteristics of multiple beams and circular polarization. It uses beam hopping to reduce the interference between different beams. By statistics the frequencies used by the LEO satellite system, eight different spectrum resource allocation mechanisms are designed for the equipment of the GEO satellite system, and a frequency hopping table is established for each of the eight mechanisms. Such that the equipment of the GEO satellite system performs frequency hopping according to the table to reduce the inline interference of the two satellite systems. And use Full Frequency Reuse to improve the transmission performance of the satellite system. In addition, this article simulates eight spectrum resource allocation mechanisms to discuss the effectiveness of each mechanism and its fairness to LEO and GEO satellite systems.
