本篇論文旨在多輸入單輸出正交分頻多工(MISO-OFDM)的架構下進行波束追蹤的設計同時測量4×4毫米波的射頻模組在空口測試 (OTA)的波束成型狀況。在通訊環境上，因為硬體限制的關係採用了單用戶的傳輸方式，並且考慮移動通訊的場景。系統中，首先傳送端的碼本會根據不同天線所對應的不同波束集束狀況去做設計，接著透過時間分工的方式，階層式的對整個碼本進行廣域的搜索，再來會在接收端透過計算對應不同碼字的平均訊號能量，找出碼本中最好的類比預編碼向量對應不同的訊號波束方向，接著透過反饋鏈路將最佳碼字資訊回傳給傳送端，利用最佳的波束做訊號傳輸，並在後續若發生訊號能量低於閥值的情況下，會隨即對相鄰的波束做區域搜索並切換，最終達到移動通訊中波束追蹤的目的，並且將這種設計實際應用在實作平台上測試其可行性。最後，利用電腦模擬在不同的環境及參數設定情況下，本篇論文的演算法以及逐一搜索碼本的方法在波束追蹤的時間消耗成本和系統效能的差異比較，結果顯示透過本篇論文低解析度階層式的碼本搜索，在16天線配置、用戶端移動速度為40km/hr.以及訊雜比在20dB的情況下，本篇論文演算法平均通道容量可以達到91.94%通道容量上限的效能，而逐一搜索碼本的方法只有56.42%的效能，對應的波束搜索的成本則分別是6.14%和11.21%。本篇論文的演算法可以有更好的搜索效能和達到更到的波束方向匹配。

This thesis aims to design beam tracking algorithms in multiple input single output-orthogonal frequency division multiplexing (MISO-OFDM) systems and measure the beamforming performance of a 4x4 millimeter-wave RF module in Over-The-Air (OTA) testing. Due to hardware limitations and considering a mobile communication scenario, a single-user transmission mode is adopted in the communication environment. In the system, the transmit-side codebook is designed based on different beamforming patterns corresponding to different number of antennas. The entire codebook is then searched hierarchically through time division to find the best analog precoding vectors corresponding to different direction of beams by calculating the average signal energy of different codewords at the receiver. The optimal codeword information is then fed back to the transmitter through a feedback link, and then transmitter use the best beam for signal transmission. In the subsequent process, if the signal energy falling below a threshold, an local beam search is performed immediately and then switch to neighboring beams to ultimately achieve the goal of beam tracking in mobile communication. This design is implemented on a M3force platform to test its feasibility. In addition, computer simulations are conducted under different environments and parameter settings to compare the time consumption and system performance between the algorithms and exhaustive codebook search method in beam tracking. The results show that the average channel capacity of low-resolution hierarchical codebook search proposed in this paper can reach 91.94% of the upper bound of channel capacity, while the exhaustive codebook search method only achieves 56.42% of the performance under a scenario with 16 antenna configurations, a user moving speed of 40 km/hr, and a signal-to-noise ratio of 20dB. The corresponding beam search costs are 6.14% and 11.21%, respectively. The algorithm presented in this paper exhibits better search efficiency and achieves more accurate beam direction matching.

論文審定書 i
致謝 ......... ii
中文摘要... iii
ABSTRACT iv
圖次…….. viii
表次…….. x
第一章 緒論 1
第二章 背景介紹 3
2.1 M3Force SDR平台介紹 3
2.2 4×4毫米波模組介紹 4
2.3 OFDM技術原理 5
2.4 循環前綴 6
2.5 波束成型技術 7
2.6 5G訊框架構介紹 8
第三章 系統模型 12
3.1 通道模型 13
3.2 系統架構 15
3.3 OTA訊框架構 16
第四章 波束搜索設計 17
4.1 優化問題建立與碼本設計 17
4.2 波束搜索演算法 20
4.3 系統初始化週期設定 24
第五章 模擬結果 26
5.1 傳送天線數探討 28
5.2 接收端移動速度探討 31
5.3 通道環境複雜度探討 34
5.4 通道存在遮蔽物下之效能與效率探討 35
第六章 實際OTA測量 37
6.1 場景一：無遮蔽物 39
6.2 場景二：有遮蔽物 40
第七章 結論 42
參考文獻… 43

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