Proceedings of Meetings on Acoustics

Underwater acoustic communication is important to a variety of scientific and commercial missions in the ocean, for example ocean exploration and monitoring. Due to hardware limitations, often limited bandwidth, for example 6-7 kHz, has been used in underwater communication systems. In addition to high spectral efficiency, large bandwidth can also lead to increased data rates. When utilizing a large frequency band, frequency-division multiplexing, which refers to dividing an available frequency band into smaller sub-bands, is the common practice. We propose to use multiband transmissions for the underwater acoustic channel, where the wide frequency band is divided into multiple separated sub-bands. The sub-band is much wider than the sub-carrier in the orthogonal frequency-division multiplexing (OFDM). The former is several kilohertz in width while the latter is often only tens of hertz. During our experiment in Hawaii, Hi, in 2011, high data rates were achieved through the use of multiband transmissions, combined with time reversal demodulation. In the meeting, we will present the receiver algorithms for singleand multi-source acoustic communication systems in the multiband transmission framework. Comparison between the multiband transmissions and OFDM schemes will be also discussed. (Work supported by ONR Code 322OA)