A weighted center of mass based trilateration approach for locating wireless devices in indoor environment

This paper presents a weighted center of mass based trilateration approach for locating a wireless device based on the signal strength received from the access points at known locations. This approach mainly consists of two phases: (1) The calculation of distance from RSSI values of various access points as received by the mobile device, (2) Determination of the most probable location of wireless device using coordinates of various known or fixed access points and calculated distances of the device from those access points. Kalman filter is also used in both phases in order to remove the measurement noise component and to increase the accuracy of estimation. The proposed algorithm provides a solution for location tracking of mobile devices in indoor environment where the configuration of access points like transmit power etc., is not fixed and the movements in environment affecting attenuation of signal is so unpredictable that any mathematical modeling of indoor RF signal propagation is infeasible.

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