A high bit rate acoustic link over an underwater channel is investigated . Design of a Digital communication system utilizing acoustic signals for underwater applications is a very challenging field due to the extremely complex nature of the underwater channel. The conventional techniques for overcoming the channel effects used in communication systems elsewhere fail to give the desired results...

The bidirectional decision feedback equalizer (BiDFE) that combines the outputs of a conventional decision feedback equalizer (DFE) and backward DFE can improve the performance of the conventional DFE by up to 1-2 dB based on simulations. In this letter, the BiDFE concept is extended to multichannel time reversal communications involving a DFE as a post-processor. Experimental data collected in...

In this paper, we calculate the capacity of a point-to-point communication link in an underwater acoustic channel. The analysis takes into account the effects of various acoustic propagation loss models. A physical model of ambient noise power spectral density is also considered. We perform a comparative assessment of the influence of various acoustic transmission loss models on the acoustic ba...

This chapter discusses the development of a short range acoustic communication channel model and its properties for the design and evaluation of MAC (Medium Access Control) and routing protocols, to support network enabled Autonomous Underwater Vehicles (AUV). The growth of underwater operations has required data communication between various heterogeneous underwater and surface based communica...

As diverse and data-heavy underwater applications emerge, demanding requirements are further imposed on underwater wireless communication systems. Future underwater wireless communication networks might consist of both mobile and stationary nodes which exchange data such as control, telemetry, speech, and video signals among themselves as well as a central node located at a ship or onshore. The...

We study the efficacy of a generalised form of differential encoding of binary phase shift keyed (BPSK) signals transmitted through a shallow underwater acoustic communication channel. Using simulations involving a fixed source and a receiver moving about with the surface waves, we show that no advantage arises from using the generalised differential encoding methods. On the contrary, the best ...

In this paper we study the HFM BOK (M-ary Hyperbolic Frequency Modulated-Binary Orthogonal Keying) modulation technology which is suitable for underwater acoustic communication. Under the guidance of the theory, we test the practicability of the system through MATLAB simulation. This system uses MFSK-MBOK cascaded technology and decreases the systematic calculated amount largely, in addition, t...

by Trym H. Eggen Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1997 This work is concerned with coherent communication by means of acoustic signals over underwater communication channels. The estimated scattering functions of real data ranging from the Arc...

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 ...