Method and apparatus for transmitting retransmission data using HARQ in wireless communication system

A wireless apparatus for transmitting retransmission data using hybrid automatic repeat request (HARQ) in a wireless communication system, the apparatus comprising:

• a radio frequency (RF) unit transmitting and receiving a radio signal;
• and
• a processor including the RF unit, wherein the processor is configured to:
• determine whether there is a radio resource for transmitting the retransmission data;
• configure downlink control information (DCI) format including a retransmission indicator field when the radio resource exists, the retransmission indicator field indicating whether the retransmission data is general retransmission data which is retransmitted after receiving an ACK/NACK signal for initial transmission data or opportunistic retransmission data which is retransmitted before receiving the ACK/NACK signal for the initial transmission data;
• receive index information of the radio resource in which a maximum power value of the retransmission data is limited and information on the maximum power value of the retransmission data from another base station adjacent to the base station;
• and
• transmits the retransmission data through the radio resource on a basis of the DCI format.