Dynamic users assignment and bandwidth allocation for energy efficient hybrid powered communication systems

In this paper, we aim to encourage the use of renewable power in communication systems through hybrid powering. The problem consists of optimizing the resource allocation problem using the hybrid powering from renewable and non-renewable sources. Minimizing a new defined power cost function instead of the net power consumption aims to encourage the use of the renewable power through collaboration between the base stations. The different degrees of freedom in the system, ranging from assignment of users to base stations, possibility of switching the unnecessary base stations to the sleep mode, and dynamic allocation of the available bandwidth, allow us to achieve important power cost savings. Although the formulated optimization problem is a mixed integer-real problem with a non-linear objective function, we propose an efficient two-step algorithm to jointly assign users to base stations and allocate the shared bandwidth among users. Simulation results confirm the important savings in non-renewable power consumption when using the proposed approach and the efficiency of the proposed algorithms.