A Distributed Energy Efficiency Optimization Scheme for Cooperative Virtual MIMO System

In this work, we propose a distributed energy efficiency (EE) optimization scheme for cooperative virtual multiple input and multiple output (V-MIMO) system. User equipments (UEs) with single antenna form cooperative V-MIMO groups to achieve their target spectral efficiency (SE) and improve their EE in a distributed manner. We decompose the scheme into two sections. Firstly, we deduce closed-form expressions of the optimal power and target SE allocations for each UE on each RB within a V-MIMO group. Then, based on this deduced expressions, a coalition formation game is utilized to choose a proper set of UEs to form V-MIMO groups. A convergent iteration of merge-split operations is adopted according to the Pareto order of UEs´ EE. Simulation results show that this proposed scheme increases the EE of UEs, especially when the number of UEs is large and their target SE is high.