Method and apparatus for determining transmission power of uplink control channel in wireless communication system

1. A method for determining transmit power of an uplink (UL) control channel of a user equipment (UE) to which two cells having different UL-downlink (DL) configurations are assigned, the method comprising:

determining, by the UE, a maximum value M between N 1 and N 2 ,

wherein N 1 is a number of downlink subframes associated with a subframe n of a first cell having a first UL-DL configuration, and

wherein N 2 is a number of downlink subframes associated with a subframe n of a second cell having a second UL-DL configuration;

determining, by the UE, a parameter value based on the maximum value M; and

transmitting, by the UE, the UL control channel in the subframe n of the first cell at a transmit power determined based on the parameter value,

wherein if the maximum value M is 3 or 4, the parameter value is either 2 or 4based on whether or not a data channel or a control channel indicating a semi-persistent scheduling (SPS) release is received by the UE in a subframe n-k of only one cell between the first cell and the second cell, and

wherein n, M, k, N 1 , and N 2 are integers greater than or equal to 0.

2. The method of claim 1 , wherein a value of k is determined by the following table for each UL-DL configuration and the subframe n of the first cell and the second cell:

UL-DL

Subframe n

Configuration

0

1

2

3

4

5

6

7

8

9

0

—

—

6

—

4

—

—

6

—

4

1

—

—

7, 6

4

—

—

—

7, 6

4

—

2

—

—

8, 7, 4, 6

—

—

—

—

8, 7,

—

—

4, 6

3

—

—

7, 6, 11

6, 5

5, 4

—

—

—

—

—

4

—

—

12, 8, 7, 11

6, 5,

—

—

—

—

—

—

4, 7

5

—

—

13, 12, 9, 8,

—

—

—

—

—

—

—

7, 5, 4, 11, 6

6

—

—

7

7

5

—

—

7

7

—.

3. The method of claim 1 , wherein the first cell is a primary cell in which the UE performs an initial connection establishment procedure or a connection re-establishment procedure with respect to a base station.

4. The method of claim 3 , wherein the second cell is a secondary cell which is added to the UE in addition to the primary cell.

5. The method of claim 1 , wherein the first UL-DL configuration and the second UL-DL configuration are two different configurations among UL-DL configurations of the following table:

UL-DL

Subframe number

configuration

0

1

2

3

4

5

6

7

8

9

0

D

S

U

U

U

D

S

U

U

U

1

D

S

U

U

D

D

S

U

U

D

2

D

S

U

D

D

D

S

U

D

D

3

D

S

U

U

U

D

D

D

D

D

4

D

S

U

U

D

D

D

D

D

D

5

D

S

U

D

D

D

D

D

D

D

6

D

S

U

U

U

D

S

U

U

D

where D denotes a downlink subframe, S denotes a special subframe, and U denotes an uplink subframe.

6. The method of claim 1 , wherein one of N 1 and N 2 is 4, and the other one of N 1 and N 2 is 0, 1, or 2.

7. The method of claim 1 , wherein the first cell and the second cell are time division duplex (TDD) cells.

8. An apparatus for determining transmit power of an uplink (UL) control channel, the apparatus comprising:

a transceiver configured to transmit and receive a radio signal; and

a processor operatively coupled to the transceiver,

wherein the processor is configured to:

determine a maximum value M between N 1 and N 2 ,

wherein N 1 is a number of downlink (DL) subframes associated with a subframe n of a first cell having a first UL-DL configuration, and wherein N 2 is a number of downlink subframes associated with a subframe n of a second cell having a second UL-DL configuration,

determine a parameter value based on the maximum value M, and

control the transceiver to transmit the UL control channel in the subframe n of the first cell at a transmit power determined based on the parameter value,

wherein if the maximum value M is 3 or 4, the parameter value is either 2 or 4 based on whether or not a data channel or a control channel indicating a semi-persistent scheduling (SPS) release is received in a subframe n-k of only one cell between the first cell and the second cell, and wherein n, M, k, N 1 , and N 2 are integers greater than or equal to 0.