The present invention relates a method in which a base station transmits a downlink signal by using a plurality of layers comprises the steps of: multiplexing and transmitting dedicated reference signals for the plurality of layers on the basis of a reference signal pattern, wherein 24 resource element positions comprised in the reference signal pattern are set as 6 groups, the 6 groups are set as 2 high-level groups, the reference signal for the plurality of layer is split and placed in the 2 high-level groups, and the reference signal for 2 or more layers placed in the same group is subjected to code-division multiplexing.