Indication of user equipment transmit power capacilty in carrier aggregation

• US 8,730,829 B2
• Filed: 09/29/2011
• Issued: 05/20/2014
• Est. Priority Date: 10/01/2010
• Status: Active Grant

• Current Assignee: HFI Innovation, Inc. (MediaTek, Inc.)
• Original Assignee: MediaTek, Inc.
• Inventors: Hsu, Chia-Chun, Plumb, Willaim, Hwang, Chien-Hwa
• Primary Examiner(s): PARK, JUNG H
• Application Number:
  US13/200,783
• Publication Number:
  US 20120082043A1
• Time in Patent Office: 964 Days
• US Class Current: 370/252
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/365 Power headroom reporting
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of power headroom reporting (PHR) is proposed. A UE is configured with a plurality of component carriers (CCs) and is served by one or more power amplifiers (PAs) in a wireless system with carrier aggregation. The UE determines transmit power limitation (TPL) information that comprises a set of TPL values, each TPL value corresponds to a UE-configured maximum transmit power for UE-level, PA-level, and CC-level. The TPL information is then reduced to non-redundant TPL values. Based on the non-redundant TPL values, the UE determines power headroom (PH) information that comprises a set of PH values. Each PH value equals to a TPL value subtracted by a UE-calculated transmit power. The UE reports the PH information to a base station via a fixed-length or variable-length MAC CE at each PHR reporting instance.

Claims

1. A method, comprising:

determining transmit power limitation (TPL) information by a UE in a wireless communication system, wherein the UE is configured with a plurality of component carriers (CCs) served by one or more power amplifiers (PAs), wherein the TPL information comprises a set of TPL values, each TPL value corresponds to a UE-configured maximum transmit power for the UE and each PA and each CC;

determining power headroom (PH) information that comprises a set of PH values based on the TPL information; and

reporting the PH information to a base station, wherein the TPL information is reduced to contain a reduced set of non-redundant TPL values, and wherein the PH information is also reduced to contain a reduced set of non-redundant PH values.

2. The method of claim 1, wherein the set of TPL values comprises a UE-level TPL value for the UE, one or more PA-level TPL values for each PA, and a plurality of CC-level TPL values for each CC.

3. The method of claim 1, wherein the set of PH values comprises a UE-level PH value for the UE, one or more PA-level PH values for each PA, and a plurality of CC-level PH values for each CC.

4. The method of claim 1, wherein the UE has only one PA, and wherein the UE-level TPL value for the UE is replaced by a PA-level TPL value for the PA.

5. The method of claim 1, wherein a PA serves only one CC, and wherein a PA-level TPL value for the PA is replaced by a CC-level TPL value for the CC.

6. The method of claim 1, wherein the PH information is reported to the based station via a fixed-length MAC control element (CE), wherein the length of the MAC CE for reporting the PH information is a function of a number of configured/activated/scheduled CCs configured by the base station.

7. The method of claim 1, wherein the PH information is reported to the based station via a variable-length MAC control element (CE), wherein the length of the MAC CE for reporting the PH information is a function of a number of configured/activated/scheduled CCs indicated in the MAC CE.

8. A method, comprising:

determining a total K number of transmit power limit (TPL) values for a user equipment (UE) in a wireless communication system, wherein the UE is configured with N number of component carriers (CCs); and

reporting power headroom (PH) information to a base station, wherein the PH information comprises N number of PH values for the N number of CCs, the K number of TPL values, the value of K, and K sets of carrier indexes each associated with each TPL, wherein the PH information is reported to the based station via a MAC control element (CE), and wherein the length of the MAC CE for reporting the PH information is a function of a number of CCs configured by the base station or indicated in the MAC CE.

16. The method of claim 8, wherein the MAC CE sub-header contains a LCID assigned for PH information reporting.

17. The method of claim 8, wherein one of the TPL values represents a UE-configured maximum transmit power for the UE.

18. The method of claim 8, wherein the UE comprises a power amplifier (PA), and wherein one of the TPL values represents a UE-configured maximum transmit power for the PA.

19. The method of claim 8, further comprising:

transmitting a maximum UE output power (P_powerclass) to the base station.

9. A user equipment (UE) device, comprising:

a power control module that determines transmit power limitation (TPL) information, wherein the UE is configured with a plurality of component carriers (CCs) served by one or more power amplifiers (PAs), wherein the TPL information comprises a set of TPL values, each TPL value corresponds to a UE-configured maximum transmit power for the UE and each PA and each CC, and wherein the power control module determines power headroom (PH) information that comprises a set of PH values based on the TPL information; and

a transmitter that reports the PH information to a base station, wherein the TPL information is reduced to contain a reduced set of non-redundant TPL values, and wherein the PH information is also reduced to contain a reduced set of non-redundant PH values.

10. The device of claim 9, wherein the set of TPL values comprises a UE-level TPL value for the UE, one or more PA-level TPL values for each PA, and a plurality of CC-level TPL values for each CC.

11. The device of claim 9, wherein the set of PH values comprises a UE-level PH value for the UE, one or more PA-level PH values for each PA, and a plurality of CC-level PH values for each CC.

12. The device of claim 9, wherein the UE has only one PA, and wherein the UE-level TPL value for the UE is replaced by a PA-level TPL value for the PA.

13. The device of claim 9, wherein a PA serves only one CC, and wherein a PA-level TPL value for the PA is replaced by a CC-level TPL value for the CC.

14. The device of claim 9, wherein the PH information is reported to the based station via a fixed-length MAC control element (CE), wherein the length of the MAC CE for reporting the PH information is a function of a number of configured/activated/scheduled CCs configured by the base station.

15. The device of claim 9, wherein the PH information is reported to the based station via a variable-length MAC control element (CE), wherein the length of the MAC CE for reporting the PH information is a function of a number of configured/activated/scheduled CCs indicated in the MAC CE.