P.A. van Walree

TL;DR: A multiband OFDM transmitter and receiver are presented for underwater communications at low SNR, and the multiband approach leads to a considerable reduction in the receiver complexity.

TL;DR: In-situ measurements of the scattering function are used to drive a channel simulator developed in the context of underwater acoustic telemetry, and it is shown that time-varying Doppler shifts due to platform motion must be eliminated from measured scattering functions in order to provide the stochastic tap gains with the true Dopplers spectrum of the channel.

TL;DR: A multicarrier modulation scheme is presented for acoustic communication at low signal-to-noise ratios (SNRs) and a reduction in complexity is achieved by equipping the subbands with separate recursive least squares tap updates, yet guided by a common error signal.

TL;DR: In this paper, a multiband equalizer with K feedforward filters is proposed for joint equalization and despreading of K frequency bands, which can be adaptively combined with a multi-channel equalizer.

TL;DR: In this paper, the use of orthogonal frequency division multiplexing (OFDM) for covert acoustic telemetry was considered and the system was tested at sea in a highly time-varying environment.