Autonomous underwater vehicles (AUVs) have gained more interest in recent years for military as well as civilian applications. One potential application of AUVs is for the purpose of undersea surveillance. As research into undersea surveillance using AUVs progresses, issues arise as to how an AUV acquires, acts on, and shares information about the undersea battle space. These issues naturally t...

There is a growing need for acoustic channel simulators. Among the reasons for this is the increased interest in underwater acoustic communications, but also the fact that measuring the characteristics of the underwater channel is very expensive. A channel simulator provides access to realistic channels, and allows us to compare algorithms and modulations under identical conditions. Channel sim...

Spawned by recent advances in technology, widespread attention has been focused on the coordination of multiple autonomous vehicles. In numerous mission scenarios, the concept of a group of agents cooperating to achieve a determined goal is very attractive when compared with the solution of one single, heavily equipped vehicle, as it exhibits better performance in terms of efficiency, flexibili...

Terrestrial wireless sensor networks with fixed and mobile nodes were initially developed for military applications such as battlefield surveillance and are now commonplace in many industrial and civilian application areas. It is easy to appreciate that such networks could be of immense value for military and civilian underwater tasks such as surveillance, monitoring and surveying. Autonomous u...

水中での通信には，吸収減衰が少なく，海水の濁りや太陽光の干渉等の影響を受けない音響通信が一般的に利用されている．しかし，音波の伝搬速度は電波と比べて5桁以上遅いことから，遅延広がり，ドップラー広がりが共に桁違いに大きい二重選択性フェージングが発生し，その伝搬路変動の克服が課題である．一般的に通信の高速化には高周波数帯を利用した広帯域伝送が有効であるが，高い周波数を利用した際により顕著となる高速な伝搬路変動に追従可能な波形等化技術が確立されていなかったため，水中音響通信の高速化には限界があった．近年，高周波数帯利用時に発生する高速な伝搬路変動の克服を目指し，マルチパス波の一部を空間領域で抑圧することで遅延広がり，ドップラー広がりを圧縮する時空間等化技術が提案されている．本論文では，時空間等化技術を解説するとともに，その動作原理や伝搬路変動への耐性を確認するための計算機シミュレーション，...

In underwater optical wireless communications (UOWC), scattering of the propagating light beam results in both intensity and phase variations, which limit transmission link range channel bandwidth, respectively. Scattering photons while through is a random process, channel-dependent noise. this work, we introduce for first time an analytical model noise investigate its effect on bit error rate ...

The paper presents a novel technique for underwater acoustic voice communications. The speech signal is compressed prior to transmission by using Linear Predictive Coding and transmission of appropriate speech parameters is achieved by Digital Pulse Position Modulation. The main emphasis here is on the reception of the multipath-dominant signal and on the demodulation process.

Two datasets, one simplistic that assumes direct observation of paths and the other based on observations derived from compressed sensing and an assumed OFDM communications underpinning, simulate underwater acoustic channels. The Cardinalized Probability Hypothesis Density filter and the Multiple Hypothesis Tracker are applied to these wireless channels. The performances of the two trackers are...