DEVICE DISCOVERY FOR DEVICE-TO-DEVICE COMMUNICATION

• US 20140064263A1
• Filed: 08/29/2012
• Published: 03/06/2014
• Est. Priority Date: 08/29/2012
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Cheng, Fang-Chen, Tatesh, Said
• Granted Patent: US 9,451,570 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

Embodiments of the claimed subject matter provide a method and apparatus for device discovery in device-to-device (D2D) communication. One embodiment of the method includes generating first information indicative of a first synchronization signal in response to a request from a first user equipment to be authenticated for D2D communication with one or more second user equipment. The first information corresponds to a sequence used to generate a primary synchronization signal for transmission by a serving cell for the first user equipment. This embodiment of the method also includes providing the first information to the first user equipment so that the first user equipment can transmit the first synchronization signal.

Claims

1. A method, comprising:

generating first information indicative of a first synchronization signal in response to a request from a first user equipment to be authenticated for device-to-device (D2D) communication with at least one second user equipment, the first information corresponding to a sequence used to generate a primary synchronization signal for transmission by a serving cell for the first user equipment; and

providing the first information to the first user equipment so that the first user equipment can transmit the first synchronization signal.

2. The method of claim 1, comprising generating second information indicative of a second synchronization signal using a physical layer cell identity of the serving cell and providing the second information to the first user equipment.

3. The method of claim 1, wherein generating the first information indicative of the first synchronization signal comprises generating information indicative of a root index of a Zadoff-Chu sequence associated with the serving cell.

4. The method of claim 3, comprising authenticating the first user equipment for D2D communication with said at least one second user equipment, wherein the D2D communication uses a network timing reference.

5. The method of claim 4, wherein generating the first information indicative of the first synchronization signal comprises generating the first information using the root index of the Zadoff-Chu sequence associated with the serving cell and a scrambling sequence that identifies the first user equipment.

6. The method of claim 5, comprising providing the scrambling sequence to said at least one second user equipment.

7. The method of claim 3, comprising authenticating the first user equipment for D2D communication with said at least one second user equipment at a subsequent time when a network timing reference is not available.

8. A method, comprising:

providing, from a first user equipment, a request to be authenticated for device-to-device (D2D) communication with at least one second user equipment; and

receiving, at the first user equipment and in response to the request, first information indicative of a first synchronization signal corresponding to a sequence used to generate a primary synchronization signal for transmission by a serving cell for the first user equipment.

9. The method of claim 8, wherein receiving the first information indicative of the first synchronization signal comprises receiving information indicative of a root index of a Zadoff-Chu sequence associated with the serving cell.

10. The method of claim 8, comprising receiving second information indicative of a second synchronization signal generated using a physical layer cell identity of the serving cell.

11. The method of claim 10, wherein receiving the first information comprises receiving a scrambling sequence that identifies the first user equipment.

12. The method of claim 11, comprising transmitting the first synchronization signal and the second synchronization signal in configurable symbols of configurable slots of a subframe using a network timing reference at a configurable power level.

13. The method of claim 12, comprising transmitting a sounding reference signal, and wherein transmitting the first and second synchronization signals comprises transmitting the first and second synchronization signals at a configurable symbol offset from the sounding reference signal and in the same subframe as the sounding reference signal.

14. The method of claim 12, comprising determining that a network is not available based on a configurable number of failed attempts to access the network and transmitting the first synchronization signal and the second synchronization signal in response to determining that the network is not available.

15. The method of claim 14, wherein transmitting the first and second synchronization signals comprises transmitting the first and second synchronization signals based on a random timing reference provided by an oscillator in the first user equipment, subframe timing configured prior to the network becoming unavailable, or subframe timing based on a Global Positioning System reference time.

16. The method of claim 14, wherein transmitting the first and second synchronization signal comprises transmitting the first and second synchronization signals at a power level that iteratively increases from a minimum to a maximum over successive time intervals.

17. The method of claim 14, comprising transmitting a sounding reference signal in response to determining that the network is not available.

18. The method of claim 17, wherein transmitting the sounding reference signal comprises transmitting the sounding reference signal at a random cyclic shift or a configurable cyclic shift relative to the first and second synchronization signals.

19. The method of claim 12, comprising receiving an acknowledgment preamble from said at least one second user equipment in response to transmitting the first and second synchronization signals.

20. The method of claim 19, comprising establishing a D2D communication link between the first user equipment and said at least one second user equipment in response to receiving the acknowledgment preamble.

21. A method, comprising:

detecting, at a second user equipment, a first synchronization signal transmitted by a first user equipment that is authenticated for device-to-device (D2D) communication, wherein the first synchronization signal corresponds to a sequence used to generate a primary synchronization signal for transmission by a serving cell for the first user equipment; and

transmitting an acknowledgment preamble from the second user equipment in response to detecting the first synchronization signal.

22. The method of claim 21, comprising detecting a second synchronization signal transmitted by the first user equipment, wherein the second synchronization signal is generated using a physical layer cell identity of the serving cell.

23. The method of claim 22, comprising synchronizing timing of the first and second user equipment based on the first and second synchronization signals.

24. The method of claim 23, comprising establishing a D2D communication link between the first user equipment and the second user equipment based on the synchronized timing.

25. A controller configurable for deployment in a network, the controller being configurable to:

generate first information indicative of a first synchronization signal in response to a request from a first user equipment to be authenticated for device-to-device (D2D) communication with at least one second user equipment, the first information corresponding to a sequence used to generate a primary synchronization signal for transmission by a serving cell for the user equipment; and

provide the first information to the first user equipment so that the first user equipment can transmit the first synchronization signal.

26. The controller of claim 25, wherein the controller is configurable to generate second information indicative of a second synchronization signal using a physical layer cell identity of the serving cell, and wherein the controller is configurable to provide the second information to the first user equipment.

27. The controller of claim 25, wherein the controller is configurable to generate information indicative of a root index of a Zadoff-Chu sequence associated with the serving cell.

28. The controller of claim 27, wherein the controller is configurable to authenticate the first user equipment for D2D communication with said at least one second user equipment, wherein the D2D communication uses a timing reference provided by the network.

29. The controller of claim 28, wherein the controller is configurable to generate the first information using the root index of the Zadoff-Chu sequence associated with the serving cell and a scrambling sequence that identifies the first user equipment.

30. The controller of claim 29, wherein the controller is configurable to provide the scrambling sequence to said at least one second user equipment.

31. The controller of claim 27, wherein the controller is configurable to authenticate the first user equipment for D2D communication with said at least one second user equipment at a subsequent time when a network timing reference is not available.

32. User equipment configurable to:

provide a request to be authenticated for device-to-device (D2D) communication with at least one other user equipment; and

receive, in response to the request, first information indicative of a first synchronization signal corresponding to a sequence used to generate a primary synchronization signal for transmission by a serving cell for the user equipment.

33. The user equipment of claim 32, wherein the user equipment is configurable to receive information indicative of a root index of a Zadoff-Chu sequence associated with the serving cell.

34. The user equipment of claim 32, wherein the user equipment is configurable to receive second information indicative of a second synchronization signal generated using a physical layer cell identity of the serving cell.

35. The user equipment of claim 34, wherein the user equipment is configurable to receive a scrambling sequence that identifies the user equipment and to generate the first synchronization signal using the scrambling sequence and the sequence used to generate the primary synchronization signal for transmission by the serving cell.

36. The user equipment of claim 35, wherein the user equipment is configurable to transmit the first synchronization signal and the second synchronization signal in configurable symbols of configurable slots of a subframe using a network timing reference at a configurable power level.

37. The user equipment of claim 36, wherein the user equipment is configurable to transmit a sounding reference signal, and wherein the user equipment is configurable to transmit the first and second synchronization signals at a configurable symbol offset from the sounding reference signal and in the same subframe as the sounding reference signal.

38. The user equipment of claim 36, wherein the user equipment is configurable to determine that a network is not available based on a configurable number of failed attempts to access the network, and wherein the user equipment is configurable to transmit the first synchronization signal and the second synchronization signal in response to determining that the network is not available.

39. The user equipment of claim 38, wherein the user equipment is configurable to transmit the first and second synchronization signals based on a random timing reference provided by an oscillator in the user equipment, subframe timing configured prior to the network becoming unavailable, or subframe timing based on a Global Positioning System reference time.

40. The user equipment of claim 38, wherein the user equipment is configurable to transmit the first and second synchronization signals at a power level that iteratively increases from a minimum to a maximum over successive time intervals.

41. The user equipment of claim 38, wherein the user equipment is configurable to transmit a sounding reference signal in response to determining that the network is not available.

42. The user equipment of claim 41, wherein the user equipment is configurable to transmit the sounding reference signal at a random cyclic shift or a configurable cyclic shift relative to the first and second synchronization signals.

43. The user equipment of claim 34, wherein the user equipment is configurable to receive an acknowledgment preamble from said at least one other user equipment in response to transmitting the first and second synchronization signals.

44. The user equipment of claim 34, wherein the user equipment is configurable to detect at least one third synchronization signal transmitted by said at least one other user equipment that is authenticated for device-to-device (D2D) communication, wherein said at least one third synchronization signal corresponds to a sequence used to generate a primary synchronization signal for transmission by a serving cell for said at least one other user equipment.

45. The user equipment of claim 44, wherein the user equipment is configurable to transmit an acknowledgment preamble in response to detecting said at least one third synchronization signal.

46. The user equipment of claim 45, wherein the user equipment is configurable to detect at least one fourth synchronization signal transmitted by said at least one other user equipment, wherein the second synchronization signal is generated using a physical layer cell identity of the serving cell of said at least one other user equipment.

47. The user equipment of claim 46, wherein the user equipment is configurable to synchronize timing with said at least one other user equipment based on at least one of the first, second, at least one third, or at least one fourth synchronization signals.

48. The user equipment of claim 47, wherein the user equipment is configurable to establish a D2D communication link with said at least one second user equipment.