Abstract
The connectivity of undersea sensors and airborne nodes across the water–air interface has been long sought. This study designs a free-space wireless laser communications system that yields a high net data rate of 850 Mbit/s when perfectly aligned. This system can also be used for an extended coverage of 1963 cm² at the receiver while sustaining a net data rate of 9 Mbit/s over 10 m. The utility of this system was verified for direct communications across the water–air interface in a canal of the Red Sea based on a pre-aligned link as well as a diving pool under a mobile signal-searching mode. The canal deployment measured a real-time data rate of 87 Mbit/s when pre-aligned in turbid water over 50 min, which confirms the system robustness in harsh water environments. In the pool deployment, a drone configured with a photodetector flew over the surface of the water and recorded the underwater signals without a structure-assisted alignment. Using a four-quadrature amplitude-modulated orthogonal frequency-division multiplexing (4-QAM-OFDM) modulation scheme provided a net data rate of 44 Mbit/s over a 2.3-m underwater and 3.5-m air link. The results validated the link stability and mitigated problems that arise from misalignment and mobility in harsh environments, which paves the way for future field applications.
Original language | English (US) |
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Pages (from-to) | 1-1 |
Number of pages | 1 |
Journal | IEEE Access |
DOIs | |
State | Published - 2020 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledged KAUST grant number(s): BAS/1/1614-01-01, GEN/1/6607-01-01, KCR/1/2081-01-01, KCR/1/4114-01-01, FCC/1/1973-27-01
Acknowledgements: This work was supported by the King Abdullah University of Science and Technology (KAUST), BAS/1/1614-01-01, KCR/1/2081-01-01, KCR/1/4114-01- 01, GEN/1/6607-01-01, and FCC/1/1973-27-01. The authors also thank Mr. Nabeel M. Moamenah and the team at Residential & Facilities Operations, KAUST, for providing support for the Red Sea canal deployment.