Energy-Efficient Uplink Power Allocation in Multi-Cell MU-Massive-MIMO Systems

In this paper, we investigate a joint uplink pilot and data power allocation strategy for energy-efficient communications under pilot contamination in multi-cell multi-user massive multiple-input multiple-output (MU-Massive-MIMO) systems. Assuming the maximum-ratio combining detection and a large number of antennas at the base station, the system energy efficiency (EE) is maximized over the individual power assignment between pilot and data transmissions of each user, subject to the per-user signal to interference-plus-noise ratio and per-user power constraints. To decentralize the optimization, game theory has to be applied, in which each cell competes against neighboring cells to maximize its own EE via fractional programming. The existence and uniqueness of Nash equilibrium of the game are discussed. Numerical results of the proposed algorithm are compared with the uplink power control scheme, which illustrates the significant advantage in EE by applying the per-user power allocation in multi-cell MU-Massive-MIMO.