Underwater acoustic sensor networks (UASNs) have emerged as a viable networking approach due to their numerous aquatic applications in recent years. As vital component of UASNs, routing protocols are essential for ensuring reliable data transmissions and extending the longevity UASNs. Recently, several clustering-based been proposed reduce energy consumption overcome resource constraints deployed nodes. However, they rarely consider hot-spots' problem sink node isolation multihop underwater...

Multipath due to reflections of the sea surface, seabed, and obstacles, as well inhomogeneity within ocean, is an important characteristic underwater acoustic channels. Mutual interference among multiple paths causes severe amplitude fading frequency selective fading. The guard interval effective anti-multipath method, but excessively long will reduce data rate multicarrier communication. In this paper, we propose a new multi-carrier communication method based on orthogonal chirp division...

Communication across the water–air interface is an open research problem. A common solution to place a relay on interface, which transmits received underwater acoustic signals shore via electromagnetic waves. However, this has limitations, such as surface relays easily floating away or becoming resource-intensive due frequent surfacing, make communications unstable and costly. In article, we investigate recently proposed cross-medium communication technique, translational radio frequency...

Mud pulse telemetry (MPT) systems are widely recognized for their effectiveness and most commonly used to transmit downhole data the surface in real time. These facilitate drilling process make it more cost-efficient. In MPT, mud channel presents a challenging communication environment, primarily due various sources of noises, with pump noise being dominant. this paper, cancellation method based on discrete Fourier transform (DFT) is proposed demodulation under low signal-to-noise ratio,...

Underwater acoustic (UWA) communication encounters significant challenges, including impulsive noise from breaking waves and marine organisms, as well long-delay taps caused by ocean properties high transmission rates. To address these issues, we enhance the channel estimation process introducing iteratively reweighted least squares (IRLS) methods propose an suppression algorithm. Furthermore, analyze inter-frequency interference (IFI) resulting variability implement IFI cancellation (IFIC)...

Frequency-domain equalization (FDE) is a computationally efficient method to recover underwater acoustic single-carrier transmissions in multipath environment. The FDE receivers often operate block-by-block manner, assuming that the channel time invariant during block duration. This assumption implies traditional block-based experience performance degradation fast time-varying conditions, since interfrequency interference (IFI) not considered. Here, we focus on IFI cancelation (IFIC)...

The Gaussian noise assumption is usually made for slowly time-varying underwater acoustic communication (UWAC) systems, which entirely adequate most cases. However, certain human activities such as geophysical surveys, multi-beam echosounders and iceberg breakup generate impulsive noise. Consequently, the degrades designed receiver based on model significantly. An optimization formulation takes channel impulse response (CIR), group-sparse encoder structure of data symbol into account...

Due to the power and transmission rate limitations, it is challenging achieve underwater acoustic (UWA) communications over long distances from unmanned vehicle (UUV) shore station. As an alternative solution, distributed sensing (DAS) communication uses submarine optical cable acquire demodulate signals. There little research on channel noise of DAS communication. This paper analyzes characteristics background a system with armored based experimental measurements. Channel analysis shows...

With the rapid development of autonomous underwater vehicles (AUVs) and continuous improvement marine exploration requirements, AUV formation has emerged as a promising technique for performing tasks with greater flexibility, adaptability, scalability. To achieve control, acoustic communication networks (UACNs) are widely used to support information exchange among AUVs. Considering broadcast communications in fully connected mobile UACNs, existing medium access control (MAC) protocols face...

Prefixes, in forms of cyclic-prefixes or zero-padding, have often been viewed as indispensable underwater acoustic single-carrier transmissions to avoid inter-block interference (IBI) and formulate circular convolution. However, the prefix introduces overhead reduces spectral efficiency. This is especially true fast time-varying channel conditions. Here, we propose a prefix-free scheme facilitate frequency-domain equalization (FDE) an communication system, based on time-reversal processing....

High frequency is a solution to high data-rate underwater acoustic communications. Extensive studies have been conducted on high-frequency (>40 kHz) channels, which are strongly susceptible surface waves. The corresponding channel statistics related communications, however, still deserve systematic investigation. Here, an efficient modeling method based statistical analysis proposed. Three wind-associated environmental models integrated into this hybrid model. Texel-Marsen-Arsole spectral...

The internet of autonomous marine vehicle systems (IoAMVSs) requires ultra-reliable communications, ultra-real-time control, and ultra-high precision computation. Classical parallel intelligence theory is a popular method for developing IoAMVSs in the literature. However, this has made it difficult to achieve anticipated performance when co-designing computing (3C) complex oceanic communication environments. This article explores efficient integration reconfigurable surface (RIS) with...

For specific wideband sound source localization tasks performed in underwater environments, high precision, low computational complexity, and robustness are required to meet the demand for accurate location real-time processes. Traditional methods that rely on models signal processing techniques perform poorly complex but common scenarios where noise, reverberation, array deviations exist. Sound systems based deep neural networks proposed recently show superiority over conventional methods....

Abstract:

The adaptive minimum symbol error rate (AMSER) equalizer is known to have better (SER) performance than the mean square equalizer. Furthermore, normalized AMSER (NAMSER) outperforms equalizer, which can be regarded as improvement of least (NLMS) by incorporating SER (MSER) criterion. Inspired that, we propose an improved recursive squares-based NAMSER (RLS-NAMSER) that takes advantage faster convergence RLS algorithm over NLMS algorithm. first reconsidered from perspective optimization...

Bubble curtain technology has been applied in underwater blasting engineering for decaying the sound wave. Applying it to acoustic countermeasure (UAC) is bound achieve certain results. So important and necessary assess effect of bubble on (UWA) communication. In this paper, we commence from resonance theory apply Bellhop ray model analyzing which damps impact signal at different depths ranges verify correctness model. With method, get communication based frequency shift keying (FSK)...

Underwater acoustic communications are required for controlling and networking a variety of underwater or sea surface objects. Due to the unique characteristics channel, e.g., complicated multipath propagation, selective frequency fading, extreme Doppler effect heavy ambient noise, FH-MFSK techniques play vital role in robust communication, especially shallow water. However, based on detecting receiving signals, demodulation scheme may be sensitive shifting caused by shifts. This paper...

Signature whistle is individually distinctive vocalization that plays a vital role in the context of social interactions and group cohesion. However, sometimes signals overlap recorded by hydrophones when several dolphins squawk simultaneously. This impedes further research signature vocal interactions. An efficient blind source separation technique can identify separate mixed necessary. Here joint approximate diagonalization eigenmatrix (JADE) method adopted to each frequency bin. To...

Forward-Looking Sonar (FLS) has started to gain attention in the field of near-bottom close-range underwater inspection because its high resolution and framerate features. Although Automatic Target Recognition (ATR) algorithms have been applied tentatively for object-searching tasks, human supervision is still indispensable, especially when involving critical areas. A clear FLS mosaic containing all suspicious information demand help experts deal with tremendous perception data. However,...

Because of the inherent interference, it is difficult for filter-bank multi-carrier (FBMC) with offset-quadrature amplitude modulation (OQAM) systems to achieve high-performance symbol detection, especially over underwater acoustic (UWA) channels. This letter explores a novel receiver approach solve this problem by establishing unified transmission matrix (UTM) model and proposing lattice-reduction-aided sphere decoder (LRA-SD). The simulation sea trial results indicate that in UWA FBMC/OQAM...

As one of the most alarming underwater noises today, pile driving noise is only anthropogenic sound source other than explosives that has caused death fish , according to available literature. The present study explored effects simulated on movement behavior Litopenaeus vannamei. experiments were conducted in a tank equipped with DSG and recording apparatus. During experimental phase, ten individuals L. vannamei allocated equally control test groups. group exposed drubbing (178dB <sub...