卫星导航接收机变换域分析抗干扰理论与方法研究

In order to ensure highly reliable positioning performance of the global navigation satellite system (GNSS) receiver in the complex interfering environment, the required anti-interference capability of the GNSS receiver becomes the key problem to be solved. In this proposed project, the GNSS anti-interference theory and methods based on transformed-domain analyses have been proposed to detect and suppress various forms of interference suffered by the GNSS receiver. In order to deal with the continuous wave interference present in the received GNSS signal, the fractional Fourier transform (FrFT) has been incorporated with the Cohen’s class of time-frequency distribution, then a novel joint hybrid time-frequency analysis method based on the Hadamard product of fractional order Choi-Williams transform and fractional order smoothed pseudo Wigner-Ville distribution has been proposed to detect continuous wave interference for GNSS receivers, and multistage of adaptive infinite impulse response (IIR) multi-pole notch filters implemented in cascade form has been designed to effectively filter out several continuous wave interferences with different frequencies. In order to deal with the pulsed interference present in the received GNSS signal, the fractional Wavelet packet decomposition (FrWPD) has been proposed in interference detection and mitigation for GNSS receivers, which is able to effectively eliminate pulsed interference and avoid distortion of GNSS useful signal. In order to deal with the sweep interference present in the received GNSS signal, the GNSS anti-interference algorithm based on Karnen-Loève transform (KLT) has been proposed, which is able to detect sweep interference hidden in the received GNSS signal with very high sensitivity and effectively suppress spurious sweep interference components, and at the same time, this proposed GNSS anti-interference method based on KLT ensures the integrity of the GNSS useful signal. In order to verify the validity and effectiveness of the proposed GNSS anti-interference theory and methods based on transformed-domain analyses, the GNSS anti-interference experimental platform and Beidou/GPS multimode high performance anti-interference receiver will be designed and developed in this proposed project. This research work will break through the limitations of traditional GNSS anti-interference techniques and the obtained important scientific achievements in this proposed GNSS anti-interference research project will definitely provide fundamental theory and key methods to support the anti-interference design for Beidou satellite navigation system.

为保障卫星导航接收机在复杂干扰环境下高可靠定位性能要求，卫星导航抗干扰成为亟待解决的关键难题。本项目创建变换域分析抗干扰理论与方法有效检测并抑制接收机遭受的多种形式干扰。针对连续波干扰，将分数阶Fourier变换与Cohen类时频分布相结合，创建基于分数阶平滑伪Wigner-Ville分布和分数阶Choi-Williams变换混合时频分布的连续波干扰检测方法，构建多级自适应IIR多极点陷波器滤除不同频率连续波干扰；针对脉冲干扰，创建分数阶小波包分解抗干扰算法，有效剔除脉冲干扰并避免卫星有用信号畸变；针对扫频干扰，建立Karnen-Loève变换抗干扰算法，以极高灵敏度检测扫频干扰并对其有效抑制，并确保卫星有用信号的完整性。研制卫星导航抗干扰实验平台和北斗/GPS抗干扰接收机对所提抗干扰理论进行验证。本研究将突破传统卫星导航抗干扰技术的局限性，为北斗卫星导航抗干扰设计提供重要理论和关键方法。

卫星导航抗干扰技术因直接关系到导航战中“制导航权”问题而深受关注和重视，在卫星导航接收机层面上提高卫星导航系统的抗干扰能力已成为导航战中关键要求。为了保障卫星导航接收机在复杂干扰环境下高可靠定位性能要求，卫星导航抗干扰成为亟待解决的关键难题。本项目创建变换域分析抗干扰理论与方法有效检测并抑制接收机遭受的多种形式干扰。首先，创建了基于Hough变换的卫星导航接收机干扰检测理论，相继提出将平滑伪Wigner-Ville分布、重排小波变换与Hough变换相结合，分别构建了基于平滑伪Wigner-Hough变换、重排小波-Hough变换的卫星导航干扰检测系列方法，能够将传统时频分析对卫星导航干扰信号调频律曲线的全局检测问题转换为参数空间中极小范围内对Hough变换能量峰的局部搜索问题，显著提升了卫星导航干扰检测效能；进一步精确估计卫星导航干扰信号特征参数，从而精准设计自适应滤波算法来有效抑制卫星导航电磁干扰。其次，通过将分数阶Fourier变换与Cohen类时频分布相结合，创建了基于分数域变换分析的卫星导航抗干扰理论。为了解决分数域变换的分数阶次优化问题，构建了分数域变换幅度峰均比模型来确定最优分数域变换阶次，能够将传统的低效二维搜索等效转化为高效的一维搜索问题，极大降低了分数域变换最优阶次的计算复杂度，并通过构建分数域滤波理论以有效抑制卫星导航电磁干扰。本项目研制了卫星导航抗干扰实验平台和北斗/GPS抗干扰接收机对所提抗干扰理论进行验证；本研究突破了传统卫星导航抗干扰技术的局限性，能够为北斗卫星导航抗干扰设计提供重要理论和关键方法。本项目开展的卫星导航接收机变换域分析抗干扰研究成果能够为研制高性能卫星导航抗干扰接收机提供关键理论与核心技术，对于提高卫星导航接收机在复杂电磁环境下的工作性能、增强其在苛刻信号条件下的适用性、安全性与可靠性具有重要意义，从而显著提升我军导航装备在导航战中对复杂电磁干扰的抵抗能力，满足我国军事领域对复杂干扰环境下卫星导航接收机的工作性能要求，并为我国北斗卫星导航系统广泛、可靠的应用提供有力保证。