Patent ID: 8213956
Filing Date: 2012-07-03
Classification: G01S,H04W

Abstract:
1. A method of tracking a state of a mobile electronic device comprising iteratively performing, using at least one apparatus: (i) representing the state of the mobile electronic device using a grid comprising a plurality of cells, each cell representing a region in state space defined by one or more state variables and having a first probability value that the state of the mobile electronic device is within that region in state space, the grid being bounded to include only cells having a probability value above a predetermined threshold; (ii) obtaining measurement signalling indicating values of one or more state variables; (iii) updating the first probability values of the grid and rebounding the grid to obtain an updated grid comprising cells having a second probability value, the second probability value of a cell of the updated grid found by multiplying the first probability value with an integration of a measurement likelihood function over the cell of the updated grid; and (iv) predicting third probability values of the grid based on the updated grid and a motion model for the mobile electronic device to obtain a predicted grid for use in step (i) of a subsequent iteration, the third probability value of a cell of the predicted grid found by summing all second probability values in the current iteration weighted by a probability of transition to the cell of the predicted grid.