Time reversal (TR) can achieve temporal and spatial focusing by exploiting diversity in complex underwater environments with significant multipath. This property makes TR useful for acoustic (UWA) communications. Conventional is realized performing equal gain combining (EGC) on the single element output signals of each vertical receive array (VRA). However, actual environment, signal-to-noise r...

The performance of Low-Density Parity-Check (LDPC)-coded Orthogonal Frequency Division Multiplexing (OFDM) is investigated over turbulence channels in underwater wireless optical communications (UWOC). relation between the bit error ratio (BER) and parameters such as scintillation coefficient, signal-to-noise (SNR), length LDPC code, order OFDM quantified by simulation. Results show that while ...

In scientific, military, and industrial sectors, the development of robust efficient submarine wireless communication links is enormous interest. Underwater communications can be carried out through acoustic, radio frequency (RF), optical waves. not a new idea, but it has recently been considered because seawater exhibits window reduced absorption both in visible spectrum long-wavelength UV lig...

Behavior of blast wave in underwater explosion is of interest to metal forming community and ship designers. Underwater detonation is, also a potential hazard to the water intakes or a plant spent fuel pool. In this paper, some techniques for calculating free-field blast parameters such as pressure and impulse in underwater explosion and prediction of bubble pulsation parameters are presented a...

Underwater communications mainly rely on acoustic propagation which is strongly affected by frequency-dependent attenuation, shallow water multipath propagation and significant Doppler spread/shift induced by source-receiver-surface motion. Time-reversal based techniques offer a low complexity solution to decrease interferences caused by multipath, but a complete equalization cannot be reached ...

Localization of mobile sensor nodes is indispensable for underwater sensor networks. For example, in aquatic environment monitoring applications, localization is a must-do task in order to get useful location-aware data. Location information is also required for geo-routing, which is proved to be more scalable and efficient in mobile underwater sensor networks. So far, only a limited number of ...

One of the challenges Internet Underwater Things (IoUT) is design nodes for collecting information from underwater, with features low cost, long term, range, voyage routing, and real-time communications. Wave glider, has shown great potential acting as IoUT through its persistent, long-range traveling, flexibility underwater. In this article, we propose an architecture IoUT, involving multiple ...

In this paper, it has considered Orthogonal Frequency Division Multiplexing (OFDM) as one of the most used technique in communications applied in a wide-band radio channel, it has been chosen as an air interface for the downlink in the framework of Long Term Evolution (LTE) standardization due to its flexibility and adaptively in the technical system design, also considered the use of undersea ...

Based on the speech coding technology, in this paper we propose a new method encoding the speech signal by the bionic pattern recognition technique. Using this new encoding method, the text message can be received after using biomimetic pattern recognition of the speaker’s voice. And the information related to the speaker’s individual characteristics can be obtained by “comparison” between the ...