CENTRALIZED CONTROL OF RELAY OPERATION

• US 20100167743A1
• Filed: 12/21/2009
• Published: 07/01/2010
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Bhushan, Naga, Palanki, Ravi, Agrawal, Avneesh, Khandekar, Aamod D.
• Granted Patent: US 8,886,113 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

Techniques for centralized control of relay operation are described. In an aspect, a designated network entity (e.g., a base station or a network controller) may control the operation of relay stations within its coverage area. The network entity may select certain user equipments (UEs) to be relay UEs that can serve as relay stations for other UEs, e.g., based on pathloss between the UEs and a base station, the locations of the UEs, battery power levels of the UEs, fairness considerations, etc. The network entity may also select a specific relay UE to serve as a relay station for a client UE desiring to communicate with a base station, e.g., based on pilot measurements from relay UEs for the client UE. The network entity may also control transmission of discovery pilots by relay UEs and/or client UEs for relay detection.

Claims

1. A method for wireless communication, comprising:

exchanging pilot between a first user equipment (UE) and at least one UE capable of serving as relay station;

obtaining an indication that a second UE will serve as a relay station for the first UE, the second UE being one of the at least one UE; and

exchanging data between the first UE and a base station via the second UE.

2. The method of claim 1, wherein the exchanging pilot comprises

transmitting pilot from the first UE to the at least one UE to enable the at least one UE to detect the first UE.

3. The method of claim 1, further comprising:

transmitting an indication that the first UE desires to communicate with the base station.

4. The method of claim 1, wherein the obtaining the indication comprises

receiving the indication that the second UE will serve as a relay station for the first UE, the second UE being selected based on at least one pilot measurement made by the at least one UE for the first UE.

5. The method of claim 1, wherein the exchanging pilot comprises

receiving pilot transmitted by the at least one UE to enable detection of the at least one UE.

6. The method of claim 1, wherein the obtaining the indication comprises

measuring pilot transmitted by each of the at least one UE, and

selecting the second UE from among the at least one UE based on at least one pilot measurement for the at least one UE.

7. The method of claim 1, wherein the data is exchanged between the first UE and the base station via the second UE after obtaining the indication that the second UE will serve as a relay station for the first UE.

8. The method of claim 1, wherein the pilot comprises at least one synchronization signal, or at least one reference signal, or at least one transmission sent on at least one physical channel for relay detection, or a combination thereof.

9. An apparatus for wireless communication, comprising:

means for exchanging pilot between a first user equipment (UE) and at least one UE capable of serving as relay station;

means for obtaining an indication that a second UE will serve as a relay station for the first UE, the second UE being one of the at least one UE; and

means for exchanging data between the first UE and a base station via the second UE.

10. The apparatus of claim 9, wherein the means for exchanging pilot comprises means for transmitting pilot from the first UE to the at least one UE to enable the at least one UE to detect the first UE.

11. The apparatus of claim 9, wherein the means for obtaining the indication comprises means for receiving the indication that the second UE will serve as a relay station for the first UE, the second UE being selected based on at least one pilot measurement made by the at least one UE for the first UE.

12. The apparatus of claim 9, wherein the means for exchanging pilot comprises means for receiving pilot transmitted by the at least one UE to enable detection of the at least one UE.

13. The apparatus of claim 9, wherein the means for obtaining the indication comprises

means for measuring pilot transmitted by each of the at least one UE, and

means for selecting the second UE from among the at least one UE based on at least one pilot measurement for the at least one UE.

14. An apparatus for wireless communication, comprising:

at least one processor configured to exchange pilot between a first user equipment (UE) and at least one UE capable of serving as relay station, to obtain an indication that a second UE will serve as a relay station for the first UE, the second UE being one of the at least one UE, and to exchange data between the first UE and a base station via the second UE.

15. The apparatus of claim 14, wherein the at least one processor is configured to transmit pilot from the first UE to the at least one UE to enable the at least one UE to detect the first UE.

16. The apparatus of claim 14, wherein the at least one processor is configured to receive the indication that the second UE will serve as a relay station for the first UE, the second UE being selected based on at least one pilot measurement made by the at least one UE for the first UE.

17. The apparatus of claim 14, wherein the at least one processor is configured to receive pilot transmitted by the at least one UE to enable detection of the at least one UE.

18. The apparatus of claim 14, wherein the at least one processor is configured to measure pilot transmitted by each of the at least one UE and to select the second UE from among the at least one UE based on at least one pilot measurement for the at least one UE.

19. A computer program product, comprising:

a computer-readable medium comprising;

code for causing at least one computer to exchange pilot between a first user equipment (UE) and at least one UE capable of serving as relay station,

code for causing the at least one computer to obtain an indication that a second UE will serve as a relay station for the first UE, the second UE being one of the at least one UE, and

code for causing the at least one computer to exchange data between the first UE and a base station via the second UE.

20. A method for wireless communication, comprising:

exchanging pilot with a first user equipment (UE) by a second UE capable of serving as a relay station for the first UE;

obtaining an indication for the second UE to serve as a relay station for the first UE; and

relaying, by the second UE, data exchanged between the first UE and a base station.

21. The method of claim 20, wherein the exchanging pilot comprises

receiving pilot transmitted by the first UE to enable detection of the first UE.

22. The method of claim 21, wherein the obtaining the indication comprises

measuring the pilot transmitted by the first UE,

sending pilot measurement for the first UE to the base station, and

receiving the indication from the base station.

23. The method of claim 21, wherein the obtaining the indication comprises

measuring the pilot transmitted by the first UE, and

making a decision by the second UE to serve as a relay station for the first UE based on pilot measurement for the first UE.

24. The method of claim 20, wherein the exchanging pilot comprises

transmitting pilot by the second UE to enable the first UE to detect the second UE.

25. The method of claim 24, further comprising:

receiving from the base station a directive to start transmitting pilot, and wherein the pilot is transmitted by the second UE in response to the directive from the base station.

26. The method of claim 24, further comprising:

receiving from the base station a directive to stop transmitting pilot, and wherein transmission of the pilot is stopped by the second UE in response to the directive from the base station.

27. The method of claim 20, wherein the obtaining the indication comprises

receiving the indication from the first UE.

28. The method of claim 20, wherein the exchanging pilot comprises

transmitting the pilot or receiving the pilot based on a low duty cycle selected to reduce power consumption by the second UE.

29. An apparatus for wireless communication, comprising:

means for exchanging pilot with a first user equipment (UE) by a second UE capable of serving as a relay station for the first UE;

means for obtaining an indication for the second UE to serve as a relay station for the first UE; and

means for relaying, by the second UE, data exchanged between the first UE and a base station.

30. The apparatus of claim 29, wherein the means for exchanging pilot comprises means for receiving pilot transmitted by the first UE to enable detection of the first UE.

31. The apparatus of claim 30, wherein the means for obtaining the indication comprises

means for measuring the pilot transmitted by the first UE,

means for sending pilot measurement for the first UE to the base station, and

means for receiving the indication from the base station.

32. The apparatus of claim 29, wherein the means for exchanging pilot comprises means for transmitting pilot by the second UE to enable the first UE to detect the second UE.

33. The apparatus of claim 32, further comprising:

means for receiving from the base station a directive to start transmitting pilot, and wherein the pilot is transmitted by the second UE in response to the directive from the base station.

34. A method for wireless communication, comprising:

identifying at least one user equipment (UE) capable of serving as relay station; and

controlling operation of the at least one UE to support communication between one or more UEs and a base station.

35. The method of claim 34, wherein the identifying at least one UE comprises selecting the at least one UE to serve as relay station based on channel conditions between the at least one UE and the base station, or geographic location of the at least one UE, or geographic location of the one or more UEs, or power supply level of the at least one UE, or fairness considerations, or a combination thereof.

36. The method of claim 34, wherein the controlling operation of the at least one UE comprises

receiving at least one pilot measurement for pilot exchanged between a first UE and the at least one UE, the first UE being one of the one or more UEs,

selecting a second UE to serve as a relay station for the first UE, the second UE being one of the at least one UE, and

sending an indication of the second UE being selected to serve as a relay station for the first UE.

37. The method of claim 34, wherein the controlling operation of the at least one UE comprises

identifying a first UE desiring to communicate with the base station, the first UE being one of the one or more UEs, and

directing the at least one UE to detect for pilot from the first UE.

38. The method of claim 34, wherein the controlling operation of the at least one UE comprises sending to the at least one UE a directive to start transmitting pilot, and wherein the pilot is transmitted by the at least one UE in response to the directive.

39. The method of claim 38, further comprising:

sending to the at least one UE a second directive to stop transmitting pilot, and wherein transmission of the pilot is stopped by the at least one UE in response to the second directive.

40. The method of claim 34, further comprising:

identifying a first UE desiring to communicate with the base station, the first UE being one of the one or more UEs;

identifying a second UE selected to serve as a relay station for the first UE, the second UE being one of the at least one UE; and

exchanging data with the first UE via the second UE.

41. An apparatus for wireless communication, comprising:

means for identifying at least one user equipment (UE) capable of serving as relay station; and

means for controlling operation of the at least one UE to support communication between one or more UEs and a base station.

42. The apparatus of claim 41, wherein the means for controlling operation of the at least one UE comprises

means for receiving at least one pilot measurement for pilot exchanged between a first UE and the at least one UE, the first UE being one of the one or more UEs,

means for selecting a second UE to serve as a relay station for the first UE, the second UE being one of the at least one UE, and

means for sending an indication of the second UE being selected to serve as a relay station for the first UE.

43. The apparatus of claim 41, wherein the means for controlling operation of the at least one UE comprises

means for identifying a first UE desiring to communicate with the base station, the first UE being one of the one or more UEs, and

means for directing the at least one UE to detect for pilot from the first UE.

44. The apparatus of claim 41, wherein the means for controlling operation of the at least one UE comprises means for sending to the at least one UE a directive to start transmitting pilot, and wherein the pilot is transmitted by the at least one UE in response to the directive.

45. The apparatus of claim 41, further comprising:

means for identifying a first UE desiring to communicate with the base station, the first UE being one of the one or more UEs;

means for identifying a second UE selected to serve as a relay station for the first UE, the second UE being one of the at least one UE; and

means for exchanging data with the first UE via the second UE.