The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for detecting patterns in a data stream. In one case, a data processing system is disclosed that includes: a pattern detector circuit operable to generate a pattern value based upon a comparison of a defined pattern to a first portion of a received input; and a comparator circuit operable to compare the pattern value to an adapted threshold, and to selectively assert a pattern found signal based at least in part on the comparison of the pattern value and the adapted threshold, where the adapted threshold is adjusted based at least in part on a noise component of a second portion of the received input.