A method and apparatus of mitigating inter-cell interference in a wireless communication system are provided. A user equipment receives serving-cell data over a first data channel indicated by a first control channel for which decoding is successful by monitoring a plurality of candidate control channels in a search space of a serving cell. The user equipment receives interfering-cell data over a second data channel indicated by a second control channel for which decoding is successful by monitoring a plurality of candidate control channels in a search space of an interfering cell. The A user equipment cancels interference from the interfering cell by processing the serving-cell data and the interfering-cell data.