Protected use of navigation and positioning signal

• US 10,644,922 B2
• Filed: 06/19/2018
• Issued: 05/05/2020
• Est. Priority Date: 04/16/2018
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Opshaug, Guttorm Ringstad, Pon, Rayman Wai, Wu, Jie, Fischer, Sven, Edge, Stephen William, Bhushan, Naga
• Primary Examiner(s): Choi, Eunsook
• Application Number:
  US16/011,770
• Publication Number:
  US 20190319827A1
• Time in Patent Office: 686 Days
• Field of Search: None
• CPC Class Codes: G01S 1/042 Transmitters
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G06F 7/584 using finite field arithmetic, e.g. using a linear feedback shift register
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 27/2662 Symbol synchronisation
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 72/27 between access points

Abstract

A periodically-transmitted reference signal can have certain proprietary properties to help to help prevent unauthorized detection and utilization of the signal. More specifically, a base station can adjust times at which a reference signal is transmitted and/or a code with which the signal is encoded. These adjustments may be based on an equation or algorithm, which can be shared with particular mobile devices as needed.

Claims

1. A method of obtaining reference signals with a mobile device in a wireless communication network, the method comprising:

obtaining, at the mobile device, base station information for a plurality of base stations in the wireless communication network, the base station information comprising a location and an identifier of each base station of the plurality of base stations;

obtaining, with a mobile device, seed information for a base station of the plurality of base stations;

determining, based on the base station information for the base station and the seed information, a first code, selected from a predetermined set of codes, with which a broadcast of a position measurement signal by the base station during a first positioning occasion is designated to be encoded; and

taking a first measurement, with the mobile device, of the position measurement signal based on the determining the first code.

2. The method of claim 1, wherein the seed information comprises a timestamp indicative of a time for which codes of at least a portion of wireless positioning measurement signals subsequently broadcast by the base station can be determined.

3. The method of claim 1, wherein obtaining the seed information comprises receiving the seed information from the base station.

4. The method of claim 1, wherein the seed information comprises initial state information.

5. The method of claim 4, wherein the determining the first code comprises inputting values into a Linear Feedback Shift Register based on the initial state information.

6. The method of claim 1, wherein the determining the first code comprises inputting data from the seed information into an equation and obtaining the first code from the equation.

7. The method of claim 1, further comprising:

determining, based on the base station information for the base station and the seed information, a second code, selected from the predetermined set of codes, designated for a broadcast of a position measurement signal by the base station during a second positioning occasion; and

taking a second measurement, with the mobile device, of the position measurement signal based on the determining the second code.

8. The method of claim 7, wherein the second code is different than the first code.

9. The method of claim 7, wherein determining the second code comprises shifting values of at least one Linear Feedback Shift Register a number of times.

10. The method of claim 9, further comprising determining the number of times to shift the values of the at least one Linear Feedback Shift Register based on an identity of the base station.

11. The method of claim 9, further comprising determining, with the mobile device, the number of times to shift the values of the at least one Linear Feedback Shift Register for each of a plurality of positioning occasions, wherein the number of times to shift the values of the at least one Linear Feedback Shift Register is different for at least two of the plurality of positioning occasions.

12. A device comprising:

a wireless communication interface;

a memory; and

a processing unit communicatively coupled with the wireless communication interface and the memory and configured to;

obtain base station information for a plurality of base stations in a wireless communication network, the base station information comprising a location and an identifier of each base station of the plurality of base stations;

obtain seed information for a base station of the plurality of base stations;

determine, based on the base station information for the base station and the seed information, a first code, selected from a predetermined set of codes, with which a broadcast of a position measurement signal by the base station during a first positioning occasion is designated to be encoded; and

take a first measurement, using the wireless communication interface, of the position measurement signal based on the determining the first code.

13. The device of claim 12, wherein the processing unit is configured to obtain, from the seed information, a timestamp indicative of a time for which codes of at least a portion of wireless positioning measurement signals subsequently broadcast by the base station can be determined.

14. The device of claim 12, wherein the processing unit is configured to obtain the seed information at least in part by receiving the seed information from the base station.

15. The device of claim 12, wherein the processing unit is configured to determine, using the seed information, initial state information.

16. The device of claim 15, wherein the processing unit is configured to determine the first code at least in part by inputting values into a Linear Feedback Shift Register based on the initial state information.

17. The device of claim 12, wherein the processing unit is configured to determine the first code at least in part by inputting data from the seed information into an equation and obtaining the first code from the equation.

18. The device of claim 12, wherein the processing unit is further configured to:

determine, based on the base station information for the base station and the seed information, a second code, selected from the predetermined set of codes, designated for a broadcast of a position measurement signal by the base station during a second positioning occasion; and

take a second measurement, using the wireless communication interface, of the position measurement signal based on the determining the second code.

19. The device of claim 18, wherein the processing unit is configured to determine the second code at least in part by shifting values of at least one Linear Feedback Shift Register a number of times.

20. The device of claim 19, wherein the processing unit is further configured to determine the number of times to shift the values of the at least one Linear Feedback Shift Register based on an identity of the base station.

21. The device of claim 19, wherein the processing unit is further configured to determine the number of times to shift the values of the at least one Linear Feedback Shift Register for each of a plurality of positioning occasions, wherein the number of times to shift the values of the at least one Linear Feedback Shift Register is different for at least two of the plurality of positioning occasions.

22. A mobile device comprising:

means for obtaining base station information for a plurality of base stations in a wireless communication network, the base station information comprising a location and an identifier of each base station of the plurality of base stations;

means for obtaining seed information for a base station of the plurality of base stations;

means for determining, based on the base station information for the base station and the seed information a first code, selected from a predetermined set of codes, with which a broadcast of a position measurement signal by the base station during a first positioning occasion is designated to be encoded; and

means for taking a first measurement of the position measurement signal based on the determining the first code.

23. The device of claim 22, wherein the means for obtaining the seed information comprises means for receiving the seed information from the base station.

24. The device of claim 22, wherein the means for determining the first code comprises means for inputting values into a Linear Feedback Shift Register based on initial state information determined using the seed information.

25. The device of claim 22, wherein the means for determining the first code comprises means for inputting data from the seed information into an equation and obtaining the first code from the equation.

26. The device of claim 22, further comprising:

means for determining, based on the base station information for the base station and the seed information,

a second code, selected from the predetermined set of codes, designated for a broadcast of the position measurement signal by the base station during a second positioning occasion; and

means for taking a second measurement, with the mobile device, of the position measurement signal based on the determining the second code.

27. The device of claim 26, wherein the means for determining the second code comprises means for shifting values of at least one Linear Feedback Shift Register a number of times.

28. The device of claim 27, further comprising means for determining the number of times to shift the values of the at least one Linear Feedback Shift Register based on an identity of the base station.

29. The device of claim 27, further comprising means for determining the number of times to shift the values of the at least one Linear Feedback Shift Register for each of a plurality of positioning occasions, wherein the number of times to shift the values of the at least one Linear Feedback Shift Register is different for at least two of the plurality of positioning occasions.

30. A non-transitory, computer-readable medium having instructions embedded thereon for causing a mobile device to obtain reference signals a wireless communication network, the instructions including computer code for:

obtaining base station information for a plurality of base stations in the wireless communication network, the base station information comprising a location and an identifier of each base station of the plurality of base stations;

obtaining seed information for a base station of the plurality of base stations;

determining, based on the base station information for the base station and the seed information, a first code, selected from a predetermined set of codes, with which a broadcast of a position measurement signal by the base station during a first positioning occasion is designated to be encoded; and

taking a first measurement of the position measurement signal based on the determining the first code.

31. A method of broadcasting reference signals from a base station of a wireless communication network, the method comprising:

broadcasting a position measurement signal during a first positioning occasion, wherein the position measurement signal is encoded with a first code of a predetermined set of codes; and

broadcasting the position measurement signal during a second positioning occasion, wherein the position measurement signal is encoded with a second code of the predetermined set of codes;

wherein the second code is different than the first code.

32. A base station comprising:

a wireless communication interface;

a memory; and

a processing unit communicatively coupled with the wireless communication interface and the memory and configured to;

broadcast a position measurement signal, using the wireless communication interface, during a first positioning occasion, wherein the position measurement signal is encoded with a first code of a predetermined set of codes; and

broadcast the position measurement signal, using the wireless communication interface, during a second positioning occasion, wherein the position measurement signal is encoded with a second code of the predetermined set of codes;

wherein the second code is different than the first code.

33. A device comprising:

means for broadcasting a position measurement signal during a first positioning occasion, wherein the position measurement signal is encoded with a first code of a predetermined set of codes; and

means for broadcasting the position measurement signal during a second positioning occasion, wherein the position measurement signal is encoded with a second code of the predetermined set of codes;

wherein the second code is different than the first code.

34. A non-transitory, computer-readable medium having instructions embedded thereon for causing a base station of a wireless communication network to broadcast reference signals, the instructions including computer code for:

broadcasting a position measurement signal during a first positioning occasion, wherein the position measurement signal is encoded with a first code of a predetermined set of codes; and

broadcasting the position measurement signal during a second positioning occasion, wherein the position measurement signal is encoded with a second code of the predetermined set of codes;

wherein the second code is different than the first code.