三正交分离式极化敏感阵列的波达方向估计

郑桂妹 陈伯孝 吴 渤



三正交分离式极化敏感阵列的波达方向估计

郑桂妹*陈伯孝 吴 渤

(西安电子科技大学雷达信号处理国家重点实验室 西安 710071)

该文研究了分离式极化敏感阵列(SS-PSA)的多目标波达方向(DOA)估计问题。首先建立三正交分离式极化敏感均匀稀疏阵列的信号模型；接着利用阵列的旋转不变性采用ESPRIT算法计算出多值模糊DOA估计；利用该模糊DOA估计值对分离式极化天线进行空间相移的补偿，然后利用共点式极化天线之间的多维角度结构求出对应的虚拟DOA估计；最后通过提取多值模糊估计值和对应虚拟估计值之差的最小范数得到多目标的DOA估计。该文所提阵列采用分离式极化天线代替传统共点式极化天线，降低了阵列的互耦影响；采用稀疏阵列结构有效地扩展了阵列的物理孔径，大大提高了DOA估计精度。计算机仿真结果证明了该算法对分离式极化天线DOA估计的有效性和高精度性。

DOA估计；极化敏感阵列；分离式极化天线；阵列互耦；ESPRIT

1 引言

2　阵列及其信号模型

图1 本文所提三正交分离式极化敏感稀疏阵列结构

则整个阵列的流形矢量等于

3 本文算法描述

3.1 基于ESPRIT的高精度模糊DOA估计

3.2 虚拟精-粗估计拟合解模糊

其中

则无模糊的目标俯仰角和方位角的精估计值为

4 计算机仿真结果

仿真1 目标两维DOA估计及其配对

仿真2 估计性能与信噪比关系比较

5 结论

本文研究了三正交分离式极化天线构成的阵列对2维DOA的估计问题。提出了一种稀疏均匀矩形极化平面阵列，阵列的稀疏配置使得在不增加阵元数和硬件复杂度情况下有效扩展了阵列物理孔径，但同时也造成了2维DOA估计的模糊问题，提出了一种虚拟精-粗估计解模糊算法去掉其模糊值。该方法同时利用了极化天线提供的极化分集和稀疏阵列带来的空间分集使得该阵列的2维DOA的估计性能大大优于常规的标量阵列；此外三正交分离式的极化天线设计灵活，解决了共点式极化天线互耦严重的问题，使得极化阵列硬件设计的难度大大降低；且绕开了电偶极子和磁偶极子响应不一致的问题。

图2 本文算法目标2维DOA估计星座图

图3 2维DOA估计均方根误差随信噪比变化曲线

[1] Yuan X. Diversely polarized antenna-array signal processing [D]. [Ph.D. dissertation], The Hong Kong Polytechnic University, 2012.

[2] 徐友根, 刘志文, 龚晓峰. 极化敏感阵列信号处理[M]. 北京:北京理工大学出版社, 2013: 1-7.

[3] Gu C, He J, Li H,.. Target localization using MIMO electromagnetic vector array systems[J]., 2013, 93(7): 2103-2107.

[4] 邵华, 苏卫民, 顾红, 等. 基于稀疏互质电磁矢量阵列的MUSIC算法[J]. 电子与信息学报, 2012, 34(9): 2033-2038.

[5] Rahamim D, Tabrikian J, and Shavit R. Source localization using vector sensor array in a multipath environment[J]., 2004, 52(11): 3096-3103.

[6] Luo F and Yuan X. Enhanced “vector-cross-product” direction-finding using a constrained sparse triangular-array [J]., 2012, DOI:10.1186/1687-6180-2012-115.

[7] Gong X F, Liu Z W, and Xu Y G. Coherent source localization: bicomplex polarimetric smoothing with electromagnetic vector-sensors[J]., 2011, 47(3): 2268-2285.

[8] Jiang J and Zhang J. A weighted inner product estimator in the geometric algebra of euclidean 3-space for source localization using an EM vector-sensor [J]., 2012, 25(1): 83-93.

[9] Chiu C Y, Yan J B, Murch R D,.. Design and implementation of a compact 6-port antenna[J]., 2009, 8: 767-770.

[10] See C-M S and Nehorai A. Source localization with distributed electromagnetic component sensor array processing[C]. IEEE Seventh International Symposium on Signal Processing and Its Applications, Pairs, France, 2003, 1: 177-180.

[11] Monte L L, Elnour B, Erricolo D,.. Design and realization of a distributed vector sensor for polarization diversity applications[C]. IEEE International Waveform Diversity and Design Conference, Pisa, Italy, 2007: 358–361.

[12] Monte L L, Elnour B, and Erricolo D. Distributed 6D vector antennas design for direction of arrival application[C]. IEEE International Conference on Electromagnetics in Advanced Applications, Torino, Italy, 2007: 431-434.

[13] Monte L L, Elnour B, Rajagopalan A,.. Circularly and linearly distributed narrowband vector antennas for direction of arrival applications[C]. North American Radio Science Conference, Ottawa, Ontario, Canada, 2007: 22-26.

[14] Hurtado M and Nehorai A. Performance analysis of passive low-grazing-angle source localization in maritime environments using vector sensors[J]., 2007, 43(2): 780-789.

[15] Wong K T and Yuan X. ‘Vector cross-product direction- finding’ with an electromagnetic vector-sensor of six orthogonally oriented but spatially non-collocating dipoles/ loops[J]., 2011, 59(1): 160-171.

[16] Li Y and Zhang J. An Enumerative NonLinear Programming approach to direction finding with a general spatially spread electromagnetic vector sensor array[J]., 2013, 93(4): 856-865.

[17] Li J. Direction and polarization estimation using arrays with small loops and short dipoles[J]., 1993, 41(3): 379-387.

[18] Yuan X, Wong K T, Xu Z,.. Various triads of collocated dipoles/loops, for direction finding & polarization estimation [J]., 2012, 12(6): 1763-1771.

[19] Zoltowski M D and Wong K T. ESPRIT-based 2-D direction finding with a sparse uniform array of electromagnetic vector sensors[J]., 2000, 48(8): 2195-2204.

郑桂妹： 男，1987年生，博士生，研究方向为矢量传感器阵列、MIMO雷达信号处理.

陈伯孝： 男，1966年生，博士，教授，博士生导师，研究方向包括新体制雷达系统与雷达信号处理、阵列信号处理、精确制导与目标跟踪等.

吴 渤： 男，1989年生，博士生，研究方向为极化敏感阵列信号处理.

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

郑桂妹 gmzheng@stu.xidian.edu.cn

2013-07-04收到，2013-12-11改回

国家自然科学基金(61001209, 61101244, 61071175)，中央高校基本科研业务费专项资金(K5051202038)及长江学者和创新团队计划(IRT0954)资助课题