Abstract
Integrated communications and sensing (ICS) systems systems hold significant promise for future 6G networks, where robust anti-jamming capabilities are critically demanded. This paper investigates an anti-jamming framework leveraging reconfigurable intelligent surfaces (RIS) for ICS systems operating in environments with imperfect channel state information. We propose a joint optimization framework that designs transmit beamforming, receive filters, and RIS phase shifts to simultaneously enhance communication rates and radar signal to interference plus noise ratio (SINR). The formulated problem is non-convex due to coupled variables, and thus we develop an iterative algorithm combining majorization-minimization (MM) and successive convex approximation (SCA) techniques. The receive filter is optimized using a closed-form minimum variance distortionless response solution, while the transmit beamforming is addressed through semidefinite programming relaxation. For RIS phase shift optimization, we utilize MM and SCA to decompose the problem into manageable convex subproblems. The simulations show that our proposed scheme achieves notable improvements in both the communication rate and radar SINR.