Reconfigurable Intelligent Surfaces for 6G Systems: Principles, Applications, and Research Directions
arXiv:2011.04300
Abstract
Reconfigurable intelligent surfaces (RISs) or intelligent reflecting surfaces (IRSs), are regarded as one of the most promising and revolutionizing techniques for enhancing the spectrum and/or energy efficiency of wireless systems. These devices are capable of reconfiguring the wireless propagation environment by carefully tuning the phase shifts of a large number of low-cost passive reflecting elements. In this article, we aim for answering four fundmental questions: 1) Why do we need RISs? 2) What is an RIS? 3) What are RIS's applications? 4) What are the relevant challenges and future research directions? In response, eight promising research directions are pointed out.
Accepted by IEEE Communications Magazine. Keywords: Reconfigurable intelligent surface (RIS), intelligent reflecting surface (IRS). In this paper, we have answered four critical questions in RIS/IRS. More importantly, we have pointed out several promising research directions