CSI acquisition in RIS-assisted mobile communication systems

ABSTRACT Reconfigurable intelligent surface- (RIS) assisted mobile communication is a promising technological paradigm thanks to the attractive advantages of low cost and flexible control electromagnetic waves. However, low-cost features RISs entail some fundamental challenges acquisition channel state information (CSI), which essential for optimal RIS design. To tackle this problem, there have been extensive studies on CSI in RIS-assisted systems, from perspective architectural improvement as well specific mathematical solutions. This article aims overview existing works systems.