Physical random access channel (PRACH) transmission in multicarrier operation

• US 9,370,003 B2
• Filed: 08/16/2013
• Issued: 06/14/2016
• Est. Priority Date: 09/12/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Damnjanovic, Jelena M., Montojo, Juan, Gaal, Peter, Chen, Wanshi, Ho, Sai Yiu Duncan
• Primary Examiner(s): Mew, Kevin
• Application Number:
  US13/968,796
• Publication Number:
  US 20130336260A1
• Time in Patent Office: 1,033 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

Systems and methodologies are described that facilitate selecting an uplink carrier for random access within a wireless environment having multiple carriers. Selection of an uplink carrier for random access can be randomly selected from a set of available uplink carriers. Additionally, the uplink carrier for random access can be selected based upon which uplink carrier is paired with an anchor carrier. Further, the uplink carrier for random access can be identified based upon a bandwidth related to the user equipment (UE). Reference signals can also be employed in order to identify an uplink carrier to perform random access.

Claims

1. A method for wireless communication at a base station, comprising:

defining a plurality of sets of Physical Random Access Channel (PRACH) parameters for a plurality of downlink carriers configured for communication at the base station; and

identifying, from the plurality of downlink carriers, a downlink carrier acquired by a UE based upon a set of PRACH parameters used by the UE to perform random access, the set of PRACH parameters used by the UE being one of the defined plurality of sets of PRACH parameters.

2. The method of claim 1, wherein the set of PRACH parameters used by the UE includes at least a specific radio frame, a subframe within the radio frame, and a physical resource block in a frequency domain.

3. The method of claim of claim 1, further comprising:

transmitting a random access response on the identified downlink carrier.

4. The method of claim 1, further comprising:

determining a downlink carrier from among the plurality of downlink carriers;

selecting an uplink carrier corresponding to the determined downlink carrier as the uplink carrier to be used for random access; and

notifying a UE about the uplink carrier selection to perform the random access.

5. The method of claim 4, wherein determining the downlink carrier further comprises selecting a cell and a downlink carrier for random access based on at least one of reference signal measurements, channel quality feedback, and loading information for detectable cells.

6. A wireless communications apparatus, comprising:

at least one processor configured to;

define a plurality of sets of Physical Random Access Channel (PRACH) parameters for a plurality of downlink carriers configured for communication at a base station; and

identify, from the plurality of downlink carriers, a downlink carrier acquired by a UE based upon a set of PRACH parameters used by the UE to perform random access, the set of PRACH parameters used by the UE being one of the defined plurality of sets of PRACH parameters.

7. The wireless communications apparatus of claim 6, wherein the set of PRACH parameters used by the UE includes at least a specific radio frame, a subframe within the radio frame, and a physical resource block in a frequency domain.

8. The wireless communications apparatus of claim 6, further comprising:

at least one processor configured to;

transmit a random access response on the identified downlink carrier.

9. The wireless communications apparatus of claim 6, further comprising:

at least one processor configured to;

determine a downlink carrier from among the plurality of downlink carriers;

select an uplink carrier corresponding to the determined downlink carrier as the uplink carrier to be used for random access; and

notify a UE about the uplink carrier selection to perform the random access.

10. The wireless communications apparatus of claim 9, wherein determining the downlink carrier further comprises selecting a cell and a downlink carrier for random access based on at least one of reference signal measurements, channel quality feedback, and loading information for detectable cells.

11. A wireless communications apparatus, comprising:

means for defining a plurality of sets of Physical Random Access Channel (PRACH) parameters for a plurality of downlink carriers configured for communication at a base station; and

means for identifying, from the plurality of downlink carriers, a downlink carrier acquired by a UE based upon a set of PRACH parameters used by the UE to perform random access, the set of PRACH parameters used by the UE being one of the defined plurality of sets of PRACH parameters.

12. The wireless communications apparatus of claim 11, wherein the set of PRACH parameters used by the UE includes at least a specific radio frame, a subframe within the radio frame, and a physical resource block in a frequency domain.

13. The wireless communications apparatus of claim 11, further comprising:

means for transmitting a random access response on the identified downlink carrier.

14. The wireless communications apparatus of claim 11, further comprising:

means for determining a downlink carrier from among the plurality of downlink carriers;

means for selecting an uplink carrier corresponding to the determined downlink carrier as the uplink carrier to be used for random access; and

means for notify a UE about the uplink carrier selection to perform the random access.

15. The wireless communications apparatus of claim 14, wherein the means for determining the downlink carrier further comprises means for selecting a cell and a downlink carrier for random access based on at least one of reference signal measurements, channel quality feedback, and loading information for detectable cells.

16. A computer program product comprising a non-transitory computer-readable medium comprising:

code for causing at least one computer to define a plurality of sets of Physical Random Access Channel (PRACH) parameters for a plurality of downlink carriers configured for communication at a base station; and

code for causing at least one computer to identify, from the plurality of downlink carriers, a downlink carrier acquired by a UE based upon a set of PRACH parameters used by the UE to perform random access, the set of PRACH parameters used by the UE being one of the defined plurality of PRACH parameters.

17. The computer program product of claim 16, wherein the set of PRACH parameters used by the UE includes at least a specific radio frame, a subframe within the radio frame, and a physical resource block in a frequency domain.

18. The computer program product of claim 16, further comprising:

code for causing at least one computer to transmit a random access response on the identified downlink carrier.

19. The computer program product of claim 16, further comprising:

code for causing at least one computer to determine a downlink carrier from among the plurality of downlink carriers;

code for causing at least one computer to select an uplink carrier corresponding to the determined downlink carrier as the uplink carrier to be used for random access; and

code for causing at least one computer to notify a UE about the uplink carrier selection to perform random access.

20. The computer program product of claim 19, wherein the code for causing at least one computer to determine the downlink carrier further comprises code for causing at least one computer to select a cell and a downlink carrier for random access based on at least one of reference signal measurements, channel quality feedback, and loading information for detectable cells.