Paired disparity code

In telecommunication, a paired disparity code is a code in which some or all of the characters are represented by two sets of digits of opposite disparity that are used in sequence so as to minimize the total disparity of a longer sequence of digits.

An alternate mark inversion signal is an implementation of a paired disparity code.

The digits may be represented by disparate physical quantities, such as two different frequencies, phases, voltage levels, magnetic polarities, or electrical polarities, each one of the pair representing a 0 or a 1.