A user equipment configured to operate in a wireless communication system, the user equipment comprising: a communication module; and a processor configured to control the communication module, wherein the processor is configured to: receive at least one physical downlink shared channel, PDSCH, on one of a plurality of downlink, DL, bandwidth parts, BWPs, of a cell, based on the reception of the at least one PDSCH, determine a physical uplink control channel, PUCCH, resource for a semi-static hybrid automatic repeat request acknowledgement, HARQ-ACK, codebook, wherein the PUCCH resource belongs to a PUCCH resource set associated with a size of the semi-static HARQ-ACK codebook, and receive a physical downlink control channel, PDCCH, - wherein, when the PDCCH is received earlier than a specific time duration prior to the PUCCH resource and the PDCCH indicates a DL BWP change of the cell, the size of the semi-static HARQ-ACK codebook is determined by not including HARQ-ACK information for one or more PDSCHs received before the DL BWP change in the cell, and - wherein, when the PDCCH is received within the specific time duration prior to the PUCCH resource, the user equipment does not expect that the PDCCH indicates the DL BWP change, whereby the size of the semi-static HARQ-ACK codebook is maintained. a communication module; and a processor configured to control the communication module, wherein the processor is configured to: receive at least one physical downlink shared channel, PDSCH, on one of a plurality of downlink, DL, bandwidth parts, BWPs, of a cell, based on the reception of the at least one PDSCH, determine a physical uplink control channel, PUCCH, resource for a semi-static hybrid automatic repeat request acknowledgement, HARQ-ACK, codebook, wherein the PUCCH resource belongs to a PUCCH resource set associated with a size of the semi-static HARQ-ACK codebook, and receive a physical downlink control channel, PDCCH, - wherein, when the PDCCH is received earlier than a specific time duration prior to the PUCCH resource and the PDCCH indicates a DL BWP change of the cell, the size of the semi-static HARQ-ACK codebook is determined by not including HARQ-ACK information for one or more PDSCHs received before the DL BWP change in the cell, and - wherein, when the PDCCH is received within the specific time duration prior to the PUCCH resource, the user equipment does not expect that the PDCCH indicates the DL BWP change, whereby the size of the semi-static HARQ-ACK codebook is maintained. receive at least one physical downlink shared channel, PDSCH, on one of a plurality of downlink, DL, bandwidth parts, BWPs, of a cell, based on the reception of the at least one PDSCH, determine a physical uplink control channel, PUCCH, resource for a semi-static hybrid automatic repeat request acknowledgement, HARQ-ACK, codebook, wherein the PUCCH resource belongs to a PUCCH resource set associated with a size of the semi-static HARQ-ACK codebook, and receive a physical downlink control channel, PDCCH, - wherein, when the PDCCH is received earlier than a specific time duration prior to the PUCCH resource and the PDCCH indicates a DL BWP change of the cell, the size of the semi-static HARQ-ACK codebook is determined by not including HARQ-ACK information for one or more PDSCHs received before the DL BWP change in the cell, and - wherein, when the PDCCH is received within the specific time duration prior to the PUCCH resource, the user equipment does not expect that the PDCCH indicates the DL BWP change, whereby the size of the semi-static HARQ-ACK codebook is maintained. - wherein, when the PDCCH is received earlier than a specific time duration prior to the PUCCH resource and the PDCCH indicates a DL BWP change of the cell, the size of the semi-static HARQ-ACK codebook is determined by not including HARQ-ACK information for one or more PDSCHs received before the DL BWP change in the cell, and - wherein, when the PDCCH is received within the specific time duration prior to the PUCCH resource, the user equipment does not expect that the PDCCH indicates the DL BWP change, whereby the size of the semi-static HARQ-ACK codebook is maintained.