Differential Reflecting Modulation for Reconfigurable Intelligent Surface Based Communications

TL;DR

This paper introduces a differential reflecting modulation scheme for RIS-based communications that eliminates the need for channel state information, simplifying the transmission process while maintaining acceptable performance.

Contribution

It proposes a novel DRM scheme that encodes information through reflecting pattern permutations and phases, removing the requirement for channel estimation in RIS systems.

Findings

DRM achieves comparable SNR performance to coherent schemes

DRM eliminates the need for channel state information

Simulation confirms DRM's effectiveness in RIS communications

Abstract

Reconfigurable intelligent surface (RIS) based communications have emerged as a new paradigm. This letter proposes a differential reflecting modulation (DRM) scheme for RIS based communication systems. In DRM, information bits are jointly carried by the activation permutations of the reflecting patterns and the phases of the transmitted signals, leading to that DRM can work without any channel state information (CSI) at the transmitter, RIS or receiver. In other words, DRM can release the intricate and resource-consuming channel estimation in the transmission process. Simulation results show that the proposed DRM pays an acceptable SNR penalty compared to non-differential modulation with coherent detection.