Contention window adjustment for group channel occupancy time sharing

1. A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the one or more processors configured to:

determine, based at least in part on an amount of unused shareable time-frequency channel occupancy time (COT) resources, an adjusted contention window size for a listen-before-talk (LBT) procedure that increases channel access time fairness between a plurality of different groups of UEs;

determine, via the LBT procedure, that a channel is idle based at least in part on the adjusted contention window size; and

transmit, to other UEs in a group of UEs that includes the UE, control information that enables a group COT associated with the channel to be shared with the other UEs in the group of UEs, and wherein the plurality of different groups of UEs correspond to different groups of COT sharing UEs.

2. The UE of claim 1 , wherein the adjusted contention window size is further based at least in part on a minimum adjusted contention window value and a maximum adjusted contention window value.

3. The UE of claim 1 , wherein the adjusted contention window size is determined further based at least in part on a quantity of UEs included in the group of UEs.

4. The UE of claim 3 , wherein the quantity of UEs included in the group of UEs is based at least in part on a configuration received from a base station.

5. The UE of claim 1 , wherein the adjusted contention window size is determined further based at least in part on an area associated with the group of UEs.

6. The UE of claim 5 , wherein the area is a radio frequency (RF) coverage area, and

wherein the one or more processors are further configured to:

determine the RF coverage area associated with the group of UEs based at least in part on one or more of: a demodulation reference signal strength associated with control information received via a control channel from the group of UEs, or a transmit beam width associated with transmitting group-sharing COT system information.

7. The UE of claim 5 , wherein the area is a radio frequency (RF) coverage area and the UE is a half-duplex UE, and

wherein the one or more processors are further configured to:

determine, in a receive mode of the UE, the RF coverage area associated with the group of UEs during a remaining group COT region.

8. The UE of claim 1 , wherein the shareable time-frequency COT resources are configured to be shareable within the group of UEs.

9. The UE of claim 1 , wherein the amount of unused shareable time-frequency COT resources is based at least in part on an amount of used shareable time-frequency COT resources.

10. The UE of claim 9 ,

wherein the one or more processors are further configured to:

determine, while operating in a listen mode of the UE, the amount of used shareable time-frequency COT resources in a remaining shared COT region based at least in part on decoding control information received from the other UEs, and

wherein the control information includes an indication of a group identifier associated with the group of UEs.

11. The UE of claim 9 , wherein the one or more processors are further configured to:

determine, while operating in a receive mode of the UE, the amount of used shareable time-frequency COT resources.

12. The UE of claim 9 , wherein the amount of unused shareable time-frequency COT resources is based at least in part on:

an amount of unused shareable time-frequency COT resources during a period that corresponds to a receive mode of the UE, and

an amount of shareable time-frequency COT resources during a period that corresponds to a transmission mode of the sidelink UE.

13. The UE of claim 1 , wherein the adjusted contention window size is determined further based at least in part on the UE successfully performing a transmission on shareable time-frequency resources associated with the group of UEs.

14. The UE of claim 13 , wherein the adjusted contention window size is valid for a duration of a timer received via a radio resource control configuration, and

wherein the one or more processors are further configured to:

revert the adjusted contention window size to a previous contention window size based at least in part on an expiry of the timer.

15. The UE of claim 1 ,

wherein the one or more processors are further configured to:

disable a feature associated with determining the adjusted contention window size based at least in part on a non-detection of other groups of UEs, and

wherein the non-detection of the other groups of UEs is based at least in part on a non-detection of COT system information that indicates group COT sharing for another group identifier.

16. A method of wireless communication performed by a user equipment (UE), comprising:

determining, based at least in part on an amount of unused shareable time-frequency channel occupancy time (COT) resources, an adjusted contention window size for a listen-before-talk (LBT) procedure that increases channel access time fairness between a plurality of different groups of UEs;

determining, via the LBT procedure, that a channel is idle based at least in part on the adjusted contention window size; and

transmitting, to other UEs in a group of UEs that includes the UE, control information that enables a group COT associated with the channel to be shared with the other UEs in the group of UEs, and wherein the plurality of different groups of UEs correspond to different groups of COT sharing UEs.

17. The method of claim 16 , wherein the adjusted contention window size is further based at least in part on a minimum adjusted contention window value and a maximum adjusted contention window value.

18. The method of claim 16 , wherein the adjusted contention window size is determined further based at least in part on a quantity of UEs included in the group of UEs.

19. The method of claim 18 , wherein the quantity of UEs included in the group of UEs is based at least in part on a configuration received from a base station.

20. The method of claim 16 , wherein the adjusted contention window size is determined further based at least in part on an area associated with the group of UEs.

21. The method of claim 20 , wherein the area is a radio frequency (RF) coverage area, and

wherein the method further comprises:

determining the RF coverage area associated with the group of UEs based at least in part on one or more of:

a demodulation reference signal strength associated with control information received via a control channel from the group of UEs, or

a transmit beam width associated with transmitting group-sharing COT system information.

22. The method of claim 20 , wherein the area is a radio frequency (RF) coverage area and the UE is a half-duplex UE, and

wherein the method further comprises:

determining, in a receive mode, the RF coverage area associated with the group of UEs during a remaining group COT region.

23. The method of claim 16 , wherein the shareable time-frequency COT resources are configured to be shareable for the UE within the group of UEs.

24. The method of claim 16 , further comprising:

determining the amount of unused shareable time-frequency COT resources based at least in part on an amount of used shareable time-frequency COT resources.

25. The method of claim 24 , further comprising:

determining, while operating in a listen mode, the amount of used shareable time-frequency COT resources in a remaining shared COT region based at least in part on decoding control information received from the other UEs, wherein the control information includes an indication of a group identifier associated with the group of UEs.

26. The method of claim 24 , further comprising:

determining, while operating in a receive mode, the amount of used shareable time-frequency COT resources.

27. The method of claim 24 , wherein the amount of unused shareable time-frequency COT resources is based at least in part on:

an amount of unused shareable time-frequency COT resources during a period that corresponds to a receive mode of the UE, and

an amount of shareable time-frequency COT resources during a period that corresponds to a transmission mode of the UE.

28. The method of claim 16 , wherein the adjusted contention window size is determined further based at least in part on the UE successfully performing a transmission on shareable time-frequency resources associated with the group of UEs.

29. A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the one or more processors configured to:

receive, from other UEs in a group of UEs that includes the UE, control information that enables a group channel occupancy time (COT) associated with a channel to be shared with the other UEs in the group of UEs, wherein the group COT is shared with the other UEs based at least in part on an adjusted contention window size for a listen-before-talk procedure that increases channel access time fairness between a plurality of different groups of UEs, wherein the adjusted contention window size is based at least in part on an amount of unused shareable time-frequency channel occupancy time (COT) resources, and wherein the plurality of different groups of UEs correspond to different groups of COT sharing UEs; and

communicate with the other UEs in the group of UEs based at least in part on the control information that enables the group COT associated with the channel to be shared with the other UEs in the group of UEs.

30. A method of wireless communication performed by a user equipment (UE), comprising:

receiving, from other UEs in a group of UEs that includes the UE, control information that enables a group channel occupancy time (COT) associated with a channel to be shared with the other UEs in the group of UEs, wherein the group COT is shared with the other UEs based at least in part on an adjusted contention window size for a listen-before-talk procedure that increases channel access time fairness between a plurality of different groups of UEs, wherein the adjusted contention window size is based at least in part on an amount of unused shareable time-frequency channel occupancy time (COT) resources, and wherein the plurality of different groups of UEs correspond to different groups of COT sharing UEs; and

communicating with the other UEs in the group of UEs based at least in part on the control information that enables the group COT associated with the channel to be shared with the other UEs in the group of UEs.