Methods and apparatus are disclosed for processing interference due to passive non-linear products of transmitted signals in a wireless network, and more specifically, but not exclusively, to reduction of interference caused to a receiver due to passive intermodulation (PIM) products generated from at least a first Multiple Input Multiple Output (MIMO) signal comprising first and second MIMO component streams at a first carrier frequency. In other scenarios, there may be two or more carrier frequencies combining to cause PIM, and each carrier frequency may have two or more MIMO component streams.