卫星导航系统中多径信号干扰分析

摘要

The multipath effect now becomes the main error source of modern high-precision satellite navigation system. The generation and characteristics of multipath are described. The multipath signal and direct signal comprised in the synthetic signal are correlated with the local recurrence code in the receiver, thus resulting in the distortion of correlation function and influencing the code loop phase error, and further leading to the error of pseudo range measurement. Based on description of carrier loop and the code loop of the receiver, this paper focuses on the multipath influence on the receiver loops, and discusses in detail the in-phase and inverse-phase multi-path signals and their resulting correlation-peak distortions of navigation signal, and it is concluded that the short-delay multipath signal has fairly great influence on the correlation function.%多径效应已成为现代高精度卫星导航的主要误差源。介绍多径信号的产生及特点，推导出多径与直达信号进入接收机后与本地复现码相关，导致相关函数畸变，影响码环鉴相误差，进而导致伪距测量上的误差。在对接收机载波环和码环进行介绍的基础上，重点研究多径对接收机环路的影响，并深入分析同相和反相多径对导航信号造成的相关峰畸变，得出中短延迟的多径对相关函数影响较大。