Method and apparatus for acquiring initial synchronization using relay-amble in wireless communication system

A relay station in a wireless communication system, the relay station comprising:

• a radio frequency (RF) unit transmitting or receiving a radio signal;
• and
• a processor connected to the RF unit,
• wherein the processor is configured to:
• determine whether or not initial synchronization is acquired;
• determine a start position of a frame using a peak of an autocorrelation signal detected based on a preamble and a relay-amble (R-amble) received from a base station in the case in which the initial synchronization is not acquired;
• and
• determine the start position of the frame using a peak of an autocorrelation signal detected based on the relay-amble received from the base station in the case in which the initial synchronization is acquired.