Multi-octave high-frequency hydro-acoustic communication

Underwater communication remains beset by a range of problems that stem from the inability of radio waves to propagate well through water. Although low frequency acoustic signals propagate well in water, the available bandwidth is limited. High acoustic frequencies can be used, although they do not propagate very far. This paper reports on high-frequency underwater communication trials using signals where the signal bandwidth is of the order of a decade. Even in open water tests, the received signals appear to be well behaved.