利用元啟發演算法於互質雙基地多輸入多輸出雷達在多重誤差環境下之角度估計

Abstract

本論文目標為探討雙基地(Bistatic)多輸入多輸出雷達系統的角度估計問題，包含估計訊號離開方向(direction of departure, DOD)與訊號到達方向(direction of arrival, DOA)。並且相較於傳統大多使用均勻線性陣列(Uniform Linear Array, ULA)作為傳送端與接收端天線架構，近年稀疏陣列(sparse array)天線架構為一大熱門研究方向，本論文主要想探討在雙基地多輸入多輸出雷達系統架構下，使用稀疏陣列中的互質陣列(coprime)作為傳送端與接收端天線架構估計DOD與DOA，並探討角度估計在實際情形下會受到的非理想環境，如天線耦合誤差(mutual coupling)、天線元件增益與相位誤差(gain and phase error)、同調環境(coherence)等。 為了對抗上述的誤差環境，首先我們參考文獻Separate MUSIC-IGRRARE演算法，利用Separate運算將接收資料矩陣分為傳送端與接收端的資料矩陣，並使用角度估計問題領域中的MUSIC演算法進行初始角度估計後，利用元啟發演算法(meta-heuristic)中的灰狼最佳化演算法(Grey Wolf Optimization,GWO)進行天線耦合誤差與增益與相位誤差的參數最佳化搜索，最終利用疊代方法修正受到天線耦合誤差與增益與相位誤差的估計角度。

This paper aims to discuss the angle estimation problem of the bistatic multiple input multiple output radar system, including estimating the signal direction of departure (DOD) and the direction of arrival (DOA). And compared with the traditional use of a uniform linear array (ULA) as the antenna structure at the transmitting and receiving end, the sparse array antenna structure has become a hot research topic in recent years. Under the multi-input multi-output radar system architecture, the coprime array of the sparse array is used as the antenna structure of the transmitting end and the receiving end to estimate DOD and DOA, and to discuss the non-ideal environment that angle estimation will be subjected to in practical situations, such as antennas coupling error (mutual coupling), antenna element gain and phase error (gain and phase error), coherent environment (coherent) and so on. To combat the above error environment, first, we refer to the separate MUSIC-IGRRARE algorithm, use the Separate operation to divide the received data matrix into the data matrix of the transmitter and the receiver, and use the MUSIC algorithm in the field of angle estimation to estimate the initial angle. Then, the Grey Wolf Optimization (GWO) in the meta-heuristic algorithm is used to optimize the parameters of the antenna coupling error, gain and phase error, and finally, the iterative method is used to correct the estimated angle of antenna coupling error and gain and phase error.