WiFi based robust positioning system in large scale and weak signal environment

Abstract

WiFi positioning system (WPS) is the best approach for the indoor navigation system in view of cost, availability and performance. Many researcher have been studied the WiFi based positioning technology, but it seems to remain several problems in the WPS. The performance of WPS is dependent on WiFi signal environment. In other words, if there are many WiFi APs are installed, the positioning accuracy is also good. However, the number of WiFi APs is coarse or a received signal strength (RSS) is weak, the positioning accuracy becomes worse. To solve this problem, we utilize the pattern of WiFi scan data that received during moving. The RSS change by moved distance is saved in the buffer. We calculate an accurate position result using this WiFi pattern data. We identify that even a weak WiFi signal is useful in the proposed method because a strong signal is already saved in the buffer. We obtain under three meter maximum error at KIST L1 building using the proposed method.