METHOD AND APPARATUS FOR CONTROLLING UPLINK POWER IN A WIRELESS ACCESS SYSTEM

• US 20130051259A1
• Filed: 04/01/2011
• Published: 02/28/2013
• Est. Priority Date: 04/01/2010
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Min Gyu, Yang, Suck Chel, Ahn, Joon Kui, Seo, Dong Youn
• Granted Patent: US 8,462,705 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/30 using constraints in the total amount of available transmission power
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/365 Power headroom reporting
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

According to one embodiment of the present invention, a method for reporting power headroom in a user equipment of a multi-carrier system, includes receiving a physical downlink control channel (PDCCH) signal comprising uplink resource allocation information from a base station; transmitting at least one of a physical uplink shared channel (PUSCH) signal and a physical uplink control channel (PUCCH) signal to the base station in a predetermined subframe based on the uplink resource allocation information in accordance with a transmission mode; calculating one or more power headroom values for the predetermined subframe in accordance with the transmission mode; and transmitting a report message comprising the one or more power headroom values to the base station, wherein the user equipment reports its first and second type power headroom values when operating in transmission mode A, or reports its first type power headroom value when operating in transmission mode B.

Claims

1. A method for reporting power headroom in a user equipment of a multi-carrier system, the method comprising:

receiving a physical downlink control channel (PDCCH) signal comprising uplink resource allocation information from a base station;

transmitting at least one of a physical uplink shared channel (PUSCH) signal and a physical uplink control channel (PUCCH) signal to the base station in a predetermined subframe on the basis of the uplink resource allocation information in accordance with a transmission mode;

calculating one or more power headroom values for the predetermined subframe in accordance with the transmission mode; and

reporting the one or more power headroom values to the base station,

wherein the user equipment reports a first type power headroom value and a second type power headroom value for the predetermined subframe when the user equipment operates in transmission mode A, and the user equipment reports the first type power headroom value when the user equipment operates in transmission mode B.

2. The method according to claim 1, wherein the user equipment transmits the PUSCH signal and the PUCCH signal to the base station in the predetermined subframe of a primary (P) cell when the user equipment operates in the transmission mode A, and

the user equipment transmits the PUSCH signal to the base station in the predetermined subframe of a serving cell when the user equipment operates in the transmission mode B.

3. The method according to claim 2, wherein:

in the transmission mode A, the PUCCH signal and the PUSCH signal are simultaneously transmitted through a PUCCH region and a PUSCH region, respectively, and

in the transmission mode B, the PUCCH signal is piggybacked into the PUSCH signal and transmitted through the PUSCH region.

4. The method according to claim 2, wherein the first type power headroom value is calculated using a maximum transmission power of the user equipment and a transmission power of the PUSCH signal, and the second type power headroom value is calculated using the maximum transmission power of the user equipment, the transmission power of the PUSCH signal, and a transmission power of the PUCCH signal.

5. The method according to claim 4, wherein the first type power headroom value is calculated using a difference value between the maximum transmission power and the transmission power of the PUCCH signal, and the second type power headroom value is calculated using a difference value between the maximum transmission power and the sum of the transmission power of the PUSCH signal and the transmission power of the PUCCH signal.

6. The method according to claim 4, wherein the second type power headroom value is calculated by

PH_SUM(i)=P_CMAXc−

10 log₁₀(10<sup>PPUSCHc—

scheduled(i)/10</sup>+10<sup>PPUCCH—

scheduled(i)/10</sup>),

where P_CMAXc represents the maximum transmission power of the user equipment, P<sub>PUSCH—

scheduled</sub>(i) represents the transmission power of the PUSCH signal, and P<sub>PUCCH—

scheduled</sub>(i) represents the transmission power of the PUCCH signal.

7. The method according to claim 4, wherein the second type power headroom value is calculated using the transmission power of the PUCCH signal even though the PUCCH signal is not transmitted in the predetermined subframe.

8. The method according to claim 4, wherein the first type power headroom value is calculated by

PH(i)=P_CMAX−

{10 log₁₀(M_PUSCH(i))+P<sub>O—

PUSCH</sub>(j)+α

(j)·

PL+Δ

_TF(i)+f(i)}

where P_CMAX represents the maximum transmission power of the user equipment,

M_PUSCH(i) represents a bandwidth for the PUSCH signal expressed as a number of resource blocks valid for the predetermined subframe,

P<sub>O—

PUSCH</sub>(j) is a parameter configured by a sum of a cell-specific nominal component and a user equipment-specific component provided from an upper layer,

α

(j) is a cell-specific parameter provided from the upper layer,

PL is an estimated value of downlink path loss calculated by the user equipment,

Δ

_TF(i) is a value provided from the upper layer, and

f(i) is a value indicating a current PUSCH power control adjustment state.

9. The method according to claim 2, wherein the user equipment further reports a maximum transmission power value of the user equipment.

10. A user equipment for performing power headroom report in a multi-carrier system, the user equipment comprising:

a reception module for receiving a channel signal;

a transmission module for transmitting a channel signal; and

a processor supporting a function for performing the power headroom report,

wherein the user equipment;

receives a physical downlink control channel (PDCCH) signal comprising uplink resource allocation information from a base station by using the reception module,

transmits at least one of a physical uplink shared channel (PUSCH) signal and a physical uplink control channel (PUCCH) signal to the base station by using the transmission module in a predetermined subframe on the basis of the uplink resource allocation information in accordance with a transmission mode,

calculates one or more power headroom values for the predetermined subframe through the processor,

reports the one or more power headroom values to the base station through the transmission module in accordance with the transmission mode, and

wherein the user equipment reports a first type power headroom value and a second type power headroom value for the predetermined subframe when the user equipment operates in transmission mode A, and the user equipment reports the first type power headroom value when the user equipment operates in transmission mode B.

11. The user equipment according to claim 10, wherein the user equipment transmits the PUSCH signal and the PUCCH signal to the base station using the transmission module in the predetermined subframe of a primary (P) cell when the user equipment operates in the transmission mode A, and

the user equipment transmits the PUSCH signal to the base station using the transmission module in the predetermined subframe of a serving cell when the user equipment operates in the transmission mode B.

12. The user equipment according to claim 11, wherein the first type power headroom value is calculated using a difference value between a maximum transmission power of the user equipment and a transmission power of the PUSCH signal, and the second type power headroom value is calculated using a difference value between the maximum transmission power of the user equipment and the sum of the transmission power of the PUSCH signal, and a transmission power of the PUCCH signal.

13. The user equipment according to claim 11, wherein the second type power headroom value is calculated using the transmission power of the PUCCH signal even though the PUCCH signal is not transmitted in the predetermined subframe.

14. The user equipment according to claim 11, wherein the first type power headroom value is calculated by

PH(i)=P_CMAX−

{10 log₁₀(M_PUSCH(i))+P<sub>O—

PUSCH</sub>(j)+α

(j)·

PL+Δ

_TF(i)+f(i)}

P_CMAX represents a maximum transmission power of the user equipment,

M_PUSCH(i) represents a bandwidth for the PUSCH signal expressed as a number of resource blocks valid for the predetermined subframe,

P<sub>O—

PUSCH</sub>(j) is a parameter configured by a sum of a cell-specific nominal component and a user equipment-specific component provided from an upper layer,

α

(j) is a cell-specific parameter provided from the upper layer,

PL is an estimated value of downlink path loss calculated by the user equipment,

Δ

_TF(i) is a value provided from the upper layer, and

f(i) is a value indicating a current PUSCH power control adjustment state, and

wherein the second type power headroom value is calculated by

PH_SUM(i)=P_CMAXc−

10 log₁₀(10<sup>PPUSCHc—

scheduled(i)/10</sup>+10<sup>PPUCCH—

scheduled(i)/10</sup>),

where P_CMAXc represents the maximum transmission power of the user equipment,

P<sub>PUSCH—

scheduled</sub>(i) represents the transmission power of the PUSCH signal, and

P<sub>PUCCH—

scheduled</sub>(i) represents the transmission power of the PUCCH signal.

15. The user equipment according to claim 11, wherein:

in the transmission mode A, the PUCCH signal and the PUSCH signal are simultaneously transmitted through a PUCCH region and a PUSCH region, respectively, and

in the transmission mode B, the PUCCH signal is piggybacked into the PUSCH signal and transmitted through the PUSCH region.