User equipment-based (UE-based) positioning based on self-radio frequency fingerprint (self-RFFP)

1 . A method of operating a user equipment (UE), comprising:

transmitting one or more reference signals;

obtaining one or more self-radio frequency fingerprint (self-RFFP) measurements based on reflections of the one or more reference signals transmitted by the UE; and

determining a location of the UE based on applying a machine learning model to the one or more self-RFFP measurements.

2 . The method of claim 1 , further comprising:

obtaining one or more downlink RFFP (DL-RFFP) measurements based on one or more downlink reference signals received by the UE, or obtaining one or more sidelink RFFP (SL-RFFP) measurements based on one or more sidelink reference signals between the UE and a second UE,

wherein the location of the UE is determined based on applying the machine learning model to (i) the one or more self-RFFP measurements and (ii) the one or more DL-RFFP measurements, or the one or more SL-RFFP measurements, or a combination thereof.

3 . The method of claim 2 , wherein both the one or more self-RFFP measurements and the one or more SL-RFFP measurements are based on the one or more sidelink reference signals transmitted by the UE.

4 . The method of claim 2 , wherein the one or more SL-RFFP measurements are based on the one or more sidelink reference signals transmitted by the UE or by the second UE.

5 . The method of claim 4 , wherein the one or more sidelink reference signals include a sidelink positioning reference signal (SL-PRS), a sidelink synchronization signal block (SL-SSB), a sidelink channel state information reference signal (SL CSI-RS), sidelink channel reference signal, or a sidelink channel signal carrying data.

6 . The method of claim 1 , wherein the one or more reference signals include a sounding reference signal (SRS), a sidelink positioning reference signal (SL-PRS), a sidelink synchronization signal block (SL-SSB), a sidelink channel state information reference signal (SL CSI-RS), an uplink channel reference signal, an uplink channel signal carrying data, a sidelink channel reference signal, or a sidelink channel signal carrying data.

7 . The method of claim 1 , wherein the machine learning model is trained based on one or more training self-RFFP measurements, each one of the one or more training self-RFFP measurements being obtained by a corresponding observer device based on reflections of a corresponding reference signal transmitted by the corresponding observer device.

8 . The method of claim 7 , wherein the machine learning model is trained further based on one or more training downlink RFFP measurements obtained based on one or more downlink training signals received by a particular observer device, or one or more training sidelink RFFP measurements obtained based on one or more sidelink training signals between the particular observer device and another UE.

9 . The method of claim 1 , further comprising:

obtaining one or more training self-RFFP measurements based on reflections of another one or more reference signals transmitted by the UE;

obtaining one or more training locations of the UE, the one or more training locations being associated with the one or more training self-RFFP measurements; and

training the machine learning model based on training input data and reference output data, the training input data including the one or more training self-RFFP measurements of the UE, and the reference output data including the one or more training locations of the UE.

10 . The method of claim 9 , further comprising determining one of the one or more training locations of the UE,

wherein one of the one or more training locations of the UE is determined based on a downlink time difference of arrival (DL-TDoA), a downlink angle-of-arrival (DL-AoA), a sidelink time difference of arrival (SL-TDoA), a sidelink angle-of-arrival (SL-AoA), round-trip time (RTT) positioning, operating the UE at a predetermined reference location, one or more sensors installed on the UE, or a global navigation satellite system (GNSS), or a combination thereof.

11 . The method of claim 9 , further comprising:

obtaining one or more training downlink RFFP (DL-RFFP) measurements based on one or more downlink training signals received by the UE, or obtaining one or more training sidelink RFFP (SL-RFFP) measurements based on one or more sidelink training signals between the UE and a second UE,

wherein the training input data further includes the one or more training DL-RFFP measurements, or the one or more training SL-RFFP measurements, or both.

12 . The method of claim 9 , further comprising receiving one of the one or more training locations of the UE from a network entity or from a second UE.

13 . The method of claim 1 , further comprising:

obtaining one or more training self-RFFP measurements based on reflections of another one or more reference signals transmitted by the UE;

transmitting, to a network entity, the one or more training self-RFFP measurements of the UE for training the machine learning model; and

receiving, from the network entity, the machine learning model after being trained based on at least the one or more training self-RFFP measurements of the UE.

14 . The method of claim 13 , further comprising:

determining a training location of the UE, the training location being associated with one of the one or more training self-RFFP measurements of the UE; and

transmitting, to the network entity, the training location of the UE for training the machine learning model.

15 . The method of claim 14 , wherein the training location of the UE is determined based on a downlink time difference of arrival (DL-TDoA), a downlink angle-of-arrival (DL-AoA), a sidelink time difference of arrival (SL-TDoA), a sidelink angle-of-arrival (SL-AoA), round-trip time (RTT) positioning, operating the UE at a predetermined reference location, one or more sensors installed on the UE, or a global navigation satellite system (GNSS), or a combination thereof.

16 . The method of claim 13 , further comprising:

obtaining one or more training downlink RFFP (DL-RFFP) measurements based on one or more downlink training signals received by the UE, or obtaining one or more training sidelink RFFP (SL-RFFP) measurements based on one or more sidelink training signals between the UE and a second UE; and

transmitting, to the network entity for training the machine learning model, the one or more training DL-RFFP measurements, or the training SL-RFFP measurements, or both.

17 . The method of claim 13 , wherein the network entity is a location server or a model repository server.

18 . A method of operating a user equipment (UE), comprising:

receiving, from a second UE, one or more self-radio frequency fingerprint (self-RFFP) measurements obtained by the second UE based on reflections of one or more reference signals transmitted by the second UE;

obtaining one or more sidelink RFFP (SL-RFFP) measurements based on one or more sidelink reference signals between the UE and the second UE; and

determining a location of the second UE based on applying a machine learning model to the one or more self-RFFP measurements and the one or more SL-RFFP measurements.

19 . The method of claim 18 , wherein the one or more self-RFFP measurements and the one or more SL-RFFP measurements are based on the one or more sidelink reference signals transmitted by the second UE.

20 . The method of claim 18 , wherein the one or more SL-RFFP measurements are based on the one or more sidelink reference signals transmitted by the UE or by the second UE.

21 . The method of claim 20 , wherein the one or more sidelink signals include a sidelink positioning reference signal (SL-PRS), a sidelink synchronization signal block (SL-SSB), a sidelink channel state information reference signal (SL CSI-RS), a sidelink channel reference signal, or a sidelink channel signal carrying data.

22 . The method of claim 18 , further comprising:

receiving one or more training self-RFFP measurements obtained by the second UE based on reflections of another one or more reference signals transmitted by the second UE;

obtaining one or more training locations of the second UE, the one or more training locations being associated with the one or more training self-RFFP measurements; and

training the machine learning model based on training input data and reference output data, the training input data including the one or more training self-RFFP measurements of the second UE, and the reference output data including the one or more training locations of the second UE.

23 . The method of claim 22 , further comprising determining one of the one or more training locations of the second UE,

wherein the one of the one or more training locations of the second UE is determined based on a sidelink time difference of arrival (SL-TDoA), a sidelink angle-of-arrival (SL-AoA), or round-trip time (RTT) positioning, or a combination thereof.

24 . The method of claim 22 , further comprising receiving one of the one or more training locations of the second UE from the second UE.

25 . A user equipment (UE), comprising:

a memory;

at least one transceiver; and

at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:

transmit, via the at least one transceiver, one or more reference signals;

obtain one or more self-radio frequency fingerprint (self-RFFP) measurements based on reflections of the one or more reference signals transmitted by the UE; and

determine a location of the UE based on applying a machine learning model to the one or more self-RFFP measurements.

26 . The UE of claim 25 , wherein the at least one processor is further configured to:

obtain one or more downlink RFFP (DL-RFFP) measurements based on one or more downlink reference signals received by the UE, or obtaining one or more sidelink RFFP (SL-RFFP) measurements based on one or more sidelink reference signals between the UE and a second UE,

wherein the location of the UE is determined based on applying the machine learning model to (i) the one or more self-RFFP measurements and (ii) the one or more DL-RFFP measurements, or the one or more SL-RFFP measurements, or a combination thereof.

27 . The UE of claim 25 , wherein the at least one processor is further configured to:

obtain one or more training self-RFFP measurements based on reflections of another one or more reference signals transmitted by the UE;

obtain one or more training locations of the UE, the one or more training locations being associated with the one or more training self-RFFP measurements; and

train the machine learning model based on training input data and reference output data, the training input data including the one or more training self-RFFP measurements of the UE, and the reference output data including the one or more training locations of the UE.

28 . The UE of claim 27 , wherein the at least one processor is further configured to:

obtain one or more training downlink RFFP (DL-RFFP) measurements based on one or more downlink training signals received by the UE, or obtaining one or more training sidelink RFFP (SL-RFFP) measurements based on one or more sidelink training signals between the UE and a second UE,

wherein the training input data further includes the one or more training DL-RFFP measurements, or the one or more training SL-RFFP measurements, or both.

29 . A user equipment (UE), comprising:

a memory;

at least one transceiver; and

at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:

receive, via the at least one transceiver, from a second UE, one or more self-radio frequency fingerprint (self-RFFP) measurements obtained by the second UE based on reflections of one or more reference signals transmitted by the second UE;

obtain one or more sidelink RFFP (SL-RFFP) measurements based on one or more sidelink reference signals between the UE and the second UE; and

determine a location of the second UE based on applying a machine learning model to the one or more self-RFFP measurements and the one or more SL-RFFP measurements.

30 . The UE of claim 29 , wherein the at least one processor is further configured to:

receive, via the at least one transceiver, one or more training self-RFFP measurements obtained by the second UE based on reflections of another one or more reference signals transmitted by the second UE;

obtain one or more training locations of the second UE, the one or more training locations being associated with the one or more training self-RFFP measurements; and

train the machine learning model based on training input data and reference output data, the training input data including the one or more training self-RFFP measurements of the second UE, and the reference output data including the one or more training locations of the second UE.