Block-Decodable Runlength-Limited Codes via Look-Ahead Technique
Kees A. Schouhamer Immink · 2005
The terms (d,k)·constrained sequence and runlength-Iimited (RLL) sequence are usually used as synonyms, and traditionally the design of encoders that generate RLL sequences is almost always conducted by designing encoders that generate (d,k)-constrained sequences followed by a precoder. It is generally believed that this design procedure does not entail a loss of performance in terms of coder complexity and error propagation. In this paper, however, we will show that it is surprisingly profitable in terms of error propagation to design RLL encoders directly, i.e. without the intermediate step of a (d,k)-constrained sequence.