초록 ▼

A system and method for assisting an integrated GPS/wireless terminal unit in acquiring one or more GPS satellite signals from the GPS satellite constellation. The invention includes a method for narrowing the PN-code phase search. That is, by accounting for the variables in geographic location and

A system and method for assisting an integrated GPS/wireless terminal unit in acquiring one or more GPS satellite signals from the GPS satellite constellation. The invention includes a method for narrowing the PN-code phase search. That is, by accounting for the variables in geographic location and time delay relative to GPS time, the systems and methods of the present invention generate a narrow code-phase search range that enables the terminal unit to more quickly acquire and track the necessary GPS satellites, and thereby more quickly provide accurate position information to a requesting entity.

대표청구항 ▼

What is claimed is: 1. A system for transmitting a GPS receiver code-phase search range to a integrated GPS/wireless terminal unit operating in a wireless network, said system comprising: a receiver operable to generate a GPS time reference; a controller operable to calculate a GPS code-phase searc

What is claimed is: 1. A system for transmitting a GPS receiver code-phase search range to a integrated GPS/wireless terminal unit operating in a wireless network, said system comprising: a receiver operable to generate a GPS time reference; a controller operable to calculate a GPS code-phase search range with reference to a base station geographic location, the wireless coverage area, an angle between a vector extending from the base station to a GPS satellite and a vector extending from the base station to the GPS/wireless terminal unit, said GPS time reference and the estimated wireless signal propagation delay within said coverage area, and a transmitter coupled to said controller and operable to transmit said calculated GPS code search range. 2. The invention of claim 1 wherein said GPS code-phase search range is defined by a center value and a size value. 3. A system for transmitting a GPS receiver code-phase search range to a integrated GPS/wireless terminal unit operating in a wireless network, comprising: a GPS receiver operable to generate a GPS time reference; means for obtaining a time offset for the GPS/wireless terminal unit relative to said GPS time reference; a controller operable to calculate a GPS code-phase search range with reference to a base station geographic location, a radius of the wireless coverage area served by the base station, an elevation angle of a GPS satellite, and said time reference; and a transmitter coupled to said controller and operable to transmit said calculated GPS code search range. 4. The invention of claim 3 wherein said GPS code-phase search range is defined by a center value and a size value. 5. The invention of claim 3 wherein said means for obtaining a time offset utilizes the round-trip wireless signal propagation time between said base station and the terminal unit to establish said time offset. 6. A system for transmitting a GPS receiver code-phase search range to a integrated GPS/wireless terminal unit operating in a wireless network, comprising: a GPS receiver operable to generate a GPS time reference; means for obtaining a time offset for the GPS/wireless terminal unit relative to said GPS time reference; means for obtaining a location reference for the GPS/wireless terminal unit; a controller operable to calculate a GPS code-phase search range with reference to a variance of a positioning error of said location reference, and said time reference; and a transmitter coupled to said controller and operable to transmit said calculated GPS code search range. 7. The invention of claim 6 wherein said GPS code-phase search range is defined by a center value and a size value. 8. The invention of claim 6 wherein said means for obtaining a location reference utilizes means for providing terrestrial based trilateration to establish said location reference. 9. A method for defining a GPS receiver code-phase search range for an integrated GPS/wireless terminal unit operating in a wireless network having a base station comprising the steps of: calculating a GPS code-phase search range with reference to the base station geographic location plus the wireless coverage area, an angle between a vector extending from the base station to a GPS satellite and a vector extending from the base station to the GPS/wireless terminal unit, and with reference to a base station GPS time reference plus the estimated wireless signal propagation delay within said coverage area and transmitting said calculated GPS code-phase search range. 10. The invention of claim 9 wherein said GPS code-phase search range is defined by a center value and a size value. 11. A method for defining a GPS receiver code-phase search range for an integrated GPS/wireless terminal unit operating in a wireless network having a base station, comprising the steps of: obtaining a time reference for the GPS/wireless terminal unit establishing the time offset relative to the base station GPS time; calculating a GPS code-phase search range with reference to the base station geographic location plus a radius of the wireless coverage area served by the base station, an elevation angle of a GPS satellite, and said time reference; and transmitting said calculated GPS code-phase search range. 12. The invention of claim 11 wherein said GPS code-phase search range is defined by a center value and a size value. 13. The invention of claim 11 wherein said obtaining step utilizes the round-trip wireless signal propagation time between said base station and the terminal unit to establish the time offset. 14. A method for defining a GPS receiver code-phase search range for an integrated GPS/wireless terminal unit operating in a wireless network having a base station, comprising the steps of: obtaining a time reference for the GPS/wireless terminal unit establishing the time offset relative to the base station GPS time; obtaining a location reference for the GPS/wireless terminal unit; calculating a GPS code-phase search range with reference to a variance of a positioning error of said location reference, and said time reference; and transmitting said calculated GPS code-phase search range by the base station. 15. The invention of claim 14 wherein said GPS code-phase search range is defined by a center value and a size value. 16. The invention of claim 14 wherein said obtaining a location reference step utilizes terrestrial based trilateration techniques to establish said location reference. 17. A system for transmitting a GPS receiver code-phase search range to an integrated GPS/wireless terminal unit operating in a wireless network, said system comprising: a receiver operable to generate a GPS time reference; a controller operable to calculate the GPS code-phase search range with reference to a base station geographic location, a position estimate of the integrated GPS/wireless terminal unit having an uncertainty area with a center distinct from the base station geographic location, and said GPS time reference; and a transmitter coupled to said controller and operable to transmit said calculated GPS code-phase search range.