PURPOSE: To shorten TDM frame synchroizing establishing time by constituting a UW correlation device by moving and cycling the leading or final symbol of a UW for the UW sequence in a TDM signal symbol by symbol and detecting the TDM signal flaming time of the UW cyclic sequence.

CONSTITUTION: A cyclic type UW correlation device is composed of total 2N multipliers corresponding to each of hard decision symbols 0(3) and 1(4), 2N of the output lines (5-1-0/1 to 5-N-0/1), (N-1) KTS symbol delay circuits 2-1 to 2-(N-1) and N lines 6-1 to 6-N corresponding to the column in a UW sequence cycled symbol by symbol. The correlation with total N kinds of U series 8-1 to 8-N obtained by shifting the UW sequence by one symbol each is determined, the maximum value of the outputs of the correlation device exceeding a stipulated threshold value is detected by a detector 9, flaming timing information 10 is derived, and the flame synchronizing establishment of a TDM signal can be performed in short time by using the information.