基于小波分析的BOC信号抗多径码相位估计

BOC signal multi-path mitigation technique based on wavelet analysis

卫星导航接收机需要精确地估计扩频信号的码相位并进行跟踪,估计的精度直接影响伪距测量的精度.卫星信号的多径传播使得简单的相关器估计存在较大的误差,针对未来导航系统普遍采用的BOC(Binary Offset Carrier)导航信号,提出了一种基于小波分析的估计算法来抑制多径误差,仿真的结果表明该算法比传统的窄相关和双Delta技术在性能上有很大的改进.并证明了在采用Haar小波时,该技术与相关器估计方法在极限条件下是等价的,同时该方法的算法复杂度比基于最大似然估计的方法MMT(Multipath Mitigating Technique)要低.

Satellite navigation receives requires to tracking code phase of satellite＇s signals precisely because it affects the precision of pseudo-range directly. However, the multi-path effect introduces quite big errors to the traditional delay locked loop（DLL）-based estimators. An algorithm of multi-path mitigation by the method of wavelet analysis was proposed. The algorithm was formulated in detail. Simulation shows that it greatly improves the estimation performance of code phase compared with narrow correlator and double delta technique. Under certain extreme condition, this technique is equivalent to correlator method when Harr wavelets are adopted. The computation complexity is much lower than muhipath mitigating technique（MMT） technique which is based on mostly likelihood method.