An operation method of a first terminal, performed in a communication system, may comprise receiving sidelink resource allocation information from a base station; receiving a first sidelink signal from a second terminal based on the sidelink resource allocation information; calculating a path loss experienced by the first sidelink signal based on the first sidelink signal; transmitting a second sidelink signal including information on the path loss experienced by the first sidelink signal to the second terminal; and receiving, from the second terminal, a third sidelink signal to which a sidelink transmit power determined based on the path loss is allocated.