Motorola Corporation

Sirf Technology, Inc.

James Stephen

Thomas Michael King

George Jeffrey Geier

Xiang Yuan

William P DeClerck

Qutub Salman Syed

An improved time-to-first-fix (TTFF) for GPS systems is provided through a comparison of the time-of-week (TOW) to the sub-frame identification (ID). In one embodiment, this comparison comprises dividing the TOW to form a ratio and performing a modulus operation on the ratio to form a remainder, which is then incremented. If the incremented remainder equals the sub-frame ID, the TOW is assumed to be valid, thereby providing a time of transmission. The time of transmission may then be used to calculate pseudoranges and determine a receiver's location.

Time-to-first-fix for position determination

A method in a satellite positioning system receiver, including acquiring () a set of satellite positioning system satellites, determining () satellite subset time based on over-determined position solutions for at least two different subsets of the satellites acquired, determining () satellite time from at least two satellite subset times, computing () a position solution based on the satellite time or a refined () satellite time.

Satellite positioning system receiver time determination in minimum satellite coverage

A method for locating a satellite positioning system receiver, for example, a satellite positioning system enabled wireless communications device in cellular network, including obtaining a coarse position and/or a time estimate (), and computing a satellite positioning system based position and/or time solution () that is constrained by uncertainty information associated with the coarse position and/or a time estimate. The uncertainty constraints may also be used to identify erroneous measurements used to compute the position solution.

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Phoenix, AZ, United States of America

James Stephen