Chinese Journal on Internet of Things ›› 2023, Vol. 7 ›› Issue (4): 63-71.doi: 10.11959/j.issn.2096-3750.2023.00348

• Theory and Technology • Previous Articles    

A UWB NLOS identification method under pedestrian occlusion

Tong WU1,2, Yeshen LI1,2, Zhenhuang HUANG1,2, Yu ZHANG3, Wanle ZHANG1,2, Ke XIONG1,2   

  1. 1 Engineering Research Center of Network Management Technology for High-Speed Railway of Ministry of Education, Beijing Jiaotong University, Beijing 100044, China
    2 School of Computer and Information Technology, Beijing Jiaotong University, Beijing 100044, China
    3 State Grid Energy Research Institute Co., Ltd., Beijing 102209, China
  • Revised:2023-07-26 Online:2023-12-01 Published:2023-12-01
  • Supported by:
    The Fundamental Research Funds for the Central Universities(2022JBGP003);The National Natural Science Foundation of China(62071033);The National Key Research and Development Program of China(2020YFB1806903)

Abstract:

Ultrawideband (UWB) is a hot technology for indoor positioning with large bandwidth, strong anti-interference ability, and high multipath resolution capacity.However, due to the complex indoor environment, UWB signal propagation will inevitably be blocked, resulting in non-line-of-sight (NLOS) propagation, which greatly reduces the accuracy of UWB positioning.Therefore, identifying NLOS signals accurately and discarding or correcting them are important to alleviate the problem of the decline in positioning accuracy.The majority of present NLOS identification work focuses on scenes with building structures such as walls.Further discussion is needed for scenes obscured by pedestrians.Since the impact of human obstacles on the signals is more complex and cannot be ignored, the NLOS identification under pedestrian occlusion was studied.By comparing a variety of machine learning methods and signal feature combinations, the random forest method based on the three-dimensional features of the first path signal power, the received signal power, and the measured distance was proposed.These features with fewer dimensions and easy extraction were used to achieve a high identification percentage for NLOS.The experimental results based on the measured data of different devices show that the NLOS identification accuracy based on the proposed method reaches 99.05%, 99.32% and 98.81% respectively.

Key words: UWB, indoor positioning, NLOS identification, random forest

CLC Number: 

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