Wireless Communications with Space-Time Modulated Metasurfaces

TL;DR

This paper introduces a mathematical model for space-time modulated metasurfaces (STMMs) that enhances wireless communication by enabling information conveyance through time-varying surface properties, offering flexible and cost-effective design options.

Contribution

It presents the first comprehensive mathematical model for STMMs, detailing their unique space-time coupling features and their application in full-duplex wireless systems.

Findings

The model accurately predicts STMM performance in simulated scenarios.

STMMs can facilitate full-duplex communication with minimal energy increase.

Numerical results validate the potential of STMMs to improve wireless systems.

Abstract

Space-time modulated metasurfaces (STMMs) are a newly investigated technology for next 6G generation wireless communication networks. An STMM augments the spatial phase function with a time-varying one across the elements, allowing for the conveyance of information that possibly modulates the impinging signal. Hence, STMM represents an evolution of reconfigurable intelligent surfaces (RIS), which only design the spatial phase pattern. STMMs convey signals without a relevant increase in the energy budget, which is convenient for applications where energy is a strong constraint. This paper proposes a mathematical model for STMM-based wireless communication, that creates the basics for two potential STMM architectures. One has excellent design flexibility, whereas the other is more cost-effective. The model describes STMM's distinguishing features, such as space-time coupling, and their impact on system performance. The proposed STMM model addresses the design criteria of a full-duplex system architecture, in which the temporal signal originating at the STMM generates a modulation overlapped with the incident one. The presented numerical results demonstrate the efficacy of the proposed model and its potential to revolutionize wireless communication.