Cooperative Beamforming Design for Multi‐BS Integrated Sensing and Communication Systems

ABSTRACT Integrated sensing and communication (ISAC) is regarded as a promising paradigm for future sixth‐generation (6G) networks, which effectively improves spectral efficiency and reduces hardware costs by simultaneously performing communication and sensing. Due to the limited coverage of a single base station (BS), the single‐BS ISAC system struggles to meet the demands of various emerging intelligent applications for high‐quality communication and high‐precision sensing. In this paper, we investigate a cooperative multi‐BS ISAC system with multi‐target and multi‐user. In particular, communication and sensing are performed by multiple BSs with a cooperative manner. We formulate a problem for the purpose of maximizing the sensing mutual information (MI) via jointly designing the transmit beamforming of multiple BSs for communication and sensing, while guaranteeing the achievable communication rate requirements. To address this non‐convex problem, an iterative optimization algorithm is developed based on the Lagrangian transform and the quadratic fractional transform. Simulation results validate the advancement of the proposed cooperative beamforming scheme in enhancing the sensing performance of multi‐BS ISAC system.