The disclosure relates to pattern detection unit and associated method. The unit comprises a shift register configured to over-sample a multi-bit input signal such that each bit of the input signal is represented by a plurality of samples in the shift register; and a correlator configured to compare a target pattern with two or more sample-sets, each sample-set comprising a corresponding sample from each of the plurality of samples of each bit, and classify each compared sample-set as one of: an exact match; an inexact match; or a non-match to the target pattern in order to determine whether or not the input signal matches the target pattern.