Power allocation for multiple input multiple output systems

Abstract

Mobile communication systems face power consumption issues, specifically multiple input multiple output (MIMO) systems, due to the vast number of antennas. Research shows the movement towards greener mobile communications, whereby utilising more energy-efficient systems. This research aims to design and develop an approach to improve the power allocation of a broadcast MIMO system. A literature review highlights the current power allocation schemes advantages and disadvantages of said schemes. Analysis shows the effectiveness of current schemes and the design of a new power allocation approach to fill the gap in the current scheme. The implementation of non-orthogonal multiple acess (NOMA) into a broadcast MIMO system significantly improves the system’s energy and spectral efficiency. A power allocation algorithm is implemented into a NOMA-based relay system, where relays aid cell-edge users. The cell center users connect directly to the base station, whereas the cell edge users connect via relay. The user equipment (UEs) and relays successfully employ successive interference cancellation (SIC) to cancel and decode unintended signals. Outage probability and ergodic rate simulations show the effectiveness of the power allocation scheme, where user fairness is also considered. Energy harvesting relays are a step closer to greener communications, where the relays harvest energy from the received signal and utilises the harvested energy to forward the signals to the connected users. Simulation results show improvements in the outage probability of the users.