Partial-Prefix Synchronizable Codes

We present a new synchronization code that uses one prefix out of a set of possible prefixes to identify the beginning of each codeword. The codewords have the additional property that none of the prefixes occurs in any codword or in any concatenation of codewords in any position except for the first position of every codeword. Such a code will be called a partial-prefix synchronizable code (PPS-code). When these codes are used to convert data packets into frames for transmission in a communication system, the receiver can recover synchronization of fixed length and variable length frames by examining the incoming symbols until it encounters a prefix. The PPS-codes are in contrast to the known prefix-synchronizable codes (PS-codes) with respect to the number of prefixes used, and the constraints imposed on the coded data sequences. We will use generating functions to determine the cardinality of PPS-codes and to show that PPS-codes have a higher cardinality than corresponding PS-codes.