Energy Efficient Antenna Selection For Downlink Massive MIMO System

Abstract

Through utilizing large numbers of antennas, massive MIMO systems offer high data speeds, which also increases the system's power consumption as a consequence. The primary concept of massive MIMO is that terminals are supported by the base station (BS) equipped with a large number of antenna components over the same time-frequency resources. For current and next generation wireless communication systems, the massive multiple-input multiple-output (MIMO) system implementing vast quantities of antennas is a promising technique to increase energy efficiency. With the exponential growth and need for highspeed wireless communications, the needed quality of service is supported by more and more energy consumption. Thus, under restricted energy resource transmission schemes, energy efficient or green communication has become a very hot topic. The power consumption of radio frequency (RF) chains can, however, be enormous, which poses major challenges. Multiple antennas often include multiple RF chains, consisting of amplifiers, mixers, ADC, filters, etc. Thus, the expense and hardware complexity of the device is improved due to numerous RF chains. In this thesis, the issue of transmitting RF chain configuration with the objective of optimizing energy efficiency in large MIMO systems under total power constraints is considered here. In order to work with optimum energy efficiency, this generates an optimization problem that determines how many antennas the device can use. The main goal is to select a fixed number of antennas in order to enable the device to work with a smaller subset of antennas, depending on the number of active user terminals that may differ over time. Thus, by applying antenna selection methods, the RF chain configuration can be determined and a minimum number of transmission antenna elements are chosen to achieve energy efficiency. The simulation results show the effect of antenna selection (random antenna selection) on the energy efficiency of a massive MIMO system using NOMA and modulation schemes in order to achieve power reduction due to the selection of antennas. This NOMA and modulation scheme used to maximize the capacity that reduced due to antenna selection.