A method for transmitting a downlink signal by a base station in a wireless communication system comprises transmitting at least a part of downlink data to a first user equipment (UE); and transmitting the other part of the downlink data of the first UE to a second UE that is paired with with the first UE when a size of the downlink data of the first UE exceeds a data reception capability of the first UE, wherein transmission for the first UE and transmission for the second UE are performed at the same time, and the other part of the downlink data of the first UE, which are transmitted to the second UE, may be shared with the first UE through direct communication between the first UE and the second UE.