Parameters Estimation of 3-D Near-Field Sources With Arbitrarily Spaced Electromagnetic Vector-Sensors

In this Letter, we consider the problem of parameters estimation for near-field sources (NFSs) in three-dimensional (3-D) space with arbitrarily spaced electromagnetic vector-sensors (EMVSs), by taking advantage of the high-order statistics (HOS) of the array observations. In particular, we devise several fourth-order cumulant (FOC) matrices and exploit them to capture the two-dimensional direction-of-arrival (2D-DOA) and polarization information at each EMVS with subspace techniques. On this basis, a linear equation is developed to determine the location parameters of NFSs. Unlike the existing methods, the proposed one is not necessary to use uniformly spaced linear or planar arrays and is applicable to arbitrary EMVS array geometries. Moreover, it is also able to achieve the 3-D localization of NFSs, as well as estimating the polarization parameters accurately. Simulation results are presented to validate the performance of the proposed algorithm.