Patent ID: 7957329

Claim:
A method of performing hybrid automatic repeat request (HARQ) in a time-division-duplex (TDD) mobile communication system, performed by a user equipment, the method comprising: receiving a first downlink assignment on a first control channel in a first downlink subframe; receiving a second downlink assignment on a second control channel in a second downlink subframe; receiving first downlink data in the first downlink subframe using a radio resource identified by the first downlink assignment; receiving second downlink data in the second downlink subframe using a radio resource identified by the second downlink assignment; determining an ACK/NACK resource in an uplink subframe, wherein the ACK/NACK resource is determined based on a number of a plurality of linked downlink subframes for HARQ feedback linked with the uplink subframe, the plurality of linked downlink subframes including the first downlink subframe and the second downlink subframe, the plurality of linked downlink subframes for the uplink subframe being pre-defined; and transmitting an ACK/NACK signal for the first downlink data and the second downlink data using the ACK/NACK resource in the uplink subframe.