Journal of Xidian University ›› 2019, Vol. 46 ›› Issue (5): 41-47.doi: 10.19665/j.issn1001-2400.2019.05.006

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Improved weighted k-nearest neighbor algorithm for WiFi fingerprint positioning

WANG Boyuan1,LIU Xuelin1,YU Baoguo2,3,JIA Ruicai2,3,GAN Xingli2,3,HUANG Lu2,3   

  1. 1. College of Information and Communication Engineering, Harbin Engineering Univ.,Harbin 150001, China
    2. The 54th Research Institute of China Electronics Technology Group Corporation, Shijiazhuang 050081, China
    3. State Key Laboratory of Satellite Navigation System and Equipment Technology, Shijiazhuang 050081, China
  • Received:2019-04-13 Online:2019-10-20 Published:2019-10-30

Abstract:

In WiFi fingerprint positioning, the traditional Euclidean distance of signals cannot well reflect the physical distance between position points. To solve this problem, the weighted k-nearest neighbor positioning algorithm is improved. First, the variance of received signal strength is introduced into the calculation of the signal distance, and a weighted Euclidean distance of signals is designed according to the nonlinear relationship between received signal strength and physical distance. Finally, the weighted Euclidean distance of signals is used for the fingerprint matching and the position estimation, and an improved weighted k-nearest neighbor algorithm is proposed. Experimental results in real environment show that the weighted Euclidean distance of signals can be used to measure the physical distance between points more accurately and select more reasonable nearest neighbor reference points. Compared with the existing weighted k-nearest neighbor algorithms, the improved weighted k-nearest neighbor algorithm can significantly improve the accuracy of WiFi fingerprint positioning.

Key words: indoor positioning, fingerprint positioning, weighted Euclidean distance, weighted k-nearest neighbor

CLC Number: 

  • TN96