Cyclic prefix (CP) extension in channel occupancy time (COT) sharing for sidelink communication
Wireless communications systems and methods related to use of cyclic prefix (CP) extensions for channel occupancy time (COT) sharing among sidelink user equipment devices (UEs) are provided. A first UE detects a first sidelink transmission in a COT, the COT for sharing with multiple sidelink UEs including the first sidelink UE. The first UE may determine a CP extension length for transmitting a second sidelink transmission after the first sidelink transmission, where a gap duration between the first sidelink transmission and the second sidelink transmission satisfies a listen-before-talk (LBT) gap time threshold. The first UE may apply a CP extension having the CP extension length to the second sidelink transmission and transmit, to a second sidelink UE, the second sidelink transmission with the CP extension.
1. A method of wireless communication performed by a first sidelink user equipment (UE), comprising:
detecting a first sidelink transmission in a channel occupancy time (COT), the COT for sharing with multiple sidelink UEs including the first sidelink UE;
determining a cyclic prefix (CP) extension length for transmitting a second sidelink transmission after the first sidelink transmission, a gap duration between the first sidelink transmission and the second sidelink transmission satisfying a listen-before-talk (LBT) gap time threshold;
applying a CP extension having the CP extension length to the second sidelink transmission; and
transmitting, to a second sidelink UE, the second sidelink transmission with the CP extension.
2. The method of claim 1 performed by the first sidelink UE, further comprising:
performing an LBT during the gap duration, wherein the transmitting the second sidelink transmission includes transmitting the second sidelink transmission based on the LBT being successful.
3. The method of claim 1 , wherein the LBT gap time threshold is at least one of 16 microseconds or 25 microseconds.
4. The method of claim 1 performed by the first sidelink UE, further comprising:
monitoring for sidelink channel information (SCI) indicating COT sharing information on the COT.
5. The method of claim 1 , wherein the second sidelink transmission includes a physical sidelink feedback channel (PSFCH), and the LBT gap time threshold is 16 microseconds.
6. The method of claim 1 , wherein the second sidelink transmission includes at least one of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH).
7. The method of claim 1 , wherein the first sidelink transmission is included in a first frequency interlace in the COT, and the second sidelink transmission is included in a second frequency interface in the COT.
8. The method of claim 1 , wherein the transmitting the second sidelink transmission includes transmitting the second sidelink transmission starting at a first symbol, and the applying includes applying the CP extension to a second symbol preceding the first symbol.
9. The method of claim 1 , wherein the detecting the first sidelink transmission includes detecting the first sidelink transmission in a first slot in the COT, and wherein transmitting the second sidelink transmission includes transmitting the second sidelink transmission in a second slot in the COT.
10. The method of claim 9 , wherein the first slot is different from the second slot.
11. The method claim 9 , wherein the first slot is the same as the second slot.
12. The method of claim 1 performed by the first sidelink UE, further comprising:
performing a category 2 (CAT2) LBT; and
acquiring the COT based on the CAT2 LBT being successful.
13. The method of claim 1 performed by the first sidelink UE, further comprising:
performing a category 1 (CAT1) LBT to transmit the second sidelink transmission with the CP extension.
14. The method of claim 1 , wherein the detecting the first sidelink transmission includes detecting the first sidelink transmission in a first slot in the COT, the first sidelink transmission ends at a first symbol in the first slot, and the first slot is devoid of PSFCH, and wherein the transmitting the second sidelink transmission includes transmitting the second sidelink transmission in a next slot after the first slot.
15. The method of claim 1 performed by the first sidelink UE, further comprising:
determining a third sidelink transmission that is transmitted between the first and second sidelink transmissions in the COT, the multiple sidelink UEs including a third sidelink UE that transmitted the third sidelink transmission.
16. The method of claim 1 performed by the first sidelink UE, further comprising:
determining a second CP extension length for transmitting a third sidelink transmission, wherein the transmitting the second sidelink transmission includes transmitting the second sidelink transmission in a first slot, and the first CP extension length being different from the second CP extension length; and
transmitting the third sidelink transmission in a second slot, the first and second slots being continuous slots.
17. The method of claim 1 performed by the first sidelink UE, further comprising:
puncturing a first symbol in a first slot in the COT, wherein the first gap duration includes a punctured portion of the first symbol and a second gap duration, and the second gap duration is in a second symbol immediately preceding the first symbol.
18. The method of claim 1 , wherein the detecting the first sidelink transmission includes detecting the first sidelink transmission from a third sidelink UE, the first sidelink transmission including COT sharing information.
19. The method of claim 1 , wherein the gap duration occurs before the second sidelink transmission.
20. A user equipment (UE), comprising:
a processor configured to:
detect a first sidelink transmission in a channel occupancy time (COT), the COT for sharing with multiple sidelink UEs including the UE, wherein the UE is a first sidelink UE;
determine a cyclic prefix (CP) extension length for transmitting a second sidelink transmission after the first sidelink transmission, wherein a gap duration between the first sidelink transmission and the second sidelink transmission satisfies a listen-before-talk (LBT) gap time threshold; and
apply a CP extension having the CP extension length to the second sidelink transmission; and
a transceiver configured to transmit, to a second sidelink UE, the second sidelink transmission with the CP extension.
21. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:
code for causing a first sidelink user equipment (UE) to detect a first sidelink transmission in a channel occupancy time (COT), the COT for sharing with multiple sidelink UEs including the first sidelink UE;
code for causing the first sidelink UE to determine a cyclic prefix (CP) extension length for transmitting a second sidelink transmission after the first sidelink transmission, wherein a gap duration between the first sidelink transmission and the second sidelink transmission satisfies a listen-before-talk (LBT) gap time threshold;
code for causing the first sidelink UE to apply a CP extension having the CP extension length to the second sidelink transmission; and
code for causing the first sidelink UE to transmit, to a second sidelink UE, the second sidelink transmission with the CP extension.
22. A user equipment (UE) comprising:
means for detecting a first sidelink transmission in a channel occupancy time (COT), the COT for sharing with multiple sidelink UEs;
means for determining a cyclic prefix (CP) extension length for transmitting a second sidelink transmission after the first sidelink transmission, a gap duration between the first sidelink transmission and the second sidelink transmission satisfying a listen-before-talk (LBT) gap time threshold;
means for applying a CP extension having the CP extension length to the second sidelink transmission; and
means for transmitting, to a second sidelink UE, the second sidelink transmission with the CP extension.
23. The UE of claim 22 , further comprising:
means for performing an LBT during the gap duration, wherein the means for transmitting the second sidelink transmission includes means for transmitting the second sidelink transmission if the LBT is successful.
24. The UE of claim 22 , wherein the LBT gap time threshold is 16 microseconds.
25. The UE of claim 22 , wherein the LBT gap time threshold is 25 microseconds.
26. The UE of claim 22 , further comprising:
means for monitoring for sidelink channel information (SCI) indicating COT sharing information on the COT.
27. The UE of claim 22 , wherein the second sidelink transmission includes a physical sidelink feedback channel (PSFCH), and the LBT gap time threshold is 16 microseconds.
28. The UE of claim 22 , wherein the second sidelink transmission includes at least one of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH).
29. The UE of claim 22 , wherein the first sidelink transmission is included in a first frequency interlace in the COT, and the second sidelink transmission is included in a second frequency interface in the COT.
30. The UE of claim 22 , further comprising:
means for puncturing a first symbol in a first slot in the COT, wherein the first gap duration includes a punctured portion of the first symbol and a second gap duration, and the second gap duration is in a second symbol immediately preceding the first symbol.
31. The UE of claim 30 , wherein the LBT gap time threshold is 25 microseconds.
32. The UE of claim 22 , wherein the means for detecting the first sidelink transmission includes means for detecting the first sidelink transmission from a third sidelink UE, the first sidelink transmission including COT sharing information.
33. The UE of claim 32 , wherein the second sidelink UE is the same as the third sidelink UE.
34. The UE of claim 32 , wherein the second sidelink UE is different from the third sidelink UE.
35. The UE of claim 22 , wherein the gap duration occurs before the second sidelink transmission.