Metasurfaces-Integrated Doubly-Dispersive MIMO: Channel Modeling and Optimization

TL;DR

This paper introduces a novel metasurfaces-parametrized doubly-dispersive channel model for MIMO systems with RISs and SIM, enabling optimized waveform design and improved performance in high-mobility wireless scenarios.

Contribution

It presents the first integrated DD channel model incorporating multiple RISs and SIM, and explores its application to waveform optimization in advanced wireless systems.

Findings

Developed a metasurfaces-parametrized DD channel model for MIMO systems with RIS and SIM.

Applied the model to optimize OFDM, OTFS, and AFDM waveforms in high-mobility environments.

Demonstrated the model's programmability and potential for enhancing wireless communication performance.

Abstract

The doubly-dispersive (DD) channel structure has played a pivotal role in wireless communications, particularly in high-mobility scenarios and integrated sensing and communications (ISAC), due to its ability to capture the key fading effects experienced by a transmitted signal as it propagates through a dynamic medium. However, extending the DD framework to multiple-input multiple-output (MIMO) systems, especially in environments artificially enhanced by reconfigurable intelligent surfaces (RISs) and stacked intelligent metasurfaces (SIM), remains a challenging open problem. In this chapter, a novel metasurfaces-parametrized DD (MPDD) channel model that integrates an arbitrary number of RISs, while also incorporating SIM at both the transmitter and receiver is introduced. Next, the application of this model to some key waveforms optimized for DD environments -- namely orthogonal frequency division multiplexing (OFDM), orthogonal time frequency space (OTFS), and affine frequency division multiplexing (AFDM) -- is discussed. Finally, the programmability of the proposed model is highlighted through an illustrative application, demonstrating its potential for enhancing waveform performance in SIM-assisted wireless systems.