Gridless Azimuth and Polarization Parameter Estimation Based on Uniform Circular COLD Arrays

In order to achieve gridless azimuth and polarization parameter estimation, the polarization atomic norm minimization (P-ANM) algorithm is proposed. The polarization-sensitive uniform circular array (P-UCA) consisting of concentered orthogonal loop and dipole (COLD) antennas is considered in this paper for its stable estimation ability for all 0 degrees ~ 360 degrees range. The proposed method is capable of estimating the parameters with only single snapshot and overcomes the grid mismatch. First, the the mathematical models of signals received by the P-UCA are established and the P-ANM algorithm is applied. Then, The P-UCA is mapped into the virtual uniform linear array based on the Fourier expansion. Subsequently, the dual method is employed to solve the P-ANM model and determine the azimuths of the signals. Ultimately, by reconstructing the signal vectors, the polarization information can be inversely estimated based on the relationship between the electrical and magnetic signals. The simulations demonstrate that the proposed P-ANM algorithm exhibits superior joint estimation ability for all the azimuth and polarization parameters of the signals.