Fundamentals for Energy-Efficient Massive MIMO
Massive MIMO uses antenna arrays with more than 100 elements to direct transmitted energy, and receiver sensitivity, individually toward multiple intended users . This large number of elements requires an individual and independent transmitter within each, in order to have complete flexibility in definition and control of each beam. This large number of transmitters places additional constraints on acceptable energy efficiency due to the complicated flow of dissipated power and its corresponding temperature rises. Any successful field implementation of massive MIMO must understand the energy efficiency of the array, both at each individual element  and in combination, to not only properly function but also to keep the hardware well within safe operating limits.