Method and Apparatus for Synchronizing Navigation Data

• US 20140062766A1
• Filed: 04/30/2013
• Published: 03/06/2014
• Est. Priority Date: 08/31/2012
• Status: Abandoned Application

• Current Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Original Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Inventors: Zou, Jinghua, Gou, Juan, Su, Yen-jung
• Application Number:
  US13/873,445
• Publication Number:
  US 20140062766A1
• Time in Patent Office: Days
• US Class Current: 342/357.25
• CPC Class Codes: G01S 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 19/243 Demodulation of navigation message
• CPC Class Codes: G01S 19/42 Determining position

Abstract

Method, apparatus, and programs for synchronizing navigation data. Data synchronization is established between a receiver and a navigation device based on matching of a header of navigation data. The receiver receives the navigation data from the navigation device. If, subsequently, the data synchronization is interrupted, information related to the data synchronization from the receiver is retrieved. The data synchronization is then re-established between the receiver and the navigation device based on the retrieved information.

Claims

1. A method implement on a machine having a processor and memory for synchronizing navigation data, the method comprising the steps of:

establishing data synchronization between a receiver and a navigation device based on matching of a header of navigation data, wherein the receiver receives the navigation data from the navigation device;

if, subsequently, the data synchronization is interrupted, retrieving information related to the data synchronization from the receiver; and

re-establishing the data synchronization between the receiver and the navigation device based on the retrieved information.

2. The method of claim 1, wherein the navigation device includes a satellite.

3. The method of claim 1, wherein the information related to the data synchronization includes at least one of:

an ephemeris of the navigation device;

a position of the receiver;

time of week (TOW) and navigation bit count;

information related to clock synchronization between a clock of the navigation device and a local clock of the receiver;

information related to the local clock of the receiver; and

information related to data synchronization between the receiver and a reference navigation device.

4. The method of claim 1, wherein

the retrieved information includes an ephemeris of the navigation device and a position of the receiver;

and

a local clock of the receiver has been synchronized with a clock of the navigation device

5. The method of claim 4, wherein the step of re-establishing the data synchronization includes the steps of:

estimating a distance between the navigation device and the receiver based on the ephemeris of the navigation device and the position of the receiver;

determining a sending time of the navigation data from the navigation device based on the distance between the navigation device and receiver; and

computing data synchronization information based on the sending time of the navigation data.

6. The method of claim 1, wherein

the retrieved information includes TOW and navigation bit count;

and

a local clock of the receiver continuously runs for a time interval after the data synchronization was interrupted.

7. The method of claim 6, wherein the step of re-establishing the data synchronization includes the steps of:

determining a sending time of the navigation data from the navigation device based on the TOW, navigation bit count, and the time interval; and

computing synchronization information based on the sending time of the navigation data.

8. The method of claim 1, further comprising the step of:

retrieving information related to a reference data synchronization between the receiver and a reference navigation device from the receiver, wherein the receiver receives reference navigation data from the reference navigation device.

9. The method of claim 1, wherein

the retrieved information related to the data synchronization includes an ephemeris of the navigation device and a position of the receiver;

and

the retrieved information related to the reference data synchronization includes an ephemeris of the reference navigation device and a reference sending time of the reference navigation data from the reference navigation device.

10. The method of claim 9, wherein the step of re-establishing the data synchronization includes the steps of:

estimating a distance between the navigation device and the receiver based on the ephemeris of the navigation device and the position of the receiver and a reference distance between the reference navigation device and the receiver based on the ephemeris of the reference navigation device and the position of the receiver;

determining a sending time of the navigation data sent from the navigation device based on the reference sending time of the reference navigation data sent from the reference navigation device and the distance and reference distance; and

computing synchronization information based on the sending time of the navigation data.

11. A receiver for navigation comprising a navigation processing unit comprising:

a default data synchronization module configured to establish data synchronization between the receiver and a navigation device based on matching of a header of navigation data, wherein the receiver receives the navigation data from the navigation device;

a synchronization information storage configured to store information related to the data synchronization; and

a rapid data synchronization module configured to;

if, subsequently, the data synchronization is interrupted, retrieve the information related to the data synchronization from the synchronization information storage, and

re-establish the data synchronization between the receiver and the navigation device based on the retrieved information.

12. The receiver of claim 11, wherein the navigation device includes a satellite.

13. The receiver of claim 11, wherein the information related to the data synchronization includes at least one of:

an ephemeris of the navigation device;

a position of the receiver;

TOW and navigation bit count;

information related to clock synchronization between a clock of the navigation device and a local clock of the receiver;

information related to the local clock of the receiver; and

information related to data synchronization between the receiver and a reference navigation device.

14. The receiver of claim 11, wherein

the retrieved information includes an ephemeris of the navigation device and a position of the receiver;

and

a local clock of the receiver has been synchronized with a clock of the navigation device

15. The receiver of claim 14, wherein the rapid data synchronization module is further configured to:

estimate a distance between the navigation device and the receiver based on the ephemeris of the navigation device and the position of the receiver;

determine a sending time of the navigation data from the navigation device based on the distance between the navigation device and receiver; and

compute data synchronization information based on the sending time of the navigation data.

16. The receiver of claim 11, wherein

the retrieved information includes TOW and navigation bit count;

and

a local clock of the receiver continuously runs for a time interval after the data synchronization was interrupted.

17. The receiver of claim 16, wherein the rapid data synchronization module is further configured to:

determine a sending time of the navigation data from the navigation device based on the TOW, navigation bit count, and the time interval; and

compute synchronization information based on the sending time of the navigation data.

18. The receiver of claim 11, wherein the rapid data synchronization module is further configured to:

retrieve information related to a reference data synchronization between the receiver and a reference navigation device from the receiver, wherein the receiver receives reference navigation data from the reference navigation device.

19. The receiver of claim 11, wherein

the retrieved information related to the data synchronization includes an ephemeris of the navigation device and a position of the receiver;

and

the retrieved information related to the reference data synchronization includes an ephemeris of the reference navigation device and a reference sending time of the reference navigation data from the reference navigation device.

20. The receiver of claim 19, wherein the rapid data synchronization module is further configured to:

estimate a distance between the navigation device and the receiver based on the ephemeris of the navigation device and the position of the receiver and a reference distance between the reference navigation device and the receiver based on the ephemeris of the reference navigation device and the position of the receiver;

determine a sending time of the navigation data sent from the navigation device based on the reference sending time of the reference navigation data sent from the reference navigation device and the distance and reference distance; and

compute synchronization information based on the sending time of the navigation data.

21. A machine-readable tangible and non-transitory medium having information for synchronizing navigation data recorded thereon, wherein the information, when read by the machine, causes the machine to perform the following:

establishing data synchronization between a receiver and a navigation device based on matching of a header of navigation data, wherein the receiver receives the navigation data from the navigation device;

if, subsequently, the data synchronization is interrupted, retrieving information related to the data synchronization from the receiver; and

re-establishing the data synchronization between the receiver and the navigation device based on the retrieved information.

22. The medium of claim 21, wherein the navigation device includes a satellite.

23. The medium of claim 21, wherein the information related to the data synchronization includes at least one of:

an ephemeris of the navigation device;

a position of the receiver;

TOW and navigation bit count;

information related to clock synchronization between a clock of the navigation device and a local clock of the receiver;

information related to the local clock of the receiver; and

information related to data synchronization between the receiver and a reference navigation device.

24. The medium of claim 21, wherein

the retrieved information includes an ephemeris of the navigation device and a position of the receiver;

and

a local clock of the receiver has been synchronized with a clock of the navigation device

25. The medium of claim 24, wherein the step of re-establishing the data synchronization includes the steps of:

estimating a distance between the navigation device and the receiver based on the ephemeris of the navigation device and the position of the receiver;

determining a sending time of the navigation data from the navigation device based on the distance between the navigation device and receiver; and

computing data synchronization information based on the sending time of the navigation data.

26. The medium of claim 21, wherein

the retrieved information includes TOW and navigation bit count;

and

a local clock of the receiver continuously runs for a time interval after the data synchronization was interrupted.

27. The medium of claim 26, wherein the step of re-establishing the data synchronization includes the steps of:

determining a sending time of the navigation data from the navigation device based on the TOW, navigation bit count, and the time interval; and

computing synchronization information based on the sending time of the navigation data.

28. The medium of claim 21, further comprising the step of:

retrieving information related to a reference data synchronization between the receiver and a reference navigation device from the receiver, wherein the receiver receives reference navigation data from the reference navigation device.

29. The medium of claim 21, wherein

the retrieved information related to the data synchronization includes an ephemeris of the navigation device and a position of the receiver;

and

the retrieved information related to the reference data synchronization includes an ephemeris of the reference navigation device and a reference sending time of the reference navigation data from the reference navigation device.

30. The medium of claim 29, wherein the step of re-establishing the data synchronization includes the steps of:

estimating a distance between the navigation device and the receiver based on the ephemeris of the navigation device and the position of the receiver and a reference distance between the reference navigation device and the receiver based on the ephemeris of the reference navigation device and the position of the receiver;

determining a sending time of the navigation data sent from the navigation device based on the reference sending time of the reference navigation data sent from the reference navigation device and the distance and reference distance; and

computing synchronization information based on the sending time of the navigation data.