Methods and apparatuses to account for timing errors of a user equipment in positioning measurements
Methods and apparatuses provide a mechanism to account for timing errors of a wireless device ( 12 ) in positioning measurements. In one example, a wireless device ( 12 ) performs reference-signal transmissions or measurements and sends information to a network node ( 20 ) that is involved in positioning of the wireless device ( 12 ). The information indicates associations of the reference-signal transmissions or measurements with respective timing groups of the wireless device ( 12 ). Each timing group represents a related set of transmission or reception timing errors within the wireless device ( 12 ). Based on the information, the network node ( 20 ) accounts for the different timing-group associations when performing positioning calculations that are based on the reference-signal transmissions or measurements performed by the wireless device ( 12 ).
1. A method performed by a wireless device, the method comprising:
performing reference-signal transmissions or measurements, for positioning of the wireless device; and
transmitting information for a network node involved in the positioning of the wireless device, the information indicating associations of the reference-signal transmissions or measurements with respective timing groups of the wireless device, each timing group representing a related set of transmission or reception timing errors within the wireless device.
2. The method of claim 1 , wherein each related set of transmission or reception timing errors are transmission or reception timing errors that are related based on having relative timing-error differences that are smaller than a maximum.
3. The method of claim 1 , wherein the transmission or reception timing errors within the wireless device are related to path-delay or timing-reference differences among multiple transmitter or receiver branches within the wireless device.
4. The method of claim 1 , wherein reference-signal transmissions or measurements involving different antennas of the wireless device have different timing-group associations.
5. The method of claim 1 , wherein reference-signal transmissions or measurements involving the same antenna of the wireless device have the same timing-group association.
6. The method of claim 1 , wherein performing the reference-signal transmissions or measurements comprises measuring times of arrival for downlink reference signals from two or more transmission points of a wireless communication network associated with the network node, wherein the wireless device transmits a time-difference-of-arrival (TDOA) report containing reference signal time difference (RSTD) measurements for respective pairs of the two or more transmission points.
7. The method of claim 6 , wherein transmitting the information comprises including the information in the TDOA report, the information indicating timing-group associations of the time-of-arrival measurements used to determine the RSTD measurements.
8. The method of claim 1 , wherein performing the reference-signal transmissions or measurements comprises determining reception/transmission (RX/TX) time differences, and wherein the information indicates the timing-group associations of the RX/TX time differences.
9. The method of claim 1 , wherein performing the reference-signal transmissions or measurements comprises performing uplink sounding reference signal (SRS) transmissions, and wherein the information indicates the timing-error-group associations of the uplink SRS transmissions.
10. The method of claim 9 , wherein performing the uplink SRS transmissions comprises transmitting on respective SRS resources, and wherein the information indicates the timing-group associations of the respective SRS resources.
11. The method of claim 1 , wherein performing the reference-signal transmissions or measurements comprises performing downlink time difference of arrival (TDOA) measurements for downlink reference signals received at the wireless device, and transmitting uplink reference signals from the wireless device, and wherein the information indicates the timing-group associations of the downlink TDOA measurements and indicates the timing-group associations of the uplink reference-signals.
12. The method of claim 1 , wherein the wireless device has multiple antenna panels, with each antenna panel comprising an array of antenna elements for transmit or receive beamforming, and with each antenna panel corresponding to a different timing group.
13. A wireless device comprising:
communication interface circuitry; and
processing circuitry configured to use the communication interface circuitry to:
perform reference-signal transmissions or measurements, for positioning of the wireless device; and
transmit information for a network node involved in the positioning of the wireless device, the information indicating associations of the reference-signal transmissions or measurements with respective timing groups of the wireless device, each timing group representing a related set of transmission or reception timing errors within the wireless device.
14. A method performed by a network node, the method comprising:
receiving information transmitted by a wireless device, wherein the information indicates associations of reference-signal transmissions or measurements by the wireless device with respective timing groups of the wireless device, each timing group representing a related set of transmission or reception timing errors within the wireless device.
15. The method of claim 14 , further comprising:
accounting for the different timing-group associations when performing positioning calculations that are based on the reference-signal transmissions or measurements performed by the wireless device.
16. The method of claim 14 , wherein a plurality of timing errors are related if the relative differences in timing errors among them do not exceed some maximum value.
17. The method of claim 14 , wherein the wireless device includes a respective plurality of receiver or transmitter chains associated with each antenna among a plurality of antennas of the wireless device.
18. The method of claim 17 , wherein one or more characteristic timing errors are common, or within a defined range of relative differences, in each respective plurality of receiver or transmitter chains, such that each respective plurality forms one of the respective timing groups.
19. The method of claim 14 , wherein the method is performed by a location management function.
20. A system comprising:
a wireless device comprising:
communication interface circuitry; and
processing circuitry configured to use the communication interface circuitry to:
perform reference-signal transmissions or measurements, for positioning of the wireless device; and
transmit information for a network node involved in the positioning of the wireless device, the information indicating associations of the reference-signal transmissions or measurements with respective timing groups of the wireless device, each timing group representing a related set of transmission or reception timing errors within the wireless device; and
the network node, which comprises:
communication interface circuitry configured to receive the information transmitted by the wireless device; and
processing circuitry configured to account for the different timing-group associations when performing positioning calculations that are based on the reference-signal transmissions or measurements performed by the wireless device.