Results 211 to 220 of about 5,103,302 (259)

Cooperative underwater acoustic communications.

IEEE Commun. Mag., 2013
This article presents a contemporary overview of underwater acoustic communication (UWAC) and investigates physical layer aspects on cooperative transmission techniques for future UWAC systems. Taking advantage of the broadcast nature of wireless transmission, cooperative communication realizes spatial diversity advantages in a distributed manner.
Suhail Al-Dharrab, Murat Uysal, Tolga M. Duman   +2 more
openaire   +3 more sources

Network-assisted underwater acoustic communications

Proceedings of the Seventh ACM International Conference on Underwater Networks and Systems - WUWNet '12, 2012
For many underwater acoustic applications, the source and receiver systems carry a single transducer antenna. The lack of spatial diversity makes it difficult to carry out phase coherent communications. Using distributed nodes of an underwater acoustic network, this paper address phase coherent underwater acoustic communications using source diversity.
T. C. Yang 0001, Kevin D. Heaney
openaire   +2 more sources

Underwater acoustic communications

Proceedings of OCEANS '93, 2002
The paper first attempts to provide a framework for the underwater acoustic communication system. An acoustic frequency band allocation, analogous to that used by radio engineers, is proposed. Similarly, the "shallow" channel is defined and the conditions pertaining to "high" bit rate explored.
openaire   +2 more sources

Signal processing for underwater acoustic communications

IEEE Communications Magazine, 2009
The performance and complexity of signal processing systems for underwater acoustic communications has dramatically increased over the last two decades. With its origins in noncoherent modulation and detection for communication at rates under 100 b/s, phase-coherent digital communication systems employing multichannel adaptive equalization with ...
Andrew C. Singer, Jill K. Nelson, Suleyman Serdar Kozat   +2 more
openaire   +2 more sources

Cooperative Transmission for Underwater Acoustic Communications

2008 IEEE International Conference on Communications, 2008
Underwater acoustic channels normally have low data rate, long propagation delay, severe multipath effect, and time varying fading. Cooperative transmission is a new wireless communication technique in which diversity gain is achieved by utilizing relay nodes as virtual antennae.
Han, Zhu, Sun, Yan Lindsay, Shi, Hongyuan   +2 more
openaire   +2 more sources

Beyond underwater acoustic communications

OCEANS 2011 IEEE - Spain, 2011
The ability to communicate underwater using acoustic energy in place of electromagnetic energy is rapidly becoming commonplace. Indeed, vendors and academic researchers in many advanced countries are pursuing the development of acoustic modems. The emphasis often varies among these efforts: some, especially academic researchers, focus on increased ...
openaire   +1 more source

Efficient use of bandwidth for underwater acoustic communication

The Journal of the Acoustical Society of America, 2013
In a recent shallow water experiment, acoustic communication transmissions were carried out over the 10 to 32 kHz band in ∼100 m deep water over a 3 km range. A natural question is how best to utilize that bandwidth. In one multiband approach discussed previously, the band was divided into four smaller subbands that were processed independently using ...
H C, Song, W S, Hodgkiss
openaire   +2 more sources

Swell effect in shallow underwater acoustic communications

2010 IEEE 15th Conference on Emerging Technologies & Factory Automation (ETFA 2010), 2010
The need for monitoring underwater sensors, communications between submarines or sonar, makes underwater acoustic communications an important field of research. Electromagnetic waves are quickly attenuated in this medium and thus acoustic waves are the best option for communications.
Joaquín Aparicio, Fernando J. Álvarez, Jesús Ureña, Ana Jiménez, Cristina Diego, Enrique García 0003   +5 more
openaire   +1 more source

On the physics of underwater acoustic communications

AIP Conference Proceedings, 2012
Digital communications have been traditionally treated using signal processing approaches. Algorithm and performance is system-model dependent. For underwater acoustic communications, the system model is very complex due to the different channel environmental conditions which can vary rapidly with time, and are location dependent.
openaire   +1 more source

Channel simulation for underwater acoustic communication network

Proceedings of the Seventh ACM International Conference on Underwater Networks and Systems - WUWNet '12, 2012
Significant advancements in underwater acoustic communication have been achieved in recent decades. In the dynamic ocean environment, various physical processes can significantly affect the communication channel. The time-varying underwater channel has both deterministic and stochastic features. Due to the dynamic environment and the complex properties
Aijun Song, Mohsen Badiey
openaire   +1 more source