Metastructure-Enabled Underwater Acoustic Integrated Sensing and Communication

In this letter, a metastructure (MS)-enabled underwater acoustic (UWA) integrated sensing and communication (ISAC) approach is investigated. Firstly, a hemisphere metastructure with multiple series-connection pore-cavity structures is designed to construct direction-dependent regulation patterns, which is equivalent to assigning different spatial-spectral regulation responses along different directions of the MS. Then, received UWA signal entering the MS from different directions is spatially regulated by different MS-driven regulation patterns, thus enabling sensing of direction of arrival (DOA) via detection among candidate regulation patterns. Upon the obtaining of DOA, a multiple metastructure-driven pattern shift keying (MMPSK) modulation and demodulation scheme are designed to regulate the signal with regulation patterns selected according to the information bits from the pattern set that obtained in direction-wise anechoic tank test in advance, and then recover the information bits by detecting the regulation patterns at receiver. Meanwhile, to overcome the impact of random UWA channel, peak characteristic of autocorrelation function of transmitted ISAC signals and multipath characteristic of UWA channel are simultaneously designed for DOA sensing and communication. Lake experiments confirm the effectiveness of the proposed system.