I. Introduction
RECENTLY, Intelligent Reflective Surface (IRS) (also called Large Intelligent Surface or Software-Defined Surface) [1] - [2] has been considered as a possible future for Beyond 5G and 6G mobile communication with substantial benefits like low power consumption, easy deployment, low cost and low latency. IRS is a 2-D electromagnetic artificial surface comprised of a sizable number of inexpensive passive reflective components. Since each component can function independently and be controlled by means of external signals, we can easily manage the phase and magnitude of the incident signal in real time. By controlling the propagation environment, IRS is able to increase the effectiveness of the spectrum and the efficiency of energy.