Low-Complexity 2D DOA and Polarization Estimation via Linear Nested COLD Array with Vertical Motion

In order to obtain two-dimensional direction-of-arrival and polarization estimation with high-precision and low-complexity, we present a linear nested polarization sensitive array with vertical motion, and then propose an estimation of signal parameters via rotational invariance technique (ESPRIT) based method. The original physical array consists of cocentered orthogonal loop and dipole antennas. Owing to the concept of difference coarray based on block submatrices, the closed-form expressions of signal model and increased degree of freedoms are provided for the resulting vertical synthetic planar array. Depending on it, the idea of ESPRIT is only utilized once, and then four parameters (i.e., azimuth angle, pitch angle, polarization angle and polarization phase difference) of each signal can be estimated and automatically paired. The computational complexity of the proposed method is analyzed theoretically. Numerical results are shown to verify the superiority of the proposed array and method in terms of multi-parameter estimation.