采用锁频环和锁相环联合捕获的载波跟踪

摘要

针对传统锁频环-锁相环跟踪算法中环路状态转换过渡中出现频率阶跃的问题,提出了一种采用锁频环和锁相环联合捕获的方式替代单一锁频环进行捕获的改进算法,同时对环路状态转换的门限进行了推导.仿真结果表明,改进的算法在转换过程中更加平稳,环路性能得到了优化.在信噪比为-10 dB且存在加加速度时跟踪环路在转换时没有出现频率阶跃,达到了设计目的.%To solve the problem of frequency step in the frequency locked loop(FLL) - phase locked loop (PLL) carrier tracking algorithm's conversion state,an improved algorithm,or PLL and FLL joint acquisi-tion,is proposed to replace the single FLL to acquire frequency,and the loop state transition threshold is deduced.Simulation results show that the improved algorithm is more stable in the conversion process,and the loop performance is more optimal.When there is a jerk rate and the signal-to-noise ratio(SNR) is-10 dB,the frequency step does not appear,which shows the expectation of design.