Optimization of Energy Efficiency for OFDMA Femtocell Networks Based on Effective Capacity

This paper addresses how to improve the energy efficiency of OFDMA femtocell networks with sleep mode. Firstly, the energy consumption of the sleep mode is analyzed. Considering the requirements of improving the energy efficiency and ensuring the QoS of users, we extend the definition of effective capacity to formulate the tradeoff relationship between the energy efficiency and the waiting delay of users. Then two optimization schemes of sleep mode parameter are proposed: (1) Maximize the energy efficiency with effective capacity constraint; and (2) Maximize the effective capacity with energy efficiency constraint. And the performances are analyzed, including average energy consumption, energy efficiency, effective capacity and waiting time. Simulation results show that the effective capacity-based parameter optimization of sleep mode can achieve a good tradeoff between energy efficiency and QoS of users in OFDMA femtocell networks.