Method and apparatus for transmitting control information in a wireless communication system
The present invention relates to a wireless communication system. More particularly, the present invention relates to a method in which a terminal performs communication in a TDD-based wireless communication system having a plurality of CCs aggregated therein, the method comprising: a step of performing an uplink transmission or a downlink reception in each subframe on a first CC according to a first UL-DL configuration; and a step of performing an uplink transmission or a downlink reception in each subframe on a second CC according to a second UL-DL configuration. If the configuration of the subframe of the first CC is [U, D] and the configuration of the subframe of the second CC is [U, U] in subframes #k and #k+1, the subframe #k+1 of the second CC is set to X. The present invention also relates to an apparatus for the method.
1. A method of performing communications by a user equipment (UE) in a time division duplexing (TDD)-based wireless communication system, the method comprising:
configuring a primary component carrier (PCC) and a secondary component carrier (SCC), wherein the PCC and the SCC are configured to have different uplink-downlink (UL-DL) configurations;
performing at least one of uplink transmission or downlink reception in each subframe of the PCC according to a first UL-DL configuration; and
performing at least one of uplink transmission or downlink reception in each subframe of the SCC according to a second UL-DL configuration,
wherein if a subframe #k is a downlink subframe in the PCC and a special subframe in the SCC, uplink transmission is limited in the subframe #k of the SCC,
wherein if the subframe #k is a special subframe in the PCC and a downlink subframe in the SCC, a procedure for receiving a physical downlink shared channel (PDSCH) is limited in the subframe #k of the SCC,
wherein each of the special subframe in the PCC and the special subframe in the SCC includes a downlink pilot time slot (DwPTS), a guard period (GP) and a uplink pilot time slot (UpPTS).
2. The method according to claim 1 , wherein subframe patterns of the PCC and the SCC are given according to UL-DL configurations as follows:
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, U denotes an uplink subframe and S denotes a special subframe.
3. The method according to claim 1 , wherein if the subframe #k is a downlink subframe in the PCC and a special subframe in the SCC, transmissions of a physical uplink control channel (PUCCH) signal, a physical random access channel (PRACH) signal and a sounding reference signal (SRS) in subframe #k of the SCC are dropped.
4. The method according to claim 1 , wherein if the subframe #k is a downlink subframe in the PCC and a special subframe in the SCC, the UE operates on the assumption that a physical uplink shared channel (PUSCH) is not allocated to subframe #k of the SCC irrespective of whether or not the PUSCH has been actually allocated to subframe #k of the SCC.
5. The method according to claim 1 , wherein if the subframe #k is a special subframe in the PCC and a downlink subframe in the SCC, the UE does not receive any downlink signal in one or more last orthogonal frequency division multiplexing (OFDM) symbols of the subframe #k of the SCC, wherein the one or more last OFDM symbols correspond to the GP and the UpPTS of the special subframe of the PCC.
6. A user equipment (UE) for use in a time division duplexing (TDD)-based wireless communication system, the UE comprising:
a radio frequency (RF) unit; and
a processor,
wherein the processor is configured to:
configure a primary component carrier (PCC) and a secondary component carrier (SCC), wherein the PCC and the SCC are configured to have different uplink-downlink (UL-DL) configurations
perform at least one of uplink transmission or downlink reception in each subframe on the PCC according to a first UL-DL configuration and
perform at least one of uplink transmission or downlink reception in each subframe on the SCC according to a second UL-DL configuration,
wherein if a subframe #k is a downlink subframe in the PCC and a special subframe in the SCC, uplink transmission is limited in the subframe #k of the SCC,
wherein if the subframe #k is a special subframe in the PCC and a downlink subframe in the SCC, a procedure for receiving a physical downlink shared channel (PDSCH) is limited in the subframe #k of the SCC,
wherein each of the special subframe in the PCC and the special subframe in the SCC includes a downlink pilot time slot (DwPTS), a guard period (GP) and a uplink pilot time slot (UpPTS).
7. The UE according to claim 6 , wherein subframe patterns of the PCC and the SCC are given according to UL-DL configurations as follows:
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, U denotes an uplink subframe and S denotes a special subframe.
8. The UE according to claim 6 , wherein if the subframe #k is a downlink subframe in the PCC and a special subframe in the SCC, transmissions of a physical uplink control channel (PUCCH) signal, a physical random access channel (PRACH) signal and a sounding reference signal (SRS) in subframe #k of the SCC are dropped.
9. The UE according to claim 6 , wherein if the subframe #k is a downlink subframe in the PCC and a special subframe in the SCC, the UE operates on the assumption that a physical uplink shared channel (PUSCH) is not allocated to subframe #k of the SCC irrespective of whether or not the PUSCH has been actually allocated to subframe #k of the SCC.
10. The UE according to claim 6 , wherein if the subframe #k is a special subframe in the PCC and a downlink subframe in the SCC, the UE does not receive any downlink signal in one or more last orthogonal frequency division multiplexing (OFDM) symbols of the subframe #k of the SCC, wherein the one or more last OFDM symbols correspond to the GP and the UpPTS of the special subframe of the PCC.