APPARATUS AND METHOD FOR RANDOM ACCESS SIGNALING IN A WIRELESS COMMUNICATION SYSTEM

• US 20110268049A1
• Filed: 11/01/2010
• Published: 11/03/2011
• Est. Priority Date: 11/02/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Luo, Tao, Montojo, Juan, Chen, Wanshi, Zhang, Xiaoxia, Gaal, Peter
• Granted Patent: US 8,923,218 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

An apparatus and method for providing random access signaling in a multiple input multiple output (MIMO) wireless communication system are provided. The apparatus and method determine a random access transmission scheme for the MIMO communication system based at least in part on a number of transmit antennas in the system. The random access signals are transmitted in a random access channel using the random access transmission scheme. Power control for the random access channel is performed based at least in part on the random access transmission scheme.

Claims

1. A method for wireless communication, comprising:

determining a random access transmission scheme for a multiple input multiple output (MIMO) communication based at least in part on a number of transmit antennas to be utilized for the MIMO communication; and

transmitting random access signals using the random access transmission scheme.

2. The method of claim 1, wherein the transmitting further comprises transmitting the random access signals over a contention-based random access channel.

3. The method of claim 2, wherein the random access transmission scheme employs beamforming.

4. The method of claim 3, wherein the determining comprises selecting a precoding vector from a set of precoding vectors and using the precoding vector to generate the random access signals.

5. The method of claim 4, wherein the determining further comprises selecting at least one of the precoding vectors for communication over the random access channel on a per-burst basis if the random access channel utilizes a format associated with a repeated preamble.

6. The method of claim 5, wherein the format comprises at least one of a physical random access channel (PRACH) format 2 or PRACH format 3.

7. The method of claim 2, wherein the MIMO communication includes random access re-transmission.

8. The method of claim 2, wherein the determining is based at least in part on a format of the random access channel.

9. The method of claim 1, wherein the random access transmission scheme comprises a transmit diversity scheme.

10. The method of claim 9, wherein the transmit diversity scheme comprises time switched transmit diversity (TSTD).

11. The method of claim 1, wherein the determining comprises receiving an indication of the random access transmission scheme.

12. The method of claim 11, wherein the random access transmission scheme comprises a non-contention-based transmission scheme.

13. The method of claim 11, wherein the determining comprises receiving a random access response (RAR) grant message containing the indication.

14. The method of claim 11, wherein the determining comprises receiving a control channel conveying the indication.

15. The method of claim 14, wherein the indication is conveyed using one or more zero-padding bits.

16. The method of claim 1, further comprising performing transmit power control for a physical random access channel based at least in part on the random access transmission scheme.

17. A method for wireless communication, comprising:

determining a random access transmission scheme to be utilized by a plurality of user devices for the MIMO communication; and

receiving a random access request from one of the plurality of user devices in accordance with the random access transmission scheme.

18. The method of claim 17, further comprising providing an indication of the random access transmission scheme to the plurality of user devices.

19. The method of claim 18, wherein the providing comprises transmitting a random access response (RAR) grant message containing the indication.

20. The method of claim 19, wherein the indication is conveyed by re-using at least one bit of the RAR grant message or adding at least one bit to the RAR grant message.

21. The method of claim 18, wherein the providing comprises transmitting a control channel conveying the indication.

22. The method of claim 21, wherein the indication is conveyed using one or more zero-padding bits.

23. The method of claim 18, wherein the providing further comprises initiating a random access procedure with the plurality of user devices in accordance with the random access transmission scheme.

24. The method of claim 17, wherein the random access transmission scheme is used for non-contention-based random access signaling.

25. An apparatus for wireless communication, comprising:

means for determining a random access transmission for a multiple input multiple output (MIMO) communication based at least in part upon a number of transmit antennas to be utilized for the MIMO communication; and

means for transmitting random access signals using the random access transmission scheme.

26. The apparatus of claim 25, wherein the means for transmitting further comprises means for transmitting the random access signals over a contention-based random access channel.

27. The apparatus of claim 25, wherein the means for transmitting comprises at least one of means for beamforming or means for transmit diversity.

28. The apparatus of claim 27, wherein the means for beamforming comprises means for selecting a precoding vector from a set of precoding vectors and means for using the precoding vector to generate the random access signals.

29. The apparatus of claim 28, wherein the means for beamforming further comprises means for selecting at least one of the precoding vectors for communication over a random access channel on a per-burst basis if the random access channel utilizes a format associated with a repeated preamble.

30. The apparatus of claim 27, wherein the means for transmit diversity comprises means for implementing a time switched transmit diversity (TSTD) scheme.

31. The apparatus of claim 25, further comprising means for performing transmit power control for a physical random access channel based at least in part on the random access transmission scheme.

32. An apparatus for wireless communication, comprising:

means for determining a random access transmission scheme to be utilized by a plurality of user devices for a multiple input multiple output (MIMO) communication; and

means for receiving a random access request from one of the plurality of user devices in accordance with the random access transmission scheme.

33. The apparatus of claim 32, wherein the MIMO communication is conducted over a contention-based random access channel.

34. The apparatus of claim 32, further comprising means for providing an indication of the random access transmission scheme to the plurality of user devices.

35. The apparatus of claim 34, wherein the indication is conveyed by re-using at least one bit of a random access response (RAR) grant message or adding at least one bit to the RAR grant message.

36. The apparatus of claim 34, wherein the indication is conveyed using one or more zero-padding bits.

37. The apparatus of claim 32, further comprising means for initiating a random access procedure with the plurality of user devices in accordance with the random access transmission scheme.

38. An apparatus for wireless communication, comprising:

a processor configured to;

determine a random access transmission for a multiple input multiple output (MIMO) communication based at least in part on a number of transmit antennas to be utilized for the MIMO communication; and

transmit random access signals using the random access transmission scheme.

39. The apparatus of claim 38, wherein the processor is further configured to perform transmit power control for a physical random access channel based at least in part on the random access transmission scheme.

40. An apparatus for wireless communication, comprising:

a processor configured to;

determine a random access transmission scheme to be utilized by a plurality of user devices for a multiple input multiple output (MIMO) communication; and

receive a random access request from one of the plurality of user devices in accordance with the random access transmission scheme.

41. The apparatus of claim 40, wherein the processor is further configured to provide an indication of the random access transmission scheme to the plurality of user devices.

42. The apparatus of claim 41, wherein the indication is conveyed by re-using at least one bit of a random access response (RAR) grant message or adding at least one bit to the RAR grant message.

43. The apparatus of claim 41, wherein the indication is conveyed using one or more zero-padding bits.

44. A computer program product that facilitates multiple input multiple output (MIMO) communication in a wireless communication system, comprising:

a computer-readable storage medium comprising;

instructions for causing at least one computer to determine a random access transmission scheme for the MIMO communication based at least in part on a number of transmit antennas to be utilized for the MIMO communication; and

instructions for causing the at least one computer to transmit random access signals using the random access transmission scheme.

45. The computer program product of claim 44, wherein the random access transmission scheme employs beamforming.

46. The computer program product of claim 44, wherein the random access transmission scheme comprises a transmit diversity scheme.

47. The computer program product of claim 44, wherein the computer-readable storage medium further comprises instructions for causing the at least one computer to perform transmit power control for a physical random access channel based at least in part on the random access transmission scheme.

48. A computer program product that facilitates multiple input multiple output (MIMO) communication in a wireless communication system, comprising:

a computer-readable storage medium comprising;

instructions for causing at least one computer to determine a random access transmission scheme to be utilized by a plurality of user devices for the MIMO communication; and

instructions for causing the at least one computer to receive a random access request from one of the plurality of user devices in accordance with the random access transmission scheme.

49. The computer program product of claim 48, wherein the computer-readable storage medium further comprises instructions for causing the at least one computer to provide an indication of the random access transmission scheme to the plurality of user devices, wherein the indication is conveyed by re-using at least one bit of a random access response (RAR) grant message or adding at least one bit to the RAR grant message.

50. The computer program product of claim 48, wherein the computer-readable storage medium instructions for causing the at least one computer to provide an indication of the random access transmission scheme to the plurality of user devices, wherein the indication is conveyed using one or more zero-padding bits.