Method for allocating control channel and device therefor
The present invention relates to a wireless communication system. More particularly, the present invention relates to a method for allowing a terminal to receive a PDCCH in a wireless communication system using multiple carriers and a device therefore, and the method comprises the steps of: receiving a plurality of search spaces through a control region on a subframe, wherein each search space includes a plurality of PDCCH candidate sets, and each search space corresponds to each carrier; and monitoring PDCCH candidates for the PDCCH, wherein the intervals between the respective search spaces within said control region are determined by considering the ratios between the number of scheduled carriers and the number of CCEs within the control region.
1. A method for receiving a physical downlink control channel (PDCCH) by a user equipment (UE) in a wireless communication system supporting multiple carriers, the method comprising:
receiving a plurality of search spaces through a control region of a subframe, wherein each search space includes a plurality of PDCCH candidate sets and corresponds to each carrier; and
monitoring PDCCH candidates for the PDCCH in the plurality of search spaces, wherein a search space S k (L) corresponding to a single carrier of the plurality of search spaces contains a plurality of control channel elements (CCEs) in a subframe k at a carrier aggregation level L,
wherein for the single carrier on which a PDCCH candidate (m) of the PDCCH candidates is monitored, a CCE index corresponding to the PDCCH candidate (m) within the search space S k (L) is determined by the following equation A:
L ·{( Y k +O c,k (L) +m )mod └ N CCE,k /L┘}+i (Equation A)
where L is a carrier aggregation level, Y k is the reference point at a subframe (k), m is denoted by m=0, . . . , M (L) −1, M (L) is a number of PDCCH candidates to be monitored in the corresponding search space, N CCE,k is a number of CCEs contained in a control region of the subframe (k), and i is denoted by i=0, . . . , L−1, and
O c,k (L) is determined by the following equation B:
O c,k (L) =c·M (L) (Equation B)
where c is a value of carrier indication field (CIF) related to the single carrier.
2. A user equipment (UE) configured to receive a physical downlink control channel (PDCCH) in a wireless communication system supporting multiple carriers, the user equipment (UE) comprising:
a radio frequency (RF) unit; and
a processor,
wherein the processor is configured to receive a plurality of search spaces through a control region of a subframe, and to monitor PDCCH candidates for the PDCCH in the plurality of search spaces, wherein a search space S k (L) corresponding to a single carrier of the plurality of search spaces contains a plurality of control channel elements (CCEs) in a subframe k at a carrier aggregation level L,
wherein for the single carrier on which a PDCCH candidate (m) of the PDCCH candidates is monitored, a CCE index corresponding to the PDCCH candidate (m) within the search space S k (L) is determined by the following equation A:
L ·{( Y k +O c,k (L) +m )mod └ N CCE,k /L┘}+i (Equation A)
where L is a carrier aggregation level, Y k is the reference point at a subframe (k), m is denoted by m=0, . . . , M (L) −1, M (L) is a number of PDCCH candidates to be monitored in the corresponding search space, N CCE,k is a number of CCEs contained in a control region of the subframe (k), and i is denoted by i=0, . . . , L−1, and
O c,k (L) is determined by the following equation B:
O c,k (L) =c·M (L) (Equation B)
where c is a value of carrier indication field (CIF) related to the single carrier.