The present disclosure relates to a method and an apparatus of a terminal for receiving, from a base station, control information for scheduling downlink data; identifying a number of temporary information bits based on a modulation order and a code rate of the downlink data, the modulation order and the code rate being associated with the control information; identifying a transport block size, TBS, based on the code rate and the number of temporary information bits; and decoding the downlink data, based on the identified TBS.