Iterated Extended Kalman Filter Based Adaptive Beam Tracking for Millimeter-Wave Systems

In this paper, an adaptive beam tracking algorithm based on the Iterated Extended Kalman Filter (AT-IEKF) is proposed for millimeter wave communications. To achieve a balance between the accuracy of beam tracking and the tracking overhead, AT-IEKF dynamically adjusts the time interval between two consecutive beam tracking updates based on the historical variations of the channel strength after beamforming. In each tracking update, AT-IEKF updates the beamforming directions by IEKF for high accuracy, where two probing beams are measured to track the beamforming direction at the base station or user equipment. The effectiveness of AT-IEKF is verified by numerical results obtained from ray-tracing experiments. The results show that AT-IEKF outperforms several state-of-the-art algorithms from the perspectives of beam tracking accuracy and tracking overhead.