Channel estimation for XL-RIS-aided Terahertz systems with dual-scale super-resolution network
摘要
Terahertz waves and extremely large antenna arrays enable future 6G wireless communications in the near-field field. In the context of the extremely large-scale reconfigurable intelligent surface (XL-RIS) assisted wireless communication system, the pilot overhead for channel estimation becomes very large and channel modeling becomes significantly more complex. In this paper, we consider modeling the cascaded channel as a combination of hybrid-field and far-field channels. To decrease pilot overhead, we design a novel channel grouping estimation method and propose a super-resolution channel reconstruction strategy. To effectively recover the channel, we construct a dual-scale super-resolution network (DSRN), which can reconstruct the channel using channel features of different scales. Moreover, the DSRN can denoise in small-scale features, learn the sparse characteristics of the channel in large-scale features, and reverse the channel grouping process to convert small-scale features into large-scale features. The simulation results reveal that the suggested channel estimation scheme outperformed existing schemes.