The present application discloses a method for transmitting a downlink signal in a multi-antenna wireless communication system. In detail, the method comprises: a step of mapping a signal of a codeword domain to a signal of a layer domain; a step of mapping the signal of the layer domain to a signal of a virtual antenna port domain using a precoding matrix; and a step of transmitting the signal of the virtual antenna port domain to a physical antenna port, wherein the precoding matrix is changed in a channel measurement unit, and the signal of the layer domain is layer-permutated in the channel measurement unit. Preferably, the channel measurement unit is constituted by one or more resource blocks (RBs).