Block pickard models for two-dimensional constraints
IEEE Transactions on Information Theory
On row-by-row coding for 2-D constraints
IEEE Transactions on Information Theory
Concave programming upper bounds on the capacity of 2-D constraints
ISIT'09 Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2
| Hi-index | 754.96 |
Runlength-limited sequences and arrays have found applications in magnetic and optical recording. While the constrained sequences are well studied, little is known about constrained arrays. In this correspondence we consider the question of how to cascade two arrays with the same runlength constraints horizontally and vertically, in such a way that the runlength constraints will not be violated. We consider binary arrays in which the shortest run of a symbol in a row (column) is d1(d2) and the longest run of a symbol in a row (column) is k1(k2). We present three methods to cascade such arrays. If k1>4d1-2 our method is optimal, and if k1⩾d1+1 we give a method which has a certain optimal structure. Finally, we show how cascading can be applied to obtain runlength-limited error-correcting array codes