Target State Tracking in Semi-Passive RIS-Aided ISAC Wireless Communication Systems

This paper proposes a target state tracking algorithm for semi-passive reconfigurable intelligent surface (RIS) aided Integrated Sensing and Communication (ISAC) systems. It enables simultaneous data transmission and location sensing using shared resources. Specifically, echo signals can be received by deploying low-cost RF chains on certain RIS elements, and measurement information about the state of the target can be obtained at the RIS side by analyzing the echo signals. Moreover, considering the nonlinearity of the equations of measurement information and vehicle motion, the extended Kalman filter (EKF) and a novel RIS phase-shift design scheme are proposed for tracking the target state with guaranteed accuracy and reduced computational complexity. Numerical simulations validate the efficacy of the proposed design and prediction scheme.