Extended prefix synchronization codes

A new synchronization code construction technique is presented which uses a so called extended prefix containing positions with fixed symbols and unconstrained data positions, followed by a constrained data sequence. In this way a set of prefixes is used to identify the frame, instead of only one prefix, as for normal prefix synchronized (PS) codes. This enlarges the code size, while the advantages of PS-codes, i.e. easy frame recognition and the availability of data mapping procedures, are maintained.