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arXiv · 2510.01411

Delay-Augmented Stacked Intelligent Surfaces: Potential, Challenges, and Opportunities

Hibatallah Alwazani·Omran Abbas·Loic Markley·Anas Chaaban
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Abstract

Stacked intelligent surfaces (SIS)s have been proposed recently as an enabling technology for Holographic Multiple Input Multiple Output (HMIMO) and Ultra-massive MIMO (umMIMO) technologies. Their utility can extend beyond spatial wave-domain processing of signals if they are enhanced with strategically-tuned symbol-duration level delays to enable temporal processing as well. In this work, we introduce the idea of a delay-augmented SIS (DA-SIS). We shed light on the feasibility of realizing delay units in an SIS. Then, we discuss the relevance of the proposed DA-SIS and present a use case that illustrates its potential, wherein the DA-SIS serves as an analog equalizer that aids in eliminating multi-path-induced inter-symbol-interference (ISI). We show how the number of elements affect the equalization process using the bit error rate (BER) as a metric, and demonstrate the potential of the DA-SIS in equalization via comparing with digital equalizers as a benchmark. Finally, we present opportunities and future research directions that can be undertaken to bring this idea to fruition.

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Hibatallah Alwazani, Omran Abbas, Loic Markley, Anas Chaaban. 2025-10-01. Delay-Augmented Stacked Intelligent Surfaces: Potential, Challenges, and Opportunities. https://arxiv.org/abs/2510.01411

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