Reconfigurable intelligent surface (RIS) aided non-terrestrial network (NTN) user equipment (UE) positioning
Disclosed are systems, apparatuses, processes, and computer-readable media for wireless communications. For example, an example of a process may include a RIS that can receive, from a satellite, a positioning reference signal. The RIS can further reflect the positioning reference signal to produce a reflection positioning reference signal radiated towards a network device for positioning of the network device.
1 . A reconfigurable intelligent surface (RIS) for wireless communication, the RIS comprising:
at least one transceiver configured to receive, from a satellite, a positioning reference signal; and
at least one element configured to reflect the positioning reference signal to produce a reflection positioning reference signal radiated towards a network device for positioning of the network device,
where the at least one transceiver is configured to receive, from a network entity, a data signal comprising assistance data, wherein the assistance data comprises at least one of a watermark identification (ID) for the reflection positioning reference signal, a positioning reference signal (PRS) ID associated with the watermark ID, a timer for the network device to switch between positioning detection modes, or a quasi-colocation configuration (QCL) between synchronization signal blocks (SSBs) and positioning reference signals (PRSs) for the positioning of the network device; and
the at least one element is configured to reflect the data signal to produce a reflection data signal radiated towards the network device.
2 . The RIS of claim 1 , wherein the network device is user equipment (UE).
3 . The RIS of claim 1 , wherein the satellite is a low earth orbiting (LEO) satellite.
4 . The RIS of claim 1 , wherein the positioning reference signal is a positioning reference signal (PRS).
5 . The RIS of claim 1 , wherein the network entity is a network server.
6 . The RIS of claim 1 , wherein the data signal is a system information block (SIB) signal.
7 . The RIS of claim 1 , wherein the watermark ID is one of a RIS on-off pattern or a RIS specific phase.
8 . The RIS of claim 1 , wherein the positioning detection modes comprise a first positioning detection mode of detecting positioning signals directly transmitted from the satellite to the network device, and a second positioning detection mode of detecting positioning signals transmitted from the satellite to the network device via the RIS.
9 . The RIS of claim 1 , wherein:
the at least one transceiver is configured to receive, from a network entity, a beam adaptation signal comprising beam adaptation information; and
the at least one element is configured to reflect the beam adaptation signal to produce a reflection beam adaptation signal radiated towards the network device.
10 . The RIS of claim 9 , wherein the beam adaptation information comprises RIS downlink (DL) positioning beam pattern information with time stamps, and wherein the RIS DL positioning beam pattern information comprises the reflection positioning reference signal.
11 . The RIS of claim 9 , wherein the beam adaptation information comprises one or more sets of beams, wherein each of the one or more sets of beams comprises a network device uplink (UL) positioning beam to align with a RIS downlink (DL) positioning beam.
12 . The RIS of claim 9 , wherein the beam adaptation information comprises an angle of departure (AoD) for a network device uplink (UL) positioning beam to align with the reflection positioning reference signal.
13 . The RIS of claim 9 , wherein the beam adaptation information comprises a relative angle difference between an angle of departure (AoD) for a network device uplink (UL) positioning beam to align with the reflection positioning reference signal.
14 . The RIS of claim 1 , further comprising at least one processor configured to dynamically apply, to the RIS, a pair of voltages to fix a direction of the reflection positioning reference signal to align with a network device uplink (UL) positioning beam.
15 . The RIS of claim 1 , wherein:
the at least one transceiver is configured to receive, from a network entity, a positioning availability signal comprising positioning reference signal (PRS) availability information; and
the at least one element is configured to reflect the positioning availability signal to produce a reflection positioning availability signal radiated towards the network device.
16 . The RIS of claim 15 , wherein the at least one transceiver is configured to receive the positioning availability signal via one of radio resource control (RRC), downlink control information (DCI), or a medium access control-control element (MAC CE), when the network device is operating in a connected mode.
17 . The RIS of claim 15 , wherein the positioning availability signal is a system information block (SIB) signal and the PRS availability information is within assistance data in the SIB signal, when the network device is operating in one of an idle mode or an inactive mode.
18 . The RIS of claim 15 , wherein the at least one transceiver is configured to receive the positioning availability signal via L1 signaling using an early page indication (EPI)/paging physical downlink control channel (PDCCH), when the network device is operating in one of an idle mode or an inactive mode.
19 . The RIS of claim 15 , wherein the at least one transceiver is configured to receive the positioning availability signal via downlink control information (DCI) and the PRS availability information is within repurposed bits of the DCI, when the network device is operating in one of an idle mode or an inactive mode.
20 . A method of wireless communication performed at a reconfigurable intelligent surface (RIS), the method comprising:
receiving, by the RIS from a satellite, a positioning reference signal; and
reflecting, by the RIS, the positioning reference signal to produce a reflection positioning reference signal radiated towards a network device for positioning of the network device, wherein the method further comprising:
receiving, by the RIS from a network entity, a data signal comprising assistance data, wherein the assistance data comprises at least one of a watermark identification (ID) for the reflection positioning reference signal, a positioning reference signal (PRS) ID associated with the watermark ID, a timer for the network device to switch between positioning detection modes, or a quasi-colocation configuration (QCL) between synchronization signal blocks (SSBs) and positioning reference signals (PRSs) for the positioning of the network device; and
reflecting, by the RIS, the data signal to produce a reflection data signal radiated towards the network device.
21 . The method of claim 20 , wherein the watermark ID is one of a RIS on-off pattern or a RIS specific phase.
22 . The method of claim 20 , wherein the positioning detection modes comprise a first positioning detection mode of detecting positioning signals directly transmitted from the satellite to the network device, and a second positioning detection mode of detecting positioning signals transmitted from the satellite to the network device via the RIS.
23 . The method of claim 20 , further comprising:
receiving, by the RIS from a network entity, a beam adaptation signal comprising beam adaptation information; and
reflecting, by the RIS, the beam adaptation signal to produce a reflection beam adaptation signal radiated towards the network device.
24 . The method of claim 23 , wherein the beam adaptation information comprises at least one of: RIS downlink (DL) positioning beam pattern information with time stamps, and wherein the RIS DL positioning beam pattern information comprises the reflection positioning reference signal; one or more sets of beams, wherein each of the one or more sets of beams comprises a network device uplink (UL) positioning beam to align with a RIS downlink (DL) positioning beam; an angle of departure (AoD) for a network device uplink (UL) positioning beam to align with the reflection positioning reference signal; or a relative angle difference between an angle of departure (AoD) for a network device uplink (UL) positioning beam to align with the reflection positioning reference signal.
25 . The method of claim 20 , further comprising dynamically applying, to the RIS, a pair of voltages to fix a direction of the reflection positioning reference signal to align with a network device uplink (UL) positioning beam.
26 . The method of claim 20 , further comprising:
receiving, by the RIS from a network entity, a positioning availability signal comprising positioning reference signal (PRS) availability information; and
reflecting, by the RIS, the positioning availability signal to produce a reflection positioning availability signal radiated towards the network device.