Comments: (no paper yet)
Ref.: Int. Conf. on Acoustics (ICA), Gyeongju (South Korea), October 2022
Abstract:
Research on low SNR communications has been encouraged for autonomous underwater vehicles (AUV)
covert communications while contributing to reducing the environmental noise level. In shallow water,
most communication systems rely on spatial diversity, requiring arrays of pressure sensors to deal
with multipath and to increase the SNR through multichannel combining. However, these multiple
sensors arrangements are not suitable for AUVs. Compact in size, acoustic vector sensors (VS)
measure both acoustic pressure and particle velocities, also providing diversity gain. But
literature about VS for communications is still limited. Thus, this paper presents a study on
the VS multichannel combining for low SNR communications in shallow water. As part of the
multidisciplinary EMSO-PT project, an experiment took place off the coast of Algarve (Portugal)
on Nov 24th,2021. A single 2-D vector sensor mounted on a tripod was posed on the bottom. An
omnidirectional source suspended from a vessel transmitted broadband signals from several positions,
varying both the source-receiver range and the bathymetry profile. Recorded impulsive noise was
added to the signals to reduce SNR. Coherent communication performance was evaluated for two distinct
time-varying channel geometries. Preliminary results show that vector sensor multichannel combining
may provide an average MSE gain of up to 3.8 dB compared to the pressure channel.