Patent ID: 8811519

Claim:
A data transmission method in a Multi-Input Multi-Output (MIMO) communication system, the data transmission method comprising: receiving first Channel State Information (CSI) fed back from a plurality of terminals, respectively, the first CSI being CSI between each of the terminals and a base station; requesting feedback of second CSI from the respective terminals, the second CSI differing from the first CSI, and the second CSI being CSI between each terminal and the base station; and determining the terminals to be grouped by using at least one of the first CSI and second CSI, when the second CSI is fed back from the respective terminals, wherein in the determining of the terminals, the terminals, which have fed back the same CSI among the first CSI and the second CSI, are determined as the terminals to be grouped, and wherein each of the first CSI is N number of upper CSI in which influence of an interference signal on a corresponding terminal is minimized among all CSI usable by the terminals, and each of the second CSI is N number of upper CSI in which influence of an interference signal on a corresponding terminal is minimized among a plurality of CSI other than the first CSI.