The present application discloses a method for a terminal to receive a downlink signal including at least one code word in a wireless communication system. Particularly, the method is characterized by: a step of receiving a first code word, through a first number of layers, and a second code word, through a second number of layers, which have been newly transmitted from a base station; a step of transmitting, to the base station, a negative acknowledgement for one of the first code word and the second code word; and receiving, from the base station, a code word which has been re-transmitted in response to the negative acknowledgement, and a third code word which has been newly transmitted, wherein the number of layers for receiving the re-transmitted code word is equal to the number of layers involved in the new transmission thereof.