| 摘要 |
The present invention relates to a wireless communication system, and more particularly to a transmission method and apparatus using a codebook in a wireless communication system supporting multiple antennas. According to one embodiment of the present invention, a method for transmitting, by a base station, a downlink signal using a plurality of transmission antennas comprises the steps of: receiving a PMI from a terminal; applying a precoding matrix indicated by the PMI in a codebook to a plurality of layers, and performing a precoding; and transmitting the precoded signal to the terminal through a plurality of transmission antennas. Among precoding matrices included in the codebook, a precoding matrix for transmission layers which are even in number can be constructed as a 2x2 matrix which contains matrices (W1) as four elements, the matrix (W1) having the number of rows equal to the number of transmission antennas and the number of columns equal to half the number of transmission antennas, wherein the first and second columns of the first row in the 2x2 matrix may be multiplied by a coefficient of 1, the first column of the second row may be multiplied by coefficient "a" of a phase, and the first column of the second row may be multiplied by "-a". |
