A Note on the Method of Poles for Code Construction

The method of poles is a method for constructing a rate 1:1 finite state code from k-ary data into a constrained channel S, where S is recognized by a given local automaton and S has capacity at least log (k). We characterize those automata to which the method of poles applies in the case where h(S) = log(k). The code produced by the method of poles has a sliding-block decoder. We also give an upper bound on the window length of the decoder that applies when h(S) > log(k). © 1994 IEEE