Method for estimating satellite navigation direct signal parameter and multipath signal number and parameter

Abstract

The invention relates to a method for estimating satellite navigation direct signal parameter and multipath signal number and parameter; the technical characteristics of the invention lie in that: Dirichlet process DP (alpha, G0) is adopted as the prior distribution of the multipath signal number M, the distribution of M conforms to DP as shown in formula I, the possible number of the multipath signal is obtained by sampling according to the prior distribution; according to the possible number of the multipath signal, an equation of state with parameters of the direct signal and the multipathsignal as the quantity of state is constructed as x(k+1)=Fx(k)+w(k) and an observation equation of observation vector is constructed as y=aR(tau)+n; according to the possible number of the multipath signal, the equation of state and the observation equation, a particle filtering method is adopted to estimate the parameters of the direct signal and the multipath signal, and simultaneously the number of the multipath can be determined. The invention can estimate number and parameter of the multipath signal under the condition of not knowing the number of the multipath signal, thus being suitablefor the condition that the direct signal is larger than the multipath signal, as well as the condition that the direct signal is smaller than the multipath signal.

Description

technical field [0001] The invention relates to a satellite navigation direct signal parameter and multipath signal number and parameter estimation method, which belongs to the satellite navigation signal processing algorithm. Background technique [0002] The satellite navigation multipath signal estimation algorithm eliminates the influence of the multipath error of the satellite navigation system (including GPS, GLONASS, GALILEO, Beidou system, etc.) on the positioning results by estimating the multipath signal. [0003] The research on estimation methods of satellite navigation multipath signals is divided into estimation methods based on maximum likelihood and methods based on Bayesian estimation. The method based on maximum likelihood estimation finds the optimal estimated value of the parameters by maximizing the likelihood function. For this method, refer to "K.Kaindl, N.Niklasch, Improving Path Separation in a Multipath Environment by Applying Nonlinear Estimation T...

AI Technical Summary

Problems solved by technology

[0007] Various existing multipath signal estimation algorithms have a common feature, that is, before applying them to estimate multipath signals, the number of multipath signals must be assumed first, and then the corresponding model can be constructed to estimate the parameters of multipath signals. Estimation, if the number of multipath signals is not known in advance, the structure of the model cannot be determined. When the assumption of the number of multipath signals does not match the reality, the error will be large, and the estimation accuracy will be greatly reduced

[0008] In the actual environment, such as urban areas where multipath has a large impact, when the carrier carrying the receiver moves, the multipath reflections from reflectors such as buildings and vehicles are constantly changing, so it is difficult to determine at a certain moment The number of multipath signals, in this case, applying the existing algorithm will lead to a large error

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