淺海水下通道之時間相關性與相位速率特性分析

近年來水下通訊的研究，從深層海域轉移到了淺層海域，由於陸地資源如石油等即將耗盡，對於水下通信技術的提升也越來越迫切。水下通信比起陸地通訊而言，遇到最大困難是每個不同的海域的通道特性皆不相同，即使是相同海域，在不同的時間點，通道特性也不一樣，即海洋的通道為一時變系統。為了瞭解淺層海洋的通道特性，本篇論文利用從南海以及碧潭所得到的實驗數據，來分析其通道的特性，包含了通道的脈衝響應、訊號與雜訊比、信號與多重路徑比，其中最重要的是討論同調時間以及相位率的相關性，同調通訊提供了較高的資料量在頻寬受限制的水下的通道中，本論文中驗證在淺水中相位率以及同調時間有直接的關聯性。

關鍵字

通道估測；淺海通道；同調時間

並列摘要

In the past decade, the research of underwater acoustic communication is focus on shallow water. Due to the land resources like petroleum are going to exhaust, improves the techniques of underwater acoustic communication are in an urgent need. For underwater communication, the most important problem is that the ocean environment is a time-varing system. That means the underwater channel changing by different time. In this paper, we use some channel analysis to understand the characteristics of shallow water channel, the most important thing is discussing the relationship between coherent time and phase rate. Phase coherent communications provide a high data rate transmission in a band-limited underwater acoustic channel. Therefore, it is important to know about the coherent time and phase rate.

並列關鍵字

channel estimation ； shallow water ； coherent time

參考文獻

[1] James Preisig , ”Acoustic Propagation Considerations for Underwater Acoustic Communications Network Development ”,Department of Applied Ocean Physics and Eng. WHOI Woods Hole, MA, USA.

[2] G.M. Wenz, ”Review of Underwater Acoustic Research : Noise ”,J. Acoust. Soc. Am., 51(3), 1010-1020, 1972.

[3] R.J. Urick, Principles of underwater sound, McGraw-Hill, 1993.

[4] V.O. Knudsen, R.S. Alford and,J.W. Emling ”Underwater Ambient Noise”,1948

[6] D. R. Dowling, “Acoustic pulse compression using passive phase conjugate processing,” J. Acoust. Soc. Amer., vol. 95, no. 3, pp. 1450-1458, 1994.

國際替代計量

淺海水下通道之時間相關性與相位速率特性分析

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