One technology that has the potential to improve wireless communications in years to come is integrated sensing and communication (ISAC). In this study, we take advantage of reconfigurable intelligent surface's (RIS) potential advantages to achieve ISAC while using the same frequency and resources. Specifically, by using the reflecting elements, the RIS dynamically modifies the radio waves' strength or phase in order to change the environment for radio transmission and increase the ISAC systems' transmission rate. We investigate a single cell downlink communication situation with RIS assistance. Combining the ISAC base station's (BS) beamforming with RIS's discrete phase shift optimization, while guaranteeing the sensing signal, The aim of optimizing the sum rate is specified. We take advantage of alternating maximization to find practical solutions with dividing the challenge into two minor issues. The first power allocation subproblem is non-convex that CVX solves by converting it to convex. A local search strategy is used to solve the second subproblem of phase shift optimization. According to the results of the simulation, using RIS with adjusted phase shifts can significantly enhance the ISAC system's performance.

翻译：具有无线通信提升潜力的技术之一是集成感知与通信（ISAC）。本研究利用可重构智能表面（RIS）的潜在优势，在相同频率和资源条件下实现ISAC。具体而言，通过反射元件，RIS动态调整无线电波的强度或相位，以改变无线电传输环境并提升ISAC系统的传输速率。我们研究了一个RIS辅助的单小区下行链路通信场景。在保证感知信号的前提下，联合优化ISAC基站（BS）的波束赋形与RIS的离散相位偏移，以最大化总速率为优化目标。采用交替最大化方法将问题分解为两个子问题以寻求实用解：第一个功率分配子问题为非凸问题，通过转化为凸问题后利用CVX求解；第二个相位偏移优化子问题则采用局部搜索策略解决。仿真结果表明，使用调整相位偏移的RIS可显著提升ISAC系统的性能。