A method to allocate physical radio resources for both distributed and localized transmission schemes of ePDCCH and configure common and UE-specific search space for UE is provided. In one embodiment, a UE receives a first high-layer information to determine a first set of PRBs. The UE determines a first set of candidate ePDCCHs within the first set of PRBs, wherein one or more candidate ePDCCHs potentially carries DCI intended for the UE. The UE then decodes the first set of candidate ePDCCHs to obtain the DCI intended for the UE. Similar steps are performed for a second set of candidate ePDCCHs potentially carrying DCI intended for the UE. The allocated radio resources of the candidate ePDCCHs may be distributed or localized and constitute either common or UE-specific search space. Blind decoding complexity is reduced.