On the use of Doppler-shift estimation for simultaneous underwater acoustic localization and communication

Abstract

Due to the relative low propagation speed of acoustic waves in underwater medium, Underwater Acoustic (UWA) communication is severely impacted by Doppler shift effect especially as the transmission link is related to a system in motion like an Autonomous Underwater Vehicle (AUV). Usually, motion-induced Doppler-shift needs to be estimated and compensated at the UWA receiver side in order to retrieve data. This estimation also provides an information on transmitter/receiver relative speed that is valuable for an underwater mobile like an AUV to perform underwater localization and navigation. In this paper, we consider a reference anchor transmitting UWA data to an AUV in operation. The latter uses UWA communication decoding process to estimate both range and relative speed with respect to the reference point in order to improve its navigation via a conventional Kalman filtering. Simulation results on a shallow water channel demonstrate the Doppler shift estimation to provide substantial enhancement of the underwater localization with respect to a range-only approach.