A system and method are provided for assisting user devices in performing OFDMA downlink interference cancellation, in which an interfering base station transmits a downlink signal in a first slot and a second slot, both slots including cell reference signals (CRSs) for physical channel estimation, the CRS of the second slot is modified to indicate encoded values of parameters characterizing the physical channel according to an encoding procedure, the slots are received by a served user device that detects the physical channel parameters carried by dedicated control signalling and encodes them by the encoding procedure, an unchanged CRS is reconstructed, and the slots are received by an interfered user device obtaining the encoded values and comparing to parameter patterns indicating absence of modifications in the CRSs, wherein if the encoded values are different from the patterns, the interfered user device decodes them to perform interference cancellation of the downlink signal.