In this paper, we investigate a reconfigurable intelligent surface (RIS)-aided multiple-input single-output (MISO) system in the presence of electromagnetic interference (EMI) and channel aging with a Rician fading channel model between the base station (BS) and user equipment (UE). Specifically, we derive the closed-form expression for downlink spectral efficiency (SE) with maximum ratio transmission (MRT) precoding. The Monte-Carlo simulation supports the theoretical results, demonstrating that amplifying the weight of the line-of-sight (LoS) component in Rician fading channels can boost SE, while EMI has a detrimental impact. Furthermore, continuously increasing the number of RIS elements is not an optimal choice when EMI exists. Nonetheless, RIS can be deployed to compensate for SE degradation caused by channel aging effects. Finally, enlarging the RIS elements size can significantly improve system performance.

翻译：本文研究了在存在电磁干扰（EMI）和信道老化的环境下，采用莱斯衰落信道模型时，可重构智能表面（RIS）辅助的多输入单输出（MISO）系统性能。具体而言，我们推导了采用最大比传输（MRT）预编码时下行链路频谱效率（SE）的闭合表达式。蒙特卡洛仿真验证了理论结果，表明增强莱斯衰落信道中视距（LoS）分量的权重可提升频谱效率，而电磁干扰则产生不利影响。此外，当存在电磁干扰时，持续增加RIS单元数量并非最优选择。然而，RIS可用于补偿由信道老化效应导致的频谱效率退化。最后，增大RIS单元规模可显著提升系统性能。