Normally, the communication in the earth surface is through electromagnetic or radio waves. But this is not possible in the underwater environments in an efficient way. In underwater environments radio does not work well due to its quick attenuation in water. Hence the acoustic signals are sent using the acoustic channels. If the communication is done with retransmission, it gives rise to the p...

Time reversal mirror (TRM) can adaptively match the sound channel without any prior knowledge. In this paper, active TRM, passive TRM and virtual TRM which are all based on a single array element and the application of TRM in the underwater acoustic communication including single-user communication and multi-user communication are studied. Single sensor TRM which has time compression performanc...

It is an auspicious time for this first-ever ISRR special session on the topic of underwater robotics. Underwater robots are now performing high-resolution acoustic, optical, and physical oceanographic surveys in the deep ocean that previously were considered impractical or infeasible. For example: in 2001 the Argo II underwater robotic vehicle, [1], was employed to discover the first off-axis ...

Multiuser underwater acoustic communication is one of the enabling technologies for the autonomous ocean-sampling network (AOSN). Multiuser communication allows vehicles, moorings, and bottom instruments to interact without human intervention to perform adaptive sampling tasks. In addition, multiuser communication may be used to send data from many autonomous users to one buoy with RF communica...

In the past few years wireless Sensor Network has been an emerging technology. As it is a permutation of computation, sensing, and communication. In the 70% of the earth, a huge amount of unexploited resources lies covered by oceans. To coordinate interact and share information among themselves to carry out sensing and monitoring function underwater sensor network consists a number of various s...

In this paper, we present the development of an in-air acoustic test-bed for rapid proof-of-concept testing of (underwater) communication technologies. In addition to more accurately representing the actual channel when compared to simulation, the test-bed also provides an easy method to introduce channel impairments, such as Doppler distortion, in a controlled manner. This can be advantageous ...

Abstract Compressed sensing technology is currently a relatively mature channel estimation technology, and the sparsity of underwater acoustic provides basis for application compressed to channel. Channel one most commonly used signal reconstruction methods. The reconstructed based on improve reliability transmission. key SL0 algorithm. Based algorithm, new objective function proposed better ap...

We propose an asynchronous acoustic chirp slope keying to map short bit sequences on single or multiple bands without preamble error correction coding the physical layer. introduce a symbol detection scheme in demodulator that uses superposed matched filter results of up and down references estimate timing, which removes requirement for synchronization. Details implementation are disclosed disc...