Cylindrical STAR-RIS Assisted Hybrid Near/Far-Field Integrated Sensing and Communications: Modeling and Sum-Rate Analysis

This paper proposes a cylindrical simultaneously transmitting and reflecting reconfigurable intelligent surface (cSTAR-RIS) configuration. In this configuration, sensing and communication are separately completed by near and far field for the integrated sensing and communication (ISAC) systems. To maximize the system sum rate, while ensuring sufficient uniformity of radio wave coverage, an alternating optimization approach is introduced, along with the element coefficients of cSTAR-RIS and the beamforming parameters of the base station (BS). The computational simulations confirm that the proposed system achieves a measurable improvement in sum rate over the popular STAR-RIS benchmark.