Engineering the Program for Error Reduction in Determining the Location of a Wi-Fi Network Connected Mobile Terminal Indoors

The main challenge the developers of local positioning systems are facing is to ensure a predefined accuracy of determining the mobile object's coordinates. The electromagnetic environment indoors is complicated by the presence of walls (partitions) and ceilings that have a complex structure, as well as furniture, people, animals and other factors that affect the passage of the radio signal. Multipath propagation, interference, additional signal attenuation can introduce a significant error in calculating the coordinates of the target object. An effective method to reduce the measurement error by correcting the experimental data is the Kalman filter. The algorithm, the model's program code and the results of the Kalman filter processing the radio signal level values obtained experimentally are presented in the paper. The results demonstrated in the paper show that the program of the experimental data filtering developed by the authors allows increasing the positioning accuracy from eight to three meters.