The present disclosure discloses a method and device for narrowband mobile communication in wireless communication. The base station transmits first information, wherein the first information comprises a first power value and a first coefficient. The product of the first power value and the first coefficient is used to determine the transmission power of the first wireless signal. The transmitter of the first wireless signal is a first node. The present disclosure enables the transmitting UE to have a lower transmission power to ensure the receiving performance of the relay UE. In addition, the present disclosure can simultaneously reduce interference of data reception for the conventional UE on the base station side, thereby improving overall system performance.