Enhanced trellis extracted synchronisation for block codes using interleavers

Previously, trellis extracted synchronisation techniques (TEST) have been presented as a purely digital method of providing bit/symbol and word synchronisation for block codes using auxiliary data obtained through trellis decoding. One of the factors affecting the complexity of the algorithm has been that any cyclic properties within the code must be countered by building confidence in a particular synchronisation point. This problem is further exasperated by a long sequence of the all-zeros (or all-ones) codeword, which presents all cyclic shifts as valid codewords. The novel algorithm presented in this Letter uses an interleaver with an inversion to overcome these two problems and significantly reduce the complexity without reducing performance