基于FLL/PLL相结合的载波跟踪在导航接收机中的应用

FLL/PLL Combination-Based Approach to Carrier Tracking Applied in Navigation Receiver

载体动态性所引入的多普勒频移给导航接收机中的载波跟踪带来了很大困难。在对比分析了载波频率跟踪(FLL)和载波相位跟踪(PLL)环路各自优点的基础上,提出一种FLL/PLL相结合的载波跟踪方法,以充分发挥FLL动态性能较好、PLL的跟踪精度较高的优点,实现动态环境下快速、精确地载波跟踪;并以相位跟踪环路为例分析了热噪声及载体动态性对环路的影响,得出了环路设计的最佳带宽。理论分析和仿真结果表明,该方法能快速、精确地实现载波的跟踪。

It is difficult for navigation receivers in dynamic environment to realize carrier tracking. Based on analyzing the advantages of PLL and FLL, a new method of carrier tracking, which combining FLL with PLL, is presented in this paper. The effect of thermal noise and vehicle dynamics on carrier tracking loop are also analyzed, and the optimal bandwidth of carrier tracking loop is obtained. The analysis and simulation results indicate that this method could realize carrier tracking quickly and precisely.