Method for transmitting an uplink signal in a wireless communication system, and apparatus for the same

1. A method of transmitting a sounding reference signal (SRS) by a user equipment in a wireless communication system, the method comprising:

receiving a radio resource control (RRC) message for configuring at least one second component carrier (CC) in addition to a first CC configured in the user equipment;

receiving a medium access control (MAC) message for activating the at least one second CC other than the first CC, the MAC message including a bitmap for indicating the at least one second CC to be activated;

activating the at least one second CC based on the bitmap;

receiving a physical downlink control channel (PDCCH) including a carrier indicator field (CIF) and a SRS field via the first CC, the CIF indicating a CC of the at least one second CC and the SRS field indicating whether to transmit the SRS via the CC indicated by the CIF; and

transmitting the SRS on an uplink subframe via the CC indicated by the CIF, when the SRS field is enabled,

wherein the CC indicated by the CIF is one of the activated at least one second CC based on the bitmap included in the MAC message.

2. The method of claim 1 , further comprising:

receiving control information for transmitting uplink data signal in the uplink subframe from a base station; and

allocating resources of the uplink subframe for the uplink data signal according to the control information,

wherein the transmitting the uplink subframe comprises transmitting the uplink subframe including the uplink data signal and the SRS using the allocated resources, and

wherein the control information includes resource extension information indicating the allocated resources for the uplink data signal are extended to a last symbol of the uplink subframe, if a frequency band at the last symbol for transmitting the uplink data signal does not overlap a bandwidth at the last symbol for transmitting the sounding reference signal.

3. The method of claim 2 , wherein the resource extension information is 1-bit information included in the control information.

4. The method of claim 2 , wherein the resource extension information is expressed by a scrambling sequence applied to the control information.

5. The method of claim 2 , wherein the control information is received via the physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH).

6. The method of claim 1 , wherein the sounding reference signal is an aperiodic sounding reference signal and the transmission of the aperiodic sounding reference signal is triggered by reception of the PDCCH including the enabled SRS field.

7. A user equipment (UE) of a wireless communication system, comprising:

a reception module configured to:

receive a radio resource control (RRC) message for configuring at least one second component carrier (CC) in addition to a first CC configured in the user equipment,

receive a medium access control (MAC) message for activating the at least one second CC other than the first CC, the MAC message including a bitmap for indicating the at least one second CC to be activated, and

receive a physical downlink control channel (PDCCH) including a carrier indicator field (CIF) and a SRS field via the first CC, the CIF indicating a CC of the at least one second CC and the SRS field indicating whether to transmit a sounding reference signal (SRS) via the CC indicated by the CIF;

a processor configured to activate the at least one second CC based on the bitmap; and

a transmission module configured to transmit the SRS on an uplink subframe via the CC indicated by the CIF, when the SRS field is enabled,

wherein the CC indicated by the CIF is one of the activated at least one second CC based on the bitmap included in the MAC message.

8. The UE of claim 7 ,

wherein the reception module receives control information for transmitting uplink data signal in the uplink subframe from a base station,

wherein the processor allocates resources of the uplink subframe for the uplink data signal according to the control information,

wherein the transmission module transmits the uplink subframe including the uplink data signal and the SRS using the allocated resources, and

wherein the control information includes resource extension information indicating the allocated resources for the uplink data signal are extended to a last symbol of the uplink subframe, if a frequency band at the last symbol for transmitting the uplink data signal does not overlap a bandwidth at the last symbol for transmitting the sounding reference signal.

9. The UE of claim 8 , wherein the resource extension information is 1-bit information included in the control information.

10. The UE of claim 8 , wherein the resource extension information is expressed by a scrambling sequence applied to the control information.

11. The UE of claim 8 , wherein the control information is received via the physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH).

12. The UE according to claim 7 , wherein the sounding reference signal is an aperiodic sounding reference signal and the transmission of the aperiodic sounding reference signal is triggered by reception of the PDCCH including the enabled SRS field.

13. The method of claim 1 , wherein the RRC message further comprises one or more sounding reference signal parameters.

14. The method of claim 13 , further comprising:

generating the SRS using the sounding reference signal parameters; and

mapping the generated SRS to physical resources of the uplink subframe using the sounding reference signal parameters,

wherein the generated SRS is mapped to a last symbol of the uplink subframe.

15. The method of claim 13 , wherein the sounding reference signal parameters comprises at least one of:

a SRS bandwidth parameter indicating a SRS transmission bandwidth;

a SRS configuration index parameter indicating a periodicity and a subframe offset;

a cyclic shift parameter used for performing cyclic shift of the SRS; and

a transmission comb parameter indicating a transmission comb offset.

16. The method of claim 1 , further comprising:

receiving another MAC message for deactivating the at least one second CC; and

deactivating the at least one the second CC according to the another MAC message for deactivating the at least one second CC.

17. The method of claim 1 , wherein the first CC is an anchor CC and is always activated.