Method and apparatus for performing HARQ-ACK transmission

A terminal device comprising:

• at least one processor;
• and
• at least one non-transitory computer-readable medium storing one or more computer-executable instructions that, when executed by the at least one processor, cause the terminal device to:
• trigger a transmission of a first hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook;
• and
• when a transmission of a second HARQ-ACK codebook is triggered before the first HARQ-ACK codebook has been transmitted:
• cancel the transmission of the first HARQ-ACK codebook, and
• transmit the second HARQ-ACK codebook, wherein:
• the first HARQ-ACK codebook defines a relationship between a slot in which the first HARQ-ACK codebook is transmitted/received and a physical downlink shared channel (PDSCH) slot corresponding to a HARQ-ACK among at least one HARQ-ACK included in the first HARQ-ACK codebook, and
• the second HARQ-ACK codebook defines a HARQ process of a PDSCH corresponding to a HARQ-ACK among at least one HARQ-ACK included in the second HARQ-ACK codebook.