Evaluation of Energy-Efficiency Problem in Orthogonal Frequency Division Multiple Access Cellular Networks

Abstract

In this study, the energy-efficiency (EE) problem is investigated for downlink Orthogonal FrequencyDivision Multiple Access (OFDMA) cellular networks. The EE maximization problem is defined undercertain prescribed per-user quality-of-service (QoS) demands and maximum system power limit. EEmetric that aims to maximize the system data rate and minimize the total power consumption at the sametime is used as the objective function of the defined problem. In this form the optimization problembelongs to a broad class of problems called mixed-integer non-linear programming problem (MINLP),that is difficult to solve in its original form in such a multi-carrier, multi-user networks. Hence, we havedecomposed the original problem into two parts and presented a solution that performs subchannelallocation and power allocation parts separately. Simulation results are obtained to confirm theperformance of the presented scheme in terms of energy-efficiency and total data rate.