Femto-assisted location estimation in macro-femto heterogeneous networks

• US 8,958,819 B2
• Filed: 06/21/2013
• Issued: 02/17/2015
• Est. Priority Date: 12/11/2012
• Status: Active Grant

• Current Assignee: K.Mizra LLC
• Original Assignee: Transpacific IP Management Group Ltd. (Transpacific IP Group Limited)
• Inventors: Lee, Ke-Ting, Tseng, Po-Hsuan, Chen, Chien-Hua, Feng, Kai-Ten
• Primary Examiner(s): Ly, Nghi H
• Application Number:
  US13/924,458
• Publication Number:
  US 20140162686A1
• Time in Patent Office: 606 Days
• Field of Search: 455/456.1, 455/404.2, 455/422.1, 455/423
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• 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: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04W 64/003 locating network equipment

Abstract

The disclosed subject matter relates to a wireless communications environment. Femto-assisted location estimation schemes can determine UE location information based on information from either macro base stations or femto base stations in a LTE-A heterogeneous network. Positions information for a femto base station can be employed even though the exact positions of fBS may not be available. The femto base station position information can be depicted as a probabilistic distribution. Bayesian estimation based on TDOA and utilization of a particle filter can facilitate determining UE location information. Furthermore, a simplified scheme can reduce computational complexity.

Claims

1. A system, comprising:

a memory to store instructions; and

a processor, coupled to the memory, that facilitates execution of the instructions to perform operations, the operations comprising;

receiving base station information related to a user equipment;

receiving particle information for a first set of particles corresponding to possible user equipment locations and embodying at least one latent variable of a state space; and

determining user equipment location information based on a first particle filtering applied to the first set of particles, wherein particle filtering comprises determining a distribution of the at least one latent variable at a time specified in a defined state space.

2. The system of claim 1, wherein the receiving the base station information comprises receiving macro base station information.

3. The system of claim 1, wherein the receiving the base station information comprises receiving femto base station information.

4. The system of claim 1, wherein the base station information comprises macro base station timing information related to determining a position of a femto base station device.

5. The system of claim 4, wherein the determining the position of the femto base station device is based on time of arrival measurements.

6. The system of claim 1, wherein the receiving the base station information comprises receiving a set of information related to a distribution of possible positions of a femto base station device.

7. The system of claim 1, the operations further comprising:

determining information related to a distribution of possible positions of a femto base station device based on the base station information.

8. The system of claim 7, wherein the determining the information is further based on a second particle filtering of a second set of particles corresponding to possible femto base station device locations.

9. The system of claim 7, wherein the determining the set of information facilitates determining a mean position value of the femto base station device.

10. The system of claim 7, wherein the determining the set of information facilitates determining a standard deviation for a mean position value of the femto base station device.

11. The system of claim 1, wherein the operations further comprise:

receiving information related to a distribution of possible positions of a femto base station device.

12. The system of claim 11, wherein the determining the user equipment location information is further based on the information, and the first particle filtering comprises importance sampling of a particle comprised in the first set of particles, the importance sampling results in a second set of particles being generated based on an importance distribution.

13. The system of claim 12, wherein the first particle filtering further comprises a mathematical weighting of a particle of the second set of particles based on the distribution of possible positions of the femto base station device, and the mathematical weighting results in a third set of particles being generated.

14. The system of claim 13, wherein the first particle filtering further comprises resampling of a particle of the third set of particles resulting in a reduced degeneracy of the third set of particles by removing a low importance particle or emphasizing a high importance particle, and the resampling further results in a fourth set of particles being generated.

15. The system of claim 14, wherein the first particle filtering updates the first set of particles by replacing the first set of particles with the fourth set of particles, resulting in an updated first set of particles, and the operations further comprise importance sampling of a particle comprised in the updated first set of particles to result in an updated second set of particles being generated.

16. The system of claim 15, wherein the first particle filtering further comprises, for a determined number of iterations:

weighting a particle of the updated second set of particles to result in an updated third set of particles being generated;

resampling a particle of the updated third set of particles to result in an updated fourth set of particles being generated; and

updating the updated first set of particles by replacing the updated first set of particles with the updated fourth set of particles, resulting in a further updated first set of particles, and importance sampling of a particle comprised in the further updated first set of particles to result in a further updated second set of particles.

17. The system of claim 1, the operations further comprising:

receiving information related to a possible position of a femto base station device; and

the determining the user equipment location information is further based on the information and the first particle filtering comprises an importance sampling of a particle comprised in the first set of particles, the importance sampling results in a second set of particles being generated.

18. The system of claim 17, wherein the first particle filtering further comprises mathematical weighting of a particle based on the possible position of the femto base station device, the particle comprised in the second set of particles, and the mathematical weighting results in a third set of particles being generated.

19. The system of claim 18, wherein the first particle filtering further comprises resampling of a particle of the third set of particles resulting in a uniform distribution of the third set of particles with reduced degeneracy, and the resampling further results in a fourth set of particles being generated.

20. The system of claim 19, wherein the first particle filtering updates the first set of particles by replacing the first set of particles with the fourth set of particles, resulting in an updated first set of particles, and the operations further comprise importance sampling of a particle comprised in the updated first set of particles to result in an updated second set of particles being generated.

21. The system of claim 20, wherein the first particle filtering further comprises, for a determined number of iterations:

weighting a particle of the updated second set of particles to result in an updated third set of particles being generated;

resampling a particle of the updated third set of particles to result in an updated fourth set of particles being generated; and

updating the updated first set of particles by replacing the updated first set of particles with the updated fourth set of particles, resulting in a further updated first set of particles, and importance sampling of a particle comprised in the further updated first set of particles to result in a further updated second set of particles.

22. A computer-readable storage medium having computer-executable instructions that, in response to execution, cause a computing device including a processor to perform operations, comprising:

receiving femto base station timing information related to a user equipment;

receiving macro base station timing information related to the user equipment;

receiving particle information for a first set of particles corresponding to possible user equipment locations;

receiving femto base station position information; and

determining user equipment location information based on a first particle filtering applied to the first set of particles, the first particle filtering employing the femto base station timing information and the macro base station timing information.

23. The computer-readable storage medium of claim 22, wherein the receiving the femto base station position information comprises receiving femto base station position distribution information or receiving femto base station estimated position information.

24. The computer-readable storage medium of claim 22, the operations further comprising:

receiving macro base station information related to a femto base station device; and

determining the femto base station position information based on the macro base station information and wherein the first particle filtering further employs the femto base station position information.

25. The computer-readable storage medium of claim 24, wherein the femto base station position information is position distribution information and is determined by a second particle filtering.

26. The computer-readable storage medium of claim 22, the operations further comprising:

receiving information related to a distribution of possible positions of a femto base station device.

27. The computer-readable storage medium of claim 26, wherein the determining user equipment location information is further based on the information and the first particle filtering comprises importance sampling of a particle comprised in the first set of particles, the importance sampling results in a second set of particles being generated, and the first particle filtering further comprises weighting of a particle of the second set of particles based on the information resulting in a third set of particles being generated.

28. The computer-readable storage medium of claim 27, wherein the first particle filtering further comprises a fourth set of particles being generated and resampling of a particle of the third set of particles resulting in uniform distribution of the third set embodied in the fourth set of particles.

29. The computer-readable storage medium of claim 28, wherein the first particle filtering updates the first set of particles by replacing the first set of particles with the fourth set of particles, resulting in an updated first set of particles, and the operations further comprise importance sampling of a particle comprised in the updated first set of particles to result in an updated second set of particles being generated.

30. A method, comprising:

receiving femto base station timing information related to a user equipment;

receiving macro base station timing information related to the user equipment;

receiving particle information for a first set of particles corresponding to possible user equipment locations;

receiving femto base station position information; and

determining user equipment location information based on a first particle filtering for particle filtering the first set of particles based on the base station information.

31. The method of claim 30, wherein the femto base station position information comprises position distribution information related to a position of a femto base station device and the position distribution information is determined by a second particle filtering of particles corresponding the position of the femto base station device.

32. The method of claim of claim 30, wherein the receiving femto base station position information comprises receiving position estimation information, and the determining the user equipment location information is further based on the position estimation information, the first particle filtering comprises importance sampling of a particle comprised in the first set of particles and results in a second set of particles being generated.

33. The method of claim of claim 32, wherein the first particle filtering further comprises weighting of a particle of the second set of particles based on the position estimation information, and results in a third set of particles being generated.

34. The method of claim of claim 33, wherein the first particle filtering further comprises resampling of a particle of the third set of particles, generating a fourth set of particles, and results in uniform distribution of the particles of the third set of particles in the fourth set of particles.

35. The method of claim of claim 34, wherein the first particle filtering updates the first set of particles by replacing the first set of particles with the fourth set of particles, resulting in an updated first set of particles, and the operations further comprise importance sampling a particle of the updated first set of particles to result in an updated second set of particles being generated.

36. A system, comprising:

means for receiving first macro base station information related to a user equipment;

means for receiving femto base station information related to a user equipment;

means for receiving second macro base station information related to a possible position of a femto base station device;

means for determining femto base station position information based on a first particle filtering of a first set of particles corresponding to the second macro base station information;

means for receiving particle information for a second set of particles corresponding to possible user equipment locations; and

means for determining, by time difference of arrival information, user equipment location information based on a second particle filtering of the second set of particles based on the first macro base station information, femto base station information, and the femto base station position information.

37. The system of claim 36 wherein the femto base station position information comprises femto base station position distribution information or femto base station position estimation information.