高动态吸波和散射信道下非均匀多载波编码调制技术研究

Recently, the hypersonic vehicle is playing an increasingly strategic role in the future war. The world's major powers are stepping up the development and equipment of these hypersonic vehicles, of which the communication system is a quite important part.This class of aircraft have some common characteristics, extremely fast flight speed, high flight altitude, and hostile electromagnetic environment, especially the absorption and scattering of electromagnetic waves caused by plume, ionosphere and the plasma sheath . As a result, the communication channel is under high dynamic change, with low data transmission rate and poor transmission reliability. More seriously, sometimes the communication interruption may lead to aircraft crash. Aiming at settling these challenges, this project focuses on several key technologies for hypersonic vehicle communication. To be more specific, (1) aiming at the fact that the communication channel of hypersonic vehicle is complex and dramatically changeable, this project introduces the Multiphase Integrated Channel Model (MICM), to describe the high-dynamic absorbing and scattering channel more effectively. (2) Based on characteristics of the channel model, this project makes full use of the flight parameter information and the real-time perception results of channel environment, to study the nonuniform spacing and diversity modulation technology. The ultimate goal is to establish a novel high-efficient communication system of high-dynamic absorbing and scattering channel with the ability to predict and match the hostile high-dynamic channel actively. (3) In view of the flight parameters and the real-time perception results of channel environment, this project constructs a kind of novel active channel coding with higher reliability, according to the mutual information maximizing principle. In a word, this project aims at providing new theoretical and technical foundations for the communication system design of hypersonic vehicle in the future.

当前，世界各国都在投入巨资开展超高声速飞行器的研制，通信系统是超高声速飞行器的重要组成部分。这类飞行器速度极快、飞行高度高且距离远，尾焰、电离层和等离子体鞘套诸因素导致对电磁波的吸收和散射，信道特性变化剧烈，因此通信传输速率低、可靠性差、易中断，超高声速飞行器的高效可靠通信体制设计面临巨大挑战。本项目拟开展以下关键技术研究：1）针对超高声速飞行器通信信道复杂和变化剧烈的问题，引入多相综合信道模型，有效描述高动态吸波和散射信道；2）基于信道模型特征，利用飞行参数信息和信道环境实时感知结果，研究非均匀载波和分集调制技术，建立能够预测和主动匹配恶劣高动态吸波和散射信道的高效新型通信体制；3）基于信道状态和飞行参数，研究匹配高动态吸波和散射信道状态的新型主动式高可靠信道编码调制技术，依据互信息量最大化信息传输效率。本项目的研究将为超高声速飞行器的高效可靠通信体制设计提供理论依据和技术支持。

高超声速飞行器有着巨大的战略价值，作为军事领域以及航空航天产业的研究热点受到世界各国的广泛关注。测控通信系统提供了飞行器运行各阶段的控制指令，是高超声速飞行器的关键模块之一。高超声速飞行器速度极快、飞行高度高且距离远，尾焰、电离层和等离子体鞘套诸因素导致对电磁波的吸收和散射，信道特性变化剧烈，因此通信传输速率低、可靠性差、易中断，超高声速飞行器的高效可靠通信体制设计面临巨大挑战。. 本课题从解决高超声速飞行器通信信道的快时变、大多普勒频偏、频率选择性衰落和高中断等问题出发，建立了高动态吸波和散射信道多相综合模型。针对信道特征，提出了频谱可调的非均匀多载波调制技术、鲁棒的联合信源信道线性索引量化编码（Quantization with Linear Index Coding，QLIC）、复杂度可接受的高增益多进制低密度奇偶校验（Low-Density Parity-Check，LDPC）编译码方案以及低中断概率自适应匹配信道的多载波体制。理论分析和仿真实验表明本课题提出的调制编码技术能够在高动态吸波和散射信道下保证数据传输的可靠性，提高传输的效率，降低数据的中断概率，能够为我国高超飞行器通信系统的设计提供理论支撑和参考。. 课题组在自然基金资助期间，发表论文44篇，其中SCI检索论文29篇（含IEEE Transactions论文11篇），EI检索论文15篇；申请专利14项，特邀报告4篇。在学生培养方面，从事相关研究的博士研究生10人，已毕业5人；硕士研究生11人，已毕业8人。