Method and apparatus for transmitting and receiving wireless signals in wireless communication system

A user equipment (UE) for receiving a signal in a wireless communication system supporting multicast broadcast services (MBSs), the UE comprising:

• a transceiver;
• and
• a processor configured to control the transceiver to:
• receive, through radio resource control (RRC) signaling, configuration information including first information regarding a group-radio network temporary identifier (G-RNTI), and second information regarding whether a hybrid automatic repeat request (HARQ) feedback for multicast is enabled;
• receive, through a physical downlink control channel (PDCCH) based on the G-RNTI, first downlink control information (DCI) including a first hybrid automatic repeat request (HARQ) process ID field and a first new data indicator (NDI) field;
• receive a first physical downlink shared channel (PDSCH) scheduled by the first DCI;
• transmit HARQ-acknowledgement (ACK) information for the first PDSCH;
• receive, based on a cell-RNTI (C-RNTI), second DCI including a second HARQ process ID field and a second NDI field;
• and
• receive a second PDSCH scheduled by the second DCI,
• wherein, based on the second HARQ process ID field and the second NDI field, the processor determines that the second PDSCH scheduled based on the C-RNTI provides a retransmission of the first PDSCH scheduled based on the G-RNTI,
• wherein the second information informs the UE that the HARQ-feedback for multicast is DCI-dependently enabled for a MBS associated with the G-RNTI, and
• wherein the HARQ-ACK information is provided for only the first PDSCH scheduled by the first DCI, based on (i) the HARQ-feedback for multicast being DCI-dependently enabled through the second information of the RRC message, and (ii) an indicator in the first DCI of the PDCCH indicates enabling of the HARQ-ACK feedback for the first PDSCH.

A method for transmitting a signal by a base station in a wireless communication system supporting multicast broadcast services (MBSs), the method comprising:

• transmitting, through radio resource control (RRC) signaling, configuration information including first information regarding a group-radio network temporary identifier (G-RNTI), and second information regarding whether a hybrid automatic repeat request (HARQ) feedback for multicast is enabled;
• transmitting, through a physical downlink control channel (PDCCH) based on the G-RNTI, first downlink control information (DCI) including a first hybrid automatic repeat request (HARQ) process ID field and a first new data indicator (NDI) field;
• transmitting a first physical downlink shared channel (PDSCH) scheduled by the first DCI;
• receiving HARQ-acknowledgement (ACK) information for the first PDSCH;
• transmitting, based on a cell-RNTI (C-RNTI), second DCI including a second HARQ process ID field and a second NDI field;
• and
• transmitting a second PDSCH scheduled by the second DCI,
• wherein, based on the second HARQ process ID field and the second NDI field, the second PDSCH scheduled based on the C-RNTI provides a retransmission of the first PDSCH scheduled based on the G-RNTI,
• wherein the second information informs a user equipment that the HARQ-feedback for multicast is DCI-dependently enabled for a MBS associated with the G-RNTI, and
• wherein the HARQ-ACK information is provided for only the first PDSCH scheduled by the first DCI, based on (i) the HARQ-feedback for multicast being DCI-dependently enabled through the second information of the RRC message, and (ii) an indicator in the first DCI of the PDCCH indicates enabling of the HARQ-ACK feedback for the first PDSCH.

A base station for transmitting a signal in a wireless communication system supporting multicast broadcast services (MBSs), the base station comprising:

• a transceiver;
• and
• a processor configured to control the transceiver to:
• transmit, through radio resource control (RRC) signaling, configuration information including first information regarding a group-radio network temporary identifier (G-RNTI), and second information regarding whether a hybrid automatic repeat request (HARQ) feedback for multicast is enabled;
• transmit, through a physical downlink control channel (PDCCH) based on the G-RNTI, first downlink control information (DCI) including a first hybrid automatic repeat request (HARQ) process ID field and a first new data indicator (NDI) field;
• transmit a first physical downlink shared channel (PDSCH) scheduled by the first DCI;
• receive HARQ-acknowledgement (ACK) information for the first PDSCH;
• transmit, based on a cell-RNTI (C-RNTI), second DCI including a second HARQ process ID field and a second NDI field;
• and
• transmit a second PDSCH scheduled by the second DCI,
• wherein, based on the second HARQ process ID field and the second NDI field, the second PDSCH scheduled based on the C-RNTI provides a retransmission of the first PDSCH scheduled based on the G-RNTI,
• wherein the second information informs a user equipment that the HARQ-feedback for multicast is DCI-dependently enabled for a MBS associated with the G-RNTI, and
• wherein the HARQ-ACK information is provided for only the first PDSCH scheduled by the first DCI, based on (i) the HARQ-feedback for multicast being DCI-dependently enabled through the second information of the RRC message, and (ii) an indicator in the first DCI of the PDCCH indicates enabling of the HARQ-ACK feedback for the first PDSCH.