A novel 2-D quaternion ESPRIT for joint DOA and polarization estimation with crossed-dipole arrays

In this paper, a novel 2-D quaternion ESPRIT (2-D Q-ESPRIT) estimator, exploiting the two dimensional invariance of the array structure of a crossed-dipole array, for both the direction-of-arrival (DOA) and polarizations of multiple narrowband plane waves is proposed. To implement the 2-D Q-ESPRIT estimator, a two-stage quaternion joint eigenvalue decomposition (QJEVD) algorithm is devised through the joint quaternion Schur decomposition and tensorial representation of the quaternion product. What is more, the two-stage QJEVD algorithm can be easily tailored if only the DOA parameters are of interest. The analyses show that our 2-D Q-ESPRIT estimator can achieve enhanced robustness and is computationally more efficient than the MUSIC like counterparts. Simulations are conducted to verify the analytical results.