MH370事件之后，全球航班跟踪问题引起全世界的高度关注，星基ADS-B被认为是未来解决此问题的最有效手段。它利用低轨卫星接收飞机发出的含有实时位置等信息的ADS-B信号，并通过卫星链路和地面网络将相关信息传输给空中交通管理（ATM）部门，从而实现全球航班跟踪。然而，星载ADS-B接收机将面临更低的信噪比和更严重的多重信号交织（重叠，也叫交织干扰）等问题。本项目重点研究利用ADS-B信号的PPM（Pulse Position Modulation）信号特点解决星载ADS-B接收机中多重交织信号分离的问题。主要研究内容包括：稳健的协方差矩阵估计、非平稳信号的信号源个数估计、基于相位恢复理论的无源阵列天线校正、利用ADS-B信号PPM特点的代数解交织算法。有关成果不仅可以推动星基ADS-B系统的研制、验证和建设，还可以推进阵列信号处理、自适应信号处理和现代谱分析等相关理论的发展。

After MH370 disaster, global flight tracking problem has attracted a lot of attention around the world, and space-based ADS-B is considered to be the most promising approach to solve this problem in the future. It receives the signals, including the real-time locations, transmitted by flights with low Earth orbit (LEO) satellites, and relays the collected flight information to ATM (Air Traffic Management) operators through satellite link and ground communication networks. However, space-based ADS-B receiver will have lower signal-to-noise ratio (SNR) and heavier overlapping signals. This project mainly focuses on the separation of overlapping signals for space-based ADS-B by utilizing the PPM (Pulse Position Modulation) properties. The main research contents include: robust covariance matrix estimation, source enumeration for non-stationary signals, array calibration without sources based on phase retrivel algorithm, separation of overlapping signals using the algeraic PPM properties of ADS-B signals. Relevant outcomes can advance the development, construction and verification of space-based ADS-B in the China. Furthermore, it will help the theory development in the fields of sensor array signal processing, adaptive signal processing and modern spectral analysis.