Transmission method for OFDM-MIMO communication system

A data transmission method in a MIMO-OFDM (Multiple Input Multiple Output-based Orthogonal Frequency Division Multiplexing) communication system including at least one receiver for receiving a signal through a plurality of reception antennas and a transmitter for selecting a transmission channel using channel information being fed back from the receiver and transmitting a signal through a plurality of transmission antennas, the method comprising the steps of:

• calculating power increments required to transmit one more bit by considering spatial modes having different multiplexing gains and spatial subchannels and subcarriers;
• checking first minimum power increments corresponding to the subcarriers and the spatial modes among the power increments, and selecting spatial subchannels corresponding to the first minimum power increments;
• checking second minimum power increments corresponding to the subcarriers among the first minimum power increments, and selecting spatial modes corresponding to the second minimum power increments;
• checking a third minimum power increment among the second minimum power increments, and selecting a subcarrier corresponding to the third minimum power increment;
• and
• updating a power for the selected subcarrier according to the third minimum power increment and at least one bit for the selected subcarrier, for data transmission.