Sidelink resource conflict indication
Apparatuses, methods, and systems are disclosed for indicating a sidelink resource conflict using a feedback channel. One apparatus includes a receiver that receives SCI from a peer UE on a first resource of a PSCCH, where the SCI contains information indicating future resources reserved for future transmissions. The apparatus includes a processor that determines whether there is a resource conflict, said resource conflict including an expected collision on the future resources. The apparatus includes a transmitter that transmits feedback to the peer UE on a feedback resource, where the feedback includes an indication of whether there is a resource conflict.
1 . A method performed by a user equipment (“UE”), the method comprising:
receiving sidelink control information (“SCI”) from a peer UE on a first resource of a physical sidelink control channel accompanied by an initial transmission of sidelink data, wherein the SCI comprises information indicating future resources reserved for future transmissions;
determining whether there is a resource conflict, said resource conflict comprising an expected collision on the future resources; and
transmitting feedback to the peer UE on a feedback resource, wherein the feedback comprises a first set of feedback resources for indicating hybrid automatic repeat request (“HARQ”) feedback and a second set of feedback resources for indicating whether there is a resource conflict.
2 . The method of claim 1 , wherein the SCI comprises a field that indicates whether conflict indication is enabled.
3 . The method of claim 2 , wherein the SCI further comprises a second field that indicates whether hybrid automatic repeat request (“HARQ”) feedback is enabled.
4 . The method of claim 1 , wherein the second set of feedback resources comprises a single conflict indication bit that indicates whether there is a resource conflict for any of the future resources.
5 . The method of claim 1 , wherein the SCI indicates multiple reservations of future resources, wherein the second set of feedback resources comprises a conflict indication bit for each reservation, each conflict indication bit indicating whether there is a resource conflict for a corresponding reservation.
6 . The method of claim 1 , wherein the first set of feedback resources and the second set of feedback resources comprise one of:
separate physical resource blocks on a common symbol in the time domain; and
separate symbols in the time domain on a common slot and on a common set of physical resource blocks.
7 . The method of claim 1 , wherein the first set of feedback resources comprises a HARQ feedback bit reporting one of: a positive acknowledgement for the initial transmission or a negative acknowledgement for the initial transmission and the first and second sets of feedback resources are separated in at least one of a time domain and a frequency-domain.
8 . A user equipment (“UE”) for wireless communication, comprising:
a memory; and
a processor coupled with the memory and configured to cause the UE to:
receive sidelink control information (“SCI”) from a peer UE on a first resource of a physical sidelink control channel accompanied by an initial transmission of sidelink data, wherein the SCI comprises information indicating future resources reserved for future transmissions;
determine whether there is a resource conflict, wherein the resource conflict comprises an expected collision on the future resources; and
transmit feedback to the peer UE on a feedback resource, wherein the feedback comprises a first set of feedback resources for indicating hybrid automatic repeat request (“HARQ”) feedback and a second set of feedback resources for indicating whether there is a resource conflict.
9 . The UE of claim 8 , wherein the SCI comprises a field indicating whether conflict indication is enabled.
10 . The UE of claim 8 , wherein the SCI comprises a field indicating whether HARQ feedback is enabled.
11 . The UE of claim 8 , wherein the second set of feedback resources comprises a single conflict indication bit indicating whether there is a resource conflict for any of the future resources.
12 . The UE of claim 8 , wherein the SCI indicates multiple reservations of future resources, the second set of feedback resources comprises a conflict indication bit for each reservation, and each conflict indication bit indicates whether there is a resource conflict for a corresponding reservation.
13 . The UE of claim 8 , wherein the first set of feedback resources comprises a HARQ feedback bit reporting one of: a positive acknowledgement for the initial transmission or a negative acknowledgement for the initial transmission and the first and second sets of feedback resources are separated in at least one of a time domain and a frequency-domain.
14 . A user equipment (“UE”) for wireless communication, comprising:
a memory; and
a processor coupled with the memory and configured to cause the UE to:
generate sidelink control information (“SCI”) that comprises information indicating future resources reserved for future transmissions;
transmit, to a peer UE, the SCI on a first resource of a physical sidelink control channel accompanied by an initial transmission of sidelink data; and
receive feedback from the peer UE on a feedback resource, wherein the feedback comprises a first set of feedback resources for indicating hybrid automatic repeat request (“HARQ”) feedback and a second set of feedback resources for indicating whether there is a resource conflict, said resource conflict comprising an expected collision on the future resources.
15 . The UE of claim 14 , wherein the processor triggers a resource reselection in response to the feedback from the peer UE indicating the resource conflict.
16 . The UE of claim 14 , wherein the SCI comprises a field that indicates whether conflict indication is enabled.
17 . The UE of claim 14 , wherein the second set of feedback resources comprises a single conflict indication bit that indicates whether there is a resource conflict for any of the future resources.
18 . The UE of claim 14 , wherein the SCI indicates multiple reservations of future resources, wherein the second set of feedback resources comprises a conflict indication bit for each reservation, each conflict indication bit indicating whether there is a resource conflict for a corresponding reservation.
19 . The UE of claim 14 , wherein the first set of feedback resources and the second set of feedback resources comprise one of:
separate physical resource blocks on a common symbol in the time domain; and
separate symbols in the time domain on a common slot and on a common set of physical resource blocks.
20 . The UE of claim 14 , wherein the first set of feedback resources comprises a HARQ feedback bit reporting one of: a positive acknowledgement for the initial transmission or a negative acknowledgement for the initial transmission and the first and second sets of feedback resources are separated in at least one of a time domain and a frequency-domain.