Discrete Channel Definition/Meaning:
A communication channel whose input and output each have an
alphabet of distinct letters, or, in the case of a physical channel, whose input
and output are signals that are discrete in time and amplitude. The size of the alphabet, or the number of amplitude
levels, is usually finite.
The discrete memoryless channel (DMC) has the property that its treatment of a
symbol input at a certain time does not depend on the symbols input, or its
treatment of them, at any earlier time. The discrete channel with memory (DCM)
has the property that its action depends on its inputs at a number of earlier
times. See also Shannon's model,
channel coding theorem.