Fluid Antenna-Assisted ISAC Systems

This letter proposes a fluid antenna-assisted integrated sensing and communication (ISAC) system, where a base station (BS) transmits signals to a communication user (CU) while sensing a target. Unlike traditional ISAC systems with fixed-position antennas (FPAs), fluid antennas are equipped at the BS and CU, and can be dynamically adjusted within a given area. Our objective is to jointly optimize the transmit beamforming and the locations of fluid antennas at the BS and CU to maximize the downlink communication rate while ensuring the requirements of the sensing beampattern gain and transmit power of the BS. Due to the non-convex nature of the original problem and the high coupling between variables, we employ an alternating optimization (AO) algorithm, dividing it into three subproblems and transforming them into convex ones for solution. Simulation results confirm that our proposed system significantly improves the performance of ISAC systems compared to benchmarks.