A method using energy harvesting including receiving, by a relay node, first information signals transmitted from a source node and second information signals transmitted from a destination node, harvesting, by the relay node, energy using energy signals transmitted from the source node while bi-directionally relaying the first information signals and the second information signals; receiving, by the source node, information signals transmitted by the relay node; and receiving, by the destination node, the information signals relayed by the relay node. The source node, the relay node, and the destination node are devices for performing communication in a full-duplex mode.