Estimation for Two-Dimensional Incoherently Distributed Source in Double L-Shape Arrays

基于双L型阵列的二维非相干分布源参数估计

¹ School of Automation, Northwestern Polytechnical University, Xi’an 710072, China
² School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an 710072, China

Received: 10 August 2018

Abstract

Distributed sources can be regarded as an assembly of point sources within a spatial distribution. In this paper, we explore the estimation of the two-dimensional incoherently distributed sources using double L-shape arrays. The rotational invariance properties of the nominal elevation and nominal elevation are firstly obtained by taking first-order Taylor series expansions with regard to the generalized steering vectors of two pairs of parallel subarrays. The rotation operators can be solved based on signal subspace. Then the nominal elevation and nominal elevation can be obtained from parameters matching method. Estimation of direction of arrival can be used in multi-source scenario and needn't peak-finding search. Lastly the angular spreads can be solved through two-dimensional Capon search based on nominal angles. The simulation experiments show that the proposed method has good performance on the estimation of two-dimensional incoherently distributed sources. Investigating different experimental conditions, sources with different angular spreads, simulations are conducted to validate better estimation accuracy of the proposed method.

摘要

分布源信号可以看作点源信号在一定空间范围内的聚集。研究二维非相干分布源的参数估计问题，提出一种基于双L型阵列结构的分布源参数估计方法。通过一阶泰勒展开推导出平行阵列广义方向矢量关于中心方位角和中心俯仰角的旋转不变关系，在此基础上利用接收矢量协方差矩阵的信号子空间得出旋转算子，依据参数配对方法解算出中心方位角和中心俯仰角，二维波达方向的估计不需要谱峰搜索，适用于角功率函数未知和多个分布源的情景。最后通过二维Capon谱峰搜索确定角度扩展参数。通过仿真考察实验条件、扩展角度对估计结果的影响，实验表明所提算法具有良好估计性能。