分布式水声定位通信网络中基于零相关窗BOC调制的时延估计研究

With the rapid development, the technique of underwater defense and marine development are widely used in the various types of the military and civilian field. Submersibles working in deep sea need wireless information transmission and passive positioning and navigation very much. So, this year, “Ship Remote Wireless Autonomous Localization and Recognition (F0107)” is the priority funding program..Distributed Acoustic Positioning-Communication Network technique is currently recognized as one of the most promising technique. This project is a development of the key project “Basic Research on Distributed Underwater Acoustic Sensor Networks for Positioning and detection (F010701)”. By using the communication signal of underwater acoustic sensor network, this project proposed a passive positioning method, which can meet the needs of Submersibles. When the mobile node is receiving the signal of information and command from the network passively, the receiver use the signal to determine the position itself automatically. No need to send any signals, so that the stealth of submersibles is protected very well. At the same time, the network can provide positioning information to any number of users..Based on the theory of the time measurement using spread spectrum signal, this project firstly constructs zero correlation zone signal which reduces the influence of the side-peak of the correlation function to signal detection. The power of the signal is focused within±1 chip, in order to distinguish multi-path and multi address. So that, multi-path and multi address interference in underwater acoustic signal transmission in deep sea are solved. Secondly, this project .focuses on the BOC modulation mode on kinds of sequence, try to find a way to improve the time measure precision, and solve the two problems below: time reference and symbol synchronization problem when communicating with acoustic communication network, and problem of signal transmission time measurement when self positioning with the Distributed Acoustic Positioning-Communication Network.

随着水下防卫技术和海洋开发技术的快速发展，以及在各类军事民用领域的广泛应用，工作于大深度海域的各类潜器，对水下信息传输和被动定位导航提出了非常迫切的需求。.分布式通信、定位信息网络技术是目前公认的最有前景的技术手段之一。依托重点项目“分布式水声网络定位与探测基础研究（F010701）”，本课题利用分布式水声网络的通信信号，移动节点在隐蔽接收信息指令的同时，实现自身位置的校准。潜器不发射信号，不会破坏自身隐蔽性。只要增加接收机，该网络可为多用户同时提供定位服务。.本课题基于扩频信号测时理论，利用零相关区信号降低边峰对信号检测的影响，使能量集中于正负一个码元之内，以便于区分多径和多址，从而解决多径干扰和多址干扰问题。同时研究多种序列的BOC调制方式，进一步提高测时精度，解决网络节点间进行远程水声通信时的符号同步与时间基准问题，以及分布式定位系统中的接收机进行时延差定位时信号传播时间的测量问题。

进入21世纪以来，人们对海上定位导航技术有了更加迫切的需求。声波是目前已知的唯一可以在海水介质中远距离传播的信息载体，所以，在海面以下，水声定位技术是水下航行器唯一可以用于定位和导航的技术手段。小型潜艇、载人潜器、水下滑翔机、水下机器人等新型水下航行器的出现又推动了水声定位技术的发展，提出了对远距离分布式水声定位技术的需求。.分布式远程水声定位系统由信标和接收机构成。在工作海域内布放多个信标，构成定位信标网络，各信标之间用水声信号进行通信和同步。分布式远程定位系统的信标工作在定时发射模式，而接收机工作于被动接收状态，不发射信号。这样，不但接收机的体积和功耗得以降低，满足了载体的轻型化要求，而且保证了载体的声学隐蔽性，同时，系统还可以为多个接收机定位，具有很好的可扩展性。.本课题针对分布式水声通信定位网络对接收机的被动定位需求，按计划首先分析了分布式定位信号的形式和性能，讨论了信号的构造方法，并建立了信号模型；然后进行了序列优选和参数优化，并利用该信号进行了信道测量和时延估计，为Rake接收机提供了较为准确的信道估计结果；最后开展了实验研究。.本课题完成了既定研究目标，发表论文15篇，获得发明专利授权3项，提出了分布式定位系统抗多径干扰和抗多址干扰信号的要求，设计了一种基于ZCZ序列的远程测距信号和同步信号，使序列组自相关边峰和互相关峰值远离自相关峰；构建了具有局部最优相关性的定位信号组，提高了有限带宽下定位信号的检测性能和抗干扰性能，解决了远海低信噪比条件下的测距信号受到噪声、多径、多址等干扰后信号到达时间的准确估计问题，为接收机提供一种信号检测和抗多径多址干扰的方法。