Event error control codes and their applications

Burst error detection codes and cyclic redundancy check (CRC) codes are gen eralized to event-error detection codes, which are useful in various noisy channels. A systematic linear block code is constructed that detects any ev ent error from an arbitrary list of event errors. The result is generalized to detection and correction of multiple event errors. Bounds are found on the minimum number of redundant bits needed to construct such codes. It is shown that, under certain conditions, the linear code construction is optim al. Various applications are discussed, where there is a Markov source or a Mar kov channel. It is argued that the codes described herein can be employed e ither as error detection codes, or as distance-enhancing codes when complet e decoders are applied. Specific examples covered in this correspondence in clude hybrid automatic repeat request (ARQ) systems, intersymbol interferen ce (ISI) channels, and Gilbert channels.