Method and apparatus for partial sensing based on SL HARQ feedback in nr V2X
Proposed is a method for operation of a first device ( 100 ) in a wireless communication system. The method may comprise the steps of: transmitting, on the basis of an initial transmission resource, SCI for scheduling of a PSSCH to a second device ( 200 ) via a PSCCH; transmitting, on the basis of the initial transmission resource, an MAC PDU to the second device ( 200 ) via the PSSCH; receiving HARQ feedback related to the PSSCH from the second device ( 200 ) via a PSFCH resource; and carrying out, on the basis of the HARQ feedback being HARQ NACK information, partial sensing for resource reevaluation or preemption for at least one retransmission resource.
1 . A method comprising:
obtaining, by a first user equipment (UE), information related to a set of resource blocks (RBs) for an inter-UE physical feedback channel transmission;
selecting, by the first UE, an initial transmission resource and at least one retransmission resource;
transmitting, by the first UE to a second UE, inter-UE control information for scheduling of an inter-UE physical shared channel through an inter-UE physical control channel, based on the initial transmission resource;
transmitting, by the first UE to the second UE, a medium access control (MAC) protocol data unit (PDU) through the inter-UE physical shared channel, based on the initial transmission resource;
allocating, by the first UE, at least one RB from the set of RBs to the inter-UE physical shared channel;
determining, by the first UE, an index an inter-UE physical feedback channel resource for an inter-UE physical feedback channel reception among the at least one RB, based on a source ID of the first UE;
receiving, by the first UE from the second UE, a hybrid automatic repeat request (HARQ) feedback related to the inter-UE physical shared channel through the inter-UE physical feedback channel resource; and
performing, by the first UE, partial sensing for resource re-evaluation or pre-emption for the at least one retransmission resource, based on the HARQ feedback being HARQ negative acknowledge (NACK) information,
wherein a partial sensing window length related to the resource re-evaluation or the pre-emption for the at least one retransmission resource is configured to be shorter than a threshold value.
2 . The method of claim 1 , wherein the partial sensing is not allowed, based on the HARQ feedback being HARQ ACK information.
3 . The method of claim 1 , wherein the resource re-evaluation or the pre-emption is not allowed, based on the HARQ feedback being HARQ ACK information.
4 . The method of claim 1 , wherein resource reselection for the at least one retransmission resource is not allowed, based on the HARQ feedback being HARQ ACK information.
5 . The method of claim 1 , further comprising:
performing, by the first UE, a retransmission related to the MAC PDU, based on the at least one retransmission resource.
6 . The method of claim 1 , wherein a partial sensing window length related to the resource re-evaluation or the pre-emption for the at least one retransmission resource is configured to be shorter than a partial sensing window length related to resource re-evaluation or pre-emption for the initial transmission resource.
7 . The method of claim 1 , wherein the resource re-evaluation or the pre-emption is not allowed from a time point of receiving the HARQ feedback, based on the HARQ feedback being HARQ ACK information.
8 . The method of claim 1 , wherein the MAC PDU is transmitted as a HARQ disabled packet even though the MAC PDU is a HARQ enabled packet, based on the HARQ feedback being HARQ NACK information and the HARQ NACK information being received less than a threshold number of times.
9 . The method of claim 1 , wherein the MAC PDU is transmitted as a HARQ disabled packet even though the MAC PDU is a HARQ enabled packet, based on channel busy ratio (CBR) is less than or equal to a threshold value.
10 . The method of claim 1 , further comprising:
obtaining, by the first UE, information related to a resource pool,
wherein the initial transmission resource and the at least one retransmission resource is selected from the resource pool, and
wherein random resource selection and a HARQ feedback is allowed on the resource pool.
11 . The method of claim 10 , wherein the initial transmission resource and the at least one retransmission resource is randomly selected.
12 . The method of claim 11 , wherein the MAC PDU is transmitted as a HARQ disabled packet even though the MAC PDU is a HARQ enabled packet, based on a priority value related to the MAC PDU being less than or equal to a threshold value.
13 . A first user equipment (UE) comprising:
one or more processors;
one or more transceivers; and
one or more memories connected to the one or more processors and storing instructions,
wherein, the instructions, when executed by the one or more processors, cause the first UE to:
obtain information related to a set of resource blocks (RBs) for an inter-UE physical feedback channel transmission;
select an initial transmission resource and at least one retransmission resource;
transmit, to a second UE, inter-UE control information for scheduling of an inter-UE physical shared channel through an inter-UE physical control channel, based on the initial transmission resource;
transmit, to the second UE, a medium access control (MAC) protocol data unit (PDU) through the inter-UE physical shared channel, based on the initial transmission resource;
allocate at least one RB from the set of RBs to the inter-UE physical shared channel;
determine an index of an inter-UE physical feedback channel resource for an inter-UE physical feedback channel reception among the at least one RB, based on a source ID of the first UE;
receiving, from the second UE, a hybrid automatic repeat request (HARQ) feedback related to the inter-UE physical shared channel through the inter-UE physical feedback channel resource; and
performing partial sensing for resource re-evaluation or pre-emption for the at least one retransmission resource, based on the HARQ feedback being HARQ negative acknowledge (NACK) information,
wherein a partial sensing window length related to the resource re-evaluation or the pre-emption for the at least one retransmission resource is configured to be shorter than a threshold value.
14 . A processing device adapted to control a first user equipment (UE), the processing device comprising:
one or more processors; and
one or more memories connected to the one or more processors and storing instructions,
wherein the instructions, upon being executed by the one or more processors, cause the first UE to:
obtain information related to a set of resource blocks (RBs) for an inter-UE physical feedback channel transmission;
select an initial transmission resource and at least one retransmission resource;
transmit, to a second UE, inter-UE control information for scheduling of an inter-UE physical shared channel through an inter-UE physical control channel, based on the initial transmission resource;
transmit, to the second UE, a medium access control (MAC) protocol data unit (PDU) through the inter-UE physical shared channel, based on the initial transmission resource;
allocate at least one RB from the set of RBs to the inter-UE physical shared channel;
determine an index of an inter-UE physical feedback channel resource for an inter-UE physical feedback channel reception among the at least one RB, based on a source ID of the first UE;
receiving, from the second UE, a hybrid automatic repeat request (HARQ) feedback related to the inter-UE physical shared channel through the inter-UE physical feedback channel resource; and
performing partial sensing for resource re-evaluation or pre-emption for the at least one retransmission resource, based on the HARQ feedback being HARQ negative acknowledge (NACK) information,
wherein a partial sensing window length related to the resource re-evaluation or the pre-emption for the at least one retransmission resource is configured to be shorter than a threshold value.