title: Spatial Signature Estimation with an Uncalibrated Uniform Linear Array.
abstract: In this paper, the problem of spatial signature estimation using a uniform linear array (ULA) with unknown sensor gain and phase errors is considered. As is well known, the directions-of-arrival (DOAs) can only be determined within an unknown rotational angle in this array model. However, the phase ambiguity has no impact on the identification of the spatial signature. Two auto-calibration methods are presented for spatial signature estimation. In our methods, the rotational DOAs and model error parameters are firstly obtained, and the spatial signature is subsequently calculated. The first method extracts two subarrays from the ULA to construct an estimator, and the elements of the array can be used several times in one subarray. The other fully exploits multiple invariances in the interior of the sensor array, and a multidimensional nonlinear problem is formulated. A Gauss-Newton iterative algorithm is applied for solving it. The first method can provide excellent initial inputs for the second one. The effectiveness of the proposed algorithms is demonstrated by several simulation results.
authors.affiliation: Institute of Artificial Intelligence and Robotics, Xi'an Jiaotong University, Xi'an 710049, China. cao.xiang@stu.xjtu.edu.cn.
authors.forename: Xiang
authors.initials: X
authors.lastname: Cao
authors.affiliation: Institute of Artificial Intelligence and Robotics, Xi'an Jiaotong University, Xi'an 710049, China. jxin@mail.xjtu.edu.cn.
authors.forename: Jingmin
authors.initials: J
authors.lastname: Xin
authors.affiliation: Department of Electrical and Electronic Engineering, Tokushima University, Tokushima 770-8506, Japan. nishio@ee.tokushima-u.ac.jp.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Nishio
authors.affiliation: Institute of Artificial Intelligence and Robotics, Xi'an Jiaotong University, Xi'an 710049, China. nnzheng@mail.xjtu.edu.cn.
authors.forename: Nanning
authors.initials: N
authors.lastname: Zheng
keywords: array signal processing; auto-calibration; parameter estimation