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High bandwidth underwater optical communication
Applied Optics, 2008We report error-free underwater optical transmission measurements at 1 Gbit/s (10(9) bits/s) over a 2 m path in a laboratory water pipe with up to 36 dB of extinction. The source at 532 nm was derived from a 1064 nm continuous-wave laser diode that was intensity modulated, amplified, and frequency doubled in periodically poled lithium niobate ...
Frank, Hanson, Stojan, Radic
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Underwater communications device
The Journal of the Acoustical Society of America, 1980A communications device for use under water by a human speaker. A tubular base member has a mouthpiece located at one open end thereof and an inflatable air bag mounted about another open end thereof. In use, the speaker places the mouthpiece around his mouth to form an air seal therebetween and blows into the air bag to partially inflate it.
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Underwater radio frequency communications
OCEANS 2011 IEEE - Spain, 2011There are actually three different types of data telemetry in the aquatic environment: acoustic, optic and electromagnetic. Table I shows the pros and cons of the different technologies. This paper will concentrate on the use of electromagnetic waves as a carrier through-water, through-ice and through-ground.
Alejandro Palmeiro +3 more
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Underwater communication device
The Journal of the Acoustical Society of America, 1990An underwater speaker system having a pressure equalization system enabling the speaker to operate in its intended fashion over a wide range of water depths, e.g. from two feet up to sixty feet. Water pressure is applied to a diaphragm that forms one wall of a variable volume an internal face of a speaker membrane.
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The Journal of the Acoustical Society of America, 1990
An underwater communicator comprising a transmitter for transmitting acoustical energy between mediums having differing impedance. The transmitter includes first and second ends. The first end is exposed to a first medium while the second end is exposed to a second medium.
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An underwater communicator comprising a transmitter for transmitting acoustical energy between mediums having differing impedance. The transmitter includes first and second ends. The first end is exposed to a first medium while the second end is exposed to a second medium.
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Underwater communication goes cognitive
OCEANS 2008, 2008Underwater acoustic channel is the most challenging channel in the world due to its time varying and frequency-selective characters. These facts obstruct the realization of most of intelligent and high bit rate underwater communication systems. Cognitive underwater communication systems build up rules of modulation method and receiver algorithm over ...
Wang Yonggang +3 more
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Modeling Underwater Communication Links
2008 Second International Conference on Sensor Technologies and Applications (sensorcomm 2008), 2008Design and operation of underwater acoustic communications systems require a capacity to model the acoustic preparation conditions under various environmental conditions. For the frequencies of interest to most applications in connection to ocean sensor networks ray tracing technique is normally the preferred method.
Jens M. Hovem +3 more
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Optical-Based Underwater Communications
Optical Fiber Communication Conference, 2018A high-speed 24 Gb/s PAM4 optical-based underwater communication (OBUC) with afocal scheme for reducing/expanding collimated beam diameter is demonstrated. Such proposed OBUC link is better than existing OBUC given its practicability for high-speed underwater link.
Jen-Chieh Chang +6 more
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Bidirectional equalization for underwater acoustic communication
The Journal of the Acoustical Society of America, 2012The bidirectional decision feedback equalizer (BiDFE) that combines the outputs of a conventional decision feedback equalizer (DFE) and backward DFE can improve the performance of the conventional DFE by up to 1–2 dB based on simulations. In this letter, the BiDFE concept is extended to multichannel time reversal communications involving a DFE as a ...
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Real time underwater communications
Proceedings of OCEANS'94, 2002Achieving reliable high speed digital communications over an underwater channel is a challenge that many scientists are trying to take up. For various applications such as remote control and data exchange, for example between an autonomous underwater vehicle and a surface vessel, the need is getting more and more important in designing reliable ...
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