FRAME SYNCHRONIZATION APPARATUS

摘要

A frame synchronization apparatus is applied to a TDMA (Time Division Multiple Access) communication system, particularly, one in which a plurality of transmission rates are available. The frame synchronization apparatus calculates correlations between sampled sequences of a received signal and an assigned sync sequence during the longest or shortest frame period in the plurality of transmission rates. The apparatus stores positions where the correlations exceed a given threshold. Then, the apparatus sets a search gate at a position after a lapse of the longest or shortest frame period from each of those positions. The apparatus calculates correlations between the sync sequence and sampled sequences of the received signal for all the search gates. The actual transmission rate is determined from the plurality of transmission rates based on a time interval of positions where the correlations beyond a second threshold were detected. Synchronization is thus established.