Reconfigurable Intelligent Surface-Aided Near-Field Communications for 6G: Opportunities and Challenges

Reconfigurable intelligent surface (RIS)-aided near-field communications are investigated. First, the necessity of investigating RIS-aided near-field communications and the advantages brought about by the unique spherical wave-based near-field propagation are discussed. Then, the family of patch array-based RISs and metasurface-based RISs is introduced along with respective near-field channel models. A pair of fundamental performance limits of RIS-aided near-field communications, namely, their power scaling law and effective degrees of freedom (EDOF), are analyzed for both patch array-based and metasurface-based RISs, which reveals the potential performance gains that can be achieved. Furthermore, associated…

• EA
  Engineering and Physical Sciences Research Council

  Awards: EP/X04047X/1, EP/W016605/1, EP/P003990/1, EP/N004558/1, EP/D056691/1, EP/W035588/1, EP/X01228X/1
• C
  CHIST-ERA

  Award: SUNRISE CHIST-ERA-20-SICT-005