Identifying and reporting beams of interest for position estimation
Disclosed are techniques for identifying beams of interest for position estimation. In an aspect, a first node receives, from a second node, a plurality of beams, determines a time of arrival of each beam, identifies one or more beams of interest for determining a position estimate based on the times of arrival, and sends, to the second node, a report identifying each of the one or more beams of interest. A second node transmits, to a first node, a plurality of beams, receives a report identifying one or more beams of interest for determining a position estimate of the first node, wherein the one or more beams of interest are a subset of the plurality of beams, and transmits, in response to receiving the report, at least one beam carrying position reference signals for the second node in a same direction as the one or more beams of interest.
1. A method for reporting beams of interest for positioning measurements, comprising: receiving, at a user equipment (UE) from a base station, a plurality of beams, wherein receiving the plurality of beams comprises detecting one or more channel taps corresponding to each of the plurality of beams; determining, by the UE, a time of arrival of each beam of the plurality of beams; identifying, by the UE from the plurality of beams, one or more beams of interest for determining a positioning measurement of the base station based on the times of arrival of the plurality of beams; sending, by the UE to the base station, a report including identifiers of each of the one or more beams of interest; and receiving, at the UE from the base station, based on the report identifying each of the one or more beams of interest, at least one beam carrying positioning reference signals for the base station in a same direction as a direction of the one or more beams of interest.
2. The method of claim 1 , wherein receiving the plurality of beams comprises receiving signals for each of the plurality of beams at the UE and processing the signals to detect the one or more channel taps corresponding to each of the plurality of beams, and wherein the time of arrival is determined based on an earliest detected channel tap of each of the plurality of beams.
3. The method of claim 1 , wherein each beam of the plurality of beams is associated with a beam index, and wherein the report identifies the one or more beams of interest using the beam index associated with each of the one or more beams of interest.
4. The method of claim 1 , wherein each of the one or more beams of interest have an earlier time of arrival at the UE than remaining beams of the plurality of beams.
5. The method of claim 3 , wherein the one or more beams of interest comprises one beam of the plurality of beams having an earliest time of arrival at the UE.
6. The method of claim 3 , wherein each of the one or more beams of interest has a time of arrival before a threshold delay from an earliest time of arrival of a beam of the plurality of beams.
7. The method of claim 1 , wherein at least one of the plurality of beams other than the one or more beams of interest has a higher signal strength than a signal strength of the one or more beams of interest.
8. The method of claim 1 , wherein the plurality of beams arrive at the UE from different angles.
9. The method of claim 1 , wherein the UE receives the plurality of beams on an extremely high frequency (EHF) band.
10. The method of claim 9 , wherein the EHF band comprises a millimeter wave (mmW) frequency band.
11. The method of claim 1 , wherein each of the plurality of beams carries synchronization signals for the base station.
12. The method of claim 11 , wherein receiving the at least one beam comprises: receiving, at the UE from the base station, the one or more beams of interest, wherein the one or more beams of interest are updated, after the report is sent, to carry the positioning reference signals for the base station instead of the synchronization signals.
13. The method of claim 11 , wherein the at least one beam comprises at least one additional beam in addition to the one or more beams of interest, and wherein the at least one additional beam carries the positioning reference signals for the base station.
14. The method of claim 11 , wherein the at least one beam comprises at least one additional beam instead of the one or more beams of interest, and wherein the at least one additional beam carries the positioning reference signals for the base station.
15. A method for transmitting beams of interest for position estimation, comprising: transmitting, to a user equipment (UE) by a base station, a plurality of beams;
receiving, at the base station from the UE, a report including identifiers of one or more beams of interest for determining a position estimate of the UE, wherein the one or more beams of interest are a subset of the plurality of beams, and wherein each of the one or more beams of interest has an earlier time of arrival at the UE than remaining beams of the plurality of beams; and
transmitting, to the UE by the base station, in response to receiving the report, at least one beam carrying positioning reference signals for the base station in a same direction as a direction of the one or more beams of interest.
16. The method of claim 15 , wherein each beam of the plurality of beams is associated with a beam index, and wherein the report identifies the one or more beams of interest using the beam index associated with each of the one or more beams of interest.
17. The method of claim 15 , wherein at least one of the plurality of beams other than the one or more beams of interest has a higher signal strength than a signal strength of the one or more beams of interest.
18. The method of claim 15 , wherein the base station transmits the plurality of beams at different angles.
19. The method of claim 15 , wherein the base station transmits the plurality of beams on an extremely high frequency (EHF) band.
20. The method of claim 15 , wherein the base station transmits synchronization signals for communication with the base station on each of the plurality of beams.
21. The method of claim 20 , wherein the at least one beam comprises the one or more beams of interest updated to carry positioning reference signals for the base station instead of the synchronization signals.
22. The method of claim 20 , wherein the at least one beam comprises at least one additional beam in addition to the one or more beams of interest, and wherein the at least one additional beam carries positioning reference signals for the base station.
23. The method of claim 20 , wherein the at least one beam comprises at least one additional beam instead of the one or more beams of interest, and wherein the at least one additional beam carries positioning reference signals for the base station.
24. An apparatus for reporting beams of interest for positioning measurements, comprising:
at least one transceiver of a user equipment (UE) configured to receive, from a base station, a plurality of beams, wherein reception of the plurality of beams comprises detection of one or more channel taps corresponding to each of the plurality of beams; and
at least one processor of the UE configured to:
determine a time of arrival of each beam of the plurality of beams;
identify, from the plurality of beams, one or more beams of interest for determining a positioning measurement of the base station based on the times of arrival of the plurality of beams;
cause the at least one transceiver to send, to the base station, a report including identifiers of each of the one or more beams of interest; and
receive, from the base station via the at least one transceiver, based on the report identifying each of the one or more beams of interest, at least one beam carrying positioning reference signals for the base station in a same direction as a direction of the one or more beams of interest.
25. An apparatus for transmitting beams of interest for position estimation, comprising:
a transmitter of a base station configured to transmit, to a user equipment (UE), a plurality of beams; and
a receiver of the base station configured to receive, from the UE, a report including identifiers of one or more beams of interest for determining a position estimate of the UE, wherein the one or more beams of interest are a subset of the plurality of beams, wherein each of the one or more beams of interest has an earlier time of arrival at the UE than remaining beams of the plurality of beams, and
wherein the transmitter is further configured to transmit, to the UE, in response to reception of the report, at least one beam carrying positioning reference signals for the base station in a same direction as a direction of the one or more beams of interest.
26. The method of claim 1 , further comprising:
measuring the positioning reference signals carried on the at least one beam to obtain the positioning measurement of the base station.