QoS-Driven Spectrum Sharing for Reconfigurable Intelligent Surfaces (RISs) Aided Vehicular Networks

Reconfigurable intelligent surfaces (RISs) have the capability of reconfiguring wireless environment in a favorable way to improve quality-of-service (QoS) communications. This makes RISs promising candidate enhance vehicle-to-everything (V2X) applications. paper investigates spectrum sharing problem RIS-aided vehicular networks, which multiple vehicle-to-vehicle (V2V) links reuse already occupied by vehicle-to-infrastructure (V2I) links. To overcome difficulty acquiring instantaneous channel state information (CSI) due fast varying nature some V2X channels, we rely upon large-scale (slowly varying) CSI order fulfill QoS requirements V2I and V2V Particularly, aim maximize sum capacity that are used for high-rate content delivery guarantee reliability exchange safety information. The transmit power vehicles, multi-user detection (MUD) matrix, links, RIS reflection coefficients jointly optimized, results mixed-integer non-convex optimization problem. tackle this problem, outage probability each link is first approximated introducing an analytical expression simplify formulated By leveraging block coordinate descent (BCD) method, considered decomposed into three sub-problems, whose optimal solutions provided independently updated alternately obtain near-optimal solution. Simulation verify theoretical analysis effectiveness proposed algorithm, as well unveil benefits enhancing performance