SPS ASI Webinar: Underwater Acoustic Communication and Positioning in Shallow Waters
Date: 10 March 2025
Time: 9:30 AM ET (New York time)/15:30 (CEST)
Presenter(s): Tadashi Ebihara
The ASI Webinar Series is an event initiated by the Autonomous System Initiative (ASI) of the IEEE Signal Processing (SP) Society. The goal is to offer the SP community with free webinars looking into the future of autonomous systems. These monthly webinars are hosted on Zoom platform.
Abstract
This study addresses the challenges of underwater acoustic (UWA) communication and positioning in shallow waters, which are characterized by significant delay and Doppler spreads. To provide a highly reliable communication, we propose Doppler-resilient orthogonal signal-division multiplexing (D-OSDM), which preserves orthogonality among data vectors even in doubly spread channels. Field tests, including MIMO configurations, demonstrate that D-OSDM enables reliable data transfer in mobile UWA environments with delay and Doppler spreads. Additionally, a new underwater positioning method is proposed for shallow waters, using direct wave arrival time groups and database matching. This method accurately measures baseline length from the impulse response of the UWA channel. Experimental trials in a harbor area showed positioning errors of about 0.2 meters and a near 0% missing rate, indicating the potential of this system for unmanned and remote underwater construction.
Biography
Dr. Tadashi Ebihara is an Associate Professor at the Faculty of Engineering, Information and Systems, University of Tsukuba, Japan. He received the B. Eng., M. Eng. and Ph.D.(in Eng.) degrees from University of Tsukuba, Tsukuba, Japan. His doctoral degree thesis was about a design of acoustic communication system. He conducts research mainly in digital communications and signal processing. He is interested in design of communication system and performance analysis, especially underwater acoustic communication. Shallow water acoustic channel is interesting because the effects of inter-symbol interference and Doppler spread can become several orders of magnitude greater than those observed in a communication system using radio. He is also interested to communication system for consumer electronics.
He is an active member of the IEEE, the Acoustical Society of America, the Marine Acoustical Society of Japan, the Acoustical Society of Japan,the Institute of Electronics, Information and Communication Engineers, and the Societies of Agricultural Structures, Japan.
