Results 171 to 180 of about 3,711 (217)

Swept Carrier Acoustic Underwater Communications

OCEANS '78, 1978
This paper describes a novel idea of reducing multipath interference in underwater acoustic communication systems. The proposed idea is based on the observation that the time separation between direct and multipath waveforms can be utilized to suppress the multipath interference.
A. Zielinski, L. Barbour
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Underwater acoustic wireless multiuser communication

2008 5th IFIP International Conference on Wireless and Optical Communications Networks (WOCN '08), 2008
The characteristics of shallow water are studied in this paper, including multipath spreading, frequency selective attenuation and so on, which is a guidance for disposing communication modems according to the sound velocity profile to mitigate intersymbol interference (ISI) and to improve the underwater acoustic (UWA) communication range.
null Yin Jingwei, null Wang Lei, null Chen Kai   +2 more
openaire   +1 more source

Digital underwater acoustic voice communications

IEEE Journal of Oceanic Engineering, 1996
This paper describes the design of an underwater acoustic diver communication system controlled by a digital signal processor. The speech signal transmission rate is compressed by using linear predictive coding (LPC) and the extracted parameters are transmitted through the water to a synchronized receiver by employing digital pulse position modulation (
B. Woodward, H. Sari
openaire   +1 more source

ECO-Friendly Underwater Acoustic Communications

Proceedings of the International Conference on Underwater Networks & Systems, 2017
This paper introduces the idea of ECO-friendly underwater acoustic communications via utilizing prediction techniques. The ultimate goal of the research is to avoid the interference caused by man-made noise to marine mammals. Specifically, we first analyze the necessity and the advantage of prediction in underwater environments.
Wei Cheng, Yu Luo, Zheng Peng, Jun-Hong Cui   +3 more
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OFDMA for underwater acoustic communications

2011 49th Annual Allerton Conference on Communication, Control, and Computing (Allerton), 2011
We investigate the possibility of using orthogonal frequency division multiple access (OFDMA) for design of efficient underwater acoustic (UWA) networks. The major challenge for the OFDMA-based UWA communication systems is the Doppler-induced frequency scaling, which may cause severe intercarrier interference (ICI), and depending on the particular user
Kai Tu, Tolga M. Duman, Milica Stojanovic, John G. Proakis   +3 more
openaire   +1 more source

Optimizing Adaptive Communications in Underwater Acoustic Networks

OCEANS 2019 MTS/IEEE SEATTLE, 2019
We consider an Underwater Acoustic Network (UAN) where each node is equipped with a suite of signals and so there is the flexibility to aim for different bit rates at each transmission slot. A Cross-Entropy (CE) centralized algorithm is explored to optimize the combination of modulation scheme and transmission power level in the presence of unreliable ...
Petroccia R., Cassara' P., Pelekanakis K.   +2 more
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Underwater acoustic communications using quasi-orthogonal chirps

2017 51st Asilomar Conference on Signals, Systems, and Computers, 2017
We propose a quasi-orthogonal chirp waveform design technique for underwater acoustic communications and study the correlation performance of binary linear chirp waveforms under different bandwidth and time constraints. Specifically, we consider binary information symbols that are carried over optimized binary linear chirp waveforms and transmitted ...
Huang, Song-Wen, Sklivanitis, Georgios, Pados, Dimitris A., Batalama, Stella N.   +3 more
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Toward continuous underwater acoustic communications

OCEANS 2008, 2008
The paper addresses the technical challenges and approaches for semi-continuous underwater acoustic communications, i.e., transmission of long packets under different environmental conditions without periodic training. The packet length is normally constrained by the channel coherence time for a given bandwidth, beyond which channel tracking using an ...
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Multipath correlations in underwater acoustic communication channels

The Journal of the Acoustical Society of America, 2013
Uncorrelated scattering (US), which assumes that multipath arrivals undergo uncorrelated scattering and are thus uncorrelated, has been the standard model for digital communications including underwater acoustic communications. This paper examines the cross-correlation of multipath arrivals based on at-sea data with different temporal coherence time ...
S H, Huang, T C, Yang, Chen-Fen, Huang
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Ocean Variability Effects On Underwater Acoustic Communications

2007
Abstract : This proposed research seeks to identify, explain, and ultimately predict, the factors that significantly alter the operational effectiveness of underwater acoustic communications through experimental work and theoretical analysis. The long-term goal is to develop reliable, high rate transceivers customized for coherent underwater acoustic ...
Mohsen Badiey, Aijun Song
openaire   +1 more source