基于天基测控模式的扩频安控终端采用传统捕获同步算法，安控处理时延长，无法满足安控实时性要求，高可靠性、快速响应同步算法的构建是扩频安控终端的关键技术。扩频安控终端同步算法，首先采用基于惯性导航+卫星导航信息辅助的部分匹配滤波与分段平均FFT谱估计结合的二维捕获算法，将惯性导航+卫星导航上报的运动状态信息转化为多普勒频偏与多普勒频偏变化率的估计值，有效缩小了多普勒频偏范围，缩短了捕获时间，分段平均FFT谱估计降低了功率谱估计的方差。载波跟踪环采用二阶锁频环辅助三阶锁相环，实现了高机动、大范围跟踪。在此基础上，载波跟踪环、伪码跟踪环增加了防假锁判决机制，可快速跳出假锁状态。工程应用表明：采用所提算法，扩频安控终端的安控处理时延不大于500ms，满足实时性要求。

The traditional acquisition synchronization algorithm for spread spectrum security terminal had some shortcomings. This approach prolonged the security control processing time and failed to meet real-time requirements. The development of a high reliability and fast response synchronization algorithm is a key technology for the space-based TT&C receiver. To address this, a two-dimensional acquisition algorithm is employed, which is based on partial matched filtering assisted by inertial navigation + satellite navigation information and piecewise average FFT spectrum estimation. This conversion effectively reduces the Doppler frequency offset range and shortens the acquisition time. Additionally, the piecewise averaging FFT spectrum estimation decreases the variance of power spectrum estimation. Furthermore, a second-order frequency-locked loop assisted by a third-order phase-locked loop is used in the carrier tracking loop to achieve high maneuverability and wide range tracking. An anti-false lock decision mechanism has been added to both the carrier tracking loop and pseudo code tracking loop to quickly escape from false lock states. Engineering applications have demonstrated that the use of this proposed algorithm results in a safety control processing delay of no more than 500 ms for the spread spectrum safety control terminal, thus meeting the real-time requirements.

国家自然科学基金项目（面上项目，重点项目，重大项目）,十三五装备预先研究项目 41418060203