Abstract:The Triple Correlation Function (TCF) and the partial TCF of sampled m-sequence are studied and described in this paper. To recognize synchronization codes of secure communications, a recognition method is proposed firstly based on the peak feature of the partial TCF to analyze and judge frame length. At first, the partial TCF is got by operating the synchronization codes; then, the information codes and synchronization codes are distinguished by the similar peak feature; finally, the code length and the first bit of synchronization code are got. The simulation results show the method can found the frame synchronization code quickly and exactly by fewer codes and recognize synchronization codes.