鄭桂妹 陳伯孝 吳 渤

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三正交分離式極化敏感陣列的波達方向估計

鄭桂妹*陳伯孝 吳 渤

(西安電子科技大學(xué)雷達信號處理國家重點實驗室 西安 710071)

該文研究了分離式極化敏感陣列(SS-PSA)的多目標波達方向(DOA)估計問題。首先建立三正交分離式極化敏感均勻稀疏陣列的信號模型；接著利用陣列的旋轉(zhuǎn)不變性采用ESPRIT算法計算出多值模糊DOA估計；利用該模糊DOA估計值對分離式極化天線進行空間相移的補償，然后利用共點式極化天線之間的多維角度結(jié)構(gòu)求出對應(yīng)的虛擬DOA估計；最后通過提取多值模糊估計值和對應(yīng)虛擬估計值之差的最小范數(shù)得到多目標的DOA估計。該文所提陣列采用分離式極化天線代替?zhèn)鹘y(tǒng)共點式極化天線，降低了陣列的互耦影響；采用稀疏陣列結(jié)構(gòu)有效地擴展了陣列的物理孔徑，大大提高了DOA估計精度。計算機仿真結(jié)果證明了該算法對分離式極化天線DOA估計的有效性和高精度性。

DOA估計；極化敏感陣列；分離式極化天線；陣列互耦；ESPRIT

1 引言

2　陣列及其信號模型

圖1 本文所提三正交分離式極化敏感稀疏陣列結(jié)構(gòu)

則整個陣列的流形矢量等于

3 本文算法描述

3.1 基于ESPRIT的高精度模糊DOA估計

3.2 虛擬精-粗估計擬合解模糊

其中

則無模糊的目標俯仰角和方位角的精估計值為

4 計算機仿真結(jié)果

仿真1 目標兩維DOA估計及其配對

仿真2 估計性能與信噪比關(guān)系比較

5 結(jié)論

本文研究了三正交分離式極化天線構(gòu)成的陣列對2維DOA的估計問題。提出了一種稀疏均勻矩形極化平面陣列，陣列的稀疏配置使得在不增加陣元數(shù)和硬件復(fù)雜度情況下有效擴展了陣列物理孔徑，但同時也造成了2維DOA估計的模糊問題，提出了一種虛擬精-粗估計解模糊算法去掉其模糊值。該方法同時利用了極化天線提供的極化分集和稀疏陣列帶來的空間分集使得該陣列的2維DOA的估計性能大大優(yōu)于常規(guī)的標量陣列；此外三正交分離式的極化天線設(shè)計靈活，解決了共點式極化天線互耦嚴重的問題，使得極化陣列硬件設(shè)計的難度大大降低；且繞開了電偶極子和磁偶極子響應(yīng)不一致的問題。

圖2 本文算法目標2維DOA估計星座圖

圖3 2維DOA估計均方根誤差隨信噪比變化曲線

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鄭桂妹： 男，1987年生，博士生，研究方向為矢量傳感器陣列、MIMO雷達信號處理.

陳伯孝： 男，1966年生，博士，教授，博士生導(dǎo)師，研究方向包括新體制雷達系統(tǒng)與雷達信號處理、陣列信號處理、精確制導(dǎo)與目標跟蹤等.

吳 渤： 男，1989年生，博士生，研究方向為極化敏感陣列信號處理.

DOA Estimation with Three Orthogonally Oriented andSpatially Spread Polarization Sensitive Array

Zheng Gui-mei Chen Bai-xiao Wu Bo

(,,’710071,)

This paper discusses the issue of multiple targets’ Direction Of Arrival (DOA) estimation for Spatially Spread Polarization Sensitive Array (SS-PSA). First, the signal model of sparsely uniform SS-PSA with three orthogonally oriented polarized-antenna is presented. Then the rotational invariance of the proposed uniform array is utilized to calculate the ambiguous DOA estimation by means of ESPRIT method. The spatial phase shift raised by spatially spread polarized-antenna is compensated by the ambiguous DOA estimation to obtain virtual collocated polarized-antenna. The corresponding virtual DOA estimation is calculated by the multi-dimensional angle structure among the virtual collocated polarized-antenna. Finally, the multiple targets’ DOA estimation is obtained by extracting the minimum norm of the difference between the ambiguous DOA estimation and the corresponding virtual DOA estimation. The proposed array can reduce the array mutual coupling by using the spatially spread polarized-antenna instead of conventional collocated polarized-antenna. Moreover, the DOA estimation accuracy can be improved greatly because of the extended aperture offered by the sparse array. Computer simulation results verify the effectiveness and high-accuracy of the proposed SS-PSA DOA estimation algorithm.

DOA estimation; Polarization Sensitive Array (PSA); Spatially spread polarized-antenna; Array mutual coupling; ESPRIT

TN911.7

A

1009-5896(2014)05-1088-06

10.3724/SP.J.1146.2013.00967

鄭桂妹 gmzheng@stu.xidian.edu.cn

2013-07-04收到，2013-12-11改回

國家自然科學(xué)基金(61001209, 61101244, 61071175)，中央高?；究蒲袠I(yè)務(wù)費專項資金(K5051202038)及長江學(xué)者和創(chuàng)新團隊計劃(IRT0954)資助課題