학술논문
Reconfigurable Intelligent Surface Phase Hopping for Ultra-Reliable Communications
Document Type
Periodical
Author
Source
IEEE Transactions on Wireless Communications IEEE Trans. Wireless Commun. Wireless Communications, IEEE Transactions on. 21(11):9082-9095 Nov, 2022
Subject
Language
ISSN
1536-1276
1558-2248
1558-2248
Abstract
We introduce a phase hopping scheme for reconfigurable intelligent surfaces (RISs) in which the phases of the individual RIS elements are randomly varied with each transmitted symbol. This effectively converts slow fading into fast fading. We show how this can be leveraged to significantly improve the outage performance especially for small outage probabilities without channel state information (CSI) at the transmitter and RIS. Furthermore, the same result can be accomplished even if only two possible phase values are available. Since we do not require perfect CSI at the transmitter or RIS, the proposed scheme has no additional communication overhead for adjusting the phases. This enables robust ultra-reliable communications with a reduced effort for channel estimation.