在第六代行動通訊的快速發展下，低軌道衛星系統獲得了大量 的關注，具有高度的覆蓋率和低延遲的特性，被視為行動通訊發展 重要的一項技術，然而在傳統的大規模MIMO 系統中，使用完全數 字預編碼對每個天線都連接一個專用的射頻（RF）鏈路，被廣泛用 來最大化系統容量，但隨著使用頻段使用頻率的演進，每個RF 鏈 路的所造成成本支出和功率損耗都有明顯的提升，所以在追求最大 化系統容量的同時也要考慮到功率損耗問題，因此本文將以兼顧能 量效率（energy efficiency）的角度來完成演算法。 本文中提出基於大規模多輸入多輸出（MIMO）低地球軌道（LEO） 衛星通訊（SATCOM）混合波束成形使用者選擇演算法，並透過編碼 簿(CODEBOOK)進行波束設計來達到波束形成增益 (Beamforming Gain) 最大化，在不提高複雜程度建立編碼簿(CODEBOOK)，並對產 生通道狀況進行使用者選擇，以達到最佳的能量效率和並將低複雜度。;As the development of sixth-generation (6G) mobile communications accelerates, Low Earth Orbit (LEO) satellite systems have garnered significant attention due to their high coverage and low latency characteristics, making them a crucial technology in the advancement of mobile communications. In traditional massive Multiple-Input Multiple- Output (MIMO) systems, the fully digital beamforming approach, where each antenna is linked to its own individual RF chain, has been widely used to maximize system capacity. However, as the operating frequency bands evolve, power consumption issues become increasingly critical. Therefore, while pursuing maximum system capacity, it is essential to address energy efficiency (EE) concerns. This paper proposes a hybrid beamforming user selection algorithm for massive MIMO LEO Satellite Communications (SATCOM). This paper proposes a hybrid beamforming user selection algorithm for massive MIMO Low Earth Orbit (LEO) satellite communications (SATCOM). The algorithm employs a codebook-based beam design to maximize beamforming gain. By constructing a codebook that avoids additional complexity and integrating user selection, the algorithm achieves optimal energy efficiency while maintaining low computational complexity.
