Patent ID: 8750270

Claim:
A method for transmitting a feedback request in a wireless communication system, the method performed by a base station (BS) and comprising: transmitting feedback request control information to a user equipment (UE), wherein the feedback request control information includes a MIMO (Multi-Input Multi-Output) feedback bitmap and common parameters, the MIMO feedback bitmap indicating at least one MIMO feedback mode to be applied to the UE among 8 different MIMO feedback modes, wherein the 8 different MIMO feedback modes are classified as including 4 closed loop (CL) MIMO feedback modes used for a closed loop feedback and 4 open loop (OL) MIMO feedback modes used for an open loop feedback and the 8 different MIMO feedback modes are also classified as including 4 subband channel quality indicator (CQI) MIMO feedback modes requesting a subband CQI and 4 wideband CQI MIMO feedback modes requesting a wideband CQI, wherein the common parameters included in the feedback request control information are the same for at least two MIMO feedback modes among the 8 different MIMO feedback modes, wherein the common parameters comprise a parameter regarding a codebook for selecting a precoding matrix index (PMI) to be fed back by the UE when the MIMO feedback bitmap indicates at least one of the 4 CL MIMO feedback modes, and wherein the common parameters comprise a parameter indicating a number of subbands as targets for generating a subband CQI when the MIMO feedback bitmap indicates at least one of the 4 subband CQI MIMO feedback modes.