A Novel Model for Multipath Delay Estimation and Its Application to a Modified Optimized Position Estimation Algorithm

Nesreen I. Ziedan

Peer Reviewed

Abstract: Multipath and non-line-of-sight (NLOS) signals are a major concern for the application of GNSS positioning in challenging environments. The positioning accuracy degradation, due to these reflected signals, hinders the dependence on GNSS systems. This has led to either integrating GNSS systems with other systems or dropping GNSS systems completely in favor of other systems. This paper proposes a novel system model for multipath delay estimation; the system is called MDE. The MDE system is integrated with a modified version of an Optimized Position Estimation (OPE) algorithm; the new algorithm is called OPEMDE. In conventional navigation algorithms, given code delays, a position is estimated. The proposed MDE system does the opposite. Given a position, code delays are estimated. Since the actual position is not known, the MDE system can serve as a validation algorithm to generate a probability that a candidate position is correct. The idea of the proposed MDE system is to construct a model that relates the errors in the individual pseudorange measurements, of each available satellite, to the errors in the estimated receiver coordinates. The proposed OPE-MDE algorithm keeps track of the most likely paths over several steps. Each path has an associated weight. After several steps, the path with the optimal weight is taken as the estimated path, and the positions that constitute the estimated path are taken as the estimated positions. The OPE-MDE algorithm utilizes the MDE system to compute a probability that a candidate position is correct, where this probability is a part of the path weight. The proposed OPE-MDE algorithm is tested using three scenarios. One of the scenarios has high dynamics properties. The OPE-MDE algorithm shows a 34% positioning accuracy enhancement over a previous optimized position estimation algorithm.
Published in: Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022)
September 19 - 23, 2022
Hyatt Regency Denver
Denver, Colorado
Pages: 2138 - 2152
Cite this article: Ziedan, Nesreen I., "A Novel Model for Multipath Delay Estimation and Its Application to a Modified Optimized Position Estimation Algorithm," Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022), Denver, Colorado, September 2022, pp. 2138-2152. https://doi.org/10.33012/2022.18334
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