Retransmission apparatus and method in wireless relay communication system

A retransmission method of a Relay Station (RS) in a wireless relay communication system, the method comprising:

• receiving data from a Base Station (BS),
• storing the data if the RS receives the data correctly;
• checking if a Mobile Station (MS) receives the data correctly by listening to a NACK transmitted directly from the MS to the BS;
• and
• transmitting the data to the MS according to scheduling by the BS.

A Relay Station (RS) in a wireless relay communication system, comprising:

• a receiver for receiving data from a Base Station (BS) or Mobile Station (MS),
• a checker for checking whether the data is corrupted or not;
• a buffer for storing correctly received data;
• and
• a transmitter for transmitting the data correctly to an MS according to scheduling by the BS, and retransmitting data corresponding to a NACK to the MS according to scheduling information received from the BS when the BS receives the NACK directly from the MS.

A Relay Station (RS) in a wireless relay communication system, comprising:

• means for receiving data from a Base Station (BS);
• means for storing the data if the RS receives the data correctly;
• means for transmitting the data to a Mobile Station (MS) according to scheduling by the BS;
• means for receiving scheduling information from the BS in order to retransmit the data when the BS receives a NACK directly from the MS;
• and
• means for retransmitting the data to the MS according to the scheduling information.

A Relay Station (RS) in a wireless relay communication system, comprising:

• means for receiving data from a Base Station (BS);
• means for storing the data if the RS receives the data correctly;
• means for checking if a Mobile Station (MS) receives the data correctly by listening to a NACK transmitted directly from the MS to the BS;
• and
• means for transmitting the data to the MS according to scheduling by the BS.