검색공간 설정을 이용한 효율적인 핑거프린팅 기법

Abstract

This paper deals with the position determination method of a mobile device which uses a database correlation technique with the received signal strength of WLAN AP complying with IEEE 802.11 standards. The computation time of a position determination method using database correlation technique directly depends on the area of service coverage, the number of reference points in the fingerprinting database, the density of WLAN AP, etc. This paper presents an efficient method which improves the computation time by setting a search space for performing the database correlation. The coarse position of a mobile device is determined using the centroid technique with observations of the received signal strength, and is used to set a search space. It is distinguished whether each reference point of the fingerprinting database is being inside the search space or not, and the database correlation using Euclidian distance method is performed to the reference point being inner search space. And then, the final position of mobile device is determined by KNN. The computer simulation shows that the proposed method reduces the computational burden and provides similar performance of the positioning accuracy in comparison with the conventional database correlation technique using KNN and the whole database correlation.