基于加权分数傅立叶变换的网络空间物理层安全机理研究

With the proliferation of information technology and the emergence of cyberspace, wireless communication services have been extremely diversified, which also give rise to a commensurate increase in security concerns. However, the lack of secure functionalities at physical layer makes the emerging cyberspace more vulnerable to malicious attacks. . To address the cyberspace’s high secrecy demand at lower layers, a novel physical layer security paradigm that can utilize existing multi-domain resources for security objective is proposed. The concept of weighted fractional Fourier transform (WFRFT) and Multi-domain coordination are adopted as main investigating tools for the proposed scheme. Particularly, this project starts with the investigation of intrinsic features associated with wireless signal for the sake of enhancing the protection of wireless communications. The superiority and practicability of WFRFT are investigated from a security perspective. Whereby, the physical layer security mechanism of WFRFT is verified, and a WFRFT-based physical layer security system is modeled to fulfill various signal feature demands(PAPR, BER ,capacity etc.), with enhanced security performance. Moreover, coordination research on multi-domain resources, such as time, frequency, code, space and processing domain, is devoted to theoretically support the upcoming studies, including “physical layer feature convertible signal waveform design”, “signal feature-based physical layer authentication” and “signal self-interference based anti-interception”. With all the aforementioned research contents, this project aims at proposing a configurable, scalable and compatible physical layer security paradigm for the emerging cyberspace.

随着信息技术的广泛应用和网络空间的兴起发展，无线业务广元化及网络类型多样化对通信安全提出更为苛刻的需求，而无线系统中物理层安全功能的缺失，致使网络空间极易形成单向透明不对称的态势。为此，本课题以未来网络空间对高效能物理层安全需求为背景，基于分数域处理和多域协同信号设计的思想，创新性地提出一种对现有多域资源综合利用的物理层安全传输新体制。课题研究以信号物理层特征为切入点，结合具体通信场景下的信号波形特征需求(如峰均比、误码性能、系统容量等)，深入探讨分数域信号处理的物理层安全机理，在统一的框架下构建兼顾不同通信需求的多域协同物理层安全系统模型；在此基础上，围绕时、频、码、空等多“域”资源协同展开研究，突破“特征动态可控的物理层安全波形设计”、“基于信号特征的物理层认证”及“信号空间自干扰抗截获”等关键技术；以期最终构建一套可配置、易扩展、兼容性强的一体化网络空间物理层安全波形设计及传输体制。

针对无线系统中物理层安全功能的缺失，致使网络空间极易形成单向透明不对称的问题，本课题以未来网络空间对高效能物理层安全需求为背景，加权类分数傅里叶变换为理论基础，多域协同信号为研究对象，提出了一种对现有多域资源综合利用的物理层安全传输波形体制，以应对未来网络空间对高效能物理层安全的需求。课题研究以信号物理层特征为切入点，基于加权类分数傅立叶多域多维信号模型，对信号域拓展、协同的特性进行分析，深入探讨了分数域信号处理的物理层安全机理，构建了兼顾不同通信需求的多域协同物理层安全系统模型；在此基础上，根据加权信号物理层特征多态可控性，建立了基于加权分数傅立叶的物理层安全体系架构，并提出了加权分数傅立叶域物理层认证方案，通过理论分析以及硬件设备验证，明确了方案的累计效用和认证性能优势；此外，根据加权信号多域协同优势，提出了基于加权分数傅立叶的多域协同的安全传输方法及多用户场景下的协同快速实现算法，高效、稳定地实现了基于加权分数傅里叶变换的多用户协作安全传输。最终，项目建立了兼容 LTE 体制的 WFRFT 预编码的演示验证平台，并验证了演示平台的抗截获传输性能及自适应抗干扰能力，构建了一套可配置、兼容性强的一体化网络空间物理层安全技术体系。