Carrier reconfiguration in multi-carrier aggregation
The present invention relates to a wireless communication system which supports carrier aggregation. In detail, the present invention relates to a method and apparatus, wherein a mobile station changes a component carrier (CC) in a wireless communication system that supports carrier aggregation. The method comprises the steps of: receiving, from a base station, a CC reconfiguration command via one or more first preconfigured CCs; reconfiguring, in accordance with the CC reconfiguration command, CC-related information to change one or more first preconfigured CCs to a second CC; and transmitting a signal indicating the completion of CC reconfiguration to the base station after the reconfiguration of the CC-related information.
1. A method of reconfiguring Component Carriers (CCs) at a user equipment (UE) in a wireless communication system supporting carrier aggregation, the method comprising:
receiving a CC reconfiguration command from a base station (BS) through a downlink (DL) CC of a plurality of first CCs;
reconfiguring serving CCs by changing at least one of the first CCs to one or more second CCs according to the CC reconfiguration command; and
transmitting a dedicated random access preamble to the BS after the serving CCs are reconfigured, the dedicated random access preamble indicating that reconfiguration of serving CCs has been completed,
wherein, when M>K (the M is a number of the first CCs and the K is a number of Reconfigured CCs of the first CCs), the dedicated random access preamble is transmitted through a non-reconfigured uplink (UL) CC, among the plurality of the first CCs, and
wherein, when M=K, the dedicated random access preamble is transmitted through a UL CC of the second CCs.
2. The method of claim 1 , further comprising:
after transmitting the dedicated random access preamble, receiving a PDCCH (Physical Downlink Control Channel) indicating a response to the reconfiguration of serving CCs completion.
3. The method of claim 2 , wherein the PDCCH does not include scheduling information.
4. The method of claim 1 , further comprising:
receiving a request signal requesting for information on a CC reconfiguration status from the base station, and
wherein the dedicated random access preamble indicating that the CC reconfiguration has been completed corresponds to a response to the request signal being transmitted to the base station.
5. A user equipment, comprising:
a radio frequency (RF) unit configured to transmit and receive radio signals to and from a base station (BS), the BS supporting carrier aggregation; and
a processor configured to:
receive a component carrier (CC) reconfiguration command from the BS through a downlink (DL) CC of a plurality of first CCs,
reconfigure serving CCs by changing at least one of the first CCs to one or more second CCs according to the CC reconfiguration command, and
transmit a dedicated random access preamble to the BS after the serving CCs are reconfigured, the dedicated random access preamble indicating that reconfiguration of the serving CCs has been completed,
wherein, when M>K (the M is a number of the first CCs and the K is a number of reconfigured CCs of the first CCs), the dedicated random access preamble is transmitted through a non-reconfigured uplink (UL) CC, among the plurality of the first CCs, and
wherein, when M=K, the dedicated random access preamble is transmitted through a UL CC of the second CCs.
6. The user equipment of claim 5 , wherein the processor is further configured to receive a PDCCH (Physical Downlink Control Channel) indicating a response to the reconfiguration of the serving CCs completion, after transmitting the dedicated random access preamble.
7. The user equipment of claim 6 , wherein the PDCCH does not include scheduling information.
8. The user equipment of claim 5 , wherein the processor is further configured to receive a request signal requesting for information on a CC reconfiguration status from the base station, and
wherein the dedicated random access preamble indicating that the CC reconfiguration has been completed corresponds to a response to the request signal being transmitted to the base station.