FIELD: information technology.
SUBSTANCE: code frame synchronisation method involves multiplication of a received input sequence consisting of several successive words by a noise-immune cyclic code verification polynomial and by a numerating sequence verification polynomial. Each word is a bitwise modulo 2 sum of the noise-immune cyclic code, a synchronising sequence and the numerating sequence. As a result, a synchronising sequence and noise-immune cyclic code syndrome sum is obtained, from which possible error vectors of the noise-immune cyclic code are determined beyond its error-correcting capability. The number of the numerating sequence is then determined, from which the possible end of the message block is determined for a threshold number of numbers. Each signal on the end of the message block is further checked for conformity with the true signal on the end of the message block through a message block decoding procedure and if the decoding result is positive, a final decision is made on code frame synchronisation of the message block.
EFFECT: high reliability of received information in high-noise level channels.
3 cl
