A modiΡed pseudo-noise（PN） code regeneration method is proposed to improve the clock tracking accuracy without impairing the code acquisition time performance.Thus,the method can meet the requirement of high accura...A modiΡed pseudo-noise（PN） code regeneration method is proposed to improve the clock tracking accuracy without impairing the code acquisition time performance.Thus,the method can meet the requirement of high accuracy ranging measurements in short time periods demanded by radio-science missions.The tracking error variance is derived by linear analysis.For some existing PN codes,which can be acquired rapidly,the tracking error variance performance of the proposed method is about 2.6 dB better than that of the JPL scheme（originally proposed by Jet Propulsion Laboratory）,and about 1.5 dB better than that of the traditional double loop scheme.展开更多
在现有的高动态微弱信号的载波跟踪算法中,针对锁频环(FLL)辅助锁相环(PLL)载波跟踪算法,环路调整不连续,易出现跟踪失锁的问题,给出了FLL与PLL的更优组合算法,并确定了组合环路状态转换的过程以及环路状态转换的门限值,从而优化环路性...在现有的高动态微弱信号的载波跟踪算法中,针对锁频环(FLL)辅助锁相环(PLL)载波跟踪算法,环路调整不连续,易出现跟踪失锁的问题,给出了FLL与PLL的更优组合算法,并确定了组合环路状态转换的过程以及环路状态转换的门限值,从而优化环路性能;针对带宽调整不准确影响环路跟踪性能的问题,分析得出最优带宽值,确定了试探法带宽调整策略,对环路带宽进行实时调整,最终在信噪比为3 d B,且存在加加速度分量时,环路的跟踪误差达到3 Hz左右.展开更多
基金supported by the National Natural Science Foundation of China (60904090)the Postdoctoral Science Foundation of China(20080431306)the Special Postdoctoral Science Foundation of China (20081458)
文摘A modiΡed pseudo-noise（PN） code regeneration method is proposed to improve the clock tracking accuracy without impairing the code acquisition time performance.Thus,the method can meet the requirement of high accuracy ranging measurements in short time periods demanded by radio-science missions.The tracking error variance is derived by linear analysis.For some existing PN codes,which can be acquired rapidly,the tracking error variance performance of the proposed method is about 2.6 dB better than that of the JPL scheme（originally proposed by Jet Propulsion Laboratory）,and about 1.5 dB better than that of the traditional double loop scheme.
文摘在现有的高动态微弱信号的载波跟踪算法中,针对锁频环(FLL)辅助锁相环(PLL)载波跟踪算法,环路调整不连续,易出现跟踪失锁的问题,给出了FLL与PLL的更优组合算法,并确定了组合环路状态转换的过程以及环路状态转换的门限值,从而优化环路性能;针对带宽调整不准确影响环路跟踪性能的问题,分析得出最优带宽值,确定了试探法带宽调整策略,对环路带宽进行实时调整,最终在信噪比为3 d B,且存在加加速度分量时,环路的跟踪误差达到3 Hz左右.
