Sidelink ranging for positioning reference signal types

1 . A user equipment (“UE”) for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

transmit, to a responder device, a sidelink (“SL”) ranging configuration message that initiates a ranging session and that indicates one or more SL ranging methods that comprise at least an SL round-trip-time (“SL-RTT”) method;

transmit, to the responder device during the ranging session, an SL positioning reference signal (“PRS”) according to the SL-RTT method;

receive, from the responder device and in response to the SL PRS, a ranging reply message and measurement report comprising SL receive-transmit (“Rx-Tx”) timing difference measurement information corresponding to the responder device; and

estimate, based on the SL Rx-Tx timing difference measurement information and locally measured timing information of the UE, a range between the UE and the responder device.

2 . The UE of claim 1 , wherein the at least one processor is configured to cause the UE to estimate the ranging information as a function of a ranging round duration of the UE, a reply time duration of the responder device, and a signal propagation time, wherein the ranging round duration and the reply time duration of the responder device is based on SL PRS Rx-Tx time difference measurements.

3 . The UE of claim 1 , wherein the at least one processor is configured to cause the UE to transmit an SL PRS capability request message to the responder device and receive an SL PRS capability response message.

4 . The UE of claim 1 , wherein the at least one processor is configured to cause the UE to estimate the ranging information based on baseband and radio frequency timing delays associated with the UE and the responder device.

5 . The UE of claim 1 , wherein the at least one processor is configured to cause the UE to:

transmit the SL PRS, to the responder device, a plurality of times; and

perform ranging for each transmitted SL PRS to increase an accuracy of the estimated ranging.

6 . The UE of claim 1 , wherein the at least one processor is configured to cause the UE to:

receive a plurality of ranging replies, wherein each ranging reply comprises an SL PRS Rx-Tx time difference measurement from the responder device in response to the SL PRS transmission; and

estimate the ranging for each of the plurality of ranging replies to increase an accuracy of the estimated ranging.

7 . The UE of claim 1 , wherein the at least one processor is configured to cause the UE to receive an SL PRS from the responder device as part of a double sided RTT (“DS-RTT”) ranging method.

8 . The UE of claim 7 , wherein the at least one processor is configured to cause the UE to:

receive the ranging reply message; and

simultaneously trigger a new phase of the DS-RTT ranging method during a same time instance of the DS-RTT ranging method without a delay.

9 . The UE of claim 1 , wherein the at least one processor is configured to cause the UE to:

transmit the SL ranging configuration message using an SL control information (“SCI”), wherein the SCI indicates one or more resources to perform ranging, a slot configuration, a cast type information, or a combination thereof; and

receive the ranging reply message and measurement report based on the same SCI.

10 . The UE of claim 1 , wherein a portion of a slot is used to transmit SL ranging control information via physical sidelink control channel (“PSCCH”), a portion of the slot is used to transmit a SL PRS Type 1 to the responder device, and a portion of the slot is configured to transmit PSSCH data.

11 . The UE of claim 1 , wherein the at least one processor is configured to cause the UE to receive time stamp information from the responder device as part of the measurement report, wherein the time stamp information comprises an actual SL PRS reception time or an SL PRS transmission time, or both.

12 . The UE of claim 1 , wherein the SL ranging configuration message indicates a ranging method that comprises an SL-RTT ranging method comprising a single-sided round-trip time (“SS-RTT”), a double sided RTT (“DS-RTT”), or a low-latency DS-RTT.

13 . The UE of claim 1 , wherein the SL ranging configuration message indicates one or more SL ranging methods that comprise a relative orientation method comprising an angle of arrival (“AoA”), a direction of arrival (“DoA”), or an angle of departure (“AoD”).

14 . A method performed by a user equipment (“UE”), the method comprising:

transmitting, to a responder device, a sidelink (“SL”) ranging configuration message that initiates a ranging session and that indicates one or more SL ranging methods that comprise at least an SL round-trip-time (“SL-RTT”) method;

transmitting, to the responder device during the ranging session, an SL positioning reference signal (“PRS”) according to the SL-RTT method;

receiving, from the responder device and in response to the SL PRS, a ranging reply message and measurement report comprising SL receive-transmit (“Rx-Tx”) timing difference measurement information corresponding to from the responder device; and

estimating, based on the SL Rx-Tx timing difference measurement information and locally measured timing information of the UE, a range between the UE and the responder device.

15 . A user equipment (“UE”) for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

receive, from an initiator device, a sidelink (“SL”) ranging configuration message that initiates a ranging session and that indicates one or more SL ranging methods that comprise at least an SL round-trip-time (“SL-RTT”) method;

receive, from the initiator device during the ranging session, an SL positioning reference signal (“PRS”) according to the SL-RTT method;

measure an SL receive-transmit (“Rx-Tx”) timing difference of the SL PRS;

generate a ranging reply message and measurement report comprising the measured SL Rx-Tx timing difference corresponding to the initiator device; and

transmit, according to the SL ranging configuration message and in response to the SL PRS, the ranging reply message and measurement report to the initiator device.

16 . A processor for wireless communication, comprising:

at least one controller coupled with at least one memory and configured to cause the processor to:

transmit, to a responder device, a sidelink (“SL”) ranging configuration message that initiates a ranging session and that indicates one or more SL ranging methods that comprise at least an SL round-trip-time (“SL-RTT”) method;

transmit, to the responder device during the ranging session, an SL positioning reference signal (“PRS”) according to the SL-RTT method;

receive, from the responder device and in response to the SL PRS, a ranging reply message and measurement report comprising SL receive-transmit (“Rx-Tx”) timing difference measurement information corresponding to from the responder device; and

estimate, based on the SL Rx-Tx timing difference measurement information and locally measured timing information of a user equipment (“UE”), a range between the UE and the responder device.

17 . The processor of claim 16 , wherein the at least one controller is configured to cause the processor to estimate the ranging information as a function of a ranging round duration of the processor, a reply time duration of the responder device, and a signal propagation time, wherein the ranging round duration and the reply time duration of the responder device is based on SL PRS Rx-Tx time difference measurements.

18 . The processor of claim 16 , wherein the at least one controller is configured to cause the processor to transmit an SL PRS capability request message to the responder device and receive an SL PRS capability response message.

19 . The processor of claim 16 , wherein the at least one controller is configured to cause the processor to estimate the ranging information based on baseband and radio frequency timing delays associated with the processor and the responder device.

20 . The processor of claim 16 , wherein the at least one controller is configured to cause the processor to:

receive a plurality of ranging replies wherein each ranging reply comprises a SL PRS Rx-Tx time difference measurement from the responder device in response to the SL PRS transmission; and

estimate the ranging for each of the plurality of ranging replies to increase an accuracy of the estimated ranging.