Patent ID: 8218701

Claim:
A communication system in which a transmitting device sends a frame-structured signal to a receiving device and the receiving device recognizes a frame synchronization pattern and performs a synchronous detection of a frame, so as to establish synchronization, wherein: the receiving device includes a frame synchronization device for comparing a frame synchronization pattern for synchronous detection based on a correction signal for correcting a phase shift of the frame-structured signal so as to establish the synchronization, the frame synchronization device prevents synchronization establishment while a frame synchronization pattern for preventing synchronization establishment state and a frame pattern of the frame-structured signal are coincident, and the frame synchronization device detects pattern coincidence by shifting a frame pattern of the frame-structured signal and the frame synchronization pattern for preventing synchronization establishment; wherein the frame synchronization pattern for synchronous detection is different from the frame synchronization pattern for preventing synchronization establishment state.