CYCLIC CODE SYNCHRONIZATION METHOD Russian patent published in 2008 - IPC H04L7/08 

FIELD: electric communications, possible use for synchronization of message, which is transmitted as a series of words of cyclic code of primitive length under conditions of parametric indeterminacy, demonstrated by absence of any data about coder structure with the exception of code base and code word length.

SUBSTANCE: cyclic code synchronization method includes receiving discrete series of code word symbols using a receiver of discrete information, a fragment of discrete series is extracted which has length equal to length of code word, discrete Fourier-Galois transform is performed over the fragment and presence of synchronous state of discrete information receiver is determined using synchronous state criterion. Synchronous state criterion for the discrete information receiver is the equality to zero of at least one spectral component in the spectrum of the extracted fragment. In case when synchronization is absent before it is established, synchronous state is found by means of successive shifting of received series for one symbol towards one and the same side with following extraction of a new fragment, its discrete Fourier-Galois transform and detection of receiver synchronous state presence based on the synchronous state criterion. After detection of synchronous state criterion, validity check of synchronous state establishment is additionally performed according to presence of phasing validity indication. For that purpose, at least four fragments of the same length are extracted, which are positioned serially after the fragment, extracted at the stage of synchronous state detection, discrete Fourier-Galois transform is performed over additionally selected fragments and presence of phasing validity indication is determined. As phasing validity indication, non-empty intersection of sets of zero component numbers in resulting spectrums is considered. In case when phasing validity indication is absent, the search for synchronous state is continued starting at the moment when synchronous state criterion is fulfilled.

EFFECT: increased number of codes being synchronized under conditions of parametric indeterminacy, apparent from absence of any data about coder structure with the exception of code base and code word length.

1 dwg, 1 tbl