Abstract
The existing positioning methods that use received signal strength indication (RSSI) and channel state information (CSI) may suffer from multipath and shadowing in a complex wireless environment, which can result in more positioning errors. This paper proposes a method for accurate multilabel positioning in the non-line-of-sight (NLOS) environment. First, the position is roughly estimated using the orthogonal variable spreading factor (OVSF-TH) algorithm, which can automatically match the signal interference. The ultra-wideband (UWB) spectral density and pulse amplitude in the time domain are used to determine the direction of the label and enhance estimation of the mobile label direction. Then, the location of the tag is obtained by triangulation, and a coordinate-based coordinate estimation method is proposed to calculate the relative displacement of multiple tags to determine the label position. Finally, by setting up a real experimental environment, the influence of the number of base stations on the accuracy and the performance of the localization method under different circumstances are analyzed. The theoretical analysis and experimental results show that the method is simple to deploy, inexpensive, and very accurate in terms of positioning, having a clearly effective indoor positioning accuracy. Compared with other existing positioning methods, this method can achieve more accurate positioning. Moreover, it has important theoretical and practical applicability because of the reliability and accuracy of indoor positioning in an NLOS environment.
Highlights
The use of ultra-wideband (UWB) signals to locate objects in indoor complex multipath environments has the advantages of high positioning accuracy, strong anti-interference, and low power consumption
In view of the problems raised in the above references, this paper focuses on the accurate multilabel positioning method in the NLOS environment
Each experimental scene is 3 m∗3m in size, and the base station 0, the base station 1, the base station 2, and the base station 3 are arranged in a counterclockwise direction
Summary
The use of ultra-wideband (UWB) signals to locate objects in indoor complex multipath environments has the advantages of high positioning accuracy, strong anti-interference, and low power consumption. UWB positioning technology is mainly based on time-of-arrival (TOA) algorithms, such as the maximum likelihood estimation algorithm [2], the threshold crossing (TC) threshold search algorithm [3], and the decoupled multiuser ranging (DEMR) algorithm [4] The use of these algorithms to achieve positioning requires at least three base stations, with each base station accurately synchronized to the same time, which may increase the cost of the system. In a dense multipath propagation environment, especially in an indoor environment, the line-of-sight (LOS) path between a reference tag and the tag to be tested is blocked due to the influence of the non-line-of-sight (NLOS) signal. This signal is difficult to accurately estimate, reducing the accuracy of ranging and positioning [8]. If the received signal is from an LOS environment, it can be addressed without any processing, and the estimated value of the ranging can be directly obtained; a more accurate tag position
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
