多用戶大規模多輸入多輸出系統中能量效率最佳化之低複雜度波束選擇法

Abstract

在大規模多天線系統中，系統耗能情況會因射頻鏈路數上升而急速加劇，且基頻數位信號處理也變得較複雜，因此需要採用有較高效率的架構 。於本論文中，吾人將探討混和式波束成型搭配波束選擇法來最大化系統能量效率，提出一套新的傳輸機制和低複雜度波束選擇法，有效地選擇所使用的射頻鏈路個數，藉以最大化系統能量效率，並評估提出波束選擇法的計算複雜度。最後，由分析及電腦模擬結果顯示 吾人所提出的波束選擇法可獲得和窮盡搜尋法接近的能量效率，而其計算複雜度遠低於後者。

The high cost and power consumption of radio-frequency (RF) in massive MIMO systems render conventional architecture infeasible. Hence, new architectures with higher efficiency are needed. In this thesis, first, we introduce a new transmission scheme based on the architecture of hybrid precoding. Then, we develop low complexity beam selection algorithm to efficiently select the RF chain configurations for energy efficiency (EE) optimization. In addition, we also evaluate the computational complexity of the proposed beam selection algorithm. Finally, analysis and simulation results show that the proposed beam selection algorithm can reduce system complexity and achieve comparable energy efficiency compared with exhaustive search with much lower complexity.