摘要
针对低信噪比及大多普勒频率变化率情况下的载波同步问题,提出一种基于最大似然估计和Kalman滤波相结合的跟踪环结构.利用最大似然估计在低信噪比环境下准确估计载波频率和相位,并结合Kalman滤波对载波变化进行稳定跟踪.其中利用二分法搜索保证低计算复杂度的同时提高了估计精度.仿真结果表明了此载波跟踪环路良好的跟踪性能.
This paper proposes a new carrier synchronization loop,which is applicable to the tracking environment with low signal-to-noise ratio（SNR） and large rate-of-change of Doppler frequency.Both maximum likelihood estimation（MLE） and Kalman filter are utilized to construct the loop.MLE could estimate carrier parameters accurately when SNR is low,and the Kalman filter would track parameter changes stably.Further,the dichotomous search of periodogram peak is adopted to improve the accuracy of estimation with low computation complexity.Simulation results show that the structure proposed has excellent tracking characteristics.
出处
《北京理工大学学报》
EI
CAS
CSCD
北大核心
2012年第1期67-71,共5页
Transactions of Beijing Institute of Technology
关键词
低信噪比
大多普勒频率变化率
载波同步
最大似然估计
KALMAN滤波
二分法搜索
low SNR
large rate-of-change of Doppler frequency
carrier synchronization
maximum likelihood estimation
Kalman filter
dichotomous search
