Sounding reference signal (SRS) resource and resource set configurations for positioning
Disclosed are techniques for using sounding reference signal (SRS) for positioning. In an aspect, a UE receives an SRS configuration, the SRS configuration defining one or more SRS resource sets, each SRS resource set comprising one or more SRS resources, and each SRS resource comprising one or more SRS ports, wherein at least one SRS port of at least one SRS resource of at least one SRS resource set defined in the SRS configuration is usable by the UE at least for positioning. The UE transmits a positioning SRS utilizing one or more positioning SRS ports, wherein the positioning SRS is transmitted in a positioning SRS pattern such that across N consecutive symbols, where N is greater than or equal to two, SRS resource elements (REs) to which the one or more positioning SRS ports are mapped are staggered in frequency and use each of the N consecutive symbols.
1. A user equipment (UE), comprising:
one or more memories;
one or more transceivers; and
one or more processors coupled to the one or more memories and the one or more transceivers, wherein the one or more processors, either alone or in combination, are configured to:
receive, via the one or more transceivers, a sounding reference signal (SRS) configuration from a cell, the SRS configuration defining one or more positioning SRS resource sets, each positioning SRS resource set comprising one or more positioning SRS resources; and
transmit, via the one or more transceivers, a positioning SRS as an uplink positioning signal, wherein the positioning SRS is transmitted in a positioning SRS pattern such that across N consecutive symbols, where N is greater than or equal to two, SRS resource elements (REs) of the positioning SRS are staggered in frequency and use each of the N consecutive symbols, and wherein the SRS REs are such that across N consecutive symbols over N consecutive subcarriers, each of the N consecutive symbols is used once and each of the N consecutive subcarriers is used once.
2. The UE of claim 1 , wherein the SRS REs of the positioning SRS are mapped to the N consecutive symbols such that all N comb offsets are used.
3. The UE of claim 2 , wherein the SRS REs of the positioning SRS are mapped to the N consecutive symbols over N consecutive subcarriers such that each of the N comb offsets is used once and each of the N consecutive subcarriers is used once.
4. The UE of claim 1 , wherein:
at least one of the one or more SRS resource sets comprises N consecutive positioning SRS resources, each positioning SRS resource being M symbols in duration, where M is greater than or equal to 1, such that the N consecutive positioning SRS resources correspond to N*M consecutive symbols, and
SRS REs in the M symbols are mapped such that across the N consecutive positioning SRS resources, the mapped SRS REs are staggered in frequency, and within the M symbols of each positioning SRS resource, the SRS REs are not staggered in frequency.
5. The UE of claim 4 , wherein the SRS REs are mapped across the N consecutive positioning SRS resources over N consecutive subcarriers such that each of the N consecutive symbols is used once and each of the N consecutive subcarriers is used once.
6. The UE of claim 4 , wherein the N consecutive positioning SRS resources are transmitted in a same slot.
7. The UE of claim 4 , wherein a same port index of the N consecutive positioning SRS resources are quasi-collocated across the N consecutive positioning SRS resources.
8. The UE of claim 1 , wherein no aperiodic SRS transmission is allowed for the positioning SRS based on the positioning SRS being an SRS resource used for positioning purposes and for communication purposes.
9. The UE of claim 1 , wherein no semi-persistent SRS transmission is allowed for the positioning SRS based on the positioning SRS being an SRS resource used for positioning purposes and for communication purposes.
10. The UE of claim 1 , wherein, based on the positioning SRS being an SRS resource used for both communication and positioning purposes in a first SRS resource set and used for communication purposes only in a second SRS resource set, and based on the SRS resource colliding on a same symbol, the SRS resource used for both communication and positioning purposes is prioritized over the SRS resource used for communication purposes only.
11. The UE of claim 1 , wherein, based on the positioning SRS being an SRS resource used for both communication and positioning purposes in a first SRS resource set and used for positioning purposes only in a second SRS resource set, and based on the SRS resource colliding on a same symbol, the SRS resource used for both communication and positioning purposes is prioritized over the SRS resource used for positioning purposes only.
12. The UE of claim 1 , wherein, based on the positioning SRS being an SRS resource used for communication purposes only in a first SRS resource set and used for positioning purposes only in a second SRS resource set, and based on the SRS resource colliding on a same symbol, the SRS resource used for communication purposes only is prioritized over the SRS resource used for positioning purposes only.
13. The UE of claim 1 , wherein a sequence used for transmission of an SRS resource used for positioning purposes differs from a sequence used for transmission of an SRS resource used for communication purposes only.
14. The UE of claim 13 , wherein the sequence used for transmission of the SRS resource used for positioning purposes is pi/2-BPSK (binary phase shift keying) based.
15. The UE of claim 13 , wherein an initialization of the sequence used for transmission of the SRS resource used for positioning purposes is based on a different sequence initialization number than an initialization of the sequence used for transmission of the SRS resource used for communication purposes only.
16. The UE of claim 1 , wherein a positioning SRS resource of the positioning SRS spans more than a last six symbols of a slot.
17. The UE of claim 16 , wherein the positioning SRS resource spans all symbols of the slot.
18. The UE of claim 17 , wherein the positioning SRS resource is repeated to all symbols of the slot.
19. The UE of claim 1 , wherein a comb offset changes in every symbol of a slot in a round robin manner.
20. The UE of claim 1 , wherein a positioning SRS resource appears before a physical uplink shared channel (PUSCH) in a slot.
21. The UE of claim 1 , wherein, based on the positioning SRS being an SRS resource used for communication purposes in a first SRS resource set and used for positioning purposes in a second SRS resource set, the positioning SRS is transmitted using a transmit (Tx) power and power control parameters that follow a power control loop of the first SRS resource set.
22. The UE of claim 1 , wherein, based on the positioning SRS being an SRS resource used for positioning purposes only, the UE supports open loop power control and does not support closed loop power control.
23. The UE of claim 1 , wherein the UE does not respond to any power control commands from the cell received within a threshold period of time from a start of transmission of the positioning SRS.
24. The UE of claim 23 , wherein the threshold period of time is:
a number of slots, or
a number of frames.
25. A method performed by a user equipment (UE), comprising:
receiving a sounding reference signal (SRS) configuration from a cell, the SRS configuration defining one or more positioning SRS resource sets, each positioning SRS resource set comprising one or more positioning SRS resources; and
transmitting a positioning SRS as an uplink positioning signal, wherein the positioning SRS is transmitted in a positioning SRS pattern such that across N consecutive symbols, where N is greater than or equal to two, SRS resource elements (REs) of the positioning SRS are staggered in frequency and use each of the N consecutive symbols, and wherein the SRS REs are such that across N consecutive symbols over N consecutive subcarriers, each of the N consecutive symbols is used once and each of the N consecutive subcarriers is used once.
26. The method of claim 25 , wherein a comb offset changes in every symbol of a slot in a round robin manner.
27. A user equipment (UE), comprising:
means for receiving a sounding reference signal (SRS) configuration from a cell, the SRS configuration defining one or more positioning SRS resource sets, each positioning SRS resource set comprising one or more positioning SRS resources; and
means for transmitting a positioning SRS as an uplink positioning signal, wherein the positioning SRS is transmitted in a positioning SRS pattern such that across N consecutive symbols, where N is greater than or equal to two, SRS resource elements (REs) of the positioning SRS are staggered in frequency and use each of the N consecutive symbols, and wherein the SRS REs are such that across N consecutive symbols over N consecutive subcarriers, each of the N consecutive symbols is used once and each of the N consecutive subcarriers is used once.
28. The UE of claim 27 , wherein a comb offset changes in every symbol of a slot in a round robin manner.
29. A non-transitory computer-readable medium stores computer-executable instructions that, when executed by a user equipment (UE), cause the UE to:
receive a sounding reference signal (SRS) configuration from a cell, the SRS configuration defining one or more positioning SRS resource sets, each positioning SRS resource set comprising one or more positioning SRS resources; and
transmit a positioning SRS as an uplink positioning signal, wherein the positioning SRS is transmitted in a positioning SRS pattern such that across N consecutive symbols, where N is greater than or equal to two, SRS resource elements (REs) of the positioning SRS are staggered in frequency and use each of the N consecutive symbols, and wherein the SRS REs are such that across N consecutive symbols over N consecutive subcarriers, each of the N consecutive symbols is used once and each of the N consecutive subcarriers is used once.