The present disclosure relates to a method and an apparatus of transmitting a hybrid automatic repeat request-acknowledgement/negative acknowledgement (HARQ-ACK/NACK). A first set of HARQ-ACK/NACK including at least one timing value is identified. The at least one HARQ-ACK/NACK timing value is a time difference between a downlink time unit in which a physical downlink shared channel (PDSCH) is received and an uplink time unit in which a HARQ-ACK/NACK associated with the PDSCH is transmitted. A second set including at least one downlink time associated with a HARQ-ACK/NACK feedback is determined based on the first set. A codebook for the HARQ-ACK/NACK is generated based on a size of the codebook. The size of the codebook is identified based on the second set including the at least one downlink time. The codebook for the HARQ-ACK/NACK is transmitted to the base station in the uplink time unit.