Method and apparatus for adjusting contention window in wireless communication system

A method for multiple sub-bands access by a terminal in a wireless communication system, the method comprising:

• transmitting, to a base station (BS), at least one hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback corresponding to at least one physical downlink shared channel (PDSCH) in a reference duration for a downlink channel occupancy, wherein the at least one PDSCH in the reference duration includes a PDSCH that partially but not fully overlaps with a sub-band among multiple sub-bands;
• and
• receiving, from the BS, a downlink signal on the sub-band, in case that the sub-band is idle,
• wherein the at least one HARQ-ACK feedback including a HARQ-ACK feedback corresponding to the PDSCH that partially but not fully overlaps with the sub-band among the multiple sub-bands is used for determination of a contention window for the sub-band among the multiple sub-bands,
• wherein whether the sub-band is idle is based on a defer duration and a number identified within the contention window for the sub-band, and
• wherein the reference duration includes a first slot corresponding to transmission of the at least one PDSCH within the downlink channel occupancy.

A base station (BS), comprising:

• a transceiver;
• and
• a controller configured to:
• identify at least one hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback corresponding to at least one physical downlink shared channel (PDSCH) in a reference duration for a downlink channel occupancy, wherein the at least one PDSCH in the reference duration includes a PDSCH that partially but not fully overlaps with a sub-band among multiple sub-bands,
• determine a contention window for the sub-band among the multiple sub-bands based on the at least one HARQ-ACK feedback including a HARQ-ACK feedback corresponding to the PDSCH that partially but not fully overlaps with the sub-band among the multiple sub-bands,
• identify a number within the contention window for the sub-band,
• sense the sub-band based on the number and a defer duration, and
• perform a downlink transmission on the sub-band, in case that the sub-band is sensed to be idle,
• wherein the reference duration includes a first slot corresponding to transmission of the at least one PDSCH within the downlink channel occupancy.

A terminal, comprising:

• a transceiver;
• and
• a controller configured to:
• transmit, to a base station (BS), at least one hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback corresponding to at least one physical downlink shared channel (PDSCH) in a reference duration for a downlink channel occupancy wherein the at least one PDSCH in the reference duration includes a PDSCH that partially but not fully overlaps with a sub-band among multiple sub-bands, and
• receive, from the BS, a downlink signal on the sub-band, in case that the sub-band is idle,
• wherein the at least one HARQ-ACK feedback including a HARQ-ACK feedback corresponding to the PDSCH that partially but not fully overlaps with the sub-band among the multiple sub-bands is used for determination of a contention window for the sub-band among the multiple sub-bands,
• wherein whether the sub-band is idle is based on a defer duration and a number identified within the contention window for the sub-band, and
• wherein the reference duration includes a first slot corresponding to transmission of the at least one PDSCH within the downlink channel occupancy.