空天高动态宽带接入传输理论与技术

An aerospace network consists of air-based platforms, satellite constellation networks and other aerospace nodes. It has three typical properties of large scale in time and space, high dynamic topologies and complex interferences in open space. The properties cause enormous technical challenges such as dynamic adaptation between link transmission rate and time-variant channel, time-variant resources and burst traffic requirements, network coding and variable minimum-cut capacity. From the viewpoint of the aeronautical application of distributed satellite constellation networks, there are three scientific problems in high dynamic aerospace broadband access transmission, including rate adaptive transmission within large range for time-variant channel, time-delayed feedback control for access system with time-variant resources, and adaptive network coding of time-variant channels transmission matrix. For these problems, this project carries out three research topics, i.e., continuous rate adaptive transmission based on random matrices for time-variant channel, delay-tolerant aerospace broadband access and dynamic on-demand resource allocation, and robust sub-space network coding for dynamic aerospace network. The project aims to make a theory and technology breakthrough to improve the efficiency and reliability of aerospace information transmissions on three aspects, including continuous rate adaptive transmission based on random matrices and gradual power assignment in time-variant channel for large range dynamic signals, bandwidth-on-demand (BoD) access control with delay-tolerant feedback for time-variant wireless resources, and robust sub-space network coding adapting to variable transmission matrix of dynamic aerospace networks. Finally, the study results could be used to provide theoretical methods and technical fundamentals for the end-to-end transmissions of aerospace information from a source to its destination.

空天网络由空基平台和星群网络等构成，具有大时空跨度、高动态拓扑和开放空间复杂干扰三大特征，面临链路传输速率与时变信道、时变资源与突发业务需求、网络编码与变化的最小割容限之间的动态适配等巨大技术挑战。项目以分布式星群网络的航空应用为背景，围绕空天高动态宽带接入传输中的时变信道大范围速率自适应传输、时变资源接入系统的时滞反馈控制、时变传输矩阵的自适应网络编码3个科学问题，开展时变信道的随机矩阵映射的连续速率自适应传输、时延容忍的空天宽带接入与资源按需动态分配、动态网络的鲁棒子空间网络编码3个方面的研究，突破时变信道大动态范围信号的随机矩阵映射和渐近功率分配的连续速率自适应传输、时变无线资源的BoD时滞反馈接入控制、动态网络传输矩阵自适应的鲁棒子空间网络编码等理论与技术，提高空天信息传输的效率和可靠性，为空天数据和信息从源到用户的网络通信传输服务能力提供理论方法和技术基础。

针对我国轨位资源、载荷功率等单星资源能力有限问题，通过多星组网协同可提升空间通信传输核心能力。而空间组网协同的通信传输能力直接受制于星群网络的链路频谱效率、网络容量和资源共享效率，在高速传输下更凸显受限资源与复杂环境等干扰的尖锐矛盾，亟需从根本上突破空天动态宽带接入传输的理论方法和技术，综合解决分布式多星网络功率受限、长时延、高动态拓扑等带来的接入传输等难题。项目围绕“资源受限条件下多星分布式协同高效可靠接入传输”核心目标，面向航空用户等开展多星协同接入传输方法与技术研究。.首先，面向高频谱效率传输需求，探索接收端自适应传输技术。提出信噪比大范围的可变权重编码矩阵自适应传输技术和低复杂度译码方法，提升编码调制的频谱效率、适应动态信道，为空天网络高速传输链路提供手段。研制接收端自适应编码调制的半实物系统。.其次，针对空间多用户动态接入需求，提出航空短报文抢断传输方法、自适应预约的长传播容忍MAC技术，减少用户碰撞和接入时延，提高长时延下的用户接入效率。.第三，面向空天动态网络高可靠传输需求，提出了一种基于秩偏差校验的无速率子空间编码（RSSC），以克服由高误码、动态拓扑变化带来传输差错问题，并降低传输冗余度；采用博弈论来分析拥塞网络的资源分配问题，提出一种基于网络编码和路由分发的网络资源共享机制，提高网络传输分发效率。设计、开发一个移动卫星网络协议仿真系统。.实施中，在IEEE TCOM等国际期刊和国际会议上发表论文86篇，其中SCI收录43篇，申请发明专利24项。相关成果应用于空中加油的飞行控制系统与受油机模拟系统、下一代导航星座系统网络协议架构及仿真系统等，获2015年度国家技术发明奖二等奖（课题组成员排名5）一项。获ICNS 2014国际会议等最佳论文奖3项，主办“2015年中荷航空科技论坛”、承办“2014民用飞机航电国际论坛”，参与组织第一届、第二届空间信息网络学术论坛。