Groupcast transmission method and apparatus therefor
A method for performing sidelink groupcast transmission by a transmission terminal includes the steps of: classifying reception terminals belonging to a subject group into two or more subgroups; allocating different groupcast feedback schemes to the two or more subgroups; performing groupcast transmission to the reception terminals; and receiving feedback information from terminals belonging to at least one subgroup among the two or more subgroups according to the different groupcast feedback schemes.
1. A method for sidelink groupcast transmission, performed in a transmitting terminal, the method comprising:
configuring a groupcast feedback scheme;
transmitting sidelink control information (SCI) indicating resource allocation information and the groupcast feedback scheme to at least one receiving terminal:
performing groupcast transmission based on the resource allocation information; and
receiving feedback information from one or more of the at least one receiving terminal according to the groupcast feedback scheme,
wherein the groupcast feedback scheme includes a scheme of assigning individual acknowledgement/negative acknowledgement (ACK/NACK) resources to the at least one receiving terminal and a scheme of assigning a common NACK resource to the at least one receiving terminal,
wherein the individual ACK/NACK resources are implicitly determined by each of the at least one receiving terminal using a specific index of a sub channel which is a basic resource unit of the data channel used for the groupcast transmission, a slot index of the data channel used for the groupcast transmission, an identifier of the transmitting terminal, and an identifier of the each of the at least receiving terminal, and
wherein the common NACK resource is implicitly determined by each of the at least one receiving terminal using a specific index of a sub channel which is a basic resource unit of the data channel used for the groupcast transmission, a slot index of the data channel used for the groupcast transmission, and an identifier of the transmitting terminal.
2. The method according to claim 1 , wherein the individual ACK/NACK resources or the common NACK resource are explicitly configured by the transmitting terminal to each of the at least one receiving terminal or to all of the at least one terminal through a control channel scheduling the groupcast transmission.
3. A method for sidelink groupcast reception, performed in a first receiving terminal, the method comprising:
receiving sidelink control information (SCI) indicating resource allocation information and a groupcast feedback scheme from a transmitting terminal;
performing groupcast reception based on the resource allocation information; and
transmitting feedback information to the transmitting terminal according to the groupcast feedback scheme,
wherein the groupcast feedback scheme includes a scheme of assigning individual acknowledgement negative acknowledgement (ACK/NACK) resources to at least one receiving terminal including the first receiving terminal and a scheme of assigning a common NACK resource to the at least one receiving terminal including the first receiving terminal,
wherein the individual ACK/NACK resources are implicitly determined by each of the at least one receiving terminal using a specific index of a sub channel which is a basic resource unit of the data channel used for the groupcast reception, a slot index of the data channel used for the groupcast reception, an identifier of the transmitting terminal, and an identifier of the each of the at least receiving terminal, and
wherein the common NACK resource is implicitly determined by each of the at least one receiving terminal using a specific index of a sub channel which is a basic resource unit of the data channel used for the groupcast reception, a slot index of the data channel used for the groupcast reception, and an identifier of the transmitting terminal.
4. The method according to claim 3 , wherein the individual ACK/NACK resources or the common NACK resource are explicitly configured by the transmitting terminal to each of the at least one receiving terminal or to all of the at least one terminal through a control channel scheduling the groupcast transmission.