Joint Transmit Beamforming and Receive Filter Design for Cooperative Multi-Static ISAC Networks

Integrated sensing and communication (ISAC) is a promising solution for future wireless networks that can greatly enhance spectral and hardware efficiency. In order to break the sensing performance limitation of mono/bi-static systems, exploring multi-static ISAC networks is crucial. This paper investigates a multi-static ISAC network based on the cloud-radio-access network (C-RAN) architecture where multiple transmit remote radio units (RRUs) and a receive RRU cooperatively detect a single point-link target and serve multiple communication users. The radar signal-to-interference-plus-noise ratio (SINR) maximization problem under communication SINR constraints and transmit power budget is investigated by jointly designing the transmit beamformers and receive filter. An iterative algorithm based on fractional programming (FP) and convex-concave procedure (CCP) is developed to efficiently solve this intractable problem. Simulation results illustrate the advancement of the C-RAN based ISAC network while demonstrating the effectiveness of the FP-CCP based joint design algorithm.