Indication of user equipment transmit power capacity in carrier aggregation

• US 9,357,421 B2
• Filed: 04/21/2014
• Issued: 05/31/2016
• Est. Priority Date: 10/01/2010
• Status: Active Grant

• Current Assignee: HFI Innovation, Inc. (MediaTek, Inc.)
• Original Assignee: MediaTek, Inc.
• Inventors: Hwang, Chien-Hwa, Hsu, Chia-Chun, Plumb, William
• Primary Examiner(s): PARK, JUNG H
• Application Number:
  US14/257,226
• Publication Number:
  US 20140226516A1
• Time in Patent Office: 771 Days
• US Class Current: 1/1
• 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;

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 is 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 is indicated in the MAC CE.

8. 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 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.

9. The device of claim 8, 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.

10. The device of claim 8, 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.

11. The device of claim 8, 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.

12. The device of claim 8, 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.

13. The device of claim 8, wherein the PH information is reported to the based station via a fixed-length MAC control element (CE), wherein the length is configured by the base station.

14. The device of claim 8, wherein the PH information is reported to the based station via a variable-length MAC control element (CE), wherein the length is indicated in the MAC CE.

15. 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 and K number of TPL values, 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 15, wherein the PH information further comprises the value of K.

17. The method of claim 15, wherein one of the TPL values represents a UE-configured maximum transmit power for the UE.

18. The method of claim 15, 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 15, further comprising:

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

20. The method of claim 15, wherein the MAC CE sub-header contains a LCID assigned for PH information reporting.