Enhanced trellis extracted synchronisation for block codes using interleavers

Previously, trellis extracted synchronisation techniques (TEST) have been p resented as a purely digital method of providing bit/ symbol and word synch ronisation for block codes using auxiliary data obtained through trellis de coding. One of the factors affecting the complexity of the algorithm has be en 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, whi ch presents all cyclic shifts as valid codewords. The novel algorithm prese nted in this letter uses an interleaver with an inversion to overcome these two problems and significantly reduce the complexity without reducing perf ormance.