毫米波頻率通訊是一種很有前途的候選技術，可以應對第五代（5G）無線蜂巢通訊系統頻寬短缺的挑戰。大規模 MIMO 可以提供較大的波束成形增益以補償毫米波頻率的高路徑損耗。然而，在實際中實作毫米波大規模 MIMO 並不容易。一個關鍵挑戰在於 MIMO 系統中的每根天線通常都需要其專用的射頻 (RF) 鏈。所幸，混合波束成形結構已被建議作為降低實作成本和能耗的解決方案之一。在本論文中，提出了一個最佳化問題，以在一定的服務質量（QoS）如每個用戶的位元/塊錯誤率和資料傳輸率下最小化下行鏈路的總系統傳輸功率，並在其中提出解決方案。我們提出的串流增量演算法可以根據通道狀態資訊動態調整每個用戶的數據流數量。模擬結果進一步驗證了根據通道狀態資訊為每個用戶分配不同數量的數據流是非常重要的。在強健性方面，我們提出的波束成形演算法在用戶數量上具有更大的靈活性。模擬結果也驗證了所提之方法可以在複雜度與效能之間取得良好的平衡。在現有的方法中，這些論文只告訴我們如何設計混合波束成形演算法，而沒有提出應該使用什麼調變或編碼方案來傳輸數據。有鑑於此，我們提出的演算法為各種數據流分配和波束成形設計中的傳輸提供了最合適的調變與編碼方案。總結，我們提出的演算法可以為毫米波大規模 MIMO 系統提供波束成形解決方案，且該解決方案可以實現與全數位塊對角化 (BD) 演算法相當的性能，並具有較低的實作成本。;Millimeter-wave frequency communication is a promising candidate that can deal with the challenge of bandwidth shortage for the fifth generation (5G) wireless cellular communication systems. Massive MIMO can provide a large beamforming gain to compensate for the high path loss in millimeter-wave frequency. However, it is not easy to implement millimeter-wave massive MIMO in practice. A key challenge is that each antenna in a MIMO system generally requires a dedicated radio frequency (RF) chain. Fortunately, a hybrid beamforming structure has been suggested as one of the solutions to reduce implementation costs and energy consumption. In this thesis, an optimization problem is formulated to minimize the total system transmission power on downlink under a certain quality-of-service (QoS) such as bit/block error rates and data rates for each user, and the solution is proposed therein. Our proposed stream incremental algorithm can dynamically adjust the number of data streams for each user according to the channel state information. Simulation results further verify that allocate the different number of data streams for each user according to the channel state information is very significant. In robustness, our proposed beamforming algorithm has greater flexibility in the number of users. Simulation results also verify that the proposed method can achieve a good balance between complexity and performance. In existing methods, these papers only tell us how to design the hybrid beamforming algorithms but do not suggest what modulation or coding scheme should be used to transmit data. In view of this, our proposed algorithm provides the most suitable modulation and coding scheme for transmission in various data stream allocation and beamforming designs. In summary, our proposed algorithm can provide a beamforming solution for a millimeter-wave massive MIMO system, which can achieve comparable performance to that of a fully digital block-diagonalization (BD) algorithm with a lower implementation cost.
