Methods and apparatuses relating to wireless communication
This specification describes an apparatus comprising: means for receiving, at a target user equipment, UE, a signal including information indicative of supporting UE measurements of signals transmitted from the target UE to a supporting UE via a multipath communications channel, the supporting UE measurements including delay and angle measurements of the signals transmitted from the target UE to the supporting UE via the multipath communications channel; means for time-aligning the supporting UE measurements with target UE measurements of signals transmitted from the supporting UE to the target UE via the multipath communications channel, the target UE measurements including delay and angle measurements for the signals transmitted from the supporting UE to the target UE via the multipath communications channel; means for determining, based on the time-aligned measurements, an association between a component of the target UE measurements and at least one respective component of the supporting UE measurements, wherein the associated components are determined to correspond to a particular reflector in an environment of the target UE; and means for determining, based on the associated components, location information for the particular reflector.
1 . An apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform:
receiving, at a target user equipment, UE, a signal including information indicative of supporting UE measurements of signals transmitted from the target UE to a supporting UE via a multipath communications channel, the supporting UE measurements including delay and angle measurements of the signals transmitted from the target UE to the supporting UE via the multipath communications channel;
time-aligning the supporting UE measurements with target UE measurements of signals transmitted from the supporting UE to the target UE via the multipath communications channel, the target UE measurements including delay and angle measurements for the signals transmitted from the supporting UE to the target UE via the multipath communications channel;
determining, based on the time-aligned measurements, an association between a component of the target UE measurements and at least one respective component of the supporting UE measurements, wherein the associated components are determined to correspond to a particular reflector in an environment of the target UE; and
determining, based on the associated components, location information for the particular reflector.
2 . The apparatus of claim 1 , wherein time-aligning the supporting UE measurements with the target UE measurements comprises determining a common delay-domain origin based on an Rx-Tx time difference of the target UE, an Rx-Tx time difference of the supporting UE, a shortest delay of the supporting UE measurements and a shortest delay of the target UE measurements.
3 . The apparatus of claim 1 , wherein the supporting UE measurements further include power measurements of the signals transmitted from the target UE to the supporting UE via the multipath communications channel, and wherein the target UE measurements further include power measurements for the signals transmitted from the supporting UE to the target UE via the multipath communications channel.
4 . The apparatus of claim 3 , wherein the target UE measurements and/or the supporting UE measurements are resampled in the delay domain such that the target UE measurements and the supporting UE measurements have a common delay resolution, and wherein the association is determined based on the resampled measurements.
5 . The apparatus of claim 4 , wherein the target UE power measurements and the supporting UE power measurements are pruned and/or normalised prior to the resampling.
6 . The apparatus of claim 4 , wherein the resampling is based on a target channel response generated based on the target UE measurements and/or a supporting channel response generated based on the supporting UE measurements.
7 . The apparatus of claim 6 , wherein the resampling comprises convolving the target channel response and/or the supporting channel response with a filter having the common delay resolution.
8 . The apparatus of claim 6 , wherein the resampling comprises applying, to the target channel response and/or the supporting channel response, a discrete Fourier transform, DFT, followed by an inverse discrete Fourier transform, IDFT, wherein the IDFT has the common delay resolution.
9 . The apparatus of claim 1 , wherein the at least one respective component of the supporting UE measurements is determined to be associated with the component of the target UE measurements based on a minimisation of a divergence metric between the component of the target UE measurements and the at least one respective component of the supporting UE measurements.
10 . The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to perform:
aligning a coordinate system of the target UE with a coordinate system of the supporting UE based on a common reference direction.
11 . The apparatus of claim 1 , wherein the at least one respective component of the supporting UE measurements is determined to be associated with the component of the target UE measurements based on either:
a delay measurement of the at least one respective component of the supporting UE measurements being within a threshold delay of a delay measurement of the component of the target UE measurements; and/or
a power measurement of the at least one respective component of the supporting UE measurements being within a threshold power of a power measurement of the component of the target UE measurements.
12 . The apparatus of claim 1 , wherein the location information for the particular reflector includes at least one of:
a distance and/or angle from the target UE to the particular reflector;
a distance and/or angle from the supporting UE to the particular reflector;
a distance and/or angle from a neighbouring UE to the particular reflector;
a position of the particular reflector with respect to a local coordinate system, LCS, of the target UE, the supporting UE, and/or a neighbouring UE; and
a position of the particular reflector with respect to a global coordinate system, GCS.
13 . The apparatus of claim 1 ,
wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to perform:
receiving, at a target user equipment, UE, a signal including information indicative of additional supporting UE measurements of signals transmitted from the target UE to an additional supporting UE via an additional multipath communications channel, the additional supporting UE measurements including delay and angle measurements of the signals transmitted from the target UE to the additional supporting UE via the additional multipath communications channel;
time-aligning the additional supporting UE measurements with additional target UE measurements of signals transmitted from the additional supporting UE to the target UE via the additional multipath communications channel, the additional target UE measurements including delay and angle measurements for the signals transmitted from the additional supporting UE to the target UE via the additional multipath communications channel; and
determining, based on the additional time-aligned measurements, an additional association between a component of the additional target UE measurements and at least one respective component of the additional supporting UE measurements, wherein the additionally associated components are determined to correspond to the particular reflector,
wherein the determination of the location information for the particular reflector is further based on the additionally associated components.
14 . An apparatus according to claim 1 , wherein the location information for the particular reflector is determined based on an average of location information determined based on the associated components and location information determined based on the additionally associated components.
15 . A user equipment device apparatus including an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform:
receiving, at a target user equipment, UE, a signal including information indicative of supporting UE measurements of signals transmitted from the target UE to a supporting UE via a multipath communications channel, the supporting UE measurements including delay and angle measurements of the signals transmitted from the target UE to the supporting UE via the multipath communications channel;
time-aligning the supporting UE measurements with target UE measurements of signals transmitted from the supporting UE to the target UE via the multipath communications channel, the target UE measurements including delay and angle measurements for the signals transmitted from the supporting UE to the target UE via the multipath communications channel;
determining, based on the time-aligned measurements, an association between a component of the target UE measurements and at least one respective component of the supporting UE measurements, wherein the associated components are determined to correspond to a particular reflector in an environment of the target UE; and
determining, based on the associated components, location information for the particular reflector.
16 . A method comprising:
receiving, at a target user equipment, UE, a signal including information indicative of supporting UE measurements of signals transmitted from the target UE to a supporting UE via a multipath communications channel, the supporting UE measurements including delay and angle measurements of the signals transmitted from the target UE to the supporting UE via the multipath communications channel;
time-aligning the supporting UE measurements with target UE measurements of signals transmitted from the supporting UE to the target UE via the multipath communications channel, the target UE measurements including delay and angle measurements for the signals transmitted from the supporting UE to the target UE via the multipath communications channel;
determining, based on the time-aligned measurements, an association between a component of the target UE measurements and at least one respective component of the supporting UE measurements, wherein the associated components are determined to correspond to a particular reflector in an environment of the target UE; and
determining, based on the associated components, location information for the particular reflector.
17 . The method of claim 16 , wherein time-aligning the supporting UE measurements with the target UE measurements comprises determining a common delay-domain origin based on an Rx-Tx time difference of the target UE, an Rx-Tx time difference of the supporting UE, a shortest delay of the supporting UE measurements and a shortest delay of the target UE measurements.
18 . The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to perform determining a position of the particular reflector relative to the target UE based on the determined location information.
19 . An apparatus according to claim 14 , wherein the average is weighted based on confidence estimates received at the target UE from the supporting UE and the additional supporting UE.
20 . An apparatus according to claim 1 , wherein the location information for the particular reflector is determined using a joint optimisation process.