Hybrid Beamforming Algorithm and Structure with Reduced Complexity in Multi-User MISO

This paper proposes a novel hybrid beamforming (HBF) algorithm and structure for multi-user multi-input singleoutput (MU-MISO) systems that groups transmit antennas and users. Conventional HBF structures grouped all transmit antennas and users into two groups, forming beams for each user. However, this structure suffers from increased processing time for grouping as the number of transmit antennas and users grows. In this case, it is difficult for this structure to perform optimal weighting under time-varying channels. Therefore, this paper proposes an HBF structure with an increased number of groups for grouping and a grouping algorithm that reduces processing time. Simulation results demonstrate that the proposed method improves performance while reducing processing time compared to conventional HBF methods and fully-connected (FC) HBF.