Multiple Diversity Using Acoustic Vector Receiver for Shallow-Water Acoustic Communication

Underwater acoustic wave propagates through multipath channels formed by interactions with the ocean boundaries such as the sea surface and bottom, and each element of the multipath has a different propagation angle each other. Acoustic vector sensors can receive not only acoustic pressure but also vector components (two or three components) such as acoustic acceleration or particle velocity, and each particle velocity signal has different multipath characteristics depending on directionality. In communication systems, directional diversity gain can be obtained if these particle velocity signals are used for multichannel combining. However, since the delay times of each component within the multipath of particle velocity are the same due to the point location of the single vector sensor, the gain from the directional diversity might be smaller than the gain from the spatial diversity of the hydrophone array. In this talk, a study on performance improvement of the communication system of a single vector sensor was conducted in terms of various types of diversity through the communication data obtained from KOREX-17. It is shown that the bidirectional block-based time reversal technique with channel parameter-based weighting gave the best performance.