Indoor location estimation using virtual fingerprint construction and zone-based remedy algorithm

Location based service relies on precise outdoor and indoor positioning technologies. Intuitively, indoor positioning is more difficult than outdoor positioning because of complicated environment. Fingerprint is a technique proposed to sketch the characteristic of every indoor location by adopting time-consuming measurements in offline phase. To minimize overhead, virtual fingerprint construction scheme (VFCS) with smart antenna system (SAS) has been proposed to fast construct the database based on the log-distance path loss model and interpolation scheme. Our experiments reveal that the VFCS may perform worse when the measured received signal strength levels (RSSIs) are unstable. This paper proposes a simple zone-based algorithm for VFCS to first localize potential zone and then estimate the possible location. Experimental results show that the proposed zone-based algorithm for VFCS and SAS indeed promotes the accuracy of indoor location estimation even using extrapolation scheme.