Energy Efficiency Optimization through RRHs ON/OFF Switching Technique in C-RAN

Energy efficiency (EE) is one of the main parameters to be considered in recent networks targeting green technology. Our system is based on cloud radio access networks and it consists of a macro base-station and many small remote radio heads (RRHs). We solve an optimization problem to improve the system's EE through resource allocation and power control. We also reduce the power consumption through switching the RRHs ON/OFF based on the current users' distribution. We formulate the problem as EE maximization with constraints to provide full frequency reuse between RRHs. Our solution divides the problem into multiple stages to relax the complexity. We first select the RRHs to be switched ON/OFF, and then based on the operating RRHs; we optimize the users' assignment and RRHs' transmission power. Finally, we assign any starving users to the macro base-station. The performance evaluation shows that our solution significantly improves the system EE and power consumption compared to other solutions where we achieve EE improvement by more than 57%. © 2019 IEEE.