Joint Optimization of Power Allocation and Reflection Coefficients for RIS-Assisted Offshore Communication Systems

In this paper, we consider a reconfigurable intelligent surface (RIS)-assisted three-dimensional (3D) offshore communication system. To characterize the offshore communication environment, we propose a 3D geometry-based stochastic channel model. Unlike existing studies that primarily focus on throughput, we adopt the mean opinion score (MOS) as a quality of experience (QoE) metric to evaluate user satisfaction. Our objective is to maximize the sum MOS of ship users by jointly optimizing power allocation and RIS reflection coefficients, while satisfying the maximum MOS constraints for ship users. To tackle this challenging problem, we propose a QoE-based optimization algorithm by alternately optimizing power allocation and RIS reflection coefficients. Simulation results demonstrate that the proposed scheme significantly improves the sum MOS.