Configuration constraints for sounding reference signals (SRS) for positioning

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

receiving at least one of a first type of sounding reference signal (SRS) configuration from a base station or a second type of SRS configuration from a location server, wherein the first type of SRS configuration is based on a first set of available configurations for SRS received over a first higher layer protocol signaling of a component carrier, wherein the second type of SRS configuration is based on a second set of available configurations for SRS received over a second higher layer protocol signaling, wherein the second set of available configurations for SRS includes SRS configurations not supported by the first set of available configurations for SRS, and wherein the first higher layer protocol signaling is different from the second higher layer protocol signaling; and

transmitting one or more SRS-for-positioning based on the first type of SRS configuration or the second type of SRS configuration.

2. The method of claim 1 , wherein the base station is a serving base station.

3. The method of claim 1 , wherein the first higher layer protocol signaling comprises radio resource control (RRC) signaling.

4. The method of claim 3 , wherein the UE receives the first type of SRS configuration over the RRC signaling based on the UE not operating according to a fifth generation (5G) New Radio (NR) radio access technology (RAT).

5. The method of claim 1 , wherein the second higher layer protocol signaling comprises Long-Term Evolution (LTE) positioning protocol (LPP) signaling.

6. The method of claim 5 , wherein the UE receives the second type of SRS configuration over the LPP signaling based on the UE operating according to a fifth generation (5G) New Radio (NR) radio access technology (RAT).

7. The method of claim 1 , wherein the first set of available configurations for SRS is used at least for positioning purposes.

8. The method of claim 1 , wherein the first set of available configurations for SRS is a subset of the second set of available configurations for SRS.

9. The method of claim 1 , wherein the first set of available configurations for SRS is subject to one or more constraints based on being received over the first higher layer protocol signaling.

10. The method of claim 9 , wherein the one or more constraints comprise:

only uplink time difference of arrival (UL-TDOA) or angle of arrival (AoA) positioning procedures are configured to the UE,

SRS resources are configured without frequency domain staggering across consecutive orthogonal frequency division multiplexing (OFDM) symbols,

spatial relation information is configured to a downlink reference signal from a serving base station,

a path loss reference is configured to a downlink reference signal from the serving base station,

SRS resources are configured only within a bandwidth part configured through RRC,

SRS resources are transmitted only within an active bandwidth part configured through RRC,

SRS resources are only transmitted within a single component carrier in any OFDM symbol, or

any combination thereof.

11. The method of claim 1 , wherein the SRS configurations not supported by the first set of available configurations for SRS comprise:

SRS resources used for a multi-round-trip-time (RTT) positioning procedure,

SRS resources configured with frequency domain staggering across consecutive OFDM symbols,

a path loss reference or spatial relation information derived based on a downlink reference resource received from one or more neighboring transmission-reception points (TRPs),

a higher number of SRS resource sets configured inside the component carrier,

SRS transmitted simultaneously across multiple component carriers in one OFDM symbol,

SRS configured outside a bandwidth part (BWP) of the component carrier,

SRS transmitted outside an active BWP of the component carrier, or

any combination thereof.

12. 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:

receive, via the at least one transceiver, at least one of a first type of sounding reference signal (SRS) configuration from a base station or a second type of SRS configuration from a location server, wherein the first type of SRS configuration is based on a first set of available configurations for SRS received over a first higher layer protocol signaling of a component carrier, wherein the second type of SRS configuration is based on a second set of available configurations for SRS received over a second higher layer protocol signaling, wherein the second set of available configurations for SRS includes SRS configurations not supported by the first set of available configurations for SRS, and wherein the first higher layer protocol signaling is different from the second higher layer protocol signaling; and

cause the at least one transceiver to transmit one or more SRS-for-positioning based on the first type of SRS configuration or the second type of SRS configuration.

13. The UE of claim 12 , wherein the base station is a serving base station.

14. The UE of claim 13 , wherein the second higher layer protocol signaling comprises Long-Term Evolution (LTE) positioning protocol (LPP) signaling.

15. The UE of claim 14 , wherein the UE receives the second type of SRS configuration over the LPP signaling based on the UE operating according to a fifth generation (5G) New Radio (NR) radio access technology (RAT).

16. The UE of claim 12 , wherein the first higher layer protocol signaling comprises radio resource control (RRC) signaling.

17. The UE of claim 16 , wherein the UE receives the first type of SRS configuration over the RRC signaling based on the UE not operating according to a fifth generation (5G) New Radio (NR) radio access technology (RAT).

18. The UE of claim 12 , wherein the first set of available configurations for SRS is used at least for positioning purposes.

19. The UE of claim 12 , wherein the first set of available configurations for SRS is a subset of the second set of available configurations for SRS.

20. The UE of claim 12 , wherein the first set of available configurations for SRS is subject to one or more constraints based on being received over the first higher layer protocol signaling.

21. The UE of claim 20 , wherein the one or more constraints comprise:

only uplink time difference of arrival (UL-TDOA) or angle of arrival (AoA) positioning procedures are configured to the UE,

SRS resources are configured without frequency domain staggering across consecutive orthogonal frequency division multiplexing (OFDM) symbols,

spatial relation information is configured to a downlink reference signal from a serving base station,

a path loss reference is configured to a downlink reference signal from the serving base station,

SRS resources are configured only within a bandwidth part configured through RRC,

SRS resources are transmitted only within an active bandwidth part configured through RRC,

SRS resources are only transmitted within a single component carrier in any OFDM symbol, or

any combination thereof.

22. The UE of claim 12 , wherein the SRS configurations not supported by the first set of available configurations for SRS comprise:

SRS resources used for a multi-round-trip-time (RTT) positioning procedure,

SRS resources configured with frequency domain staggering across consecutive OFDM symbols,

a path loss reference or spatial relation information derived based on a downlink reference resource received from one or more neighboring transmission-reception points (TRPs),

a higher number of SRS resource sets configured inside the component carrier,

SRS transmitted simultaneously across multiple component carriers in one OFDM symbol,

SRS configured outside a bandwidth part (BWP) of the component carrier,

SRS transmitted outside an active BWP of the component carrier, or

any combination thereof.

23. A user equipment (UE), comprising:

means for receiving at least one of a first type of sounding reference signal (SRS) configuration from a base station or a second type of SRS configuration from a location server, wherein the first type of SRS configuration is based on a first set of available configurations for SRS received over a first higher layer protocol signaling of a component carrier, wherein the second type of SRS configuration is based on a second set of available configurations for SRS received over a second higher layer protocol signaling, wherein the second set of available configurations for SRS includes SRS configurations not supported by the first set of available configurations for SRS, and wherein the first higher layer protocol signaling is different from the second higher layer protocol signaling; and

means for transmitting one or more SRS-for-positioning based on the first type of SRS configuration or the second type of SRS configuration.

24. The UE of claim 23 , wherein:

the base station is a serving base station, and

the first higher layer protocol signaling comprises radio resource control (RRC) signaling.

25. The UE of claim 23 , wherein:

the second higher layer protocol signaling comprises Long-Term Evolution (LTE) positioning protocol (LPP) signaling.

26. A non-transitory computer-executable medium storing computer-executable instructions, the computer-executable instructions comprising:

at least one instruction instructing a user-equipment (UE) to receive at least one of a first type of sounding reference signal (SRS) configuration from a base station or a second type of SRS configuration from a location server, wherein the first type of SRS configuration is based on a first set of available configurations for SRS received over a first higher layer protocol signaling of a component carrier, wherein the second type of SRS configuration is based on a second set of available configurations for SRS received over a second higher layer protocol signaling, wherein the second set of available configurations for SRS includes SRS configurations not supported by the first set of available configurations for SRS, and wherein the first higher layer protocol signaling is different from the second higher layer protocol signaling; and

at least one instruction instructing the UE to transmit one or more SRS-for-positioning based on the first type of SRS configuration or the second type of SRS configuration.