Performance Analysis of Near-Field ISAC Based on an Accurate Channel Model

In this paper, a near-field ISAC framework is proposed with an accurate channel model, in which the loss caused by effective aperture and polarization mismatch are considered. Based on the proposed model, sensing and communication (S&C) performance are analyzed in terms of three different designs: the communications-centric design, the sensing-centric design, and the Pareto optimal design. Within each design, sensing rates (SRs) and communication rates (CRs) are derived. Moreover, the attainable SR-CR regions of the near-field ISAC are characterized. Numerical results reveal that 1) the adopted channel model is more accurate than the conventional models within near field; 2) ISAC achieves a more extensive rate region than the conventional frequency-division S&C.