Method and system for determining user location in a wireless communication network

A method for locating an addressable source of electromagnetic radiation relative to locations of a plurality of addressable receivers of the electromagnetic radiation in a wireless communication network, the method comprising the steps of:

• establishing a plurality of radio maps having coordinates corresponding to locations in space at which a calibration signal strength from the addressable source is measured at each of a set of the plurality of addressable receivers, each of said radio maps having stored at said coordinates thereof a probability distribution of said calibration signal strength measured at a corresponding one of said set of said plurality of addressable receivers;
• measuring a received signal strength of the addressable source at each of said set of addressable receivers;
• compensating said received signal strength measurement of the addressable source at each of said set of addressable receivers for temporal variations therein;
• and
• identifying one of said coordinates of said plurality of radio maps corresponding to a location in space at which said compensated signal strength of the addressable source would be measured at said set of addressable receivers with maximum probability given said probability distribution of calibration signal strength of said addressable source at said set of addressable receivers, said identified coordinate being a discrete-space estimate of the location of the addressable source.

A system for locating a user in a wireless communication network comprising:

• a computing device having a wireless network interface card installed therein, said wireless network interface card adapted to the wireless communication network;
• a plurality of access points for communicating signals between said wireless network interface card and the wireless communication network;
• a radio map builder for establishing a plurality of radio maps having coordinates corresponding to locations in space at which a calibration signal strength as measured between each of a set of said plurality of access points and said wireless network interface card, each of said radio maps having stored at said coordinates thereof a probability distribution of said calibration signal strength for each of said plurality of access points;
• a radio map database for storing said plurality of radio maps therein;
• a correlation modeler for performing time-series analysis on said calibration signal measurement and compensating said calibration signal measurement for temporal variations therein;
• a correlation handler for compensating a location determination signal between said wireless network interface card and each of said access points;
• and
• a discrete-space estimator for providing a discrete-space estimate of the user location by identifying one of said coordinates of said plurality of radio maps corresponding to a location in space at which said compensated location determination signal would be measured with maximum probability given said probability distribution of calibration signal strength measurements between said wireless network interface card and said plurality of access points stored in said corresponding radio maps.