Abstract
This paper investigates a pinching-antenna (PA)based integrated sensing and communication (ISAC) system, where the base station (BS) employs a multi-waveguide PA architecture to serve multiple communication users while detecting multiple sensing targets. Based on this, a joint pinching and baseband beamforming optimization problem is formulated to minimize the angle-estimation Cramér-Rao Bound (CRB), subject to a minimum communication rate constraint and PA deployment constraint. To address the resultant highly-coupled and non-convex problem, a Riemannian optimization-based method is developed. In particular, the original constrained problem is first reformulated into an unconstrained one on the Riemannian product manifold by invoking the lift technique and exact penalty function. A conjugate gradient method is then employed to explore the manifold space for obtaining high-quality solutions. Simulation results demonstrate that the proposed PA-based ISAC significantly outperforms the conventional multiple-antenna-array-based ISAC.