A new method for improving Wi-Fi-based indoor positioning accuracy

摘要

Wi-Fi- and smartphone-based positioning technologies are playing a more andrnmore important role in location-based service industries due to the rapidrndevelopment of the smartphone market. However, the low positioning accuracyrnof these technologies is still an issue for indoor positioning. To address thisrnproblem, a new method for improving the indoor positioning accuracy wasrndeveloped. The new method initially used the nearest neighbour (NN) algorithmrnof the fingerprinting method to identify the initial position estimate of thernsmartphone user. Then two distance correction values in two roughlyrnperpendicular directions were calculated by the path loss model based on therntwo signal strength indicator values observed. The systematic error from the pathrnloss model were eliminated by differencing two model-derived distances fromrnthe same access point. The new method was tested and the results compared andrnassessed against that of the commercial Ekahau RTLS system and the NNrnalgorithm. The preliminary results showed that the positioning accuracy hasrnbeen improved consistently after the new method was applied and the root meanrnsquare accuracy improved to 3.3m from 3.8m compared with the NN algorithm.