Method and apparatus for tracking a global navigation satellite system within the constraints of an indoor facility
View Patent ↗A method and chipset for tracking a global navigation satellite system (GNSS) within the constraints of an indoor facility. The method includes receiving assistance information on the GNSS on a mobile communication system; and sorting orbiting satellites within the GNSS by elevation angles. Additionally, lower elevation satellites are correlated within the GNSS prior to correlating higher elevation satellites.
1. A method for tracking a global navigation satellite system (GNSS) within the constraints of an indoor facility, comprising the steps of:
receiving assistance information on the GNSS and additional assistance information including facility information on a mobile communication system;
sorting orbiting satellites within the GNSS by elevation angles; and
correlating lower elevation satellites within the GNSS using azimuth masking based on the additional assistance information prior to correlating higher elevation satellites.
2. The method according to claim 1 ; wherein the lower elevation satellites are less than 50 degrees above earth's horizon.
3. The method according to claim 1 ; wherein the step of sorting further comprises sorting from a lower elevation angle to a higher elevation angle.
4. The method according to claim 1 ; wherein the step of sorting further comprises sorting from a higher elevation angle to a lower elevation angle.
5. The method according to claim 1 ; wherein the assistance information on the GNSS includes almanac and ephemeris data.
6. The method according to claim 1 ; wherein the indoor facilities are selected from the group consisting of:
parking garages, indoor malls, domed arenas, enterprise facilities, convention centers, and indoor retail/grocery markets.
7. The method according to claim 1 ; wherein the additional assistance information includes an approximate location and facility structure information comprising known large openings in the facility structure.
8. The method according to claim 1 ; further comprising the step of determining whether the mobile communication device was inside prior to employing correlation of lower elevation satellites within the GNSS in advance of correlating higher elevation satellites.
9. A chipset within a mobile communication system, comprising,
an RF receiver comprising an antenna for receiving satellite ranging signals;
a controller for converting the satellite ranging signals into latitude and longitude information;
wherein the controller also receives assistance information about a global navigation satellite system (GNSS) and additional assistance information including facility information on the mobile communication system;
sorts orbiting satellites within the GNSS by elevation angles; and
correlates lower elevation satellites within the GNSS using azimuth masking based on the additional assistance information prior to correlating higher elevation satellites.
10. The chipset according to claim 9 ; wherein the lower elevation satellites are less than 50 degrees above earth's horizon.
11. The chipset according to claim 9 ; wherein the controller sorts satellite elevation angles beginning with lower elevation angles to higher elevation angles.
12. The chipset according to claim 9 ; wherein the controller sorts satellite elevation angles beginning with higher elevation angles to lower elevation angles.
13. The chipset according to claim 9 ; wherein the assistance information on the GNSS includes almanac and ephemeris data.