基于非线性滤波估计的北斗B1 QPSK 信号跟踪方法

复杂环境下的多普勒频移变化及信号功率衰减均会对载波准确跟踪造成影响. 在研究北斗卫星B1 频点信号结构的基础上, 建立以环路中相关积分值为观测量的非线性EKF 模型和UKF模型, 并提出利用滤波估计状态量进行状态反馈控制的方法, 从而解决了载波跟踪环路在高动态及弱信号环境中难以高性能工作的问题. 实验结果表明,状态反馈控制的EKF 模型和UKF滤波模型能准确地跟踪弱信号及高动态下的信号变化, 从而有效控制跟踪误差, 为实现快速准确的载波跟踪奠定了基础.

BeiDou B1 quadrature phase shift keying carrier tracking method based on nonlinear Kalman filter

Doppler shift and signal power attenuation in the complex environment both can make damage in the accuracy of carrier tracking. Therefore, the non-linear Kalman filter for carrier tracking is designed, which makes correlated observations in the EKF and UKF model based on the analysis of the structure of BeiDou B1 signal. By using measurements from the estimation of filtering in feedback control of the carrier tracking loop, higher and more stable performance can be given in high dynamic and weak signal environments. Finally, the test results show that the feedback control-based EKF and UKF model can perform precise carrier tracking, and make a good limitation of loop error, both of which lead to realization of high performance of signal tracking.