Indoor Positioning Using WLAN Signal Strength

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  • 김숙자 (서울대학교 전기공학부) ;
  • 이진현 (건국대학교 전자정보통신공학과) ;
  • 지규인 (건국대학교 전자정보통신공학과) ;
  • 이장규 (서울대학교 전기공학부) ;
  • 김욱 ((주)삼성전자)
  • Published : 2004.08.01


Outdoors we can easily acquire our accurate location by GPS. However, the GPS signal can't be acquired indoors because of its weak signal power level. Adequate positioning method is demanded for many indoor positioning applications. At present, wireless local area network (WLAN) is widely installed in various areas such as airport, campus, and park. This paper proposes a positioning algorithm using WLAN signal strength to provide the position of the WLAN user indoors. There are two methods for WLAN based positioning, the signal propagation method uses signal strength model over space and the empirical method uses RF power propagation database. The proposed method uses the probability distribution of the power propagation and the maximum likelihood estimation (MLE) algorithm based on power strength DB. Test results show that the proposed method can provide reasonably accurate position information.


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