基于水声的水下无线通信研究

Underwater Acoustic Wireless Communications

介绍在水声随机多途径传输的信道中 ,基于水声的水下无线通信的方法及其实现 .海洋环境的水声信道不仅是一个极其复杂的时—空—频变随机多途径传输信道 ,尚有环境噪声高、带宽窄、载波频率低、传输延时大等因素制约数据传输速率 .介绍的通信方法及支持实现的关键技术 ,都对这些方面的影响予以考虑 .做出的语音、图像以及数据 3种不同的应用系统 ,多数已通过海上实验 ,效果良好 ,可实际应用 .并指出国际上技术先进的国家致力这领域研究的也仅在最近才有极少数取得重大突破 ,该结果展示它与国际近于同水平同步地进展 .

The methods and the implementations of underwater acoustic (UWA) communications in the stochastic acoustic multipath propagation channels have been studied. The ocean underwater stochastic acoustic propagation channels with their time , space , and frequency varying multipath have demonstrated the great complexities and difficulties for wireless communications. In addition, there are many other problems encountered in UWA channels, such as large ambient noise, limited bandwidth, low carrier frequency, and extended propagation latency. All of these substantially limit the data rates of underwater digital communications. The paper describes the methods of underwater communications, as well as the key supporting technologies of the implementations based on the considerations to overcome the difficulties stated above. We have designed three different systems for the applications of audio, video and data underwater transmission respectively. The performance of the systems has been investigated on the experimental trials in real ocean environments. Presented results indicate the superior quality of the systems tested, and the systems have been proven to be suitable for the practical applications in real ocean environments. Of late, a great deal of valuable research work has gone into the field of UWA communications in a number of technologically leading nations. Nevertheless, it is only until lately, a very small number of them have reached the major breakthrough. It has been demonstrated that our research work results are equivalent to the current ones obtained in those leading nations.