Repeat-Free Codes

© 2019 IEEE. In this paper we consider the problem of encoding data into repeat-free sequences in which sequences are imposed to contain any k-tuple at most once (for predefined k). First, the capacity and redundancy of the repeat-free constraint are calculated. Then, an efficient algorithm, which uses a single bit of redundancy, is presented to encode length-n sequences for k = 2 + 2 log n. This algorithm is then improved to support any value of k of the form k = a log n, for 1 a ≤ 2, while its redundancy is o(n). Lastly, we also calculate the capacity of this constraint when combined with local constraints which are given by a constrained system