Method whereby user equipment receives downlink control information in wireless communication system, and device therefor
Provided are a method whereby user equipment (UE) receives downlink control information in a wireless communication system and UE using the method. The method comprises: receiving configuration information (MUCC-DCI configuration information) on multi-carrier downlink control information (MUCC-DCI) that may include pieces of scheduling information related to multiple serving cells; and performing blind decoding (BD) on the MUCC-DCI in a shared search space (shared SS) determined on the basis of the MUCC-DCI configuration information.
1. A method for receiving downlink control information (DCI) by a user equipment (UE) in a wireless communication system, the method comprising:
receiving at least one of single-carrier downlink control information (SICC-DCI) which schedules only one serving cell or multi-carrier downlink control information (MUCC-DCI) which simultaneously schedules multiple serving cells in a subframe; and
blind-decoding the at least one of the SICC-DCI or the MUCC-DCI,
wherein the SICC-DCI is received in a physical downlink control channel (PDCCH) region located at first N (N is a natural number) orthogonal frequency division multiplexing (OFDM) symbols of the subframe,
wherein the MUCC-DCI is received in an enhanced PDCCH (EPDCCH) region located at OFDM symbols following the first N OFDM symbols of the subframe,
wherein, when the UE receives both the SICC-DCI and the MUCC-DCI in the subframe, the UE discards the SICC-DCI and regards the MUCC-DCI as valid.
2. The method of claim 1 , wherein the MUCC-DCI and the SICC-DCI are configured to have the same bit size.
3. The method of claim 1 , wherein the UE blind-decodes only MUCC-DCI on a shared search space (SS).
4. The method of claim 1 , wherein the UE blind-decodes the SICC-DCI in a shared search space (SS) in the PDCCH region.
5. The method of claim 1 , wherein aggregation level (AL) candidates when the MUCC-DCI is blind-decoded and AL candidates when the SICC-DCI is blind-decoded are configured to be different from each other.
6. The method of claim 5 , wherein the number of times of blind decoding in each AL when the MUCC-DCI is blind-decoded and the number of times of blind decoding in each AL when the SICC-DCI is blind-decoded are configured to be different.
7. The method of claim 1 , wherein the MUCC-DCI includes only downlink grant as downlink scheduling information.
8. The method of claim 1 , wherein the MUCC-DCI includes only uplink grant as uplink scheduling information.
9. The method of claim 1 , wherein a cyclic redundancy check (CRC) of the MUCC-DCI is longer than a CRC of the SICC-DCI.
10. The method of claim 1 , wherein, in order to detect the MUCC-DCI, the UE performs blind decoding per aggregation level (AL) a predetermined number of times in a shared search space (SS).
11. The method of claim 10 , wherein the number of times of blind decoding previously determined per AL is re-set.
12. A user equipment (UE), comprising:
a transceiver transmitting and receiving a radio signal; and
a processor connected to the transceiver, wherein the processor:
receives at least one of single-carrier downlink control information (SICC-DCI) which schedules only one serving cell or multi-carrier downlink control information (MUCC-DCI) which simultaneously schedules multiple serving cells in a subframe, and
blind-decodes at least one of the SICC-DCI or the MUCC-DCI,
wherein the SICC-DCI is received in a physical downlink control channel (PDCCH) region located at first N (N is a natural number) orthogonal frequency division multiplexing (OFDM) symbols of the subframe,
wherein the MUCC-DCI is received in an enhanced PDCCH (EPDCCH) region located at OFDM symbols following the first N OFDM symbols of the subframe, and
wherein, when the processor receives both the SICC-DCI and the MUCC-DCI in the subframe, the processor discards the SICC-DCI and regards the MUCC-DCI as valid.