FIELD: information transmission systems. SUBSTANCE: method of cycle synchronization consists in that at transmission side synchronization combination of binary signals is formed in the form of two code groups of m and n binary signals in each group, where n is bigger than m, m is not equal to 0. Code group of n binary signals is input with (m-1) binary signals following in succession inverse to inverse to first and last binary signals of given code group ahead of which code group of m binary signals inverse to first binary signal of code group of n binary signals is placed. At reception side synchronization combination of binary signals is extracted by element-by-element comparison of received sequence of binary signals with code group of n elements of standard synchronization combination of binary signals. Number of coincidences received in running i this case is compared with preassigned threshold value equal to n and phase of cycle of used sequence is established by moment of emergence of signal of detection. Device for implementation of method has cycle counter 1, switch 2, error counter 3, OR gate 4, modulo two adder 5, standard synchronization combination former 6, flip-flops 7 and 8, univibrators 9 and 10, multiplexer 11, former 12 of shortened synchronization group. EFFECT: improved stability of operational characteristics. 2 cl, 1 dwg
