Systematic t-Error Correcting All Unidirectional Error Detecting Codes

In this paper we give two new methods for the construction of systematic t-random error correcting and all unidirectional error detecting codes. Also we give the encoding/decoding algorithms and discuss their implementation.Beginning from a k-error correcting systematic parity check code we append check symbols in order to construct t-EC/AUED codes, with t≤k. This code construction technique takes into account the Hamming distance of the parity check code in order to reduce the number of bits for the check symbols. Thus the codes derived are significantly more efficient than the known codes with the same capabilities. Moreover these codes have a very useful property. Discarding some check symbols we get codes with weaker capabilities against random errors. This property offers the ability of uniform coding over system units which have different demands on random errors.