Patent ID: 7196662

Claim:
A method for estimating a target device's location, wherein the target device is operable to move in a wireless environment and to communicate with the wireless environment using signals each of which has at least one measurable signal value, the method comprising: forming a plurality of submodels of the wireless environment, each submodel indicating a probability distribution for signal values at one or more locations in the wireless environment; combining the submodels to provide a probabilistic model of the wireless environment, the probabilistic model indicating a probability distribution for signal values at several locations in the wireless environment; making a set of observations of signal values in the wireless environment at the target device's location; and estimating the target device's location based on the probabilistic model and the set of observations, wherein the combining of the submodels comprises: for each submodel, forming a cumulative distribution function and weighting the cumulative distribution function with a relative weight; forming a combination of the weighted cumulative distribution functions; and forming the probability distribution for the probabilistic model based on the combination of the weighted cumulative distribution functions.