Signaling for joint user equipment (UE) and group ambient radio frequency identification (RFID) device positioning

1 . A method of wireless communication performed by a user equipment (UE), comprising:

obtaining one or more first positioning measurements of one or more downlink positioning reference signals transmitted by one or more transmission-reception points (TRPs) during a downlink time-difference of arrival (DL-TDOA) positioning session between the UE and a location server; and

obtaining one or more second positioning measurements of one or more backscattered signals of the one or more downlink positioning reference signals during the DL-TDOA positioning session, wherein the one or more backscattered signals are transmitted by one or more ambient radio frequency identification (RFID) devices.

2 . The method of claim 1 , further comprising:

transmitting, to the location server, the one or more first positioning measurements and the one or more second positioning measurements.

3 . The method of claim 2 , wherein transmitting the one or more first positioning measurements and the one or more second positioning measurements comprises:

transmitting, for each first positioning measurement of the one or more first positioning measurements, an identifier of a corresponding second network node of the one or more TRPs; and

transmitting, for each second positioning measurement of the one or more second positioning measurements, an identifier of a corresponding ambient RFID device of the one or more ambient RFID devices.

4 . The method of claim 1 , further comprising:

determining an estimated location of the UE based, at least in part, on the one or more first positioning measurements; and

determining estimated locations of the one or more ambient RFID devices based, at least in part, on the one or more second positioning measurements.

5 . The method of claim 4 , further comprising:

transmitting, to the location server, the estimated location of the UE and the estimated locations of the one or more ambient RFID devices.

6 . The method of claim 5 , wherein transmitting the estimated location of the UE and the estimated locations of the one or more ambient RFID devices comprises:

transmitting an identifier of the UE with the estimated location of the UE; and

transmitting, for each estimated location of an ambient RFID device of the one or more ambient RFID devices, an identifier of the ambient RFID device.

7 . The method of claim 1 , further comprising:

transmitting, to the location server, a capability message indicating at least that the UE is capable of jointly processing positioning measurements of the one or more second nodes and positioning measurements of the one or more ambient RFID devices.

8 . The method of claim 7 , wherein the capability message further indicates a maximum number of ambient RFID devices from which the UE is capable of jointly processing positioning measurements.

9 . The method of claim 7 , wherein the capability message further indicates a capability of the UE to estimate a location of the UE, estimate locations of the one or more ambient RFID devices, or both.

10 . The method of claim 1 , further comprising:

receiving assistance data from the location server, wherein the assistance data includes at least an identifier of each of the one or more ambient RFID devices.

11 . The method of claim 10 , wherein the assistance data further includes:

a frequency shift of each of the one or more ambient RFID devices,

a group delay of each of the one or more ambient RFID devices, or

any combination thereof.

12 . The method of claim 10 , wherein:

the assistance data further includes locations of each of the one or more TRPs.

13 . A user equipment (UE), comprising:

one or more memories;

one or more transceivers; and

one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to:

obtain one or more first positioning measurements of one or more downlink positioning reference signals transmitted by one or more transmission-reception points (TRPs) during a downlink time-difference of arrival (DL-TDOA) positioning session between a user equipment (UE) and a location server; and

obtain one or more second positioning measurements of one or more backscattered signals of the one or more downlink positioning reference signals during the DL-TDOA positioning session, wherein the one or more backscattered signals are transmitted by one or more ambient radio frequency identification (RFID) devices.

14 . The UE of claim 13 , wherein the one or more processors, either alone or in combination, are further configured to:

transmit, via the one or more transceivers, to the location server, the one or more first positioning measurements and the one or more second positioning measurements.

15 . The UE of claim 14 , wherein the one or more processors configured to transmit the one or more first positioning measurements and the one or more second positioning measurements comprises the one or more processors, either alone or in combination, configured to:

transmit, via the one or more transceivers, for each first positioning measurement of the one or more first positioning measurements, an identifier of a corresponding second network node of the one or more TRPs; and

transmit, via the one or more transceivers, for each second positioning measurement of the one or more second positioning measurements, an identifier of a corresponding ambient RFID device of the one or more ambient RFID devices.

16 . The UE of claim 13 , wherein the one or more processors, either alone or in combination, are further configured to:

determine an estimated location of the UE based, at least in part, on the one or more first positioning measurements; and

determine estimated locations of the one or more ambient RFID devices based, at least in part, on the one or more second positioning measurements.

17 . The UE of claim 16 , wherein the one or more processors, either alone or in combination, are further configured to:

transmit, via the one or more transceivers, to the location server, the estimated location of the UE and the estimated locations of the one or more ambient RFID devices.

18 . The UE of claim 17 , wherein the one or more processors configured to transmit the estimated location of the UE and the estimated locations of the one or more ambient RFID devices comprises the one or more processors, either alone or in combination, configured to:

transmit, via the one or more transceivers, an identifier of the UE with the estimated location of the UE; and

transmit, via the one or more transceivers, for each estimated location of an ambient RFID device of the one or more ambient RFID devices, an identifier of the ambient RFID device.

19 . The UE of claim 13 , wherein the one or more processors, either alone or in combination, are further configured to:

transmit, via the one or more transceivers, to the location server, a capability message indicating at least that the UE is capable of jointly processing positioning measurements of the one or more second nodes and positioning measurements of the one or more ambient RFID devices.

20 . The UE of claim 19 , wherein the capability message further indicates a maximum number of ambient RFID devices from which the UE is capable of jointly processing positioning measurements.

21 . The UE of claim 19 , wherein the capability message further indicates a capability of the UE to estimate a location of the UE, estimate locations of the one or more ambient RFID devices, or both.

22 . The UE of claim 13 , wherein the one or more processors, either alone or in combination, are further configured to:

receive, via the one or more transceivers, assistance data from the location server, wherein the assistance data includes at least an identifier of each of the one or more ambient RFID devices.

23 . The UE of claim 22 , wherein the assistance data further includes:

a frequency shift of each of the one or more ambient RFID devices,

a group delay of each of the one or more ambient RFID devices, or

any combination thereof.

24 . The UE of claim 22 , wherein:

the assistance data further includes locations of each of the one or more TRPs.

25 . A user equipment (UE), comprising:

means for obtaining one or more first positioning measurements of one or more downlink positioning reference signals transmitted by one or more transmission-reception points (TRPs) during a downlink time-difference of arrival (DL-TDOA) positioning session between a user equipment (UE) and a location server; and

means for obtaining one or more second positioning measurements of one or more backscattered signals of the one or more downlink positioning reference signals during the DL-TDOA positioning session, wherein the one or more backscattered signals are transmitted by one or more ambient radio frequency identification (RFID) devices.

26 . A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a user equipment (UE), cause the UE to:

obtain one or more first positioning measurements of one or more downlink positioning reference signals transmitted by one or more transmission-reception points (TRPs) during a downlink time-difference of arrival (DL-TDOA) positioning session between a user equipment (UE) and a location server; and

obtain one or more second positioning measurements of one or more backscattered signals of the one or more downlink positioning reference signals during the DL-TDOA positioning session, wherein the one or more backscattered signals are transmitted by one or more ambient radio frequency identification (RFID) devices.