On the bit oriented trellis structure of run length limited codes on discrete local data dependent channels Original Research Article

We investigate bit oriented decoder trellises for binary constrained codes. In particular, we are interested in destined trellises, where each state determines the last bits leading into the state and the first bits coming out of the state. A destined trellis can be constructed from a conventional trellis by state splitting. However, we demonstrate that integrating the design of destined encoders into the conventional encoder design process for constrained codes yields simpler trellises. We also prove lower bounds on the number of states in such trellises.