IMPROVED METHOD FOR ESTIMATING TDOA AND FDOA IN A IMPROVED METHOD FOR ESTIMATING TDOA AND FDOA IN A WIRELESS LOCATION SYSTEM WIRELESS LOCATION SYSTEM

摘要

A method, used in locating a mobile transmitter, includes providing a set of cross-correlation values, wherein each cross-correlation value is associated with a corresponding TDOA and/or FDOA estimae and is produced by cross- correlating a reference signal with a cooperating signal (fig. 5). The reference signal comprises a copy of a signal transmitted by the mobile transmitter as received at a first antenna and the cooperating signal comprises a copy of the same signal as received at a second antenna. The method further includes determining a most likely range of TDOA and/or FDOA estimates, and then identifying an optimal cross-correlation value within a subset of cross-correlation values (fig. 10) corresponding to the most likel y range of TDOA and/or FDOA estimates. The TDOA and/or FDOA value correspondin g to the optimal cross-correlation value is then employed in calculating the location of the mobile transmitter.