A method of a user equipment (UE) in a wireless communication system includes receiving resource allocation information related to a configured grant (CG)-based uplink transmission, receiving configuration information indicating multiplexing between CG uplink control information (CG UCI) and hybrid automatic repeat request acknowledgement (HARQ-ACK) information, performing joint encoding of the CG UCI and the HARQ-ACK information based on the configuration information, and transmitting a CG physical uplink shared channel (CG PUSCH) based on the resource allocation information. The joint-encoded information is multiplexed in the CG PUSCH. A beta offset value corresponding to one of a first index, a second index, or a third index related to a beta offset for the HARQ-ACK information is applied to the joint encoding.