Indoor Positioning Fingerprint Method Based on Propagation Delay

This paper introduces a method of indoor positioning where multipath propagation exists due to reflective obstacles. In this method the fingerprint pattern is yielded by analyzing propagation delay data. Unlike received signal strength (RSS) level data needed for conventional RSS fingerprint method, propagation delay data needed in this method is not altered by reflection from obstacles, meaning: while conventional RSS method requires actual measurements, using the proposed method, one can construct finger print pattern by mere analysis. Furthermore, the results from this method are more accurate and less ambiguous than those of RSS. This is due to the fact that whereas the signal strength level data is received at one instance, the propagation delay data as its nature suggests is received at a number of separate instances meaning it contains more information. The paper also provides an example to demonstrate the simplicity of the method and the accuracy of its results, which for the mentioned problem are of an average error of less than 3.7cm and a variance of less than 6.5cm.