Localization of unknown indoor wireless transmitter

Many management tasks, for instance optimizing placement of a new Wi-Fi or femtocell access points (AP), or detecting unauthorized transmitter (Tx), requires the ability to locate individual Tx inside buildings. Available techniques to locate Txs require extensive war driving measurements and significant computations, or complex and additional hardware. This paper presents a time-efficient method, based on only collected received signal strength (RSS) data to estimate the location of unknown Tx installed inside a multi-storey building. Three-stage algorithm is proposed. Firstly, the building´s location from which the signal is transmitted from, is defined on the area map. Secondly, the floor level of the determined building on which the unknown Tx is installed, is determined. Finally, 2-dimensional location coordinates of Tx and the path loss parameters are jointly estimated. The method is evaluated using realistic simulated data obtained from iBuildNet^® wireless network design and optimization tool developed by Ranplan. The simulation results confirm that developed algorithm works accurately and is especially helpful to locate an unknown Tx in changing and unknown environments.