AOA Estimation Techniques for Analog Beamforming in Millimeter Wave 5G NR

The paper is dedicated to the angle of arrival (AOA) estimation problem in the millimeter wave 5G New Radio (NR). The user equipment with switched multiple arrays and analog beamforming is considered. The emphasis is put on power-based algorithms that do not require phase synchronization between pilot signals and could be applied in the frame of the 3GPP protocols. Hierarchical search, auxiliary beam and adaptive compressed sensing algorithms are studied. The modification of the hierarchical search algorithm is proposed to overcome the discretization error problem. The AOA estimation precision of the algorithms is investigated in static line-of-sight (LOS) / non-line-of-sight (NLOS) channels, in rapidly varying channels and in static NLOS channels under low-SNR (signal to noise ratio) conditions. A practical ray-tracing-based channel model was used for numerical simulations.