Chaotic Noncoherent SWIPT in Multi-Functional RIS-Aided Systems

TL;DR

This paper explores the use of chaotic waveforms in a multi-functional RIS system for simultaneous wireless information and power transfer, analyzing energy harvesting and error rate trade-offs.

Contribution

It introduces a differential chaos shift keying scheme for MF-RIS, modeling energy harvesting and transmission, and proposes waveform designs for system self-sustainability.

Findings

Characterized energy harvesting and bit error rate performance.

Derived a lower bound on the number of elements for EH operation.

Proposed waveform designs to optimize system parameters.

Abstract

In this letter, we investigate the design of chaotic signal-based transmit waveforms in a multi-functional reconfigurable intelligent surface (MF-RIS)-aided set-up for simultaneous wireless information and power transfer. We propose a differential chaos shift keying-based MF-RIS-aided set-up, where the MF-RIS is partitioned into three non-overlapping surfaces. The elements of the first sub-surface perform energy harvesting (EH), which in turn, provide the required power to the other two sub-surfaces responsible for transmission and reflection of the incident signal. By considering a frequency selective scenario and a realistic EH model, we characterize the chaotic MF-RIS-aided system in terms of its EH performance and the associated bit error rate. Thereafter, we characterize the harvested energy-bit error rate trade-off and derive a lower bound on the number of elements required to operate in the EH mode. Accordingly, we propose novel transmit waveform designs to demonstrate the importance of the choice of appropriate system parameters in the context of achieving self-sustainability.