Extensions of the method of poles for code construction
The method of poles is a method introduced by Franaszek for constructing a rate-1 : 1 finite-state code from k-ary data into a constrained channel of finite type whose capacity is strictly greater than log(k). The method is based on the computation of a set of states called poles. With each pole is associated, a set of paths going from this pole to others. Each set verifies an entropy condition. The code produced by the method of poles has a sliding-block decoder if each set of paths satisfies moreover an optimization condition based on the sum of the path lengths of the set. In this correspondence, we give a new optimization condition which guarantees the sliding-block window decoding property and has a lower computational complexity than the previous one. We also extend the method of poles to the more general case of sofic constrained channels.
method of poles sliding-block decoder encoder shift of finite type sofic system strongly synchronizing state