Method and apparatus of performing harq in multiple antenna system

PURPOSE: A method and apparatus for performing HARQ(Hybrid Automatic Repeat Request) in a multiple antenna system are provided to efficiently perform the HARQ by preventing collisions of resources including a plurality of PHICH(Physical Hybrid-ARQ Indicator Channel)s. CONSTITUTION: An uplink data is transmitted to a PUSCH(Physical Uplink Shared Channel) through a plurality of antennas(S200). The ACK/NACK(Acknowledgement/Non-Acknowledgement) signal is received to a PHICH corresponding to the PUSCH through the antenna. The ACK/NACK signal directs the reception state of the uplink data. The downlink resources are determined based on the minimum PRB(Physical Resource Block) index, an uplink DMRS(Demodulation Reference Signal) cyclic shift parameter, and an OCC(Orthogonal Code Cover) index.