Method and apparatus for performing mixed mode retransmission in NR V2X
An operating method of a first device ( 100 ) in a wireless communication system is proposed. The method may comprise the steps of: transmitting sidelink control information (SCI) to a second device ( 200 ) through a physical sidelink control channel (PSCCH); performing initial transmission of a medium access control (MAC) protocol data unit (PDU) to the second device ( 200 ) through a physical sidelink shared channel (PSSCH) on the basis of the SCI; and performing N blind retransmissions and M HARQ-based retransmissions for the MAC PDU within a packet delay budget (PDB), on the basis of the initial transmission and the number of hybrid automatic repeat request (HARQ)-based retransmissions being less than the number of transmissions related to the PSSCH required within the PDB.
1 . A method, comprising:
transmitting, by a first device, to a second device, control information through a physical control channel;
performing, by the first device, based on the control information, an initial transmission of a medium access control protocol data unit, to the second device, through a physical shared channel; and
performing, by the first device, based on that a number of the initial transmission and hybrid automatic repeat request-based retransmissions is less than a transmission number related to the physical shared channel required in a packet delay budget, N blind retransmissions and M hybrid automatic repeat request-based retransmissions for the medium access control protocol data unit in the packet delay budget,
wherein a number of the initial transmission, the N blind retransmissions, and the M hybrid automatic repeat request-based retransmissions is the same as the transmission number related to the physical shared channel required in the packet delay budget,
wherein the medium access control protocol data unit is generated based on a logical channel in which hybrid automatic repeat request feedback is enabled,
wherein hybrid automatic repeat request feedback related to the M hybrid automatic repeat request-based retransmissions is not performed, based on that there is no resource related to a physical feedback channel between contiguous resources on which the initial transmission or a retransmission of the medium access control protocol data unit is performed,
wherein N is zero or a positive integer, and
wherein M is zero or a positive integer.
2 . The method of claim 1 , wherein the hybrid automatic repeat request feedback is enabled for each of the M hybrid automatic repeat request-based retransmissions, based on a field related to hybrid automatic repeat request feedback application of the control information related to each of the M hybrid automatic repeat request-based retransmissions.
3 . The method of claim 1 , wherein hybrid automatic repeat request feedback is all enabled for each of the N blind retransmissions, based on a field related to hybrid automatic repeat request feedback application of the control information related to each of the N blind retransmissions.
4 . The method of claim 1 , wherein the N blind retransmissions are performed before the M hybrid automatic repeat request-based retransmissions.
5 . The method of claim 4 , wherein hybrid automatic repeat request feedback is enabled for a last retransmission among the N blind retransmissions, based on a field related to hybrid automatic repeat request feedback application of the control information related to the last retransmission among the N blind retransmissions.
6 . The method of claim 1 , wherein the M hybrid automatic repeat request-based retransmissions are performed before the N blind retransmissions.
7 . The method of claim 1 , wherein the N blind retransmissions are performed before hybrid automatic repeat request feedback related to each of the N blind retransmissions is received.
8 . The method of claim 1 , wherein hybrid automatic repeat request feedback related to the initial transmission is not received.
9 . The method of claim 1 , wherein a resource related to the N blind retransmissions is selected from resources excluding a time interval between a time point related to the M hybrid automatic repeat request-based retransmissions and a time point related to a physical feedback channel related to the physical shared channel.
10 . The method of claim 1 , wherein the transmission number related to the physical shared channel required in the packet delay budget is determined based on at least one of a service priority, a congestion level, a resource pool related to wireless communication, a cast type related to the wireless communication, a hybrid automatic repeat request feedback scheme, or a sidelink operation mode.
11 . The method of claim 1 , wherein a ratio of the M to the Nis determined based on at least one of a service priority, congestion level, a resource pool related to wireless communication, a cast type related to the wireless communication, a hybrid automatic repeat request feedback scheme, or a sidelink operation mode.
12 . A first device, comprising:
at least one transceiver;
at least one processor; and
at least one memory connected to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause the first device to perform operations comprising:
transmitting, to a second device, control information through a physical control channel;
performing, based on the control information, an initial transmission of a medium access control protocol data unit, to the second device, through a physical shared channel; and
performing, based on that a number of the initial transmission and hybrid automatic repeat request-based retransmissions is less than a transmission number related to the physical shared channel required in a packet delay budget, N blind retransmissions and M hybrid automatic repeat request-based retransmissions for the medium access control protocol data unit in the packet delay budget,
wherein a number of the initial transmission, the N blind retransmissions, and the M hybrid automatic repeat request-based retransmissions is the same as the transmission number related to the physical shared channel required in the packet delay budget,
wherein the medium access control protocol data unit is generated based on a logical channel in which hybrid automatic repeat request feedback is enabled,
wherein hybrid automatic repeat request feedback related to the M hybrid automatic repeat request-based retransmissions is not performed, based on that there is no resource related to a physical feedback channel between contiguous resources on which the initial transmission or a retransmission of the medium access control protocol data unit is performed,
wherein N is zero or a positive integer, and
wherein M is zero or a positive integer.
13 . A processing device comprising:
at least one processor; and
at least one memory connected to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause a first device to perform operations comprising:
transmitting, to a second device, control information through a physical control channel;
performing, based on the control information, an initial transmission of a medium access control protocol data unit, to the second device, through a physical shared channel; and
performing, based on that a number of the initial transmission and hybrid automatic repeat request-based retransmissions is less than a transmission number related to the physical shared channel required in a packet delay budget, N blind retransmissions and M hybrid automatic repeat request-based retransmissions for the medium access control protocol data unit in the packet delay budget,
wherein a number of the initial transmission, the N blind retransmissions, and the M hybrid automatic repeat request-based retransmissions is the same as the transmission number related to the physical shared channel required in the packet delay budget,
wherein the medium access control protocol data unit is generated based on a logical channel in which hybrid automatic repeat request feedback is enabled,
wherein hybrid automatic repeat request feedback related to the M hybrid automatic repeat request-based retransmissions is not performed, based on that there is no resource related to a physical feedback channel between contiguous resources on which the initial transmission or a retransmission of the medium access control protocol data unit is performed,
wherein N is zero or a positive integer, and
wherein M is zero or a positive integer.
14 . The method of claim 1 ,
wherein the control information is sidelink control information,
wherein the physical control channel is a physical sidelink control channel, and
wherein the physical shared channel is a physical sidelink shared channel.
15 . The method of claim 1 ,
wherein the physical feedback channel is a physical sidelink feedback channel.
16 . The method of claim 1 ,
wherein the method is performed by the first device.