This letter considers an active reconfigurable intelligent surface (RIS)-aided multi-user uplink massive multipleinput multiple-output (MIMO) system with low-resolution analog-to-digital converters (ADCs). The letter derives the closedform approximate expression for the sum achievable rate (AR), where the maximum ratio combination (MRC) processing and low-resolution ADCs are applied at the base station. The system performance is analyzed, and a genetic algorithm (GA)-based method is proposed to optimize the RIS's phase shifts for enhancing the system performance. Numerical results verify the accuracy of the derivations, and demonstrate that the active RIS has an evident performance gain over the passive RIS.

翻译：本文考虑了一种采用低分辨率模数转换器（ADC）的主动式可重构智能表面（RIS）辅助多用户上行大规模多输入多输出（MIMO）系统。文中推导了系统总可达速率（AR）的闭式近似表达式，其中基站采用最大比合并（MRC）处理与低分辨率ADC。在分析系统性能的基础上，提出了一种基于遗传算法（GA）的优化方法，通过调整RIS的相位偏移来提升系统性能。数值结果验证了理论推导的准确性，并表明主动RIS相比被动RIS具有显著的性能增益。