The synchronization of variable-length codes

Many variable-length codes exhibit a tendency for resynchronization to occur automatically following any error, However, attempts to identify an underlying synchronization mechanism, and to accurately predict the expected synchronization delay (ESD), for even quite specific variable-length codes, appear to have been largely unsuccessful. The present paper explores a novel method for estimating the synchronization performance for a wide variety of variable length codes, based on the T-Codes, T-Codes are a class of self-synchronizing codes, which typically synchronize within 2-3 codewords by a mechanism that derives from a recursive T-augmentation construction, It is observed that the T-Code mechanism for synchronization is followed, more or less, by other variable-length codes wherever substantial numbers of codewords are shared with a T-Code set, T-augmentation itself provides a means for assessing the contribution individual codewords make to the overall synchronization process for a T-Code set, Thus codeword differences between sets may be specifically evaluated to estimate the synchronization performance of a variable-length code set from a closely related T-Code set.