Patent ID: 8843168

Claim:
A method for allocating a control channel to reduce a number of control channel candidates in a search space for carrier aggregation in a mobile communication system, comprising: selecting a control channel element (CCE) aggregation level for a control information allocation for a user equipment (UE) at an evolved NodeB (eNB); identifying a value selected from at least one of a transmission mode of each of a plurality of component carriers (CCs), a carrier index (CI) in a downlink control information (DCI) format for of each of the plurality of CCs, and a DCI size of each of the plurality of CC's control information determined by the transmission mode, wherein each CC is associated with a physical downlink control channel (PDCCH); and assigning, at the eNB, each CC's control information into CCEs in a search space in the control channel starting at a CCE location based on a value identified for a CC and the CCE aggregation level for the UE receiving the CC.