Method for signal transmission in device-to-device communication and apparatus therefor

A user equipment (UE) configured to perform D2D (device-to-device) communication in a wireless communication system, comprising:

• a radio frequency (RF) unit;
• and
• a processor configured to:
• control to RF unit to receive a message including information on a specific signal from a serving base station (BS),
• wherein information on the specific signal to be transmitted is received by the serving BS from the neighboring BS through a backhaul link;
• determine whether the specific signal corresponds to an inter-cell broadcast signal to be transmitted by a peer UE served by a neighboring BS based on the information included in the message,
• wherein the inter-cell broadcast signal is a signal between a cell of the neighboring BS and a cell of the serving BS;
• and
• when the specific signal corresponds to the inter-cell broadcast signal, control the RF unit to receive, from the peer UE, the inter-cell broadcast signal using the information included in the message and information on a time synchronization difference between the serving BS and the neighboring BS,
• wherein the information on the time synchronization difference comprises information on a subframe difference between the serving BS and the neighboring BS, and
• wherein the time synchronization difference is set so that a time required for the backhaul link transmission is secured.