基于稀疏傅立叶变换的北斗接收机关键技术研究

In the Beidou space-based link, rapid capture technology and anti-jamming technology has become the focus of the Beidou receiver under the environment of complex electromagnetic interference which caused by high dynamic and confrontation of aircrafts. There exists problems such as high complexity and large amount of computation in the research of pseudo-code capture algorithm in parallel and suppression algorithm of interference, which seriously constraints the application of Beidou system in military communications and navigation.However, there exists a high degree of overlap between the two algorithms mentioned above while at the same time both the interference signal in time-domain and despreading peaks in frequency-domain are sparse. Inspired by the two points above, this topic will take advantage of the SFT in the Beidou receiver signal processing.Based on SFT, we will combine anti-jamming and capture together to study the signal processing of DS system. We will use the low computational complexity of SFT to realize the fast and reliable reception of Beidou signals under the environment of strong interference and high dynamic to explore cutting-edge theories for the future development of Beidou anti-jamming receiver with low-complexity and high-performance.

在以北斗系统为平台的天基链路中，飞行器的高动态特性和对抗下的复杂电磁干扰使得快速捕获技术和抗干扰技术成为了北斗接收机研究的重点。目前伪码并行捕获算法与干扰抑制算法均存在复杂度高、运算量大等问题，严重制约北斗系统在军用通信与导航方面的应用。频域并行捕获算法与变换域干扰抑制算法具有高度重合性，干扰信号与解扩后相关峰分别在频域和时域具有稀疏性。受上述两点启发，本课题将稀疏傅里叶变换应用于北斗接收机信号处理中，研究基于稀疏傅里叶变换的直扩系统抗干扰和捕获联合处理算法，利用稀疏傅里叶变换极低运算复杂度的特点，解决强干扰、高动态环境下北斗信号快速可靠接收的问题，为未来低复杂度、高性能北斗抗干扰接收机的研制进行前沿理论探索。

在以北斗系统为平台的天基链路中，飞行器的高动态特性和对抗下的复杂电磁干扰使得快速捕获技术和抗干扰技术成为了北斗接收机研究的重点。然而，目前基于直扩系统的伪码并行捕获算法与变换域干扰抑制算法仍然存在复杂度高、运算量大等问题，在一定程度上限制了卫星系统在军用通信与导航等方面的应用。.本报告针对基于直扩通信的导航卫星接收机设计中的信号快速捕获及抗干扰算法展开研究。考虑到频域并行捕获算法与变换域干扰抑制算法具有高度重合性以及解扩后相关峰的稀疏性，本课题在大量理论分析的基础上，研究基于稀疏傅里叶变换的直接序列扩频系统抗干扰和捕获联合处理算法。一方面，提出将级联的频域干扰抑制算法与捕获算法合二为一的新思路，将信号处理复杂度降低了一倍；另一方面，为进一步降低联合算法的复杂度，将SFT技术应用到频域并行捕获当中，用以简化联合算法中的IFFT流程。理论和仿真结果均表明：虽然基于SFT的频域捕获-抗干扰联合算法存在轻微的性能损失，但它能以极低的计算量实现强干扰、高动态环境下卫星信号的快速、可靠接收。