Mitigating passive intermodulation interference in a wireless network

Apparatus for mitigating interference in a waveform received at the input of a receiver in a wireless network, the interference comprising passive intermodulation (PIM) products of at least a first signal, the apparatus comprising a digital signal processor configured to:

• generate a first stream of time samples of a simulated first PIM product of at least the first signal, and generating a second stream of time samples of the simulated first PIM product, wherein the second stream has a delay with respect to the first stream;
• generate a replica of the interference by processing at least the first stream and the second stream, wherein said processing comprises determining a first weighting factor by correlating the first stream with a stream of time samples of the received waveform, and determining a second weighting factor by correlating the second stream with the stream of time samples of the received waveform, and weighting the first stream by a first weighting factor and weighting the second stream by a second weighting factor;
• and
• combine the replica of the interference with the stream of time samples of the received waveform, whereby to reduce the interference in the received waveform.