A 32 kHz Bandwidth, Robust TDD Synchronization, Underwater Small Area Acoustic Network (USAAN) System

Underwater acoustic wireless communication is one of the important foundation key technology to develop the ocean with using equipment such as AUV (Autonomous Underwater Vehicle), ROV (Remotely Operated Vehicle). This paper proposes Underwater Small Area Acoustic Network (USAAN) System with a 32 kHz bandwidth OFDM signals and robust TDD synchronization. We have developed the small hardware system, and ocean experiment has been performed at the barge in Uchiura bay, Shizuoka prefecture Japan. The base station (BS) side transducers are moved vertically with a motor drive for maximum 1.1 m/sec speed. Although the BS-TX is moving, stable DL to UL signal delay time is measured and fine synchronization performance is confirmed, and the demodulated 16QAM constellation is successfully confirmed at the user equipment (UE) side.