L-shaped COLD arrays-based near-field localization with exact spherical wavefront

In this paper, an exact near-field (NF) polarization localization algorithm is proposed to estimate the fivedimensional (5D) parameters by establishing an L-shaped cocentered orthogonal loop and dipole (COLD) array. First, estimation of manifold matrices aligned with each coordinate axis is performed by forming the delay cross-correlation covariance matrices, and employing parallel factor decomposition. The unambiguous phases present in each sub-manifold matrix are employed to disambiguate the remaining phases, enabling the construction of linear equations in spatial geometry, from which linear least squares parameter estimation is allowed. In particular, based on the rotational invariance relationship between the horizontal and vertical components received by the COLD array, the polarization parameters are estimated via total least squares. Simulations are provided to demonstrate the superiority of the proposed method. © 2025 IEEE.