Patent ID: 7545732

Claim:
A method in a Node B for transmitting data to a user equipment (UE) in an orthogonal frequency division multiplex (OFDM) system that transmits data through at least one transmit antenna, for data transmission, the method comprising the steps of: receiving channel condition information about each of sub-carrier groups for each transmit antenna of the Node B from the UE; preferentially selecting sub-carrier groups for the UE, which are to be used for transmission of the data based on the channel condition information and preferentially selecting a transmit antenna for transmission of the data in a descending order of channel conditions based on the channel condition information; and transmitting the data, information about the selected sub-carrier groups, through the selected transmit antenna, wherein the sub-carrier groups for transmission of the data comprise adjacent sub-carriers, the channel condition information is a ranked preset value representing channel conditions of sub-carriers of the sub-carrier groups, and each of the sub-carrier groups has more sub-carriers in a case of a frequency flat fading channel; wherein the selecting step further comprises the step of: assigning the sub-carrier group to the UE according to quality of service and the type of a service requested by the UE if the Node B receives channel condition information about the sub-carrier groups from at least two UEs; and further comprising the step of: selecting a transmit antenna for the UE according to the channel condition information about the sub-carrier groups if at least two transmit antennas are used.