Positioning methods for uplink power-limited user equipment

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

sending, to a first entity, first information indicating a maximum number of positioning signal transmissions that the UE can support, a maximum power for positioning signal transmissions that the UE can support, or both;

receiving, from the first entity, configuration information for changing a positioning mode of the UE to a selected positioning mode selected from a first positioning mode and a second positioning mode; and

performing a positioning operation according to the selected positioning mode, wherein in the first positioning mode, performing the positioning operation comprises receiving a first positioning signal from a first transmission/reception point (TRP) identified by the configuration information, sending a second positioning signal to the first TRP, and reporting, to the first entity, a time delay between receiving the first positioning signal and sending the second positioning signal, and wherein in the second positioning mode, performing the positioning operation comprises receiving the first positioning signal from the first TRP identified by the configuration information, sending a second positioning signal to a second TRP identified by the configuration information, and reporting, to the first entity, the time delay between receiving the first positioning signal and sending the second positioning signal.

2 . The method of claim 1 , wherein the first entity comprises a location server, a serving base station, or a primary or relay positioning peer UE.

3 . The method of claim 1 , wherein at least one of the first TRP and the second TRP comprises a base station or a positioning peer UE.

4 . The method of claim 1 , wherein the selected positioning mode comprises the first positioning mode.

5 . The method of claim 4 , wherein the first TRP comprises a base station, the first positioning signal comprises a downlink positioning reference signal (DL-PRS), and the second positioning signal comprises an uplink sounding reference signal (UL-SRS).

6 . The method of claim 4 , wherein the first TRP comprises a positioning peer UE, the first positioning signal comprises a first sidelink positioning reference signal (SL-PRS), and the second positioning signal comprises a second SL-PRS.

7 . The method of claim 1 , wherein the selected positioning mode comprises the second positioning mode.

8 . The method of claim 7 , wherein the first TRP comprises a first base station, the first positioning signal comprises a downlink positioning reference signal (DL-PRS), the second TRP comprises a second base station, and the second positioning signal comprises an uplink sounding reference signal (UL-SRS).

9 . The method of claim 7 , wherein the first TRP comprises a first positioning peer UE, the first positioning signal comprises a first sidelink positioning reference signal (SL-PRS), the second TRP comprises a second positioning peer UE, and the second positioning signal comprises a second SL-PRS.

10 . The method of claim 1 , wherein the first information further identifies a set of one or more TRP for which the UE measures pathloss reference signals, spatial transmit beam reference signals, or both.

11 . The method of claim 1 , wherein the first information indicates a start time, an end time, a duration, a periodicity, an offset, or a combination thereof, during which the maximum number of positioning signal transmissions that the UE can support or the maximum power for positioning signal transmissions that the UE can support will apply.

12 . A method of wireless positioning performed by a positioning entity, the method comprising:

receiving, from a first user equipment (UE), first information indicating a maximum number of positioning signal transmissions that the first UE can support, a maximum power for positioning signal transmissions that the first UE can support, or both;

selecting, based on the first information, a positioning mode for the first UE, wherein the selected positioning mode is selected from a first positioning mode, in which the UE is configured to receive a first positioning signal from a first transmission/reception point (TRP), to send a second positioning signal to the first TRP, and to report, to the positioning entity, a time delay between receiving the first positioning signal and the second positioning signal, and a second positioning mode, in which the UE is configured to receive the first positioning signal from the first TRP, to send a second positioning signal to a second TRP, and to report, to the positioning entity, the time delay between receiving the first positioning signal and sending the second positioning signal;

selecting at least one neighboring TRP to be involved in the selected positioning mode as at least the first TRP; and

sending, to the first UE, configuration information for changing a positioning mode of the UE to the selected positioning mode, the configuration information identifying the at least one neighboring TRP.

13 . The method of claim 12 , wherein the positioning entity comprises a location server or a positioning peer UE.

14 . The method of claim 13 , wherein at least one of the positioning signal transmissions that the first UE can support comprises a sounding reference signal (SRS) or a sidelink positioning reference signal (SL-PRS).

15 . The method of claim 13 , wherein selecting the at least one neighboring TRP comprises selecting at least one neighboring base station or positioning peer UE.

16 . The method of claim 13 , wherein selecting the at least one neighboring TRP to be involved in the selected positioning mode comprises:

sending, to a serving base station that is serving the first UE, a request for an updated sounding reference signal (SRS) configuration for the selected positioning mode;

receiving, from the serving base station, an updated SRS configuration for the selected positioning mode; and

selecting the at least one neighboring TRP based at least in part on the updated SRS configuration for the selected positioning mode.

17 . The method of claim 12 , wherein the first information further identifies a set of one or more recommended TRPs and wherein selecting the at least one neighboring TRP comprises selecting at least one TRP from the set of one or more recommended TRPs.

18 . The method of claim 12 , further comprising:

instructing the at least one neighboring TRP to stop measuring positioning signal transmissions from the first UE; and

instructing a serving node that is serving the first UE to start measuring positioning reference signals from the at least one TRP, and to start reporting, to the positioning entity, a set of measurements comprising at least one time delay between receiving a PRS from the at least one TRP and receiving the second positioning signal from the first UE.

19 . The method of claim 18 , further comprising:

receiving the set of measurements from the serving node; and

estimating a position of the first UE based on the set of measurements.

20 . A user equipment (UE), comprising:

a memory;

at least one transceiver; and

at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:

send, via the at least one transceiver, to a first entity, first information indicating a maximum number of positioning signal transmissions that the UE can support, a maximum power for positioning signal transmissions that the UE can support, or both;

receive, via the at least one transceiver, from the first entity, configuration information for changing a positioning mode of the UE to a selected positioning mode selected from a first positioning mode and a second positioning mode; and

perform a positioning operation according to the selected positioning mode, wherein in the first positioning mode, the at least one processor is configured to receive a first positioning signal from a first transmission/reception point (TRP) identified by the configuration information, send a second positioning signal to the first TRP, and report, to the first entity, a time delay between receiving the first positioning signal and sending the second positioning signal, and wherein in the second positioning mode, the at least one processor is configured to receive the first positioning signal from the first TRP identified by the configuration information, send a second positioning signal to a second TRP identified by the configuration information, and report, to the first entity, the time delay between receiving the first positioning signal and sending the second positioning signal.

21 . The UE of claim 20 , wherein the first entity comprises a location server, a serving base station, or a primary or relay positioning peer UE.

22 . The UE of claim 20 , wherein at least one of the first TRP and the second TRP comprises a base station or a positioning peer UE.

23 . The UE of claim 20 , wherein the selected positioning mode comprises the first positioning mode.

24 . The UE of claim 23 , wherein the first TRP comprises a base station, the first positioning signal comprises a downlink positioning reference signal (DL-PRS), and the second positioning signal comprises an uplink sounding reference signal (UL-SRS).

25 . The UE of claim 23 , wherein the first TRP comprises a positioning peer UE, the first positioning signal comprises a first sidelink positioning reference signal (SL-PRS), and the second positioning signal comprises a second SL-PRS.

26 . The UE of claim 20 , wherein the selected positioning mode comprises the second positioning mode.

27 . The UE of claim 26 , wherein the first TRP comprises a first base station, the first positioning signal comprises a downlink positioning reference signal (DL-PRS), the second TRP comprises a second base station, and the second positioning signal comprises an uplink sounding reference signal (UL-SRS).

28 . The UE of claim 26 , wherein the first TRP comprises a first positioning peer UE, the first positioning signal comprises a first sidelink positioning reference signal (SL-PRS), the second TRP comprises a second positioning peer UE, and the second positioning signal comprises a second SL-PRS.

29 . The UE of claim 20 , wherein the first information further identifies a set of one or more TRP for which the UE measures pathloss reference signals, spatial transmit beam reference signals, or both.

30 . The UE of claim 20 , wherein the first information indicates a start time, an end time, a duration, a periodicity, an offset, or a combination thereof, during which the maximum number of positioning signal transmissions that the UE can support or the maximum power for positioning signal transmissions that the UE can support will apply.

31 . A positioning entity, comprising:

a memory;

at least one transceiver; and

at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:

receive, via the at least one transceiver, from a first user equipment (UE), first information indicating a maximum number of positioning signal transmissions that the UE can support, a maximum power for positioning signal transmissions that the first UE can support, or both;

select, based on the first information, a positioning mode for the first UE, wherein the selected positioning mode is selected from a first positioning mode, in which the UE is configured to receive a first positioning signal from a first transmission/reception point (TRP), to send a second positioning signal to the first TRP, and to report, to the positioning entity, a time delay between receiving the first positioning signal and the second positioning signal, and a second positioning mode, in which the UE is configured to receive the first positioning signal from the first TRP, to send a second positioning signal to a second TRP, and to report, to the positioning entity, the time delay between receiving the first positioning signal and sending the second positioning signal;

select at least one neighboring TRP to be involved in the selected positioning mode as at least the first TRP; and

send, via the at least one transceiver, to the first UE, configuration information for changing a positioning mode of the UE to the selected positioning mode, the configuration information identifying the at least one neighboring TRP.

32 . The positioning entity of claim 31 , wherein the positioning entity comprises a location server or a positioning peer UE.

33 . The positioning entity of claim 32 , wherein at least one of the positioning signal transmissions that the first UE can support comprises a sounding reference signal (SRS) or a sidelink positioning reference signal (SL-PRS).

34 . The positioning entity of claim 32 , wherein, to select the at least one neighboring TRP, the at least one processor is configured to select at least one neighboring base station or positioning peer UE.

35 . The positioning entity of claim 32 , wherein, to select the at least one neighboring TRP to be involved in the selected positioning mode, the at least one processor is configured to:

send, via the at least one transceiver, to a serving base station that is serving the first UE, a request for an updated sounding reference signal (SRS) configuration for the selected positioning mode;

receive, via the at least one transceiver, from the serving base station, an updated SRS configuration for the selected positioning mode; and

select the at least one neighboring TRP based at least in part on the updated SRS configuration for the selected positioning mode.

36 . The positioning entity of claim 31 , wherein the first information further identifies a set of one or more recommended TRPs and wherein selecting the at least one neighboring TRP comprises selecting at least one TRP from the set of one or more recommended TRPs.

37 . The positioning entity of claim 31 , wherein the at least one processor is further configured to:

instruct the at least one neighboring TRP to stop measuring positioning signal transmissions from the first UE; and

instruct a serving node that is serving the first UE to start measuring positioning reference signals from the at least one TRP, and to start reporting, to the positioning entity, a set of measurements comprising at least one time delay between receiving a PRS from the at least one TRP and receiving the second positioning signal from the first UE.

38 . The positioning entity of claim 37 , wherein the at least one processor is further configured to:

receive, via the at least one transceiver, the set of measurements from the serving node; and

estimate a position of the first UE based on the set of measurements.