Patent ID: 8284754

Claim:
An apparatus for a Base Station (BS) in a multihop relay wireless communication system based on a centralized scheduling, the apparatus comprising: a calculator for calculating a time interval which specifies when a Relay Station (RS) transmits an ACKnowledge (ACK)/Non ACK (NACK) and for providing a transmitter with information on the time interval, wherein the time interval is expressed in units of frames and is calculated using: a DownLink (DL) data processing delay time within the RS and a DL data processing delay time within each of any other RS between the RS and a Mobile Station (MS), an ACK/NACK transmission delay time within the MS, and an ACK/NACK processing delay time within the RS and an ACK/NACK processing delay time within each of any other RS between the RS and the MS; and the transmitter for transmitting the information on the time interval to the RS, the information on the time interval comprising one of: a frame offset between a first frame at which the RS receives the packet and a second frame at which the RS transmits the ACK/NACK, a frame offset between a third frame at which the RS receives the ACK/NACK scheduling information and the second frame at which the RS transmits the ACK/NACK, and an absolute frame number of the second frame at which the RS transmits the ACK/NACK.