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.