Two Stage Beam Management for High Speed Multi-UAV Communications With Doppler Shift

In autonomous aerial vehicles (AAVs) communications, beam management is of vital importance for establishing and maintaining a directional link between a base station (BS) and multi-UAVs. However, it is challenging to acquire an actual angle of arrival (AoA) due to the Doppler frequency offset (DFO) caused by the mobility of UAV in high-speed. To deal with this challenge, we propose the two stage beam management consisting of beam training and beam tracking. In first phase, DFT beam training is proposed, especially with a phase rotation matrix to extract the actual AoA information by eliminating the DFO term. In second phase, Kalman filter (KF) beam tracking is proposed with monopulse signal to reduce the linearization loss. Simulation results demonstrate that our proposed scheme accurately estimates the actual AoA during beam training phase and is well tracking the AoA in high-speed scenarios.