Low Complexity Channel Tracking for Hybrid Beamforming Systems

Mitigating the complexity associated with capturing swiftly changing channels in high-mobility systems is challenging, primarily due to the considerable relative speed between transceivers. In this paper, a channel tracking method with hybrid beamforming is proposed to alleviate this. First, a hybrid combiner is designed as a unitary matrix to achieve the real-valued transformation. Then, a sparse signal recovery problem containing prior information is formulated, and a homotopy-based channel tracking algorithm with low complexity is developed. Simulation results indicate that the proposed algorithm is of lower computational complexity.