Improving network energy efficiency through cooperative idling in the multi-cell systems

Network energy efficiency (NEE) is considered as the metric to address the energy efficiency problem in the cooperative multi-cell systems in this article. At first, three typical schemes with different levels of cooperation, i.e., interference aware game theory, inter-cell interference cancellation, and multi-cell joint processing, are discussed. For both unconstrained and constrained case, efficient power control strategies are developed to maximize the NEE. During the optimization, both the optimization objects and strategies are distinct because of different levels of data and channel state information at the transmitter sharing. In order to further improve NEE, a novel cooperative idling (CI) scheme is proposed through cooperatively switching some BSs into micro-sleep and guaranteeing the data transmission with the other active BSs' cooperative transmission. Simulation results indicate that cooperation can improve both NEE and network capacity and demonstrate that CI can further improve the NEE significantly.