A Codebook-Based Phased Near-Field Beam Search Scheme With Uniform Circular Array

The introduction of extremely large-scale antenna array (ELAA) further increases the aperture of the array, which results in the communication system may operate in the near-field region where the beam can focus both in angular-domain and distance-domain. In this paper, the algorithm is proposed to reduce excessive pilot overhead due to high resolution of uniform circular array (UCA). We start with an angular-domain search and find the best set of angular code words, and in the second stage find the best distance-domain code word. Simulation results verify that the proposed algorithm have a good performance in actual channel with low pilot overhead.