Multipath mitigation and NLOS detection using vector tracking in urban environments

Abstract

Multipath interference and non-line-of-sight (NLOS) reception are major error sources when using global navigation satellite systems (GNSS) in urban environments. A promising approach to minimize the effect of multipath interference and aid NLOS detection is vector tracking. Therefore the objective of this research is to assess vector tracking in a dense urban environment to determine its effect on multipath interference and NLOS reception. Here, a vector delay lock loop (VDLL) is implemented using an adaptive extended Kalman filter (EKF). This replaces the individual code-tracking loops and navigation filter but retains conventional carrier frequency tracking. The positioning and tracking performance of the conventional and vector tracking implementations with and without a strobe correlator are compared using intermediate frequency (IF) signals recorded in the Koto-Ku district of urban canyon Tokyo city environment. Both static and dynamic tests were performed. It is shown that vector tracking reduces the root mean square positioning error by about 30% compared to an equivalent conventional receiver in urban environments and is capable of detecting long-delay NLOS reception for a GPS receiver without any external aiding. Introduction Multipath interference and non-line of sight (NLOS) reception are major sources of error for

Multiple Faulty GNSS Measurement Exclusion Based on Consistency Check in Urban Canyons

“…Novel receiver-based technique, vector tracking, is proposed to utilize the dynamic model of receiver to predict the code/carrier frequencies [13]. This characteristic can detect both multipath and NLOS signals to further mitigate their effect of localization accuracy [14]. Even through the main benefit of vector tracking is information exchange among the channels, but this sharing procedure could be the source of a new problem for the receiver [15].…”

GNSS Positioning in Non-line-of-Sight Context—a Survey for Technological Innovation

“…• Modified receiver processing strategies -describes approaches were the receiver architectures is modified in order to achieve better signal processing aspects: [59], [60], [61], [62], [63], [64], [65], [66], [67], [68].…”

“…Thus, building boundary data, digital terrain models and building models were used. [8], [14], [33], [50], [80], [98], [99] [4], [14], [30], [33], [35], [92], [47], [48], [50], [51], [58], [67], [68], [70], [74], [81], [82], [83], [85] Via person [18], [22] [43], [49], [66], [71] (No information) [28], [29], [31], [32], [34], [37], [73], [84], [86], [87], [88] Simulation Static measurement…”

GNSS multipath detection using three-frequency signal-to-noise measurements

“…These techniques reduce the code tracking errors due to multipath interference with medium and large path delays. Vector tracking may also be used to reduce the impact of both multipath interference and NLOS reception on the position solution (Hsu et al 2014). …”

“…It builds on some preliminary work presented within and forms part of a wider programme of research to improve GNSS positioning This is the author archive version of the same paper published in GPS Solutions (DOI: 10.1007/s10291-015-0449-1). The final publication is available at http://link.springer.com/article/10.1007/s10291-015-0449-1 © Springer 2015 in dense urban areas (Jiang and Groves 2014;Wang et al 2013;Hsu et al 2014). …”