Asynchronous Channels with Synchrosymbols

In certain discrete channels, failure to maintain synchronization causes the length of output blocks to be a random variable. This paper considers one such channel in which synchrosymbols are received without errors. For this channel the class of nonuniform codes formed of blocks containing the same number of synchrosymbols is determined. The largest rate with which information can be transmitted with these codes and still yield an arbitrarily small error or probability is ascertained. Examples are given.