Study of the Configuration of Sub-arrays for 2D Passive Antenna Beam-Forming for Beyond 5G Cellular Base Stations

Commercial introduction of massive multiple-input m ultip leo utput (MIM 0) units (MMU s) is being promoted for the 5th generation (5G) mobile communication system. MMUs implement beam-forming (BF) to reduce interference to neighboring cells and compensate for radio propagation loss, and MIMO spatial multiplexing to improve communication speed and increase system capacity. Recently, installation and maintainability have become issues for MMU s. Passive multiport base station antennas supporting BF (passive BF antenna) have been standardized in Next Generation Mobile Network Alliance MIMO multiplexing and BF can be actualized through passive BF antennas according to communication conditions using singular value decomposition and other techniques used for MMU s. Alternatively, BF can be achieved by selecting from a predefined weight matrix, which reduces processing overhead. This paper investigates the optimization of antenna sub-array configurations for passive antenna BF in beyond 5G cellular systems based on system simulations. The passive BF antenna is shown to mitigate inter-cell interference and enhance communication capacity.