SYSTEMATIC RANDOM ERROR CORRECTING AND ALL UNIDIRECTIONAL ERROR DETECTING CODES

In this correspondence, we present t-random error correcting and all unidirectional error detecting (t-EC/AUED) codes obtained by appending a suffix to each codeword of a linear block code. Although this technique has been used previously to construct such codes, we propose a different approach, which involves starting with a nonoptimal t-EC linear code to obtain more efficient t-EC/AUED codes. Specifically, r-EC/AUED codes constructed from an even-weight t-EC linear code are shown to require a shorter suffix than when a general t-EC linear code is used. The t-EC/AUED codes obtained in this manner are thoroughly compared to the best known codes and are shown to require fewer bits in almost all cases. © 1990 IEEE