分布式空时编码协作分集水下无人航行器网络技术研究

项目名称： 分布式空时编码协作分集水下无人航行器网络技术研究

项目编号： No.61001153

项目类型： 青年科学基金项目

立项/批准年度： 2011

项目学科： 金属学与金属工艺

项目作者： 韩晶

作者单位： 西北工业大学

项目金额： 7万元

中文摘要： 无人水下航行器（UUV）是实现海洋数据采集、离岸勘察等应用的重要工具，伴随着UUV的研究和发展，各国对基于此平台的水声通信技术的需求也越来越迫切。本报告重点研究UUV水声通信的空时编码协作分集发射与接收处理算法等关键问题。主要研究成果与创新点如下： 1. 提出基于基扩展模型的多普勒分集均衡算法，其可将双选择性衰落信道分离为多个独立的多普勒分集子信道，并通过多通道均衡器实现符号检测，具有更好的信道时变跟踪能力； 2. 提出空间-多普勒分集二维均衡算法，引入接收端空间分集处理，从而进一步提高算法相对于多径时变双选择性衰落水声信道的可靠性； 3. 针对时间反转空时分组编码协作分集系统，提出一种联合自适应空时译码均衡算法。此算法无需显式信道估计，且基于自适应联合处理，同时通过基于BiDFE结构的空间-时反二维分集，可使通信可靠性得到改善。 4. 提出一种适用于时变多径水声信道的空时编码协作分集方法，其结合基扩展模型多普勒分集与联合自适应空时译码处理的思想，可有效地克服节点异步、信道多径与多普勒扩展等困难。 本项目研究成果可为增强现有UUV平台工作效能，并在今后进一步建立水声通信网络提供参考。

中文关键词： 水声通信；水声网络；协作分集；空时编码

英文摘要： Unmanned Underwater Vehicle (UUV) is the main solution for underwater applications, such as oceanographic data collection and offshore exploration. With UUV research and development, the demand for underwater acoustic communications and networking technologies based on this platform becomes more and more pressing. This report focuses on the areas related to UUV underwater acoustic communication, including space-time coding cooperative diversity method and receiver processing algorithms. The main contributions and original ideas are summarized as follows: 1. Based on basis expansion model, a Doppler Diversity Equalization (DDE) algorithm is proposed, which separates doubly-selective fading channel into several time-invariant independent Doppler diversity subchannels, detects symbols by multichannel equalization and thus has better ability to track time variability. 2. A Space-Doppler Diversity Equalization (SDDE) algorithm is further proposed, which extends diversity in spatial domain by introducing multiple sensors at receiver end. With the aid of diversity in 2-dimension simultaneously, better reliability can be achieved for multipath time-varing underwater channels suffered from doubly-selective fading. 3. A Joint Adaptive Space-Time Decoding and Equalization (JASTDE) algorithm is proposed for time reversal space-time coding cooperative diversity system in the limitation of node asynchronism and multipath channel. By using joint adaptive processing and space-time reversal diversity provided by BiDFE structure, the JASTDE algorithm can improve the reliability of transmission significantly with no need for explicit channel estimation. 4. A space-time coding cooperative diversity method is proposed for time-varying multipath underwater acoustic channels with doubly-selective fading. By combining the ideas of Doppler diversity based on basis expansion model and of adaptive space-time decoding and equalizing jointly, this new method can suppress node asynchronism, multipath transmission and Doppler spread efficiently. Such theoretical results can be used for enhancing UUV platform capability, and provide reference for establishing underwater acoustic network in future.

英文关键词： underwater acoustic communication; underwater acoustic network; cooperative diversity; space-time coding