Signaling of reception-to-transmission measurements for round-trip-time (RTT)-based positioning
Disclosed are techniques for signaling of reception-to-transmission measurements from gNBs and user equipments (UEs) for round trip time (RTT) based positioning in wireless networks such as new radio (NR). In multi-RTT positioning, the flow of messages that are exchanged differ depending on the entity acting as the location server determining the position of the UE.
1. A method performed by a positioning entity, comprising:
obtaining a plurality of transmission-reception point (TRP) round trip time (RTT) related measurements, the plurality of TRP RTT-related measurements being one-to-one associated with a plurality of TRPs, wherein each TRP RTT-related measurement is associated with one TRP of the plurality of TRPs;
receiving a plurality of user equipment (UE) RTT-related measurements from a primary TRP in data communication with a UE, wherein each of the plurality of UE RTT-related measurements is associated with one TRP of the plurality of TRPs; and
determining a position of the UE based on the plurality of TRP RTT-related measurements and the plurality of UE RTT-related measurements,
wherein for each TRP of the plurality of TRPs,
the TRP RTT-related measurement associated with that TRP represents a duration between that TRP transmitting a downlink reference signal (DL RS) to the UE and that TRP receiving a corresponding uplink reference signal (UL RS) from the UE, and
the UE RTT-related measurement associated with that TRP represents a duration between the UE receiving the DL RS from that TRP and the UE transmitting the corresponding UL RS to that TRP.
2. The method of claim 1 , wherein the DL RS is a positioning reference signal (PRS) and/or the UL RS is a sounding reference signal (SRS).
3. The method of claim 1 ,
wherein for each TRP k,
the associated TRP RTT-related measurement is expressed as Δ k gNB =T k gNB,Rx −T k gNB,Tx in which T k gNB,Tx represents a transmission time of the DL RS from that TRP and T k gNB,Rx represents a reception time of the corresponding UL RS at that TRP, and
the associated UE RTT-related measurement is expressed as Δ k UE =T k UE,Rx −T k UE,Tx in which T k UE,Rx represents a reception time of the DL RS at the UE and T k UE,Tx represents a transmission time of the corresponding UL RS from the UE,
wherein the plurality of TRP RTT-related measurements comprise quantities one Δ 1 gNB , zero or more Δ 2 gNB , and zero or more Δ 3 gNB such that a total number of TRP RTT-related measurements is two or greater, the Δ 1 gNB corresponding to the primary TRP, each Δ 2 gNB corresponding to each secondary TRP in data communication with the UE, and each Δ 3 gNB corresponding to a neighboring TRP not in data communication with the UE, and
wherein the plurality of UE RTT-related measurements comprises quantities Δ 1 UE , zero or more Δ 2 UE , and zero or more Δ 3 UE such that a total number of UE RTT-related measurements is two or greater, the Δ 1 UE corresponding to the primary TRP, each Δ 2 UE corresponding to each secondary TRP, and each Δ 3 UE corresponding to each neighboring TRP.
4. The method of claim 3 , wherein for at least one TRP k,
the T UE,Rx k , T UE,Tx k measurements are derived from a received timing at the UE of a downlink radio subframe i from the TRP k defined by a first detected path in time, and a transmit timing at the UE of an uplink radio subframe i corresponding to the downlink radio subframe i, and/or
the T gNB,Rx k , T gNB,Tx k measurements are derived from a received timing at the TRP k of the uplink radio subframe i defined by a first detected path in time, and a transmit timing at the TRP k of the downlink radio subframe.
5. The method of claim 3 , wherein the primary TRP is the positioning entity.
6. The method of claim 5 , wherein obtaining the plurality of TRP RTT-related measurements comprises:
determining the TRP RTT-related measurement Δ gNB 1 through direct measurements of the transmission time of the DL RS transmitted from the primary TRP and the reception time of the corresponding UL RS received from the UE; and
receiving the TRP RTT-related measurement Δ gNB 2 , Δ gNB 3 from each secondary TRP and from each neighboring TRP.
7. The method of claim 5 , wherein receiving the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 comprises:
receiving the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 from the UE.
8. The method of claim 5 , wherein obtaining the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 comprises:
receiving the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 from the secondary TRP.
9. The method of claim 8 ,
wherein a non-coherent coordinated multipoint (CoMP) is in effect, and
wherein the secondary TRP is determined to have a higher link quality to the UE than the primary TRP.
10. The method of claim 5 , wherein receiving the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 comprises:
receiving the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 from the UE; or
receiving the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 from the secondary TRP.
11. The method of claim 3 , wherein the positioning entity is outside of any of the primary and secondary TRPs and is outside of the UE.
12. The method of claim 11 , wherein obtaining the plurality of TRP RTT-related measurements comprises:
receiving all of the plurality of TRP RTT-related measurements Δ gNB 1 , Δ gNB 2 , Δ gNB 3 from a designated TRP, the designated TRP being the primary TRP or a secondary TRP.
13. The method of claim 12 ,
wherein the designated TRP is the primary TRP when no non-coherent coordinated multipoint (CoMP) is in effect, and
wherein the designated TRP is a serving TRP among the primary and secondary TRPs with a highest link quality when the non-coherent CoMP is in effect.
14. The method of claim 11 , wherein obtaining the plurality of TRP RTT-related measurements comprises:
receiving individually the TRP RTT-related measurement Δ gNB 1 , Δ gNB 2 , Δ gNB 3 from each of the primary TRP, the secondary TRPs, and the neighboring TRPs.
15. The method of claim 11 , wherein receiving the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 comprises:
receiving all of the plurality of UE RTT-related measurements Δ UE 1 , Δ UE 2 , Δ UE 3 from a designated TRP, the designated TRP being the primary TRP or one of the secondary TRP.
16. The method of claim 15 ,
wherein the designated TRP is the primary TRP when no non-coherent coordinated multipoint (CoMP) is in effect, and
wherein the designated TRP is a serving TRP among the primary and secondary TRPs with a highest link quality when the non-coherent CoMP is in effect.
17. A positioning entity, comprising:
at least one network interface or at least one transceiver or a combination thereof;
a memory; and
at least one processor communicatively coupled to the memory and the at least one transceiver,
wherein the at least one processor is configured to:
obtain a plurality of transmission-reception point (TRP) round trip time (RTT) related measurements, the plurality of TRP RTT-related measurements being one-to-one associated with a plurality of TRPs, wherein each TRP RTT-related measurement is associated with one TRP of the plurality of TRPs,
receive a plurality of user equipment (UE) RTT-related measurements from a primary TRP in data communication with a UE, wherein each of the plurality of UE RTT-related measurements is associated with one TRP of the plurality of TRPs; and
determine a position of the UE based on the plurality of TRP RTT-related measurements and the plurality of UE RTT-related measurements,
wherein for each TRP of the plurality of TRPs,
the TRP RTT-related measurement associated with that TRP represents a duration between that TRP transmitting a downlink reference signal (DL RS) to the UE and that TRP receiving a corresponding uplink reference signal (UL RS) from the UE, and
the UE RTT-related measurement associated with that TRP represents a duration between the UE receiving the DL RS from that TRP and the UE transmitting the corresponding UL RS to that TRP.
18. The positioning entity of claim 17 ,
wherein for each TRP k,
the associated TRP RTT-related measurement is expressed as Δ k gNB =T k gNB,Rx −T k gNB,Tx in which T k gNB,Tx represents a transmission time of the DL RS from that TRP and T k gNB,Rx represents a reception time of the corresponding UL RS at that TRP, and
the associated UE RTT-related measurement is expressed as Δ k UE =T k UE,Rx −T k UE,Tx in which T k UE,Rx represents a reception time of the DL RS at the UE and T k UE,Tx represents a transmission time of the corresponding UL RS from the UE,
wherein the plurality of TRP RTT-related measurements comprise quantities one Δ 1 gNB , zero or more Δ 2 gNB , and zero or more Δ 3 gNB such that a total number of TRP RTT-related measurements is two or greater, the Δ 1 gNB corresponding to the primary TRP, each Δ 2 gNB corresponding to each secondary TRP in data communication with the UE, and each Δ 3 gNB corresponding to a neighboring TRP not in data communication with the UE, and
wherein the plurality of UE RTT-related measurements comprises quantities Δ 1 UE , zero or more Δ 2 UE , and zero or more Δ 3 UE such that a total number of UE RTT-related measurements is two or greater, the Δ 1 UE corresponding to the primary TRP, each Δ 2 UE corresponding to each secondary TRP, and each Δ 3 UE corresponding to each neighboring TRP.
19. The positioning entity of claim 18 , wherein the positioning entity is outside of any of the primary and secondary TRPs and is outside of the UE.
20. The positioning entity of claim 19 , wherein the at least one processor being configured to obtain the plurality of TRP RTT-related measurements comprises the at least one processor being configured to:
receive individually the TRP RTT-related measurement Δ gNB 1 , Δ gNB 2 , Δ gNB 3 from each of the primary TRP, the secondary TRPs, and the neighboring TRPs.
21. A positioning entity, comprising:
means for obtaining a plurality of transmission-reception point (TRP) round trip time (RTT) related measurements, the plurality of TRP RTT-related measurements being one-to-one associated with a plurality of TRPs, wherein each TRP RTT-related measurement is associated with one TRP of the plurality of TRPs;
means for receiving a plurality of user equipment (UE) RTT-related measurements from a primary TRP in data communication with a UE, wherein each of the plurality of UE RTT-related measurements is associated with one TRP of the plurality of TRPs; and
means for determining a position of the UE based on the plurality of TRP RTT-related measurements and the plurality of UE RTT-related measurements,
wherein for each TRP of the plurality of TRPs,
the TRP RTT-related measurement associated with that TRP represents a duration between that TRP transmitting a downlink reference signal (DL RS) to the UE and that TRP receiving a corresponding uplink reference signal (UL RS) from the UE, and
the UE RTT-related measurement associated with that TRP represents a duration between the UE receiving the DL RS from that TRP and the UE transmitting the corresponding UL RS to that TRP.
22. A non-transitory computer-readable medium storing computer-executable instructions for a positioning entity, the computer-executable instructions comprising:
one or more instructions causing the positioning entity to obtain a plurality of transmission-reception point (TRP) round trip time (RTT) related measurements, the plurality of TRP RTT-related measurements being one-to-one associated with a plurality of TRPs, wherein each TRP RTT-related measurement is associated with one TRP of the plurality of TRPs;
one or more instructions causing the positioning entity to receive a plurality of user equipment (UE) RTT-related measurements from a primary TRP in data communication with a UE, wherein each of the plurality of UE RTT-related measurements is associated with one TRP of the plurality of TRPs; and
one or more instructions causing the positioning entity to determine a position of the UE based on the plurality of TRP RTT-related measurements and the plurality of UE RTT-related measurements,
wherein for each TRP of the plurality of TRPs,
the TRP RTT-related measurement associated with that TRP represents a duration between that TRP transmitting a downlink reference signal (DL RS) to the UE and that TRP receiving a corresponding uplink reference signal (UL RS) from the UE, and
the UE RTT-related measurement associated with that TRP represents a duration between the UE receiving the DL RS from that TRP and the UE transmitting the corresponding UL RS to that TRP.