Sidelink reference signal configuration
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may receive an indication of a configuration for transmitting a sidelink reference signal (SL-RS) that is to be transmitted independently of data transmission and that has a frequency bandwidth that is independent of a frequency bandwidth configured for transmission on a physical sidelink shared channel. The UE may transmit the SL-RS to a second UE according to the configuration. Numerous other aspects are described.
1. A first user equipment (UE) for wireless communication, comprising:
one or more memories; and
one or more processors coupled to the one or more memories, the one or more memories including instructions executable by the one or more processors to cause the first UE to:
receive an indication of a configuration for transmitting a sidelink reference signal (SL-RS) that is to be transmitted independently of a data transmission and that has a frequency bandwidth that is wider than a frequency bandwidth configured for transmission on a physical sidelink shared channel (PSSCH); and
transmit the SL-RS to a second UE according to the configuration,
wherein the one or more memories further include instructions executable by the one or more processors to cause the first UE to, if a transmission of the SL-RS is to overlap at least in a time domain with a transmission of other SL or uplink transmissions, prioritize the transmission of the SL-RS based at least in part on one or more of:
a component carrier index, or
a periodicity of the SL-RS.
2. The first UE of claim 1 , wherein the configuration specifies that the SL-RS is to be transmitted in one or more symbols of a sidelink slot after the PSSCH or a physical sidelink control channel in the sidelink slot.
3. The first UE of claim 1 , wherein the configuration specifies that the SL-RS is to be transmitted in one or more specified resource elements of a sidelink slot.
4. The first UE of claim 1 , wherein the configuration specifies that the SL-RS is to be transmitted in a sidelink slot that is allocated for the SL-RS.
5. The first UE of claim 1 , wherein the configuration specifies that resources allocated for SL-RSs are not included in a resource pool configuration or that SL-RSs included in the resource pool configuration are not available for transmission on a physical sidelink channel.
6. The first UE of claim 1 , wherein the one or more memories further include instructions executable by the one or more processors to cause the first UE to receive the indication of the configuration as part of a resource pool configuration.
7. The first UE of claim 1 , wherein the configuration specifies a bandwidth for the SL-RS.
8. The first UE of claim 1 , wherein the configuration specifies one or more of:
a quantity of one or more symbols for the SL-RS in a sidelink slot,
a location of the one or more symbols for the SL-RS in the sidelink slot,
a quantity of one or more gap symbols in the sidelink slot,
a location of the one or more gap symbols in the sidelink slot,
a quantity of one or more automatic gain control (AGC) symbols in the sidelink slot, or
a location of the one or more AGC symbols in the sidelink slot.
9. The first UE of claim 1 , wherein the configuration specifies one or more of:
a comb pattern for one or more symbols for the SL-RS in a sidelink slot,
a hopping pattern for the one or more symbols for the SL-RS in the sidelink slot, or
a repetition factor for a symbol for the SL-RS in the sidelink slot.
10. The first UE of claim 1 , wherein the one or more memories further include instructions executable by the one or more processors to cause the first UE to transmit an index, via sidelink control information or a medium access control control element (MAC CE), that corresponds to the configuration.
11. The first UE of claim 1 , wherein the one or more memories further include instructions executable by the one or more processors to cause the first UE to, if the transmission of the SL-RS is to overlap at least in the time domain with the transmission of other SL or uplink transmissions, prioritize the transmission of the SL-RS further based at least in part on a priority of the SL-RS relative to a priority of the other SL or uplink transmissions.
12. A second user equipment (UE) for wireless communication, comprising:
one or more memories; and
one or more processors coupled to the one or more memories, the one or more memories including instructions executable by the one or more processors to cause the second UE to:
generate a configuration for transmitting a sidelink reference signal (SL-RS) that is to be transmitted independently of a data transmission and that has a frequency bandwidth that is wider than a frequency bandwidth configured for transmission on a physical sidelink shared channel (PSSCH),
wherein the configuration specifies one or more of:
a quantity of one or more gap symbols in a sidelink slot, or
a quantity of one or more automatic gain control (AGC) symbols in the sidelink slot; and
transmit an indication of the configuration to a first UE.
13. The second UE of claim 12 , wherein the one or more memories further include instructions executable by the one or more processors to cause the UE to:
receive the SL-RS from the first UE; and
transmit, to the first UE, a report that is based at least in part on the SL-RS.
14. The second UE of claim 12 , wherein the configuration specifies that the SL-RS is to be transmitted in one or more symbols in a sidelink slot after the PSSCH or a physical sidelink control channel in the sidelink slot.
15. The second UE of claim 12 , wherein the configuration specifies that the SL-RS is to be transmitted in one or more specified resource elements of a sidelink slot.
16. The second UE of claim 12 , wherein the configuration specifies that the SL-RS is to be transmitted in a sidelink slot that is allocated for the SL-RS.
17. The second UE of claim 12 , wherein the configuration specifies that resources allocated for SL-RSs are not included in a resource pool configuration or that SL-RSs included in the resource pool configuration are not available for transmission on a physical sidelink channel.
18. The second UE of claim 12 , wherein the one or more memories further include instructions executable by the one or more processors to cause the second UE to transmit the indication of the configuration as part of a resource pool configuration.
19. The second UE of claim 12 , wherein the configuration specifies a bandwidth for the SL-RS.
20. The second UE of claim 12 , wherein the configuration further specifies one or more of:
a location of the one or more gap symbols in the sidelink slot,
a location of the one or more AGC symbols in the sidelink slot,
a location of one or more symbols for the SL-RS in the sidelink slot, or
a quantity of the one or more symbols for the SL-RS in a sidelink slot.
21. The second UE of claim 12 , wherein the configuration further specifies one or more of:
a comb pattern for one or more symbols for the SL-RS in a sidelink slot,
a hopping pattern for the one or more symbols for the SL-RS in the sidelink slot, or
a repetition factor for a symbol for the SL-RS in the sidelink slot.
22. The second UE of claim 12 , wherein the one or more memories further include instructions executable by the one or more processors to cause the second UE to receive an index, via sidelink control information or a medium access control control element (MAC CE), that corresponds to the configuration.
23. A method of wireless communication performed by a first user equipment (UE), comprising:
receiving an indication of a configuration for transmitting a sidelink reference signal (SL-RS) that is to be transmitted independently of a data transmission and that has a frequency bandwidth that is wider than a frequency bandwidth configured for transmission on a physical sidelink shared channel (PSSCH); and
transmitting the SL-RS to a second UE according to the configuration,
wherein, if a transmission of the SL-RS is to overlap at least in a time domain with a transmission of other SL or uplink transmissions, transmitting the SL-RS to the second UE according to the configuration includes prioritizing the transmission of the SL-RS based at least in part on one or more of:
a component carrier index, or
a periodicity of the SL-RS.
24. The method of claim 23 , wherein the configuration specifies that the SL-RS is to be transmitted in one or more symbols of a sidelink slot after the PSSCH or a physical sidelink control channel in the sidelink slot.
25. The method of claim 23 , wherein the configuration specifies that the SL-RS is to be transmitted in one or more specified resource elements of a sidelink slot.
26. The method of claim 23 , wherein the configuration specifies that the SL-RS is to be transmitted in a sidelink slot that is allocated for the SL-RS.
27. A method of wireless communication performed by a second user equipment (UE), comprising:
generating a configuration for transmitting a sidelink reference signal (SL-RS) that is to be transmitted independently of a data transmission and that has a frequency bandwidth that is wider than a frequency bandwidth configured for transmission on a physical sidelink shared channel (PSSCH),
wherein the configuration specifies one or more of:
a quantity of one or more gap symbols in a sidelink slot, or
a quantity of one or more automatic gain control (AGC) symbols in the sidelink slot; and
transmitting an indication of the configuration to a first UE.
28. The method of claim 27 , wherein the configuration further specifies that the SL-RS is to be transmitted in one or more symbols in a sidelink slot after the PSSCH or a physical sidelink control channel in the sidelink slot.
29. The method of claim 27 , wherein the configuration further specifies that the SL-RS is to be transmitted in one or more specified resource elements of a sidelink slot.
30. The method of claim 27 , wherein the configuration further specifies that the SL-RS is to be transmitted in a sidelink slot that is allocated for the SL-RS.