基于超Nyquist结构的无速率编码水声单载波通信迭代接收机技术研究

A Single Carrier underwater acoustic communication system operating at rates approaching channel capacity will be proposed under simulation and experimental underwater channel conditions, the scheme incorporate techniques such as super-Nyquist signaling, rateless coding, Precoding technique approaching Shannon's capacity and iterative receiver techniques. The study involves: (a) the design and performance analysis of underwater acoustic Single Carrier communication tranceiver approaching channel capacity under time-invariant and known channels, that aims to develope the encoding and decoding techniques for QC-LDPC convolutional, soft-in soft-out bidirectional decision feedback equalizer algorithm and soft-in soft-out seft-Iterating soft equalizer algorithm under a super-Nyquist architechture. (b) the design and performance analysis of a rateless coding iterative receiver based on super-Nyquist signaling under time-varying narrowband doubly spread channel conditions, that aims to develope the iterative time-varying sparse doubly spread channel estimation algorithm under narrowband assumption. (c) the design and analysis of a rateless coding iterative receiver based on super-Nyquist signaling under time-varying wideband doubly spread channel condition, that aims to develope the iterative time-varying close loop wideband doppler estimation and compensation algorithms based on soft-in soft-out bidirectional decision feedback equalizer. The study contributes to a development of the communication theory approaching channel capacity, to establish a reliable, capacity-approaching communication link under highly dispersive, dynamic and large delay ocean environment.

基于超Nyquist结构结合无速率编码技术、逼近Shannon限预编码技术以及迭代接收机技术开展仿真及实际水声信道条件下的逼近信道容量的单载通信技术研究。研究内容包括：（a）时不变已知多途信道条件下的、可靠的、逼近信道容量的水声单载波通信系统结构设计与分析研究，重点开展超Nyqusit结构下的QC-LDPC卷积码预编码技术、软入软出双向判决反馈均衡器技术及软入软出自迭代软均衡器技术的研究；（b）时变窄带双扩信道条件下的基于超Nyquist结构的无速率迭代接收技术研究，重点解决迭代时变窄带稀疏双扩信道估计问题；（c）时变宽带双扩信道条件下的基于超Nyquist结构的无速率迭代接收机技术研究，重点解决迭代时变双向闭环宽带多普勒估计与补偿问题。研究意义在于促进逼近信道容量通信理论的发展，为在高度弥散、动态以及大延时的海洋环境中建立可靠的、逼近信道容量的水声通信链路提供切实可行的手段。

水声通信技术在军事和民用水下信息传输领域扮演着愈来愈重要的角色，虽然水声通信技术的研究已经开展了三四十年，但在高度弥散、动态以及大延时的海洋环境中建立可靠的、逼近信道容量的水声通信链路仍面临着巨大的挑战。针对可靠的、逼近信道容量的水声通信技术面临的诸多挑战。本项目完成了基于超Nyquist结构的无速率水声单载波迭代接收机技术的研究，突破了无速率码及其预编码技术的编译码技术、迭代窄带双扩信道的估计与均衡、迭代宽带双扩信道多普勒估计与补偿、均衡与译码技术等相关关键技术；并通过大量的仿真实验、多次水池试验、1次湖试、2次海试验证了提出的技术方案的有效性。通过本项目的顺利实施，取得了一下研究成果：（1）、通过湖试和海试试验的验证，研究提出的通信技术可以达到以下的通信技术指标：湖试及海试条件下，通信距离大于3公里（吉林省松花湖湖试条件）/30公里（南海海试条件），可实现逼近信道容量的可靠传输；（2）、完成了4份年度进展报告；（3）、发表高水平的SCI论文7篇，EI论文21篇，出版学术专著1部，待出版专著1部（科学出版社，预计2019年出版）；（4）、培养博士研究生3名，硕士研究生12名。