Receiving positioning signals at different frequencies

• US 9,279,886 B2
• Filed: 02/07/2013
• Issued: 03/08/2016
• Est. Priority Date: 02/08/2012
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hadef, Mahmoud
• Primary Examiner(s): Liu, Harry
• Application Number:
  US13/761,904
• Publication Number:
  US 20140062783A1
• Time in Patent Office: 1,125 Days
• Field of Search: 342/357.73, 342/357.72
• US Class Current: 1/1
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/33 Multimode operation in different systems which transmit time stamped messages, e.g. GPS/GLONASS
• CPC Class Codes: G01S 19/36 relating to the receiver frond end
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 19/425 by combining or switching between signals derived from different satellite radio beacon positioning systems

Abstract

A method and a receiver for receiving positioning signals are disclosed. The positioning signals are received from a plurality of first sources in a first frequency range and from a plurality of second sources in a second frequency range different from the first frequency range. The receiver is switched between the first and second frequency ranges to receive the positioning signals, and the receiver obtains time offset information about a time taken to switch the receiver between the first and second frequency ranges, by obtaining a solution to a set of simultaneous equations based on combined navigation data for the first and second sources.

Claims

1. A method for receiving positioning signals from a plurality of first sources in a first frequency range in a receiver, the method comprising the steps of:

receiving signals in a second frequency range different from the first frequency range;

receiving positioning signals from a plurality of second sources in the second frequency range at the receiver;

calculating time offset information related to a switching time taken to switch the receiver between the first and second frequency ranges; and

compensating for the switching time, based on the calculated time offset information.

2. The method of claim 1, further comprising:

obtaining predicted pseudoranges for each of the plurality of first sources and the plurality of second sources;

obtaining compensated pseudoranges for each of the plurality of second sources based on the time offset information and the predicted pseudorange for the source; and

obtaining location coordinates of the receiver based on the compensated pseudoranges for the plurality of second sources and the predicted pseudoranges for each of the plurality of first sources.

3. The method of claim 2, wherein each positioning signal includes information about a transmission time at which a signal was transmitted, and

wherein if the received positioning signals from the first and second sources were transmitted at different times, the pseudoranges are predicted based on positions of the first and second sources at the transmission time among the received positioning signals.

4. The method of claim 1, further comprising:

storing information about the time offset information; and

periodically obtaining updated location coordinates of the receiver based on the stored time offset information.

5. The method of claim 1, further comprising:

determining whether to calculate the time offset information, based on whether predetermined criteria are fulfilled.

6. The method of claim 5, wherein the predetermined criteria includes whether a minimum total number of first and second sources are available,

whether the received positioning signals from the plurality of first and second sources have a minimum signal-to-noise ratio (SNR) value, and

whether a dilution of precision, based on a current geometric arrangement of the receiver and the first and second sources, is less than or equal to a predetermined maximum value.

7. The method of claim 6, wherein if two-dimensional location coordinates are to be obtained for the receiver, the minimum total number of available first and second sources is four, and if three-dimensional location coordinates are to be obtained for the receiver, the minimum total number of available first and second sources is five.

8. The method of claim 1, wherein the plurality of first sources are satellites in a first navigation system, and the plurality of second sources are satellites in a second navigation system.

9. The method of claim 8, wherein one of the first and second satellite navigation systems is the Global Positioning System (GPS), and the other one of the first and second satellite navigation systems is the Global Orbiting Navigational Satellite System (GLONASS).

10. The method of claim 1, wherein the plurality of first sources and the plurality of second sources are satellites in the same satellite navigation system, and signals from the plurality of first sources are received in a different frequency band from signals from the plurality of second sources.

11. A computer-readable storage medium storing a computer program which, when executed on a processor, causes the processor to perform a method for receiving positioning signals from a plurality of first sources in a first frequency range at a receiver, the method comprising the steps of:

receiving signals in a second frequency range different from the first frequency range;

receiving positioning signals from a plurality of second sources in the second frequency range at the receiver;

calculating time offset information related to a switching time taken to switch the receiver between the first and second frequency ranges; and

compensating for the switching time, based on the calculated time offset information.

12. A receiver for receiving positioning signals, the receiver comprising:

a receiving module for receiving positioning signals, the receiving module being arranged to receive the positioning signals from a plurality of first sources in a first frequency range and from a plurality of second sources in a second frequency range different from the first frequency range, and being configured to switch between the first and second frequency ranges; and

a processing module configured to calculate time offset information related to a switching time taken to switch the receiver between the first and second frequency ranges, and compensate for the switching time, based on the calculated time offset information.

13. The receiver of claim 12, wherein the processing module obtains predicted pseudoranges for each of the plurality of first sources and the plurality of second sources, obtains compensated pseudoranges for each of the plurality of second sources based on the time offset information and the predicted pseudorange for that source, and obtains location coordinates of the receiver based on the compensated pseudoranges for the plurality of second sources and the predicted pseudoranges for each of the plurality of first sources.

14. The receiver of claim 13, wherein each positioning signal includes information about a transmission time at which the signal was transmitted, and

wherein if the received positioning signals from the first and second sources were transmitted at different times, the processing module predicts the pseudoranges based on positions of the first and second sources at the transmission time among the received positioning signals.

15. The receiver of claim 12, wherein the receiver stores the information about the time offset information and periodically obtains updated location coordinates of the receiver based on the stored time offset information.

16. The receiver of claim 12, wherein the processing module determines whether to calculate the time offset information, based on whether predetermined criteria are fulfilled.

17. The receiver of claim 16, wherein the predetermined criteria includes whether a minimum total number of first and second sources are available,

whether the received positioning signals from the plurality of first and second sources have a minimum signal-to-noise ratio (SNR) value, and whether a dilution of precision, based on a current geometric arrangement of the receiver and the first and second sources, is less than or equal to a predetermined maximum value.

18. The receiver of claim 17, wherein if two-dimensional location coordinates are to be obtained for the receiver, the minimum total number of available first and second sources is four, and if three-dimensional location coordinates are to be obtained for the receiver, the minimum total number of available first and second sources is five.

19. The receiver of claim 12, wherein the plurality of first sources are satellites in a first satellite navigation system, and the plurality of second sources are satellites in a second navigation system.

20. The receiver of claim 19, wherein one of the first and second satellite navigation systems is the Global Positioning System (GPS), and the other one of the first and second satellite navigation systems is the Global Orbiting Navigational Satellite System (GLONASS).

21. The receiver of claim 12, wherein the plurality of first sources and the plurality of second sources are satellites in the same satellite navigation system, and signals from the plurality of first sources are received in a different frequency band from signals from the plurality of second sources.