Abstract: Aiming at the characteristics of navigation satellite system，theoretical expressions of frequency-locked and phase-locked algorithm are gained according to practical system.The results of AFC algorithm are processed using modified smoothed algorithm，and its covariance is decreased.Simultaneously，Frequency-locked loop and costas loop work synchronously，which shorten the update time of them.Above algorithm is realized using single FPGA，frequency-locked loop and phase-locked loop are implemented by NiosII replacing conventional DSP，and these enhance stability and reliability of system.Some tests prove that contradiction between tracking precision and dynamic performance is resolved basically.All required technical guideline of the system are achieved or exceeded.

Key words: frequency-locked loop, phase-locked loop, high dynamic synchronization, NiosII soft kernel processor

摘要： 针对卫星定位导航系统多谱勒频移大的特点，根据设计的实际系统推导出锁频锁相算法的理论表达式。对叉积算法得到的结果利用改进的平滑算法进行处理，降低了噪声方差。与此同时使锁频环和锁相环同时工作，加快了更新时间。对上述改进算法进行单片FPGA实现，采用NiosII代替传统的DSP对算法的锁频锁相部分进行实现，增加了系统的稳定性和可靠性。通过实验验证，提出的改进算法解决了环路跟踪精度和动态性能不能兼顾的矛盾，各项技术指标达到或超过系统设计的要求。

关键词: 锁频环, 锁相环, 高动态同步, NiosII软核处理器