Method and apparatus for retransmitting scheduling assignment information in wireless communication system supporting device to device (D2D) communication

A method for transmitting scheduling assignment (SA) information between half-duplex user equipments (UE) in a wireless communication system, the method performed by a first UE and comprising:

• receiving a plurality of SA information for the first UE from a plurality of UEs;
• determining that SA information for transmission to a second UE and SA information transmitted from the second UE are included in the plurality of SA information;
• determining that the second UE is in a same group with the first UE;
• and
• transmitting an identifier (ID) of the second UE to a third UE from which the SA information for transmission to the second UE was received,
• wherein the first UE is a UE nearest the second UE among the plurality of UEs, and
• wherein the ID is transmitted a number of times within a predetermined period, the number of times determined based on a measured power of the SA information transmitted from the second UE.

A first user equipment (UE) for supporting transmission of scheduling assignment (SA) information between half-duplex UEs in a wireless communication system, the first UE comprising:

• a radio frequency unit configured to transmit and receive signals;
• and
• a processor is configured to:
• control the RF unit to receive a plurality of SA information for the first UE from a plurality of UEs;
• determine that SA information for transmission to a second UE and SA information transmitted from the second UE are included in the received plurality of SA information;
• determine that the second UE is in a same group with the first UE;
• and
• control the RF unit to transmit the SA information for transmission to the second UE to the second UE,
• wherein the first UE is a UE nearest the second UE among the plurality of UEs, and
• wherein the SA information is transmitted a number of times within a predetermined period, the number of times determined based on a measured power of the SA information transmitted from the second UE.