Method and Apparatus for Receiving a Global Positioning System Signal Using a Cellular Acquisition Signal

Abstract

Method and apparatus for a GPS device that uses at least one cellular acquisition signal is described. More particularly, a GPS device is configured to receive at least one cellular acquisition signal for obtaining benefits associated with AGPS with only a small subset of AGPS circuitry to interact with a cell phone network. This facilitates use of GPS devices without subscription to a cell phone service provider, thus avoiding cellular subscription fees.

1 . A method for determining position of a Global Positioning System (GPS) handheld device in proximity to a base station of a wireless network, the method comprising:
 obtaining from the base station without having to have fee-based access to the wireless network at least one of location information and identification information; and   determining, responsive to the at least one of location information and identification information, a position estimate of the GPS handheld device.   
     
     
         2 . The method of  claim 1 , further comprising: computing, responsive to the position estimate, any of a pseudorange and a pseudorange rate. 
     
     
         3 . The method of  claim 2 , further comprising:
 computing, responsive to the position estimate, a pseudorange; and   determining, responsive to the pseudorange, a window of delay search for receiving GPS signals.   
     
     
         4 . The method of  claim 1 , further comprising: synchronizing, responsive to the pseudorange, coherent averaging to navigation data bits. 
     
     
         5 . The method of  claim 1 , further comprising:
 computing, responsive to the position estimate, a pseudorange rate; and   determining, responsive to a pseudorange rate, a window of frequency search for receiving a GPS signal.   
     
     
         6 . The method of  claim 1 , wherein the location information comprises a location of the base station. 
     
     
         7 . The method of  claim 1 , wherein the identification information is a cell identifier of the base station. 
     
     
         8 . The method of  claim 8 , wherein determining the position estimate comprises: using the cell identifier to obtain a location of the base station from a lookup table having a relationship between the location and the cell identifier. 
     
     
         9 . A Global Positioning System (GPS) mobile device, comprising:
 at least one antenna;   a first front end communicatively coupled to the at least one antenna, the first front end being adapted to receive an acquisition signal from a wireless network;   a second front end communicatively coupled to the at least one antenna, the second front end being adapted to receive a satellite signal from at least one satellite of a GPS network;   a baseband processor adapted to (i) receive from the first front end a first signal that is associated with the acquisition signal, and (ii) receive from the second front end a second signal that is associated with the satellite signal;   a reference oscillator communicatively coupled to the baseband processor;   a general-purpose processor communicatively coupled to the baseband processor; and   memory communicatively coupled to the general-purpose processor.   
     
     
         10 . The device of  claim 10 , wherein the device does not comprise a transmitter for transmitting signals to the wireless network. 
     
     
         11 . The device of  claim 10 , wherein the device is not combined with a handset for communicating with the wireless network. 
     
     
         12 . The device of  claim 10 , wherein the first and second front ends are formed in a single integrated circuit. 
     
     
         13 . The device of  claim 10 , wherein the baseband processor comprises a first baseband processor for receiving the first signal that is associated with the acquisition signal, and a second baseband processor for receiving the second signal that is associated with the satellite signal, and wherein the first and second baseband processors are combined in a single integrated circuit. 
     
     
         14 . The device of  claim 10 , further comprising: a timekeeping counter communicatively coupled with the reference oscillator and the baseband processor.