Multiple-input and multiple-output (MIMO) technology is the use of multiple antennas at both one or more transmitters and one or more receivers. A MIMO system can be used to increase data throughput and link reliability of a network. A three-dimentional (3D) or full-dimentional (FD) MIMO system can be used in MIMO network to enhance the cellular performance by deploying antenna elements in horizontal and vertical dimensions, e.g., a two dimensional (2D) antenna array.
In the legacy MIMO system, an evolved node B (eNB) may have to use the same electrical downtilt for all data transmissions, which may also introduce interference to a neighbor cell.