Method for transmitting or receiving ack/nack signal in wireless communication system and apparatus for same

A user equipment (UE) for receiving an ACK/NACK signal in a wireless communication system, the UE comprising:

• a transmitter to transmit an uplink signal including a UE identifier of the UE through one of a plurality of resources belonging to a first resource pool, in accordance with a contention-based multiple access scheme;
• and
• a processor to attempt to detect at least one of an ACK signal or a NACK signal for the uplink signal from a second resource pool associated with the first resource pool,
• wherein in attempting to detect the ACK signal or the NACK signal, the processor assumes that the ACK signal is UE-specifically signaled based on the UE identifier, and the NACK signal is broadcasted through a bitmap that is specific to the first resource pool.

A method for transmitting an ACK/NACK signal by a base station in a wireless communication system, the method comprising:

• attempting to detect an uplink signal including a user equipment (UE) identifier transmitted in accordance with a contention-based multiple access scheme through one of a plurality of resources belonging to a first resource pool;
• and
• transmitting at least one of an ACK signal or a NACK signal for the uplink signal on a second resource pool associated with the first resource pool,
• wherein in transmitting the ACK signal or the NACK signal, the base station UE-specifically signals the ACK signal based on the UE identifier, and broadcasts the NACK signal through a bitmap that is specific to the first resource pool.

A base station for transmitting an ACK/NACK signal in a wireless communication system, the base station comprising:

• a processor to attempt to detect an uplink signal including a user equipment (UE) identifier transmitted in accordance with a contention-based multiple access scheme through one of a plurality of resources belonging to a first resource pool;
• and
• a transmitter to transmit at least one of an ACK signal or a NACK signal for the uplink signal from a second resource pool associated with the first resource pool under control of the processor,
• wherein in transmitting the ACK signal or the NACK signal, the processor UE-specifically signals the ACK signal based on the UE identifier, and broadcasts the NACK signal through a bitmap that is specific to the first resource pool.