本篇論文中，探討在毫米波頻段下多用戶多輸入多輸出(Multu-User Multi-input Multi-Output; MU-MIMO)的混合式預編碼系統及混合式解碼系統提升用戶頻譜使用效率。由於基地台及用戶端使用大規模天線陣列，傳統的預編碼和解碼需要隨著天線增加射頻電路元件(Radio Frequency; RF)個數，不僅成本高且佔空間，透過本篇提出的方法，不只在用戶端降低RF元件的需求量，更能利用分離子陣列型的解碼設計，降低相位轉移器(Phase Shift; PS)的數量，以此方式增進下鍊(Downlink)系統的傳輸率。在論文中，我們利用傳送端及用戶端之間的通道資訊，設計傳送端的混合式預編碼矩陣及用戶端混合式解碼矩陣，其中為了要消除用戶間產生的干擾，我們利用迫零(Zero-Forcing; ZF)的準則設計數位預編碼矩陣來消除干擾。由於用戶端類比解碼矩陣的最佳化問題相當困難，僅在用戶端使用兩根子天線時存在最佳解，因此我們提出了數值演算法來求得類比解碼器的次佳解。最後為了讓總傳輸率(Sum-rate)達到最高，我們使用注水原理的演算法找出最佳的功率分配。從模擬數值中，證實了我們提出的方法能有效降低用戶其射頻電路元件以及相位轉移器的數量，並且能達到一定的傳輸率。

In this paper, we proposed the hybrid precoding and hybrid decoding systems of multi-user multi-input multi-output (MU-MIMO) over the millimeter-wave band to improve the system’s spectrum efficiency. Consider that the base station and user equipments (UEs) are equipped with large-scale antenna array, the traditional precoding and decoding require a large number of radio frequency (RF), which demands high cost and large space. Through the proposed design of digital and analog precoding and decoding RF components is reduced, but also the number of phase shift (Phase Shift; PS) components is decreased by sub-connecting the antennas to each RF component at the UEs. The proposed method aims to increase the transmission rate. The hybrid design of the precoding and decoding fully exploit the knowledge of channel state information. In order to eliminate the inter-user interference, we adopt the zero-forcing (ZF) criterion to design digital precoding matrix. Because of block-diagonal and constant-modulus on the analog precoder, it is difficult to obtain the analytical solution. Therefore, we propose a numerical algorithm to obtain the sub-optimal solution of analog decoder. Finally, in order to maximize the sum-rate, we use the water-filling algorithm to obtain optimal power allocation to the precoding at the BS. From the numerical simulations, it shows that the proposed method can effectively reduce the number of RF components and phase shifter components, and can achieve satisfactory transmission rate.

口試委員會審定書 i
誌謝 ii
中文摘要 iii
ABSTRACT iv
目錄 v
圖次 vii
表次 ix
第一章 緒論 1
第二章 文獻探討 5
2.1 預編碼基本架構 5
2.2 相關預編碼技術 5
2.2.1 迫零預編碼 6
2.2.2 塊對角化預編碼 7
2.3 相關混合式預編碼文獻 9
2.3.1 混合式預編碼系統 10
第三章 系統架構 16
3.1 毫米波通道模型 16
3.2 多用戶毫米波多輸入多輸出混合型預編碼系統 18
第四章 混合式預編碼及混合式解碼設計 21
4.1 架構最佳化問題 21
4.2 傳送端類比預編碼矩陣 23
4.3 傳送端數位預編碼矩陣 25
4.4 接收端類比解碼矩陣 27
4.5 接收端數位解碼矩陣 30
4.6 注水原理 31
第五章 模擬結果 33
第六章 結論 41
參考文獻 42

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