Adapting the number of antennas and power to traffic load: When to turn on massive MIMO?

In this work, we consider the downlink of a multi-user multiple-input multiple-output (MIMO) system and aim to find the jointly optimal number of base station (BS) antennas and transmission powers that minimize the power consumption while satisfying each user's signal-to-interference-and-noise-ratio (SINR) constraint and the BS's power constraint. Different… (More)