On the capacity of a cascade of identical discrete memoryless nonsingular channels (Corresp.)

A simplified procedure for calculating the channel capacity of a cascade of
N
identical discrete memoryless nonsingular channels is presented. The result depends only upon the
M
eigenvalues and
M
eigenvectors of any one of the subchannel transition matrices. Thus, for small
M
and large
N
(the usual case of interest) the result represents a considerable saving in computation relative to the standard technique of finding the overall channel transition matrix. The procedure is illustrated for an
N
cascade of binary symmetric channels.