Enhancing polarization diversity in RIS-aided Integrated Communication and Sensing Networks

Reconfigurable Intelligent Surfaces (RIS) and Integrated Sensing and Communication (ISAC) enhance network performance by optimizing both sensing and communication. This paper investigates a polarization-modulating RIS to improve sensing diversity and target classification in a distributed Multiple Input Multiple Output (MIMO) ISAC system. The RIS acts as a virtual transmitter, converting a 1×2 distributed Single Input Multiple Output (SIMO) system into a 2×2 distributed MIMO ISAC system, enhancing spatial diversity, detection probability, Doppler robustness, and resolution while reducing noise. Additionally, polarization diversity enables full polarimetric processing, improving target classification. Simulations show that the RIS-aided system improves radar resolution by 40%, reduces noise by 88.6%, and increases detection probability. These findings highlight the potential of polarization-diverse RIS for ISAC applications in vehicular networks and autonomous driving.