可重构智能表面辅助无线网络的信道互易性研究
信息论
2022-05-05 v2 math.IT
摘要
信道互易性极大地方便了时分双工（TDD）多输入多输出（MIMO）通信中的下行预编码，而无需信道状态信息（CSI）反馈。近来，可重构智能表面（RISs）作为增强未来无线网络性能的一项有前景技术而出现。然而，由于 RISs 的人工电磁特性并不严格遵循自然常规，这带来一个问题：在 RIS 辅助的 TDD 无线网络中信道互易性是否成立？在简要回顾互易定理后，本文中我们表明，对于满足特定条件的 RIS 辅助无线网络，仍存在信道互易性。我们还利用两块 fabricated RISs 在 sub-6 GHz 与毫米波频段实验演示了该互易性。此外，我们介绍了几种实现非互易信道的 RIS 辅助方法。最后，概述了互易/非互易 RISs 带来的潜在机遇与未来研究方向。
引用
@article{arxiv.2103.03753,
title = {On Channel Reciprocity in Reconfigurable Intelligent Surface Assisted Wireless Network},
author = {Wankai Tang and Xiangyu Chen and Ming Zheng Chen and Jun Yan Dai and Yu Han and Shi Jin and Qiang Cheng and Geoffrey Ye Li and Tie Jun Cui},
journal= {arXiv preprint arXiv:2103.03753},
year = {2022}
}
备注
In general, when the control signals applied to the unit cells remain unchanged, commonly designed and fabricated RISs inherently obey the reciprocity theorem. Nevertheless, there are several RIS-assisted approaches to realizing nonreciprocal channels. Potential opportunities brought by reciprocal/nonreciprocal RISs and future research directions are outlined