On construction of non-systematic t-symmetric error correcting/all unidirectional error detecting codes

In this paper we describe a technique for deriving non-systematic t-Symmetric Error Correcting/All Unidirectional Error Detecting (t-SyEC/AUED) codes. The method developed here is suitable for binary as well as non-binary codes. We have used spectral techniques to derive these codes. These codes are shown to be of asymptotically optimal order for constant weight semidistance codes.