METHOD AND APPARATUS FOR EFFICIENT FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM THAT SUPPORTS MULTIPLE ANTENNAS

摘要

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for efficient feedback in a wireless communication system that supports multiple antennas. According to one embodiment of the present invention, a method for transmitting channel state information for downlink transmission via an uplink in a wireless communication system comprises the following steps: transmitting a rank indicator (RI) and a precoder-type indicator (PTI) in a first subframe; transmitting, in a second subframe, a first precoding matrix indicator (PMI) if the PTI has a first value, and a second PMI and a wideband CQI if the PTI has a second value; and transmitting, in a third subframe, the second PMI and the wideband CQI if the PTI has said first value, and a sub-band CQI and the second PMI if the PTI has said second value. The precoding matrix to be applied to the downlink transmission is determined by a combination of the first PMI and the second PMI, and sub-sampled codebooks of precoding codebooks for each of ranks 2, 3 and 4 may be applied to the second PMI.