Session: 04-06-02 Underwater Vehicles and Subsea Communications II

Submission Number: 181615

Development of High-Rate Underwater Acoustic Communication System for Ultra-Deep-Sea Submersible 

To monitor deep-sea exploration instruments from the sea surface and understand their operational status, wireless communication via underwater acoustics is indispensable. Human Occupied Vehicles (HOVs) used in scientific research, such as Shinkai 6500, carry only a few crew members despite having pilots on board. Consequently, most operators and researchers cannot directly observe the underwater environment. Therefore, for efficient mission planning and execution, it is desirable to transmit video and sensor data from the underwater vehicle to the surface vessel.
In this study, time-domain communication signal processing techniques using single carrier modulation signaling with adaptive equalization techniques were applied to experimental data obtained in real ocean environments to evaluate the impact of time-varying channels caused by surface waves on communication performance. In the experiment, the acoustic communication signals of multilevel modulation signals including 64 to 256 quadrature amplitude modulation were transmitted from deep sea to mother ship. The acoustic signals were recorded at the hull-mount hydrophone array. The recorded signals are equalized by a direct adaptive decision feedback equalizer, and the communication performance was mainly investigated in terms of bit-error rate.

Furthermore, to enhance the survey efficiency of HOV operations, a dedicated underwater acoustic communication system was developed. The device was installed on HOV Shinkai6500, and demonstration experiment was performed. Finally, a case study is presented in which the system successfully transmitted real-time underwater camera images and sensor data to the surface support vessel.

 

Presenting Author: Yukihiro Kida JAMSTEC

Presenting Author Biography: Dr. Yukihiro Kida is an Engineer at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), where he has been engaged in the development of advanced underwater acoustic communication systems since 2013. His research interests include sparse adaptive equalization, adaptive and passive time-reversal processing, and multiple-input multiple-output (MIMO) communication techniques for both stationary and mobile platforms such as autonomous underwater vehicles (AUVs), autonomous surface vehicles (ASVs), and human-occupied vehicles (HOVs).
He has led numerous full-scale sea trials, achieving high-speed and long-range data transmission exceeding several tens of kilobits per second over distances of more than 10 km, and has contributed to the development of integrated acoustic communication and positioning systems. His work bridges theoretical signal processing and practical system implementation, contributing to the advancement of deep-sea and mobile-to-mobile acoustic networking.
Dr. Kida received his Doctor of Engineering degree from the Tokyo Institute of Technology, and his Master and Bachelor of Engineering degrees from Kyoto University. Since 2023, he has also served as a Visiting Professor at Ritsumeikan University, where he collaborates with graduate students on mobile underwater communication research.
He is an active member of the Marine Acoustical Society of Japan, contributing to its editorial and technical committees. In 2025, he was appointed as an External Expert Committee Member at the University of Tsukuba for the development of an ultrasonic positioning system for shallow-water robot operations.
Dr. Kida’s achievements have been widely recognized in domestic level. He received the Paper Award from the Acoustical Society of Japan in 2025, the JAMSTEC Nakanishi Award in 2018 and 2019, the Young Researcher Award at the Symposium on Ultrasonic Electronics in 2018, and the Research and Development Achievement Award(internal) in 2021.

Authors:

Yukihiro Kida JAMSTEC
Mitsuyasu Deguchi JAMSTEC
Yoshitaka Watanabe JAMSTEC
Takuya Shimura JAMSTEC