Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"Underwater Acoustic Communications"”.
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A distributed approach to underwater acoustic communications
A novel distributed underwater acoustic networking (UAN) protocol suitable for ad-hoc deployments of both stationary and mobile nodes dispersed across a relatively wide coverage area is presented. Nodes are dynamically clustered in a distributed manner based on the estimated position of one-hop …
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Underwater acoustic communications and adaptive signal processing
… dissertation proposes three new algorithms for underwater acoustic wireless communications. One is a new tail-biting circular MAP decoder for full tail-biting convolution (FTBC) codes for very short data blocks intended for Internet of Underwater Things (IoUT). The proposed algorithm was …
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A distributed approach to underwater acoustic communications
Thesis (S.M.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, the Woods Hole Oceanographic Institution), 2003.
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Inter-carrier interference mitigation for underwater acoustic communications
… data rate through the ocean is challenging. Such communications must be acoustic in order to travel long distances. The underwater acoustic channel has a long delay spread, which makes orthogonal frequency division multiplexing (OFDM) an attractive communication scheme. However, the underwater …
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Lorentz actuators for turbulence control and underwater acoustic communications
… contributions are the turbulence control and underwater acoustic communication fields. The ability to control turbulence is directly associated with controlling drag. Shipping industries and naval institutions are constantly seeking ways to reduce drag on marine vessels. A reduction in drag …
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Spatiotemporal processing and time-reversal for underwater acoustic communications
High-rate underwater acoustic communication can be achieved using transmitter/receiver arrays. Underwater acoustic channels can be characterized as rapidly time-varying systems that suffer severe Inter Symbol Interferences (ISI) caused by multi-path propagation. Multi-channel combining and …
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A phased array sonar for an underwater acoustic communications system
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1980.
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Harvesting time-frequency-space diversity with coded modulation for underwater acoustic communications
… is to design a low-complexity, high data-rate acoustic communications system with robust performance under various channel conditions. The need for robust performance emerges because underwater acoustic (UWA) channels have time-varying statistics, thus a coded modulation scheme optimally …
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Environmental effects of the Beaufort Lens on underwater acoustic communications during Arctic operations
… presence of the Beaufort Lens is changing the acoustic propagation paths throughout the Arctic region. Here a network of buoys were employed to communicate with an Autonomous Undersea Vehicle (AUV) while it operated under the ice throughout the Beaufort Lens with the goal of achieving near GPS …
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Environmental Effects of the Beaufort Lens on Underwater Acoustic Communications during Arctic Operations
… presence of the Beaufort Lens is changing the acoustic propagation paths throughout the Arctic region. Here a network of buoys were employed to communicate with an Autonomous Undersea Vehicle (AUV) while it operated under the ice throughout the Beaufort Lens with the goal of achieving near GPS …
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New method of polar channel coding for reducing the bit error rate with low complexity in the F-OFDM underwater acoustic communications
Underwater Acoustic (UWA) communication system plays a crucial role in various applications and contributes significant performance in comparison to other communication systems. UWA is essential in various applications such as oceanographic, oil exploration, military applications etc. However, it …
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Underwater sound propagation and acoustic communication in a time-varying shallow estuarine environment
… and other coastal engineering activities. Underwater acoustic technology offers a series of effective applications and technical supports for real-time monitoring and long-term preservation of the nature environment and ecosystem in these regions. However, estuaries are shallow waters with …
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A Novel Chirp Slope Keying Modulation Scheme for Underwater Communication
… Keying (CSK) is developed for coherent underwater acoustic communications. Effective signal detection is a critical stage in the implementation of any communications system; we will see that CSK solves some significant challenges to reliable detection. This thesis is primarily based on …
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Cooperative localisation in underwater robotic swarms for ocean bottom seismic imaging.
… nodes, implemented by a swarm of Autonomous Underwater Vehicles (AUVs). In autonomous deployment of ocean-bottom seismic nodes, a swarm of sensor-equipped AUVs are deployed to achieve ocean-bottom seismic imaging through collaboration and communication. However, the severely limited bandwidth …
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A channel subspace post-filtering approach to adaptive equalization
One of the major problems in wireless communications is compensating for the time-varying intersymbol interference (ISI) due to multipath. Underwater acoustic communications is one such type of wireless communications in which the channel is highly dynamic and the amount of ISI due to multipath is …
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Efficient Communication Protocols for Underwater Acoustic Sensor Networks
Underwater sensor networks find applications in oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation, tactical surveillance, and mine reconnaissance. The enabling technology for these applications is acoustic wireless networking. …
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Use of Reinforcement Learning for Interference Avoidance or Efficient Jamming in Wireless Communications
… learning in the context of wireless communications in two very different settings. In the first setting, we study the use of reinforcement learning in an underwater acoustic communications network to adapt its transmission frequencies to avoid interference and potential malicious …
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Digital communication receiver algorithms and architectures for reduced complexity and high throughput
… algorithms and architectures for digital communications are studied. As the demand for higher data communication rate increases, the dimension of communication systems is rapidly growing, thereby requiring computationally efficient detection and decoding algorithms in the receiver. Hence, …
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Communication-Aware, Scalable Gaussian Processes for Decentralized Exploration
… is to compute a spatial field that represents underwater acoustic communication performance from a set of measurements. We compare kriging to cokriging with vehicle range as a secondary variable using a simple approximate linear-log model of the communication performance. Next, we propose a …
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Blind CFO Estimation for Zero-Padded OFDM over Underwater Acoustic Channels
… shift for zero-padded OFDM transmissions over underwater acoustic channels: the null subcarrier based method, the O-M algorithm, and the Y-G algorithm. Performances of these three methods are evaluated by extensive numerical simulations and by data sets collected from the Mobile Acoustic …