在非理想環境中之可適性陣列波束成型技術

在許多的通訊應用中，可適性陣列波束成型器被廣泛的用來優化系統的輸出訊號對干擾與雜訊比(Output SINR)，因其能自動抑制干擾訊號以及雜訊，並且截取欲接收訊號，可適性波束成型器只需知道欲接收訊號的入射角度即可，其他諸如波形等參數皆不是必要資訊。本論文主要目的在於解決可適性陣列波束成型器在非理想環境中系統效能的衰落，並提出了兩種方法增強系統的強健性，第一種方法修改了傳統廣義旁波辦消除器(Generalized Sidelobe Canceller, GSC)的架構，加入了兩個雜訊阻隔矩陣，藉以降低誤差對系統造成的影響，第二種方法則擷取了幾種強健式演算法的優點，其亦降低了誤差對系統造成的影響。另外本論文所討論到的非理想環境包含：指引向量誤差(Steering Vector Mismatch)、天線耦合效應(Mutual Coupling Effect)以及同調環境(Coherent Environment)，其中指引向量誤差的部分又分為三種不同的誤差模型來描述，包含固定形式(Fixed type)、隨機形式(Random type)以及相加形式(Additive type)。最後在模擬分析的部分，本論文分別在一維均勻線性陣列(Uniform Linear Array, ULA)以及二維均勻圓形陣列(Uniform Circular Array, UCA)上驗證演算法的效能，得出本論文提出的作法具有不錯的強健性可用於對抗非理想環境。

關鍵字

波束成型器；廣義旁波辦消除器；指引向量誤差；天線耦合效應；同調環境

並列摘要

In many applications of communications, adaptive array beamforming is widely used to improve the output signal to interference and noise ratio (SINR). This technique can suppress interference and noise automatically, in the meanwhile, capture the desired signal. The a priori information of beamforming is the direction of the desired signal, for example linearly constrained minimum variance beamformer (LCMV). The main purpose of this thesis is to solve the degradation of the system performance when the system is under non-ideal environment. This thesis has proposed two robust methods used to improve system performance. First method has modified the architecture of the conventional generalized side-lobe canceller (GSC). It adds two noise block matrics to reduce the influence of mismatch. The second method is to catch the advantage from lots of algorithms, and it also reduces the influence of mismatch. Otherwise, for the non-ideal environments, this thesis discusses steering vector mismatch, mutual coupling effect and coherent environment. The part of steering vector mismatch also separates to three types of model, include: fixed type, random type and additive type. Finally, we will present the simulation results to show the performance of the former proposed methods.

並列關鍵字

Beamforming ； Generalized side-lobe canceller (GSC) ； Steering vector mismatch ； Mutual Coupling Effect ； Coherent Environment

參考文獻

[12] 駱文城, 在非理想環境下使用支持向量機之強健式陣列波束成型技術, 國立台灣大學電機資訊學院電信工程學研究所碩士論文, 2013.

[20] 趙家慶, 在非理想環境下具有快速收斂與強健能力之波束成型技術, 國立台灣大學電信工程學研究所碩士論文, 2014.

[1] P. W. Howells, "Exploration in fix and adaptive resolution at GE and SURC," IEEE Transactions Antennas Propagation, Vols. AP-24, pp. 575-584, Sept. 1976.

[2] S. P. Applebaum, "Adaptive Arrays," IEEE Transactions Antennas Propagation, pp. 585-598, Sept. 1976.

[3] B. Widrow, S.D. Stearns, Adaptive Signal Processing, Englewood Cliffs: N.Y.: Prentice-Hall, 1985.

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在非理想環境中之可適性陣列波束成型技術

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