Apparatus and method for monitoring control channel in multi-carrier system
Provided are an apparatus and a method for monitoring a control channel in a multiple-carrier system. The user equipment monitors downlink control channels for a plurality of scheduled component carriers in an extended search space. The user equipment receives downlink control information for the scheduled component carrier via a successfully decoded downlink control channel.
1. A method for monitoring a control channel in multi-cells, the method comprising:
if a received carrier indicator field (CIF) is configured, monitoring by a user equipment (UE) plural UE-specific search spaces according to aggregation levels;
monitoring, by the UE, downlink control channel candidates within the plural UE-specific search spaces; and
receiving, by the UE, downlink control information on at least one of the downlink control channel candidates which is successfully decoded.
2. The method of claim 1 , wherein a size of the plural UE-specific search spaces varies according to a number of downlink component carriers.
3. The method of claim 1 , wherein a size of the plural UE-specific search spaces varies according to a number of the downlink control channel candidates.
4. The method of claim 1 , further comprising:
receiving the CIF.
5. The method of claim 1 , wherein each of the plural UE-specific search spaces includes one or more of the downlink control channel candidates.
6. The method of claim 5 , wherein the plural UE-specific search spaces are consecutive.
7. The method of claim 5 , wherein the plural UE-specific search spaces are not consecutive.
8. The method of claim 1 , wherein the plural UE-specific search spaces are disposed in the order of carrier index.
9. The method of claim 8 , wherein the plural UE-specific search spaces are disposed in ascending carrier index order.
10. The method of claim 8 , wherein the plural UE-specific search spaces are disposed in descending carrier index order.
11. A user equipment for monitoring a control channel in multi-cells, comprising:
a radio frequency unit configured to transmit and receive radio signals; and
a processor operatively connected to the radio frequency unit and configured to;
if a received carrier indicator field (CIF) is configured, monitor plural UE-specific search spaces according to aggregation levels;
monitor downlink control channel candidates within the plural UE-specific search spaces; and
receive downlink control information on at least one of the downlink control channel candidates which is successfully decoded.