US 7,321,776 B2
Estimating GPS time at cellular terminals based on timing of information from base stations and satellites
William O. Camp, Jr., Chapel Hill, N.C. (US); Gerald Michalak, Cary, N.C. (US); and L. Scott Bloebaum, Cary, N.C. (US)
Assigned to Sony Ericsson Mobile Communications AB, (Sweden)
Filed on Sep. 25, 2003, as Appl. No. 10/672,547.
Prior Publication US 2005/0070223 A1, Mar. 31, 2005
Int. Cl. H04Q 7/20 (2006.01)
U.S. Cl. 455—456.1  [455/12.1; 455/13.2; 455/3.02; 455/502; 455/503; 342/358; 342/357.1; 701/213; 701/214] 18 Claims
OG exemplary drawing
 
13. A mobile terminal comprising:
a receiver that is configured to receive communication signals from cells in a wireless communication system;
a GPS receiver that is configured to receive GPS signals;
a memory containing a repository of cell-to-GPS timing data that is representative of timing offset between GPS time and cell time for two or more cells; and
a processor that is configured to identify an originating cell of a received communication signal from a base station, and is configured to estimate GPS time using the repository of cell-to-GPS timing data, the identity of the originating cell, and a time indicator portion of the received communication signal, and timing advance data that indicates distance between the mobile terminal and the base station.