Energy efficient user association scheme in cellular machine to machine communications

Machine-to-Machine (M2M) communications is regarded as an important enabler towards the realization of the Internet of Things (IoT). M2M communication also referred to as machine type communication (MTC) enables devices to communicate directly or via a network gateway over the cellular network without or with-limited human intervention. Most MTC devices are operated by batteries and it is very critical to design algorithms that will evaluate the energy efficiency in order to ensure the lifespan and performance of the system. In this work, we propose a low complexity resource allocation algorithm that maximizes the energy efficiency for the uplink in a single carrier frequency division multiple access (SC-FDMA) based LTE-A systems. The restrictions of SC-FDMA are enforced and the optimization problem is formulated as a mixed integer non-linear programming (MINLP) problem, which is then solved using the Lagrangian dual decomposition method. The proposed energy efficient user association scheme was simulated in MATLAB environment. The simulation results shows a rapid convergence with minimal complexity as the number of users increases.