Resource Allocation for WSR Maximization in Multi-Active RISs Assisted Cell-Free Systems with ISAC

This paper investigates the resource allocation in a cell-free (CF) system assisted by multiple active reconfigurable intelligent surfaces (RISs), which can support integrated sensing and communication (ISAC). An optimization problem is formulated to maximize the weighted sum-rate while satisfying the sensing requirements. This is achieved through the joint optimization of the RIS reflection coefficients, user equipment (UE) association, UE transmit power allocation, and receive beamforming. An alternating optimization framework is developed to address this challenging issue, wherein subproblems are alternatively resolved through successive convex approximation and multidimensional complex quadratic transformation. Accordingly, the resource allocation scheme based on joint optimization is proposed. Simulation results demonstrate the effectiveness of the proposed scheme which provides a substantial improvement in performance compared to the benchmark methods.