Measurement period formulation for reference signal time difference (RSTD) measurements
Disclosed are techniques for wireless positioning. In an aspect, a user equipment (UE) receives a positioning reference signal (PRS) configuration, the PRS configuration including at least a PRS periodicity defining repetitions of one or more PRS resources associated with at least a first transmission-reception point (TRP), receives a measurement gap configuration including at least a measurement gap repetition period (MGRP) defining repetitions of a measurement gap, and performs one or more positioning measurements of at least the one or more PRS resources during one or more repetitions of a measurement period, the one or more repetitions of the measurement period having an effective measurement periodicity, the effective measurement periodicity based on an alignment periodicity and a time period T during which the UE can process a duration N of PRS symbols, the alignment periodicity based on the PRS periodicity and the MGRP.
1. A method of positioning performed by a location server, comprising:
transmitting, to a user equipment, a reference signal configuration for at least a first transmission-reception point (TRP), the reference signal configuration including at least a reference signal periodicity defining repetitions of one or more downlink reference signal resources usable for positioning associated with the first TRP; and
receiving, from the UE, one or more positioning measurements of at least the one or more downlink reference signal resources obtained by the UE during one or more repetitions of a measurement period, the one or more repetitions of the measurement period having an effective measurement periodicity, the effective measurement periodicity based on an alignment periodicity and a time period T during which the UE can process a duration N of reference signal symbols, the alignment periodicity based on the reference signal periodicity and a measurement gap repetition period (MGRP) defining repetitions of a measurement gap.
2. The method of claim 1 , wherein the effective measurement periodicity is the alignment periodicity multiplied by a ceiling function of the time period T divided by the alignment periodicity.
3. The method of claim 1 , wherein the measurement period is determined for each positioning frequency layer of one or more positioning frequency layers on which the UE is configured to measure reference signals.
4. The method of claim 1 , wherein the alignment periodicity and the effective measurement periodicity are determined for each positioning frequency layer of one or more positioning frequency layers on which the UE is configured to measure reference signals.
5. The method of claim 1 , wherein the time period T, the reference signal periodicity, and the MGRP are determined for each positioning frequency layer of one or more positioning frequency layers on which the UE is configured to measure reference signals.
6. The method of claim 1 , wherein the alignment periodicity is based on an integer multiple of the reference signal periodicity and the MGRP.
7. The method of claim 1 , wherein the one or more positioning measurements are expected to meet an accuracy requirement.
8. A location server, 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:
transmit, to a user equipment (UE) via the one or more transceivers, a reference signal configuration for at least a first transmission-reception point (TRP), the reference signal configuration including at least a reference signal periodicity defining repetitions of one or more downlink reference signal resources usable for positioning associated with the first TRP; and
receive, from the UE, one or more positioning measurements of at least the one or more downlink reference signal resources during one or more repetitions of a measurement period, the one or more repetitions of the measurement period having an effective measurement periodicity, the effective measurement periodicity based on an alignment periodicity and a time period T during which the UE can process a duration N of reference signal symbols, the alignment periodicity based on the reference signal periodicity and a measurement gap repetition period (MGRP) defining repetitions of a measurement gap.
9. The location server of claim 8 , wherein the effective measurement periodicity is the alignment periodicity multiplied by a ceiling function of the time period T divided by the alignment periodicity.
10. The location server of claim 8 , wherein the measurement period is determined for each positioning frequency layer of one or more positioning frequency layers on which the UE is configured to measure reference signals.
11. The location server of claim 8 , wherein the alignment periodicity and the effective measurement periodicity are determined for each positioning frequency layer of one or more positioning frequency layers on which the UE is configured to measure reference signals.
12. The location server of claim 8 , wherein the time period T, the reference signal periodicity, and the MGRP are determined for each positioning frequency layer of one or more positioning frequency layers on which the UE is configured to measure reference signals.
13. The location server of claim 8 , wherein the alignment periodicity is based on an integer multiple of the reference signal periodicity and the MGRP.
14. The location server of claim 13 , wherein the integer multiple of the reference signal periodicity is 20, 40, 80, 160, or 320 milliseconds (ms) or the reference signal periodicity based on a value of the reference signal periodicity.
15. The location server of claim 14 , wherein the integer multiple of the reference signal periodicity is:
20 ms based on the value of the reference signal periodicity being 10 ms, 20 ms, or less than or equal to 5 ms,
40 ms based on the value of the reference signal periodicity being 8 ms or 40 ms,
80 ms based on the value of the reference signal periodicity being 16 ms or 80 ms,
160 ms based on the value of the reference signal periodicity being 32 ms or 160 ms,
320 ms based on the value of the reference signal periodicity being 64 ms, or
the reference signal periodicity based on the value of the reference signal periodicity being greater than or equal to 320 ms.
16. The location server of claim 8 , wherein the one or more positioning measurements are expected to meet an accuracy requirement.
17. The location server of claim 8 , wherein a start of the one or more downlink reference signal resources occurs at the same time offset inside the measurement gap.
18. The location server of claim 8 , wherein the reference signal configuration is received from a location server in Long-Term Evolution (LTE) positioning protocol (LPP) assistance data.
19. The location server of claim 8 , wherein the measurement gap configuration is received from the serving base station via radio resource control (RRC) signaling.
20. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a location server, cause the location server to:
transmit, to a user equipment (UE), a reference signal configuration for at least a first transmission-reception point (TRP), the reference signal configuration including at least a reference signal periodicity defining repetitions of one or more downlink reference signal resources usable for positioning associated with the first TRP; and
receive, from the UE, one or more positioning measurements of at least the one or more downlink reference signal resources during one or more repetitions of a measurement period, the one or more repetitions of the measurement period having an effective measurement periodicity, the effective measurement periodicity based on an alignment periodicity and a time period T during which the UE can process a duration N of reference signal symbols, the alignment periodicity based on the reference signal periodicity and a measurement gap repetition period (MGRP) defining repetitions of a measurement gap.