Ieee Access Special Section Editorial: Reconfigurable Intelligent Surface Aided Communications for 6G and Beyond

Reconfigurable intelligent surface (RIS)-aided wireless communications is a hot research topic in academic and industry communities since it can enhance both the spectrum and energy efficiency of wireless systems by artificially reconfiguring the wireless propagation environment. An RIS can configure tiny antenna elements or scatterers, which can be judiciously tuned to enhance the signal power for desired users, such as primary users in cognitive radio networks, or suppress the signal power for undesired users, such as eavesdroppers for physical layer security. RISs also find promising applications in dense urban areas or indoor scenarios, where the electromagnetic waves are prone to be blocked by obstacles such as buildings and walls. There are numerous advantages associated with RISs. For instance, since an RIS needs no analog-to-digital converters or radiofrequency chains, it reduces the power consumption, hence improving sustainability and reducing cost. RISs can be fabricated at a limited complexity and cost, and they can be easily deployed on buildings facades, walls, ceilings, and streetlamps. Furthermore, RISs can be readily integrated into current wireless networks (both cellular networks and WiFi). Due to these appealing advantages, RIS is envisioned to be one of the key technologies for the sixth-generation (6G) wireless networks.