System and Method for Providing Aiding Information to a Satellite Positioning System Receiver Over Short-Range Wireless Connections

• US 20080258965A1
• Filed: 04/20/2007
• Published: 10/23/2008
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Inventors: Azim, Syed Khalid
• Granted Patent: US 7,724,612 B2
• Time in Patent Office: Days
• US Class Current: 342/357.1
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset

Abstract

Systems and methods for obtaining corrected time information in a GPS enabled device connected to a mobile handset via a short-range wireless network, such as a Bluetooth Piconet. The mobile handset includes a GPS time and a network clock synchronized with a network clock in a short-range wireless network interface in the GPS enabled device. The GPS enabled device may send requests for time information to the mobile handset. The mobile handset receives the request and latches the network clock time and the GPS time. The captured network clock time and GPS times are sent to the GPS enabled device in response to the request. The GPS enable device substracts the captured network clock time from its own network clock time and adds the difference to the captured GPS time to obtain a corrected GPS time.

Claims

1. A Global Positioning System (GPS) enabled device comprising:

a GPS receiver to receive GPS signals from GPS satellites;

a short-range wireless network interface to a short-range wireless network connected to at least one other node, the short-range wireless network interface including a network clock synchronized with the network clock in the other node; and

a GPS device time info handler to send requests for time information over the short-range wireless network and to receive, in response to the request, a captured network clock time and a captured GPS time from the other device, the GPS device time info handler being operable to subtract the captured network clock time from the network clock time, and to add the difference to the captured GPS time, the result being a corrected GPS time.

2. The GPS enabled device of claim 1 where the other node is a mobile handset.

3. The GPS enabled device of claim 1 where the short-range wireless network is a Bluetooth Piconet and the network clock is a Bluetooth clock.

4. The GPS enabled device of claim 3 further comprising:

a GPS Bluetooth clock register for receiving the Bluetooth clock time in the Bluetooth clock on the GPS enabled device;

a captured Bluetooth clock register for receiving the captured Bluetooth time; and

a GPS time register for receiving the captured GPS time.

5. A system comprising:

a mobile handset having a first network interface to a short-range wireless network and a GPS time, the first network interface including a first network clock, the first device including a handset time info handler to receive a time info request, to capture the GPS time and first network clock time, and to send the captured GPS time and first network clock time in response to the request; and

a GPS enabled device having a second network interface to the short-range wireless network, the second network interface including a second network clock synchronized with the first network clock, the GPS enabled device further including a GPS device time info handler;

where the GPS device time info handler sends requests for time information over the short-range wireless network and receives, in response to the request, the captured network clock time and the captured GPS time from the other device, the GPS device time info handler being operable to subtract the captured network clock time from the network clock time, and to add the difference to the captured GPS time, the result being a corrected GPS time.

6. The system of claim 5 where the other node is a mobile handset.

7. The system of claim 5 where the short-range wireless network is a Bluetooth Piconet and the network clock is a Bluetooth clock.

8. The system of claim 7 further comprising:

a GPS Bluetooth clock register for receiving the Bluetooth clock time in the Bluetooth clock on the GPS enabled device;

a captured Bluetooth clock register for receiving the captured Bluetooth time; and

a GPS time register for receiving the captured GPS time.

9. A method for obtaining a corrected GPS time comprising:

sending a request for time information;

receiving a captured GPS time and a captured network clock time from a network clock on a mobile handset in response to the request for time information;

subtracting the captured network clock time from a network clock time from a network clock that is synchronized with the network clock on the mobile handset;

adding the difference to the captured GPS time to obtain the corrected GPS time.