Practical Beam Codebook Design via Path Direction Estimation for mmWave Massive MIMO Systems

This paper proposes a new site-specific codebook design method for millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems to avoid unnecessary time and power consumption during beam search. In order to achieve a highly practical beam codebook, the proposed method utilizes reference signal received power (RSRP) regularly reported by users and pre-calculated transmit beamforming gains in predefined directions to estimate the dominant path directions of the users. The beam directions in the codebook are determined by the path direction estimates after applying K-means clustering. Simulation results show that the proposed method can accurately estimate the dominant path directions of users and improve received power and throughput performance compared to a conventional method. The proposed method can reduce beam search overhead by about 33% compared with the conventional method when achieving a throughput of 2.3 Gbps.