Full Dimensional Multiple Input Multiple Output (FD MIMO) refers to a technology that arranges the signals transmitted to antennas in the form of virtual beams that are able to power multiple receivers in three dimensions. The technology involves the deployment by an evolved Node B (eNB), a large number of active antenna elements in a 2-dimensional (2D) grid and is capable of supporting many users on the same bandwidth simultaneously. This reduces interference from overlapping transmissions to other receivers and increases the power of the signal. 

FD-MIMO is expected to significantly increase spectrum efficiency and is included in the 3GPP LTE (Long Term Evolution) and LTE-advanced (LTE-A) specifications, and is also evaluated for 5G.