Method for transmitting/receiving data in a wireless access system and base station for same
The present invention relates to a method for transmitting/receiving data in a Time Division Duplex (TDD) wireless access system supporting multiple cells, and a base station for same. In more detail, on the basis of a multi-cell TDD uplink-downlink configuration, the method includes confirming whether a collision subframe occurs, which is caused when an uplink subframe of a first cell and a downlink subframe of a second cell exists in the same time interval; and performing cross cell scheduling on the second cell through the first cell according to a TDD uplink-downlink configuration of the first cell. When data transmission is scheduled in the collision subframe by cross cell scheduling, by changing the transmission position of an uplink or a downlink according to the cross cell scheduling, the scheduled data are transmitted in the collision subframe.
1. A method for transmitting a signal by a user equipment in a wireless communication system, the user equipment being configured with a plurality of cells including a first cell and a second cell, each of the first cell and the second cell operating in time division duplex (TDD), the method comprising:
receiving, by the user equipment, uplink (UL) grant information in a first downlink (DL) subframe on the first cell, the UL grant information scheduling a UL transmission on the second cell; and
performing, by the user equipment, the UL transmission in a UL subframe on the second cell via a physical UL shared channel based on the UL grant information,
wherein the first cell and the second cell have different TDD UL-DL configurations, and
wherein the UL subframe on the second cell is determined based on a TDD UL-DL configuration of the second cell.
2. The method according to claim 1 , wherein when the first DL subframe is a subframe n and the UL subframe is a subframe n+k, a timing relation k between the first DL subframe and the UL subframe is given based on the TDD UL-DL configuration of the second cell according to the following table:
TDD UL-DL
subframe number n
Configuration
0
1
2
3
4
5
6
7
8
9
0
4
6
4
6
1
6
4
6
4
2
4
4
3
4
4
4
4
4
4
5
4
6
7
7
7
7
5.
3. The method according to claim 1 , wherein subframe configuration on each of the first cell and the second cell is given based on a TDD UL-DL configuration of a corresponding cell according to the following table:
TDD 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 U denotes a UL subframe, D denotes a DL subframe, and S denotes a subframe comprising a DL period, a guard period, and a UL period.
4. The method according to claim 1 , further comprising:
receiving, by the user equipment, hybrid automatic repeat and request (HARQ) acknowledgement/negative-acknowledgement (ACK/NACK) information for the UL transmission in a second DL subframe on the second cell,
wherein a timing relation between the UL subframe and the second DL subframe is determined based on the TDD UL-DL configuration of the second cell.
5. The method according to claim 4 , wherein when the second DL subframe is a subframe i and the UL subframe is a subframe i-k, the timing relation k between the second DL subframe and the UL subframe is given based on the TDD UL-DL configuration of the second cell according to the following table:
TDD UL-DL
subframe number i
Configuration
0
1
2
3
4
5
6
7
8
9
0
7
4
7
4
1
4
6
4
6
2
6
6
3
6
6
6
4
6
6
5
6
6
6
4
7
4
6.
6. The method according to claim 4 , wherein the HARQ ACK/NACK information is received via a physical HARQ indicator channel.
7. The method according to claim 1 , wherein the UL grant information is received via a physical DL control channel.
8. A user equipment configured to transmit a signal in a wireless communication system, the user equipment being configured with a plurality of cells including a first cell and a second cell, each of the first cell and the second cell operating in time division duplex (TDD), the user equipment comprising:
a radio frequency (RF) unit ; and
a processor operatively connected to the RF unit and configured to:
receive uplink (UL) grant information in a first downlink (DL) subframe on the first cell through the RF unit, the UL grant information scheduling a UL transmission on the second cell, and
perform the UL transmission in a UL subframe on the second cell via a physical UL shared channel based on the UL grant information through the RF unit,
wherein the first cell and the second cell have different TDD UL-DL configurations, and
wherein the UL subframe on the second cell is determined based on a TDD UL-DL configuration of the second cell.
9. The user equipment according to claim 8 , wherein when the first DL subframe is a subframe n and the UL subframe is a subframe n+k, a timing relation k between the first DL subframe and the UL subframe is given based on the TDD UL-DL configuration of the second cell according to the following table:
TDD UL-DL
subframe number n
Configuration
0
1
2
3
4
5
6
7
8
9
0
4
6
4
6
1
6
4
6
4
2
4
4
3
4
4
4
4
4
4
5
4
6
7
7
7
7
5.
10. The user equipment according to claim 8 , wherein subframe configuration on each of the first cell and the second cell is given based on a TDD UL-DL configuration of a corresponding cell according to the following table:
TDD 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 U denotes a UL subframe, D denotes a DL subframe, and S denotes a subframe comprising a DL period, a guard period, and a UL period.
11. The user equipment according to claim 8 , wherein the processor is further configured to receive hybrid automatic repeat and request (HARQ) acknowledgement/negative-acknowledgement (ACK/NACK) information for the UL transmission in a second DL subframe on the second cell,
wherein a timing relation between the UL subframe and the second DL subframe is determined based on the TDD UL-DL configuration of the second cell.
12. The user equipment according claim 11 , wherein when the second DL subframe is a subframe i and the UL subframe is a subframe i-k, the timing relation k between the second subframe and the UL subframe is given based on the TDD UL-DL configuration of the second cell according to the following table:
TDD UL-DL
subframe number i
Configuration
0
1
2
3
4
5
6
7
8
9
0
7
4
7
4
1
4
6
4
6
2
6
6
3
6
6
6
4
6
6
5
6
6
6
4
7
4
6.
13. The user equipment according to claim 11 , wherein the HARQ ACK/NACK information is received via a physical HARQ indicator channel.
14. The user equipment according to claim 8 , wherein the UL grant information is received via a physical DL control channel.