Joint user association and energy efficiency maximization in beyond 5G heterogeneous networks

Heterogeneous networks (HetNets) seem to be the future of data networks supported by macrocells, small cells, relays, and D2D communication. The main purpose of HetNets is to facilitate maximum users while keeping energy efficiency (EE) to its peak. In this research work, we have formulated joint users association and EE maximization problem for HetNets, where our main goal is to increase the number of users associated with HetNets while keeping EE to its maximum. Formulated problem is a concave fractional problem in nature. We have used Charnes-Cooper Transformation to convert it to the concave optimization problem. We have used the (MADS) algorithm to solve the formulated optimization problem. Results have been analyzed after extensive simulations. Performance of MADS algorithm have been shown with respect to different system parameters, that is, the number of users associated, the minimum required data rate, and joint maximization of users associated and EE.