Non prefix-free codes for constrained sequences

M. Dalai, R. Leonardi
2005 Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.  
In this paper we consider the use of variable length non prefix-free codes for coding constrained sequences of symbols. We suppose to have a Markov source where some state transitions are impossible, i.e. the stochastic matrix associated with the Markov chain has some null entries. We show that classic Kraft inequality is not a necessary condition, in general, for unique decodability under the above hypothesis and we propose a relaxed necessary inequality condition. This allows, in some cases,
more » ... ws, in some cases, the use of non prefix-free codes that can give very good performance, both in terms of compression and computational efficiency. Some considerations are made on the relation between the proposed approach and other existing coding paradigms.
doi:10.1109/isit.2005.1523601 dblp:conf/isit/DalaiL05 fatcat:6csrdzrrebh4zl4cov2nalw3mi