Beam ranking for positioning

1. A client device for wireless communication, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the client device to at least:

in response to a received beam ranking indication comprising at least beam specific first reference data and beam ranking criteria for positioning for downlink transmission beams between a network node device and the client device, wherein the beam ranking criteria is based on at least spatial/angular separation, ranking the downlink transmission beams based on the received beam ranking indication;

select at least one downlink transmission beam based on the ranking;

transmit a downlink transmission beam selection indication to the network node device indicating the selected at least one downlink transmission beam; and

in response to a triggering event, determining a need to change beam ranking for downlink transmission beams between the network node device and the client device.

2. The client device according to claim 1 , wherein the triggering event comprises identifying a new synchronization signal block/channel state information reference signal (CSI-RS) or a downlink reference signal with spatial separation above a threshold level.

3. The client device according to claim 2 , wherein the threshold level comprises a threshold level for transmission of an uplink reference signal for positioning.

4. The client device according to claim 1 , wherein the triggering event comprises identifying a new synchronization signal block/channel state information reference signal (CSI-RS) or a downlink reference signal based on at least one of time of flight, received reference signal power, or spatial separation.

5. The client device according to claim 1 , wherein the triggering event comprises identifying a new synchronization signal block/channel state information reference signal (CSI-RS) or a downlink reference signal with at least one of time of flight, received reference signal power, or spatial separation for transmission of an uplink reference signal for positioning.

6. The client device according to claim 1 , wherein the determination of the need to change beam ranking is based on at least one of: a service requirement by the client device, an identification of beams resolvable by the client device, or an indication from a network to change beam ranking.

7. The client device according to claim 1 , wherein the beam specific first reference data comprises at least one of a synchronization signal block with a unique index or a positioning reference signal with a unique index.

8. The client device according to claim 1 , wherein the beam ranking indication is received periodically, semi-persistently or aperiodically.

9. The client device according to claim 1 , wherein the beam ranking criteria for positioning is based on at least one of: received signal information of the downlink transmission beams, angular information of the downlink transmission beams, time information of the downlink transmission beams, velocity information of movement of the client device, direction information of the movement of the client device, or a service requirement of the client device.

10. The client device according to claim 1 , wherein the ranking of the downlink transmission beams comprises at least one of a hierarchic ranking or a weighted ranking.

11. The client device according to claim 1 , wherein the downlink transmission beam selection indication comprises at least one of a beam index of each selected downlink transmission beam, a resource identifier or a resource set identifier associated with each selected downlink transmission beam.

12. The client device according to claim 1 , wherein the downlink transmission beam selection indication comprises a transmission power boosting request for a subset of the selected downlink transmission beams.

13. The client device according to claim 12 , wherein the subset of the downlink transmission beams is selected based on at least one of local information at the client device or network-provided information.

14. The client device according to claim 1 , wherein the second reference data comprises at least one positioning reference signal.

15. The client device according to claim 1 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the client device to at least:

in response to second reference data received from the network node device with at least one downlink transmission beam according to the transmitted downlink transmission beam selection indication, estimate the signal quality of the received second reference data; and

transmit a signal quality estimation indication to the network node device indicating the estimated signal quality of the received second reference data.

16. A method, comprising:

in response to a received beam ranking indication comprising at least beam specific first reference data and beam ranking criteria for positioning for downlink transmission beams between a network node device and a client device, wherein the beam ranking criteria is based on at least spatial/angular separation, ranking, by the client device, the downlink transmission beams based on the received beam ranking indication;

selecting, by the client device, at least one downlink transmission beam based on the ranking;

transmitting, by the client device, a downlink transmission beam selection indication to the network node device indicating the selected at least one downlink transmission beam;

in response to second reference data received from the network node device with at least one downlink transmission beam according to the transmitted downlink transmission beam selection indication, estimating the signal quality of the received second reference data; and

transmitting a signal quality estimation indication to the network node device indicating the estimated signal quality of the received second reference data.