Efficient DOA-polarization estimation for 2-D mirrored array based on the hybrid aperture expansion

At present, there are fewer studies on the polarization-sensitive mirrored array (PS-MA). Meantime, estimation accuracy will decrease when the array element spacing is lower than half wavelength. This paper focuses on the aperture expansion of the PS-MA to improve the estimation accuracy. To this end, we establish the received signal model of the 2-D PS-MA with two perpendicular reflectors. Unlike the existing virtual array without polarization information, a novel model of the polarization-sensitive virtual array (PS-VA) is suggested based on the hybrid coarray technique. Additionally, the spatial smoothing (SS) technique is used to recover the rank of the covariance matrix, and the modulus value boundedness (MVB) of the polarization vector is to reduce the dimension of the polarization-spatial spectrum. Then, the MVB-MA-SS algorithm is proposed polarization-DOA estimation, which is much more efficient than the standard group-lasso algorithm used the 1-D PS-MA. Numerical experiments show that the proposed algorithm can provide satisfactory estimation accuracy with significantly reduced computational complexity.