System and method for sharing a control channel for carrier aggregation
A method for processing a control channel at a user agent (UA) to identify at least one of an uplink and a downlink resource allocated by a resource grant within a multi-carrier communication system wherein resource grants are specified by control channel element (CCE) subset candidates, the method comprising the steps of identifying the number of configured carriers used to communicate with the access device, based on the number of configured carriers used to communicate with the access device, identifying a number of CCE subset candidates to decode and decoding up to the identified number of CCE subset candidates in an attempt to identify the resource grant.
1. A method for user equipment (UE) in a wireless communication system, the method comprising:
receiving a signal indicating a first carrier index associated with a first carrier and a second carrier index associated with a second carrier;
monitoring a first search space including a first group of physical downlink control channel (PDCCH) candidates, and a second search space including a second group of PDCCH candidates, the first search space and the second search space being on the first carrier, wherein the first group of PDCCH candidates is used to transmit resource grants for the first carrier, and the second group of PDCCH candidates is used to transmit resource grants for the second carrier;
receiving a resource grant via at least one PDCCH candidate of the first or second group of PDCCH candidates, the resource grant including a field identifying the first carrier index or the second carrier index; and
determining that the at least one PDCCH candidate is used to transmit resource grants for the first carrier or the second carrier based on priorities of the first carrier and the second carrier, wherein the at least one PDCCH candidate includes an overlapping PDCCH candidate of the first and second groups of PDCCH candidates.
2. The method of claim 1 , wherein receiving the resource grant comprises receiving the resource grant for the first carrier via the first group of PDCCH candidates.
3. The method of claim 1 , wherein receiving the resource grant comprises receiving the resource grant for the second carrier via the second group of PDCCH candidates.
4. The method of claim 1 , wherein, for an aggregation level 1, each PDCCH candidate of the first and second groups includes a single control channel element.
5. The method of claim 1 , wherein, for an aggregation level 2, each PDCCH candidate of the first and second groups includes two control channel elements.
6. The method of claim 1 , wherein, for an aggregation level 4, each PDCCH candidate of the first and second groups includes four control channel elements.
7. The method of claim 1 , wherein, for an aggregation level 8, each PDCCH candidate of the first and second groups includes eight control channel elements.
8. The method of claim 1 , wherein the first group and the second group are located sequentially within a set of control channel elements.
9. The method of claim 1 , wherein the field comprises a three-bit field.
10. User equipment (UE) in a wireless communication system, the UE comprising:
a receiver configured to:
receive a signal indicating a first carrier index associated with a first carrier and a second carrier index associated with a second carrier; and
receive a resource grant via at least one physical downlink control channel (PDCCH) candidate of a first group of PDCCH candidates or a second group of PDCCH candidates, the resource grant including a field identifying the first carrier index or the second carrier index; and
a processor configured to:
monitor a first search space including the first group of PDCCH candidates, and a second search space including the second group of PDCCH candidates, the first search space and the second search space being on the first carrier, wherein the first group of PDCCH candidates is used to transmit resource grants for the first carrier, and the second group of PDCCH candidates is used to transmit resource grants for the second carrier, and
determine that the at least one PDCCH candidate is used to transmit resource grants for the first carrier or the second carrier based on priorities of the first carrier and the second carrier when the at least one PDCCH candidate includes an overlapping PDCCH candidate of the first and second groups of PDCCH candidates.
11. The UE of claim 10 , wherein the processor is configured to receive the resource grant for the first carrier via the first group of PDCCH candidates.
12. The UE of claim 10 , wherein the processor is configured to receive the resource grant for the second carrier via the second group of PDCCH candidates.
13. The UE of claim 10 , wherein, for an aggregation level 1, each PDCCH candidate of the first and second groups includes a single control channel element.
14. The UE of claim 10 , wherein, for an aggregation level 2, each PDCCH candidate of the first and second groups includes two control channel elements.
15. The UE of claim 10 , wherein, for an aggregation level 4, each PDCCH candidate of the first and second groups includes four control channel elements.
16. The UE of claim 10 , wherein, for an aggregation level 8, each PDCCH candidate of the first and second groups includes eight control channel elements.
17. The UE of claim 10 , wherein the first group and the second group are located sequentially within a set of control channel elements.
18. The UE of claim 10 , wherein the field comprises a three-bit field.