Low-layer (DCI or MAC CE) DL puncturing indicator for positioning reference signals (PRS)
During positioning of a user equipment (UE), (DL) positioning reference signals (PRS) transmitted by one or more transmission reception point (TRP) in a wireless communication system may be preempted or punctured by higher priority transmissions, such as ultra-reliable low-latency traffic (URLLC). A PRS preemption indication (PI) may be provided to a UE identifying one or more TRPs affected by preemption. The PRS PI may further identify the time domain and frequency domain of the preempted DL PRS transmissions. The PRS PI may identify the time domain, e.g., based on a number of PRS symbols between two monitoring occasions, wherein only PRS symbols that contain positioning reference signals associated with the group of TRPs are counted. The PRS PI may identify the frequency domain by identifying at least one of four or more frequency sub-bands of the preempted DL PRS transmissions.
1. A method for supporting positioning of a user equipment (UE) performed by the UE, comprising:
receiving assistance data for positioning reference signals from a plurality of transmission reception points (TRPs);
receiving a plurality of positioning reference signals from the plurality of TRPs;
receiving a positioning reference signal preemption indication (PRS PI) indicating that one or more positioning reference signals associated with one or more TRPs have been preempted; and
performing positioning measurements using received positioning reference signals from the plurality of TRPs based at least on the PRS PI indication, wherein performing the positioning measurements comprises excluding the preempted positioning reference signals from the positioning measurements.
2. The method of claim 1 , wherein the positioning reference signals are downlink positioning reference signals and the PRS PI is received from a serving TRP.
3. The method of claim 1 , wherein the positioning reference signals are sidelink positioning reference signals and the plurality of TRPs comprise sidelink UEs.
4. The method of claim 1 , wherein the positioning reference signals associated with the one or more TFPs have been preempted by another transmission that has higher priority than preempted positioning reference signals.
5. The method of claim 1 , further comprising receiving replacement positioning reference signals from the one or more TRPs, wherein performing positioning measurements uses the received positioning reference signals from the plurality of TRPs and the replacement positioning reference signals from the one or more TRPs.
6. The method of claim 1 , wherein the PRS PI contains a set of bits associated with an identifier for the one or more TRPs.
7. The method of claim 1 , wherein the PRS PI contains a set of bits associated with time domain and frequency domain for the preempted positioning reference signals.
8. The method of claim 7 , wherein the set of bits associated with the time domain and the frequency domain for the preempted positioning reference signals identifies a time of the preempted positioning reference signals based on a number of PRS symbols between two monitoring occasions, wherein only PRS symbols that contain positioning reference signals associated with the one or more TRPs are counted.
9. The method of claim 8 , wherein the monitoring occasions comprise physical downlink control channel (PDCCH) or medium access control control element (MAC CE).
10. The method of claim 7 , wherein the set of bits associated with the time domain and the frequency domain for the preempted positioning reference signals identifies at least one frequency sub-band of the preempted positioning reference signals, wherein the preempted positioning reference signals are divided into four or more frequency sub-bands.
11. The method of claim 10 , wherein the set of bits identifies only one frequency sub-band of the preempted positioning reference signals.
12. The method of claim 11 , wherein the set of bits contains K bits and the preempted positioning reference signals are divided into 2K frequency sub-bands.
13. The method of claim 10 , wherein the set of bits identifies one or more frequency bandwidths of the preempted positioning reference signals.
14. The method of claim 13 , wherein the set of bits contains K bits and the positioning reference signals are divided into K frequency sub-bands.
15. The method of claim 1 , wherein the UE is configured with a plurality of groups of TRPs, each group of TRPs comprising one or more TRPs, wherein the PRS PI identifies one of the plurality of groups of TRPs.
16. A user equipment (UE) capable of supporting positioning for the UE, the UE comprising:
at least one wireless transceiver configured to wirelessly communicate with a plurality of transmission reception points (TRPs);
at least one memory; and
at least one processor coupled to the at least one wireless transceiver and the at least one memory and configured to:
receive assistance data for positioning reference signals from the plurality of TRPs;
receive a plurality of positioning reference signals from the plurality of TRPs;
receive a positioning reference signal preemption indication (PRS PI) indicating that one or more positioning reference signals associated with one or more TRPs have been preempted; and
perform positioning measurements using received positioning reference signals from the plurality of TRPs based at least on the PRS PI indication, wherein the at least one processor configured to perform the positioning measurements is configured to exclude the preempted positioning reference signals from the positioning measurements.
17. The UE of claim 16 , wherein the positioning reference signals are downlink positioning reference signals and the PRS PI is received from a serving TRP.
18. The UE of claim 16 , wherein the positioning reference signals are sidelink positioning reference signals and the plurality of TRPs comprise sidelink UEs.
19. The UE of claim 16 , wherein the positioning reference signals associated with the one or more TRPs have been preempted by another transmission that has higher priority than preempted positioning reference signals.
20. The UE of claim 16 , wherein the at least one processor is further configured to receive replacement positioning reference signals from the one or more TRPs, wherein the at least one processor is configured to perform positioning measurements using the received positioning reference signals from the plurality of TRPs and the replacement positioning reference signals from the one or more TRPs.
21. The UE of claim 16 , wherein the PRS PI contains a set of bits associated with an identifier for the one or more TRPs.
22. The UE of claim 16 , wherein the PRS PI contains a set of bits associated with time domain and frequency domain for the preempted positioning reference signals.
23. The UE of claim 22 , wherein the set of bits associated with the time domain and the frequency domain for the preempted positioning reference signals identifies a time of the preempted positioning reference signals based on a number of PRS symbols between two monitoring occasions, wherein only PRS symbols that contain positioning reference signals associated with the one or more TRPs are counted.
24. The UE of claim 23 , wherein the monitoring occasions comprise physical downlink control channel (PDCCH) or medium access control element (MAC CE).
25. The UE of claim 22 , wherein the set of bits associated with the time domain and the frequency domain for the preempted positioning reference signals identifies at least one frequency sub-band of the preempted positioning reference signals, wherein the preempted positioning reference signals are divided into four or more frequency sub-bands.
26. The UE of claim 25 , wherein the set of bits identifies only one frequency sub-band of the preempted positioning reference signals.
27. The UE of claim 26 , wherein the set of bits contains K bits and the preempted positioning reference signals are divided into 2K frequency sub-bands.
28. The UE of claim 25 , wherein the set of bits identifies one or more frequency bandwidths of the preempted positioning reference signals.
29. The UE of claim 28 , wherein the set of bits contains K bits and the positioning reference signals are divided into K frequency sub-bands.
30. The UE of claim 16 , wherein the UE is configured with a plurality of groups of TRPs, each group of TRPs comprising one or more TRPs, wherein the PRS PI identifies one of the plurality of groups of TRPs.
31. A user equipment (UE) capable of supporting positioning for the UE, the UE comprising:
means for receiving assistance data for positioning reference signals from a plurality of transmission reception points (TRPs);
means for receiving a plurality of positioning reference signals from the plurality of TRPs;
means for receiving a positioning reference signal preemption indication (PRS PI) indicating that one or more positioning reference signals associated with one or more TRPs have been preempted; and
means for performing positioning measurements using received positioning reference signals from the plurality of TRPs based at least on the PRS PI indication, wherein the means for performing the positioning measurements is configured to exclude the preempted positioning reference signals from the positioning measurements.
32. A non-transitory storage medium including program code stored thereon, the program code is operable to configure at least one processor in a user equipment (UE) to support positioning for the UE, the non-transitory storage medium comprising:
program code to receive assistance data for positioning reference signals from a plurality of transmission reception points (TRPs);
program code to receive a plurality of positioning reference signals from the plurality of TRPs;
program code to receive a positioning reference signal preemption indication (PRS PI) indicating that one or more positioning reference signals associated with one or more TRPs have been preempted; and
program code to perform positioning measurements using received positioning reference signals from the plurality of TRPs based at least on the PRS PI indication, wherein performing the positioning measurements comprises excluding the preempted positioning reference signals from the positioning measurements.