面向非平稳通信波形设计的安全可控序列设计

Non-stationary communications signal design based on the dynamic physical parameters is a novel design compared with the conventional secure communications signal design. Among them, the secure and controlled sequence design is one of the key issues for the design of non-stationary communication system design. Through the study on the mechanism of the non-stationary communications waveforms, propose the means to build non-stationary communications waveforms by using pseudorandom sequences to control the physical parameters of communications waveforms; By revealing the internal relations between the pseudorandom sequences and non-stationary communications waveforms, construct the pseudorandom sequences by the means of finite field methods, and then construct the non-stationary communications waveforms, thereby laying the foundation for the realization of non-stationary communications. This project analysis the distribution of the m-order moment on the sample space of the stochastic processes parameter on different time, establish non-stationary metrics by defining the difference sequence of m-order moment, which provide a theoretical basis for measuring anti-detection and anti-interception performance of non-stationary communication signals. Research results of the project have a greater reference value for the study on the anti-detection and anti-interception of communication signals and systems, but also have a positive impact on the physical layer security. In addition, non-stationary signals is widely present in a number of engineering fields such as communications, radar and medical. Therefore, the research results of this project has great theoretical significance and engineering applications value.

基于物理参量非平稳化的非平稳通信信号设计是突破传统安全通信信号设计的新方法。其中，决定系统非平稳性质的安全可控序列设计是非平稳通信系统设计的核心问题之一。本项目通过对非平稳通信波形机理的研究，提出用伪随机序列控制通信波形物理参量的非平稳通信波形构建方法；揭示伪随机序列和非平稳通信波形间的内在联系，基于有限域分析方法构造具有非平稳化特性的伪随机序列，进而构造出非平稳通信波形，为实现非平稳通信奠定基础。本项目对于不同时间点上的随机过程参量分析其样本空间上m阶矩的分布特征，通过定义m阶矩的差值序列来建立随机过程的非平稳度量，为衡量非平稳通信信号的抗侦测、抗截获性能提供理论依据。本项目的研究成果对抗侦测、抗截获通信信号和系统的研究有较大参考价值，对物理层安全通信也有积极影响。此外，非平稳信号广泛存在于通信、雷达、医学等多个工程领域，因此，本项目的研究成果具有较大的理论意义和工程应用价值。

现有通信机理下的通信信号均具有平稳特性，当前有多种检测平稳信号的方法与技术，使得平稳信号的参数存在安全威胁，伪随机序列是控制或构建非平稳通信波形的核心途径。将伪随机序列通过一定的对应关系去控制通信波形的某一种物理参量或某几种物理参量，使得最终输出的通信信号消除循环平稳特性和各态历经特性而具备非平稳特性。设计具有非平稳特性的通信信号传输机理，是突破传统通信信号机理的新技术，基于非平稳通信信号的非平稳通信系统将具有重要的理论意义和应用价值。本项目提出了非平稳通信信号波形的构造途径和构造方法，总结和分析了非平稳性的度量指标；提出了一类随机性良好的伪随机序列；设计了非平稳性良好的伪随机序列，该序列的非平稳度逼近维纳过程的非平稳度；基于希尔伯特黄变换提出了两类改善端点效应和模态混叠问题的非平稳信号分析方法。