High-Speed Hidden Aerial Acoustic Communication Exploiting the Whole Available Bandwidth

Aerial Acoustic Communication (AAC) has attracted much attention recently due to its ubiquitous device support. However, the transmission rate has largely throttled the boom of AAC-enabled applications. In this paper, we propose a high-speed AAC system that modulates messages over the entire bandwidth but is unobtrusive to end users. We achieve high bandwidth efficiency through a dynamic modulation mechanism. Specifically, we propose a high-order phase-based modulation mechanism on existing audio channels. Additionally, we leverage the auditory masking effect to embed data streams over the unused frequency band. Through a sophisticated power analysis and frequency allocation scheme, the changes made by these two modulation techniques on existing audio can be imperceptible to human ears. Furthermore, we utilize the loose orthogonal modulation on the inaudible channel to further boost the transmission rate. Our system prototype reveals that we can achieve up to 2 kbps link rate.