Acoustic Sensing and Communication Using Metasurface

Acoustic sensing is increasingly popular owing to widely available devices that support them. Yet the sensing resolution and range are still limited due to limited bandwidth and sharp decay in the signal at inaudible frequencies. Inspired by recent development in acoustic metasurfaces, in this paper, we first perform an in-depth study of acoustic metasurface (AMS) and compare it with the phased array speaker. Our results show that AMS is attractive as it achieves a significant SNR increase while maintaining a compact size. A major limitation of existing AMS is its static configuration. Since our target may be at any possible location, it is important to support scanning in different directions. We develop a novel acoustic system that leverages a metasurface and a small number of speakers. We jointly optimize the configuration of metasurface and transmission signals from the speakers to achieve low-cost dynamic steering. Using a prototype implementation and extensive evaluation, we demonstrate its effectiveness in improving SNR, acoustic sensing accuracy, and acoustic communication reliability over a wide range of scenarios.