The disclosure relates to a 5G or 6G communication system for supporting a higher data transfer rate beyond a 4G communication system, such as LTE. A method by a base station in a communication system according to an embodiment may include: determining the number of DFT-precoding chunks on which DFT precoding is performed; determining a power backoff value of a power amplifier (PA) of the base station; transmitting information indicating the number of DFT-precoding chunks to a terminal; transmitting downlink control information (DCI) including a resource allocation field, configured based on the number of DFT-precoding chunks, to the terminal; and transmitting data to the terminal according to the resource allocation field included in the DCI.