An Energy Efficiency Evaluation of MIMO Based LTE RANs with DTX Operation

Abstract

This paper presents a system level evaluation of the energy consumption of a 4G LTE radio access network RAN when upgrading the access base stations from SISO to MIMO base stations. A macro only cell deployment scenario is evaluated, and the power consumption of the base stations is estimated by a parametric power consumption model. The impact of the discontinuous transmission feature (DTX) on the energy consumption of 2x2 and 4x4 MIMO radio access network with reference to the SISO radio access network is analyzed. A non-full buffer FTP traffic model is used in the analysis. Our results show that, without DTX, the 2x2 MIMO deployment consumes the least amount of energy. No energy savings are observed when more than 2 transmit antennas is used. When DTX is enabled, and at high values of offered traffic, the 4x4 MIMO deployment becomes the most energy efficient deployment option among the SISO and 2x2 MIMO deployments.