An Energy Saving Strategy for LTE-A Multiantenna Systems

Abstract

Long Term Evolution - Advanced (LTE-A) supports closed-loop Multiple Input Multiple Output (MIMO) techniques to improve its performance, but in order to exploit multiuser (MU) MIMO channel capabilities, the design of an efficient Medium Access Control (MAC) scheme that supports MU-MIMO is still an open issue in the literature. This paper proposes a novel energy efficient MAC scheme for LTE-A, which aims to achieve simultaneous downlink transmissions to multiple users, through the deployment of a low complexity beamforming technique at the physical layer. Our proposed scheme takes advantage from the multiuser gain of the MIMO channel and the multiplexing gain of the Multibeam Opportunistic Beamforming (MOB) technique, to improve the system throughput and the energy efficiency of wireless networks. We provide a closed form mathematical expression of the energy efficiency, where the results from the proposed scheme achieve a considerable energy saving at the Base Station (eNB).