Method, apparatus, and system for generating HARQ-ACK codebook in wireless communication system

A user equipment (UE) for use in a wireless communication system, the UE comprising:

• a processor;
• and
• a communication module,
• wherein the processor is configured to:
• receive downlink control information (DCI) for downlink scheduling, wherein the DCI includes a sub-slot offset k, and k is an element of a set K:
• {k0, k1, . . . , km−1} (m>0);
• for each element ki (ki>0) of the set K, perform one of:
• if a first downlink (DL) slot corresponding to UL sub-slot #(nu−ki) is different from a second DL slot corresponding to UL sub-slot #(nu−ki−1), including hybrid automatic repeat request acknowledgement (HARQ-ACK) information for the first DL slot in a semi-static HARQ-ACK codebook, and
• if the first DL slot is same as the second DL slot, skipping to include the HARQ-ACK information for the first DL slot in the semi-static HARQ-ACK codebook;
• and
• transmit the semi-static HARQ-ACK codebook in UL sub-slot #nu,
• wherein a generation of the HARQ-ACK information includes:
• determining a set of valid physical downlink shared channel (PDSCH) candidates for the first DL slot, based on whether an end of a corresponding PDSCH candidate in the first DL slot is within any UL sub-slot #(nu-ko), where ko is at least part of the set K.