Semantic communication, which focuses on conveying the meaning of information rather than exact bit reconstruction, has gained considerable attention in recent years. Meanwhile, reconfigurable intelligent surface (RIS) is a promising technology that can achieve high spectral and energy efficiency by dynamically reflecting incident signals through programmable passive components. In this paper, we put forth a semantic communication scheme aided by RIS. Using text transmission as an example, experimental results demonstrate that the RIS-assisted semantic communication system outperforms the point-to-point semantic communication system in terms of BLEU scores in Rayleigh fading channels, especially at low signal-to-noise ratio (SNR) regimes. In addition, the RIS-assisted semantic communication system exhibits superior robustness against channel estimation errors compared to its point-to-point counterpart. RIS can improve performance as it provides extra line-of-sight (LoS) paths and enhances signal propagation conditions compared to point-to-point systems.

翻译：语义通信专注于传递信息的意义而非精确比特重建，近年来受到广泛关注。同时，可重构智能表面（RIS）作为一种有前途的技术，能够通过可编程无源组件动态反射入射信号，实现高频谱效率和能量效率。本文提出了一种基于RIS辅助的语义通信方案。以文本传输为例，实验结果表明，在瑞利衰落信道中，RIS辅助语义通信系统在BLEU评分上优于点对点语义通信系统，尤其在低信噪比（SNR）条件下。此外，与点对点系统相比，RIS辅助语义通信系统对信道估计误差表现出更强的鲁棒性。RIS能够提升性能，因为它提供了额外的视距（LoS）路径，并相比点对点系统改善了信号传播条件。