Reasonable Resolution of Fingerprint Wi-Fi Radio Map for Dense Map Interpolation

Abstract

In Wi-Fi based location fingerprinting, the cost of building a radio map is high. Though interpolating a coarse radio map into a dense one may reduce the cost, low accuracy at space discontinuity such as walls deteriorates the reliability of interpolated radio map. We present an interpolation of radio map, which preserves the discontinuity of received signal strength in accordance with the layout of a building. Furthermore, a closed form solution of reasonable resolution of radio map is derived. Experimental results show that, with sampling density >35 %, the localization accuracy is comparable to that of a full density map.