Various embodiments of the present invention provide systems and methods for pattern identification. As an example, a pattern detection circuit is discussed that include: a distance calculation circuit operable to calculate a distance value corresponding to a difference between a first pattern and a second pattern; a threshold comparator circuit operable to compare the distance value to a variable threshold value; and a threshold value calculation circuit. The threshold value calculation circuit is operable to modify the variable threshold value based at least in part on the distance value.