基于最大似然估计的GPS多径估计  

GPS Multipath Estimation Based on Maximum Likelihood Estimation

作　　者：刘亚欢[1] 田宇[1] 李国通[1] 

机构地区：[1]中国科学院微小卫星联合重点实验室,上海200050

出　　处：《宇航学报》2009年第4期1466-1471,共6页Journal of Astronautics

基　　金：国家863计划(2006AA12Z301)

摘　　要：当存在多径信号时,基于伪距测量的GPS(Global Position System)定位接收机跟踪的是直射信号和反射信号组成的复合信号的相位,这将造成伪距测量误差和定位误差[1]。提出了一种相关输出的线性模型。在无噪的情况下,多径信号的位置和幅度能够被准确估计。在加性高斯白噪声信道下,利用最小二乘法得到多径信号的位置和幅度的最大似然估计,并对该估计的噪声性能做出了理论分析和仿真;分析表明观测间隔和接收信噪比是决定估计性能的关键。When muhipath happens, the GPS receiver based on pseudorange measurement tracks the phase of signal which is composed with LOS （Light of Sight） signal and reflecting signal, this will cause pseudorange error and position error. A Linear Model of correlation outputs is builded. The accurate amplitudes and positions of the multipath signals are obtained with noiseless channel and the Maximum Likelihood Estimations of positions and amplitudes of multipath signals are obtained with AWGN channel, and then the theoretic analysis of the noise performance and simulation are given. Analysis shows that the key of estimation performance is observation interval and signal to noise ratio.

关 键 词：多径估计 最大似然估计 GPS DLL 

分 类 号：P228.4[天文地球—大地测量学与测量工程]