EKF-Based Beam Tracking for mmWave MIMO Systems

Beam tracking is an effective way to maintain high-quality links in mobile millimeter wave MIMO systems, which is achieved by accurately estimating angle-of-departure (AoD) and angle-of-arrival (AoA) of the desired path. Considering the slow variations of angular velocity for time-varying AoD and AoA, a second-order AoD/AoA variation model is proposed for extended Kalman filter (EKF) based beam tracking. By utilizing two well configured tracking beam pairs, the unknown path gain is removed from EKF's measurement model and the optimal estimation of AoD/AoA is derived. Simulation results demonstrate that the proposed EKF-based beam tracking method achieves higher AoD estimation accuracy than previous methods.