Reference timing determination based on sidelink propagation delay
In an embodiment, a UE establishes, with a peer sidelink UE, at least one sidelink communications link that each comprises one or more hops. The UE determines estimates a propagation delay between the UE and the peer sidelink UE based in part upon a relationship between a propagation time, between the UE and the peer sidelink UE, and Reference Signal Received Power (RSRP) irrespective of whether the UE remains synchronized with respect to the network clock.
1. A method of operating a user equipment (UE), comprising:
establishing, with a peer sidelink UE, at least one sidelink communications link that each comprises one or more hops;
estimating, while the UE is synchronized with respect to a network clock, a propagation delay between the UE and the peer sidelink UE based in part upon a relationship between a propagation time, between the UE and the peer sidelink UE, and Reference Signal Received Power (RSRP); and
determining, while the UE is synchronized with respect to the network clock, a reference timing based on the estimated propagation delay.
2. The method of claim 1 , wherein the network clock is for a Global Navigation Satellite System (GNSS) or a terrestrial network.
3. The method of claim 1 ,
wherein the relationship is determined locally at the UE, or
wherein the relationship is crowdsourced from one or more other UEs, or
a combination thereof.
4. The method of claim 1 , wherein the estimating estimates the propagation delay as a function of a current RSRP based on the relationship.
5. The method of claim 4 , wherein the current RSRP is measured with respect to a sidelink synchronization signal.
6. The method of claim 1 , wherein the relationship between the RSRP and the propagation time is based at least in part on a measurement of a reference signal or a sidelink synchronization signal that occurs while the UE or another UE is synchronized with respect to the network clock.
7. A user equipment (UE), comprising:
means for establishing, with a peer sidelink UE, at least one sidelink communications link that each comprises one or more hops;
means for estimating, while the UE is synchronized with respect to a network clock, a propagation delay between the UE and the peer sidelink UE based in part upon a relationship between a propagation time, between the UE and the peer sidelink UE, and Reference Signal Received Power (RSRP); and
means for determining, while the UE is synchronized with respect to the network clock, a reference timing based on the estimated propagation delay.
8. The UE of claim 7 , wherein the network clock is for a Global Navigation Satellite System (GNSS) or a terrestrial network.
9. The UE of claim 7 ,
wherein the relationship is determined locally at the UE, or
wherein the relationship is crowdsourced from one or more other UEs, or
a combination thereof.
10. The UE of claim 7 , wherein the means for estimating estimates the propagation delay as a function of a current RSRP based on the relationship.
11. The UE of claim 10 , wherein the current RSRP is measured with respect to a sidelink synchronization signal.
12. The UE of claim 7 , wherein the relationship between the RSRP and the propagation time is based at least in part on a measurement of a reference signal or a sidelink synchronization signal that occurs while the UE or another UE is synchronized with respect to the network clock.
13. A user equipment (UE), comprising:
a memory;
at least one transceiver; and
at least one processor coupled to the memory and the at least the transceiver, the at least one processor configured to:
establish, with a peer sidelink UE, at least one sidelink communications link that each comprises one or more hops;
estimate, while the UE is synchronized with respect to a network clock, a propagation delay between the UE and the peer sidelink UE based in part upon a relationship between a propagation time, between the UE and the peer sidelink UE, and Reference Signal Received Power (RSRP); and
determine, while the UE is synchronized with respect to the network clock, a reference timing based on the estimated propagation delay.
14. The UE of claim 13 , wherein the network clock is for a Global Navigation Satellite System (GNSS) or a terrestrial network.
15. The UE of claim 13 ,
wherein the relationship is determined locally at the UE, or
wherein the relationship is crowdsourced from one or more other UEs, or
a combination thereof.
16. The UE of claim 13 , wherein the at least one processor is configured to estimate the propagation delay as a function of a current RSRP based on the relationship.
17. The UE of claim 16 , wherein the current RSRP is measured with respect to a sidelink synchronization signal.
18. The UE of claim 13 , wherein the relationship between the RSRP and the propagation time is based at least in part on a measurement of a reference signal or a sidelink synchronization signal that occurs while the UE or another UE is synchronized with respect to the network clock.
19. A non-transitory computer-readable medium containing instructions stored thereon, which, when executed by a user equipment (UE), cause the UE to perform actions, the instructions comprising:
at least one instruction configure to cause the UE to establish, with a peer sidelink UE, at least one sidelink communications link that each comprises one or more hops;
at least one instruction configure to cause the UE to estimate, while the UE is synchronized with respect to a network clock, a propagation delay between the UE and the peer sidelink UE based in part upon a relationship between a propagation time, between the UE and the peer sidelink UE, and Reference Signal Received Power (RSRP); and
at least one instruction configure to cause the UE to determine, while the UE is synchronized with respect to the network clock, a reference timing based on the estimated propagation delay.
20. The non-transitory computer-readable medium of claim 19 , wherein the network clock is for a Global Navigation Satellite System (GNSS) or a terrestrial network.
21. The non-transitory computer-readable medium of claim 19 ,
wherein the relationship is determined locally at the UE, or
wherein the relationship is crowdsourced from one or more other UEs, or
a combination thereof.
22. The non-transitory computer-readable medium of claim 19 , wherein the at least one instruction configure to cause the UE to estimate causes the UE to estimate the propagation delay as a function of a current RSRP based on the relationship.
23. The non-transitory computer-readable medium of claim 22 , wherein the current RSRP is measured with respect to a sidelink synchronization signal.
24. The non-transitory computer-readable medium of claim 19 , wherein the relationship between the RSRP and the propagation time is based at least in part on a measurement of a reference signal or a sidelink synchronization signal that occurs while the UE or another UE is synchronized with respect to the network clock.