Method and apparatus for resource reservation for NR sidelink
Embodiments of the present application are related to a method and apparatus for resource reservation for 3GPP 5G New Radio (NR) sidelink (SL). A method for wireless communication performed by a user equipment (UE) according to an embodiment of the present application includes: transmitting a code block group (CBG)-based transmission on a SL, wherein the CBG-based transmission includes one or more CBGs; receiving hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback corresponding to the one or more CBGs; and determining, based on contents of the HARQ-ACK feedback, whether there is resource(s) to be released during a CBG-based retransmission.
1. A method performed by a user equipment (UE), the method comprising:
transmitting a code block group (CBG)-based transmission on a sidelink (SL), wherein the CBG-based transmission includes one or more CBGs;
receiving hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback corresponding to the one or more CBGs;
determining, based at least in part on contents of the HARQ-ACK feedback, whether there are one or more resources to be released during a CBG-based retransmission, wherein the one or more resources are a percentage of a plurality of resources allocated for at least one of the CBG-based transmission or the CBG-based retransmission; and
releasing the one or more resources based at least in part on the percentage satisfying a threshold value.
2. The method of claim 1 , comprising:
transmitting sidelink control information (SCI), wherein the SCI includes a first indicator that indicates one or more allocated resources for the CBG-based transmission and the CBG-based retransmission, and the one or more allocated resources include the one or more resources to be released.
3. A user equipment (UE) for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
transmit a code block group (CBG)-based transmission on a sidelink (SL), wherein the CBG-based transmission includes one or more CBGs;
receive hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback corresponding to the one or more CBGs;
determine, based at least in part on contents of the HARQ-ACK feedback, whether there are one or more resources to be released during a CBG-based retransmission, wherein the one or more resources are a percentage of a plurality of resources allocated for at least one of the CBG-based transmission or the CBG-based retransmission; and
release the one or more resources based at least in part on the percentage satisfying a threshold value.
4. The UE of claim 3 , wherein the at least one processor is further configured to cause the UE to:
transmit sidelink control information (SCI), wherein the SCI includes a first indicator that indicates the plurality of resources, and wherein the plurality of resources include the one or more resources to be released.
5. The UE of claim 4 , wherein the at least one processor is further configured to cause the UE to:
determine whether all bits included in the HARQ-ACK feedback corresponding to the one or more CBGs are decoded successfully;
in response to all the bits included in the HARQ-ACK feedback corresponding to the one or more CBGs being decoded successfully, release the plurality of resources; or
in response to at least one bit in the HARQ-ACK feedback corresponding to the one or more CBGs not being decoded successfully, refrain from releasing the plurality of resources based at least in part on the plurality of resources being used by the CBG-based retransmission.
6. The UE of claim 4 , wherein the SCI indicates a location of the one or more resources to be released in a time domain and a frequency domain.
7. The UE of claim 6 , wherein the location of the one or more resources to be released is an edge of the plurality of resources.
8. The UE of claim 4 , wherein the at least one processor is further configured to cause the UE to:
determine a total number of the one or more resources to be released.
9. The UE of claim 8 , wherein each of the one or more CBGs includes one or more code blocks (CBs), and wherein the total number of the one or more resources to be released is determined based at least in part on:
a total number of successfully decoded CBs, wherein the total number of successfully decoded CBs is determined based at least in part on the HARQ-ACK feedback corresponding to the one or more CBGs;
a total number of CBs transmitted on the SL, wherein the total number of CBs transmitted on the SL is determined based at least in part on the SCI; and
a total number of resources of the plurality of resources.
10. The UE of claim 8 , wherein the one or more resources to be released include one or more sub-channels in a frequency domain, and wherein the total number of the one or more resources to be released is calculated by:
X =floor( M/N*P ),
wherein: X represents the total number of the one or more sub-channels to be released;
M represents a total number of successfully decoded CBs, wherein the total number of successfully decoded CBs is determined based at least in part on the HARQ-ACK feedback corresponding to the one or more CBGs;
N represents a total number of CBs transmitted on the SL, wherein the total number of CBs transmitted on the SL is determined based at least in part on the SCI; and
P represents a total number of sub-channel(s) allocated for the CBG-based retransmission.
11. The UE of claim 4 , wherein the SCI includes a second indicator to indicate whether the UE will use the one or more resources to be released.
12. The UE of claim 11 , wherein the second indicator is a bit carried in the SCI, and wherein one of values 0 and 1 of the bit represents that the UE will use the one or more resources to be released and another one of the values 0 and 1 of the bit represents that the UE will not use the one or more resources to be released.
13. The UE of claim 11 , wherein, in response to the second indicator indicating that the UE will not use the one or more resources to be released, the one or more resources to be released are used by another UE.
14. The UE of claim 4 , wherein the SCI indicates at least one resource in a time domain reserved for the CBG-based retransmission.
15. The UE of claim 14 , wherein the at least one processor is further configured to cause the UE to:
in response to determining that the one or more resources are to be released, release a same number of sub-channels from the at least one resource in the time domain.
16. The UE of claim 3 , wherein the at least one processor is further configured to cause the UE to refrain from using the one or more resources to be released to transmit the CBG-based retransmission.
17. The UE of claim 3 , wherein the at least one processor is further configured to cause the UE to refrain from using the one or more resources to be released to transmit the CBG-based retransmission, wherein the one or more resources to be released are used by another UE.
18. The UE of claim 3 , wherein to satisfy the threshold value, the percentage is equal to or greater than the threshold value.
19. A user equipment (UE) for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
receive sidelink control information (SCI) including a first indicator, wherein the first indicator indicates a plurality of resources allocated for at least one of a CBG-based transmission or a CBG-based retransmission, and wherein the CBG-based transmission includes one or more CBGs;
monitor hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback corresponding to the one or more CBGs; and
determine, based at least in part on the SCI and contents of the HARQ-ACK feedback, whether there are one or more resources available, wherein the one or more resources are a percentage of the plurality of resources allocated for at least one of the CBG-based transmission or the CBG-based retransmission, and wherein the one or more resources are available based at least in part on the percentage satisfying a threshold value.
20. A processor for wireless communication, comprising:
at least one controller coupled with at least one memory and configured to cause the processor to:
transmit a code block group (CBG)-based transmission on a sidelink (SL), wherein the CBG-based transmission includes one or more CBGs;
receive hybrid automatic repeat request-acknowledge (HARQ-ACK) feedback corresponding to the one or more CBGs;
determine, based at least in part on contents of the HARQ-ACK feedback, whether there are one or more resources to be released during a CBG-based retransmission, wherein the one or more resources are a percentage of a plurality of resources allocated for at least one of the CBG-based transmission or the CBG-based retransmission; and
release the one or more resources based at least in part on the percentage satisfying a threshold value.