Optimum Energy Efficiency in Massive MIMO Systems

Abstract

Ever growing demand for new services and ubiquitous connectivity increases the energy consumption. Energy efficient communication system cover a given area with maximal energy efficiency (bit/joule) using massive MIMO setup. Energy efficiency of a large MIMO system is closely related to its power consumption. It depends on various design parameters; in particular, the network architecture, the user terminals, spectral efficiency, the average radiated signal power per user, the number of antennas that are deployed at the access points and circuit power consumption. In BS large number of antennas serve comparatively small number of user to fulfil the Massive multiple-input multiple-output (MIMO) requirements as a result more energy and spectral efficiency is achieved as compared to traditional MIMO technology. Using different processing schemes at the base station a new detailed power consumption model is propose that shows how different parameters like active users, optimal number of antennas at base station and transmit power affect the energy efficiency. Numerical and analytical results show that using massive MIMO setup where large number of BS antennas are deployed to serve less number of users, maximal energy efficiency is obtained. Interestingly, increasing number of antennas at base station also increases the total circuit power consumption from analog devices but energy efficiency is less sensitive to power consumption in Massive MIMO setup. So energy efficiency after reaching its maximum value maintain its position.