METHOD FOR CODE CYCLIC SYNCHRONISATION Russian patent published in 2009 - IPC H04L7/08 

FIELD: physics, communication.

SUBSTANCE: invention is related to electric communication and is applicable for synchronisation of message sent by sequence of words of block turbo-code, in which component codes are binary cyclic codes of primitive lengths with generator polynomials having common divisor and expanded due to addition of verification for parity, under conditions of parametric uncertainty expressed in absence of any data on coder structure, excluding length of code word. Substance of code cyclic synchronisation method consists in the fact that discrete sequence of code word symbols is accepted with application of discrete information receiver. From received discrete sequence fragment is separated with length that is less than length of code word by one symbol, discrete Fourier Galois transform (DFGT) is carried out for this fragment, and synchronous condition of discrete information receiver is defined by availability of synchronous condition criterion. Criterion of synchronous condition of discrete information receiver is equality to zero of at least one spectral component in spectrum of separated fragment. In case of synchronisation absence prior to its establishment, synchronous condition is searched by means of serial shift by received sequence by one symbol into one and the same side with further separation of new fragment, its DFGT and determination of receiver synchronous condition availability by criterion of synchronous condition. After synchronous condition criterion has been detected, additionally synchronous condition establishment verity is confirmed by availability of phasing verity criterion. For this purpose at least four fragments of the same length are separated, which are serially installed downstream fragment selected at the stage of synchronous condition definition, at that beginning of another fragment is separated from the end of preceding fragment by one symbol of sequence, DFGT of additionally separated fragments is carried out, and phasing verity criterion availability is defined. Criterion for verity of phasing is nonempty crossing of multiple numbers of zero components in received spectra. In case phasing verity criterion is not available, searching of synchronous condition is restored from the moment of synchronous condition criterion detection.

EFFECT: increased number of synchronized codes under conditions of parametric uncertainty.

1 tbl, 1 dwg