Downlink localization of a user equipment

Abstract

There is provided techniques for downlink localization of a UE in a repeater-assisted network. A method is performed by a network node. The network node serves the UE via a repeater device in the repeater-assisted network. The method comprises transmitting at least one first localization signal for downlink localization of the UE. The method comprises receiving a first indication from the UE about a first localization result based on measurements made by the UE on the at least one first localization signal. The method comprises determining, based on the first indication from the UE about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device. The method comprises transmitting auxiliary information to the UE for refined downlink localization of the UE.

Description

[0001] DOWNLINK LOCALIZATION OF A USER EQUIPMENT

[0002] TECHNICAL FIELD

[0003] Embodiments presented herein relate to methods, a network node, a user equipment, computer programs, and a computer program product for downlink localization of the user equipment in a repeater-assisted network.

[0004] BACKGROUND

[0005] To increase the data rate and provide capacity for serving an increasing number of served devices, such as user equipment (UEs), in wireless networks, different techniques are considered, among which network densification and millimeter wave (mmW) communications are the dominant ones. In general terms, network densification refers to the deployment of multiple access points of different types in, e.g., metropolitan areas. Particularly, (small) network nodes, such as relays, integrated access and backhaul (IAB) nodes, repeaters, etc., can be densely deployed to support existing macro network nodes, such as base stations (BS).

[0006] As an example, IAB nodes are rather complex and expensive and thereby, depending on the deployment, alternative (small) network nodes with low complexity and cost might be needed for, e.g., blind spot removal. Here, a candidate type of network node is radio frequency (RF) repeaters which simply amplify-and-forward any signal that it receives. RF repeaters have been considered to supplement the coverage provided by regular fullstack cells. However, RF repeater lacks, e.g., accurate beamforming capabilities, which may limit its operational efficiency in, for instance, certain frequency bands, such as FR2.

[0007] The characteristics of Network-controlled Repeater (NCR) have been specified with this in mind. In general terms, an NCR can be regarded as a beamforming-capable relay node. Thus, an NCR can be considered as a normal RF repeater with beamforming capabilities. In this way, the NCR could be considered as a network-controlled beam bender when compared to a (controlling) network node such as a gNB. As such, the NCR is logically part of the (controlling) network node for all management purposes, i.e., it can be assumed that the NCR is deployed and under the control of the mobile network operator. The NCR is based on an amplify-and-forward relaying scheme, and is according to the third generation partnership project (3GPP) currently limited to single-hop communication in stationary deployments. In other words, the NCR is an enhancement over conventional RF repeaters with the capability to receive and process side control information from the network. Side control information could allow an NCR to perform an amplify-and-forward operation efficiently. Potential benefits include, for instance, mitigation of unnecessary noise amplification, transmissions and receptions with better spatial directivity, simplified network integration, etc.

[0008] The NCR is equipped with an antenna configuration, where a signal is first received in downlink (DL) (or, uplink (UL)), and, after power amplification, transmitted further in DL (or, UL). Since the NCR only amplifies and (analogously) beamforms the signal, no advanced digital receiver or transmitter chains are required. In its simplest (and, practical) architecture, different antenna modules can be used for the network-side and the UE- side, i.e., the antennas targeting the (parent) network node and the UEs, respectively A more complex architecture, including self-interference cancellation, would allow for using the same antenna modules for both sides.

[0009] Intelligent reflecting surfaces (IRSs), also known as reconfigurable intelligent surfaces (RISs), represent another emerging technology that is capable of intelligently manipulating the propagation of electro-magnetic waves. In general terms, an IRS is composed of a 2-dimensional array of reflecting elements, where each element acts as a passive reconfigurable scatterer, i.e., a piece of manufactured material, which can be programmed to change an impinging electro-magnetic wave in a customizable way. Such elements are usually low-cost passive surfaces that do not require dedicated power sources, and the radio waves impinged upon them can be forwarded without the need of employing power amplifier or RF chain. Moreover, IRS can, potentially, work in full duplex mode without significant self-interference or increased noise level and requires only low-rate control link or backhaul connections. IRSs can be flexibly deployed due to their low weight and low power consumption.

[0010] There are similarities and differences between NCRs and IRSs. For example, an IRS can be regarded as an NCR with small positive or negative amplification (depending on if the IRS is active or passive). In general, an IRS is expected to be a simpler and cheaper network node compared to the NCR with less focused beamforming capability, or accuracy, and without active amplification. That is, IRSs may be capable of signal reflection via adapting a phase matrix while NCRs are capable of advanced beamforming with power amplification. Hereinafter, the term repeater device will be used to represent an NCR, an IRS, or any other network nodes with similar functionalities.

[0011] A key feature is that the repeater devices should be transparent to the UEs served by the network. This means that the UE is unaware of the presence of the repeater devices. A consequence of this is that the UEs can follow the same procedures as if served directly by the network nide (with no repeater device in-between).

[0012] This is thus of benefit for traditional communication between the UE and the network since no dedicated protocols must be used when the UE is served via a repeater device. In terms of downlink localization of the UE, however, where the geographic location of the UE is determined based on downlink localization signals the UE receives from the network node, the transparency of the repeater devices may cause mis-localizations of the UE. This is particularly because, with no knowledge about the presence of the repeater device, the UE takes the network node position as the reference point in localization, and the UE does not take into the account, e.g., the power boost, the beam type change and / or the internal delay of the repeater device, during the localization.

[0013] As disclosed above, when the repeater device is an NCR, different antenna modules can be used for the network-side and the UE-side. In practice these antenna modules may be considerably separated in space. For example, the antenna module facing the network node might be placed on one side of a tall building whereas the antenna module intended to face the UEs might be placed on another side of the same tall building. For example, the antenna module facing the network node might be placed an outside wall of a building whereas the antenna module intended to face the UEs might be placed on an inside wall of the building. As a result, the signal received by the repeater device at one position may be forwarded by the repeater device towards the UEs from a completely different position.

[0014] Different methods can be considered for downlink localization of the UE. For instance, assume that the downlink localization is based on using the received signal power of the localization signals. Depending on whether the repeater device is an NCR or an IRS (or some other type of repeater device), there might be a positive or negative amplification of the localization signal before it reaches the UE. This amplification is not known by the UE. As a result, the UE might estimate the distance between itself and the network node to be either less than it is or larger than it is. For instance, assume that the downlink localization is based on using the signal travel delay of the localization signals. Here, due to possible internal delay in the repeater device, the UE may estimate that it is further located from the network node than it actually is. For instance, assume that the downlink localization is based on using angular information, such as direction of arrival, of the localization signals. Here, while the network node may use one type of beam (narrow, semi-wide or wide) and one particular direction for transmitting the localization signals, the repeater device may reflect the localization signals with a different type of beam, possibly in another direction. This change in beam type and direction is not understood by the UE, which affects the localization quality.

[0015] Hence, there is still a need for technologies enabling accurate downlink localization of UEs in repeater-assisted networks.

[0016] SUMMARY

[0017] An object of embodiments herein is to provide accurate downlink localization of UEs in repeater-assisted networks that does not suffer from the above issues, or at least where the above issues have been mitigated or reduced.

[0018] As noted above, the repeater devices should be transparent to the UEs served by the network, and that the UEs therefore is unaware of the presence of the repeater devices. Some negative consequences of this have been mentioned above.

[0019] Particularly, the UE itself cannot compensate for any mis-localizations caused by the UE being unaware of the repeater device. On the other hand, the network node is indeed aware of the presence of the repeater devices. A particular object is therefore to provide network-assisted downlink localization of UEs in repeater-assisted networks.

[0020] A further particular object is to provide accurate downlink localization of UEs in repeater-assisted networks where the network node is enabled to resolve issues caused by the repeater devices being transparent to the UEs served by the network. All these objects are met by the independent claims, as here represented by the following aspects.

[0021] According to a first aspect there is presented a method for downlink localization of a UE in a repeater-assisted network. The method is performed by a network node. The network node serves the UE via a repeater device in the repeater-assisted network. The method comprises transmitting at least one first localization signal for downlink localization of the UE. The method comprises receiving a first indication from the UE about a first localization result based on measurements made by the UE on the at least one first localization signal. The method comprises determining, based on the first indication from the UE about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device. The method comprises transmitting auxiliary information to the UE for refined downlink localization of the UE.

[0022] According to a second aspect there is presented a network node for downlink localization of a UE in a repeater- assisted network. The network node is configured to server the UE via a repeater device in the repeater-assisted network. The network node comprises processing circuitry. The processing circuitry is configured to cause the network node to transmit at least one first localization signal for downlink localization of the UE. The processing circuitry is configured to cause the network node to receive a first indication from the UE about a first localization result based on measurements made by the UE on the at least one first localization signal. The processing circuitry is configured to cause the network node to determine, based on the first indication from the UE about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device. The processing circuitry is configured to cause the network node to transmit auxiliary information to the UE for refined downlink localization of the UE.

[0023] According to a third aspect there is presented a network node for downlink localization of a UE in a repeater- assisted network. The network node is configured to serve the UE via a repeater device in the repeater-assisted network. The network node comprises a first transmit module configured to transmit at least one first localization signal for downlink localization of the UE. The network node comprises a receive module configured to receive a first indication from the UE about a first localization result based on measurements made by the UE on the at least one first localization signal. The network node comprises a determine module configured to determine, based on the first indication from the UE about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device. The network node comprises a second transmit module configured to transmit auxiliary information to the UE for refined downlink localization of the UE.

[0024] According to a fourth aspect there is presented a computer program for downlink localization of a UE in a repeater-assisted network. The computer program comprises computer code which, when run on processing circuitry of a network node, causes the network node to perform actions. The network node is configured to serve the UE via a repeater device in the repeater-assisted network. One action comprises the network node to transmit at least one first localization signal for downlink localization of the UE. One action comprises the network node to receive a first indication from the UE about a first localization result based on measurements made by the UE on the at least one first localization signal. One action comprises the network node to determine, based on the first indication from the UE about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device. One action comprises the network node to transmit auxiliary information to the UE for refined downlink localization of the UE.

[0025] According to a fifth aspect there is presented a method for downlink localization of a UE in a repeater-assisted network. The UE is served by a network node in the repeater-assisted network. The method is performed by the UE. The method comprises receiving at least one first localization signal, originating from the network node, for downlink localization of the UE. The method is performed by the UE. The method comprises calculating a first localization result based on measurements made by the UE on the at least one first localization signal. The method is performed by the UE. The method comprises sending a first indication to the network node about the first localization result. The method is performed by the UE. The method comprises receiving auxiliary information, originating from the network node, for refined downlink localization of the UE. The method is performed by the UE. The method comprises updating the first localization result based on the auxiliary information.

[0026] According to a sixth aspect there is presented a UE for downlink localization of the UE in a repeater-assisted network. The UE is configured to be served by a network node in the repeater-assisted network. The UE comprises processing circuitry. The processing circuitry is configured to cause the UE to receive at least one first localization signal, originating from the network node, for downlink localization of the UE. The processing circuitry is configured to cause the UE to calculate a first localization result based on measurements made by the UE on the at least one first localization signal. The processing circuitry is configured to cause the UE to send a first indication to the network node about the first localization result. The processing circuitry is configured to cause the UE to receive auxiliary information, originating from the network node, for refined downlink localization of the UE. The processing circuitry is configured to cause the UE to update the first localization result based on the auxiliary information.

[0027] According to a seventh aspect there is presented a UE for downlink localization of the UE in a repeater-assisted network. The UE is configured to be served by a network node in the repeater-assisted network. The UE comprises a first receive module configured to receive at least one first localization signal, originating from the network node, for downlink localization of the UE. The UE comprises a calculate module configured to calculate a first localization result based on measurements made by the UE on the at least one first localization signal. The UE comprises a send module configured to send a first indication to the network node about the first localization result. The UE comprises a second receive module configured to receive auxiliary information, originating from the network node, for refined downlink localization of the UE. The UE comprises an update module configured to update the first localization result based on the auxiliary information. According to an eighth aspect there is presented a computer program for downlink localization of UE in a repeater-assisted network. The computer program comprises computer code which, when run on processing circuitry of a UE, causes the UE to perform actions. The UE is configured to be served by a network node in the repeater-assisted network. One action comprises the UE to receive at least one first localization signal, originating from the network node, for downlink localization of the UE. One action comprises the UE to calculate a first localization result based on measurements made by the UE on the at least one first localization signal. One action comprises the UE to send a first indication to the network node about the first localization result. One action comprises the UE to receive auxiliary information, originating from the network node, for refined downlink localization of the UE. One action comprises the UE to update the first localization result based on the auxiliary information.

[0028] According to a ninth aspect there is presented a computer program product comprising a computer program according to at least one of the fourth aspect and the eighth aspect and a computer readable storage medium on which the computer program is stored. The computer readable storage medium could be a non-transitory computer readable storage medium.

[0029] Advantageously, these aspects provide accurate downlink localization of UEs in repeater-assisted networks that does not suffer from the above issues. This, in turn, will improve the network’s understanding of the location of the UEs and / or their moving trajectory. This thereby enables the network node to select the proper scheduling, beamforming, etc. for the UEs, hence improving the communication quality for the UEs.

[0030] Advantageously, these aspects still allow the repeater devices to be transparent to the UEs served by the network.

[0031] Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings.

[0032] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / an / the element, apparatus, component, means, module, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, module, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which:

[0035] Fig. 1 is a schematic diagram illustrating repeater-assisted networks according to embodiments; Figs. 2 and 3 are flowcharts of methods according to embodiments;

[0036] Fig. 4 is a schematic diagram showing structural units of a network node according to an embodiment;

[0037] Fig. 5 is a schematic diagram showing functional modules of a network node according to an embodiment;

[0038] Fig. 6 is a schematic diagram showing structural units of a UE according to an embodiment;

[0039] Fig. 7 is a schematic diagram showing functional modules of a UE according to an embodiment; and

[0040] Fig. 8 shows one example of a computer program product comprising computer readable means according to an embodiment.

[0041] DETAILED DESCRIPTION

[0042] The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.

[0043] Fig. 1 is a schematic diagram illustrating repeater-assisted networks 100a, 100b where embodiments presented herein can be applied. The repeater-assisted networks 100a, 100b comprise a network node 110 and a repeater device 120a, 120b. The network node 110 can thereby serve UEs, as represented by UE 130, either directly (over a wireless link 150) or via the repeater device 120a, 120b (over wireless links 140a, 140b). Here, in repeater-assisted networks 100a the repeater device 120a is illustrated as an NCR, with separated antenna modules, and in repeater-assisted networks 100b the repeater device 120b is illustrated as an IRS. However, also other types of repeater devices 120a, 120b are envisioned. The network node 110 could be any of a (radio) access network node, radio base station, base transceiver station, node B (NB), evolved node B (eNB), gNB, access point, access node, transmission and reception point, integrated access and backhaul (IAB) node, etc. The UE 130 can be any of a portable wireless device, mobile station, mobile phone, handset, wireless local loop phone, smartphone, laptop computer, tablet computer, wireless modem, wireless sensor device, network- equipped vehicle, Internet-of-Things (loT) device, etc.

[0044] As noted above, there is still a need for technologies enabling accurate downlink localization of UEs 130 in repeater-assisted networks 100a, 100b.

[0045] The embodiments disclosed herein therefore relate to techniques for downlink localization of a UE 130 in a repeater-assisted network 100a, 100b. In order to obtain such techniques, there is provided a network node 110, a method performed by the network node 110, a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the network node 110, causes the network node 110 to perform the method. In order to obtain such techniques, there is further provided a UE 130, a method performed by the UE 130, and a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the UE 130, causes the UE 130 to perform the method.

[0046] According to at least some of the herein disclosed embodiments, the accurate downlink localization of a UE 130 is based on the network node 110 understanding, based on signaling from the UE 130 in terms of measurements on localization signals, that the UE 130 received the localization signal via the repeater device 120a, 120b, and the network node 110 providing the UE 130 with appropriate auxiliary information so that the UE 130 can update its localization.

[0047] Reference is now made to Fig. 2 illustrating a method for downlink localization of a UE 130 in a repeater device 120a, 120b-assisted network 100a, 100b as performed by the network node 110 according to an embodiment. The network node 110 serves the UE 130 via a repeater device 120a, 120b in the repeater-assisted network 100a, 100b.

[0048] The network node 110 needs to understand that the UE 130 is receiving the localization signals via the repeater device 120a, 120b which might result in mis-localization of the UE 130. The network node 110 is therefore configured to perform steps S102 and S104.

[0049] S102: The network node 110 transmits at least one first localization signal for downlink localization of the UE 130.

[0050] S104: The network node 110 receives a first indication from the UE 130 about a first localization result based on measurements made by the UE 130 on the at least one first localization signal.

[0051] As will be further disclosed below, there can be different ways for the network node 110 to determine whether the UE 130 has been localized based on localizations signals as forwarded by the repeater device 120a, 120b or not. In any case, once the UE 130 has performed the localization, the UE 130 sends some type of feedback to the network node 110 and to informs the network node 110 about the localization result, either implicitly or explicitly. This feedback is based on measurements made by the UE 130 on the localization signals transmitted by the network node 110.

[0052] The network node 110 provides the UE 130 with appropriate information so that the UE 130 can perform accurate localization based on the received localization signal. The network node 110 is therefore configured to perform steps S112 and S114. S112: The network node 110 determines, based on the first indication from the UE 130 about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device 120a, 120b.

[0053] S114: The network node 110 transmits auxiliary information to the UE 130 for refined downlink localization of the UE 130.

[0054] In this way the network node 110 will provide the UE 130 with further information (such as a new reference point for positioning, the beam type, a new reference time, power compensation parameter, etc., with further details to be disclosed below) which will help the UE 130 to re-localize itself accurately. In this way, mis-localizations are avoided in repeater-assisted networks 100a, 100b, while the repeater device 120a, 120b still remains transparent to the UE 130.

[0055] Embodiments relating to further details of downlink localization of a UE 130 in a repeater device 120a, ^Ob- assisted network 100a, 100b as performed by the network node 110 will now be disclosed with continued reference to Fig. 2.

[0056] In some aspects, the network node 110 transmits multiple first localization signals in the beams towards the repeater device 120a, 120b in different time resources symbols, slots, etc. In particular, in some embodiments, the at least one first localization signal is transmitted in different time resources of at least two directional beams, where one of the directional beams is directed towards the repeater device 120a, 120b.

[0057] In some aspects, an explicit indication is provided to the network node 110 with the localization results obtained at the UE 130. That is, in some embodiments, the first indication from the UE 130 is the first localization result itself and specifies a location of the UE 130 in relation to the network node 110 or another reference point known to the network node 110 and the UE 130.

[0058] In some aspects, an implicit indication is provided to the network node 110 with different types of information. In particularly, in some embodiments, the first indication from the UE 130 comprises information of at least one of: angle of arrival, or direction, of the at least one first localization signal as received by the UE 130, beam indicator associated with the at least one first localization signal, received signal power and / or received signal quality of the at least one first localization signal, a line-of-sight (LOS) or non-line-of-sight (NLOS) link estimation made by the UE 130 based on measurements on the at least one first localization signal, estimated signal travel time for the at least one first localization signal.

[0059] In some aspects, the determination in step S112 is based on considering different configurations for the repeater device 120a, 120b and comparing corresponding first and the second localization results. In particular, in some embodiments, the network node 110 is configured to perform (optional) steps S 106, S108, and S110. S106: The network node 110 reconfigures the repeater device 120a, 120b after having transmitted the at least one first localization signal.

[0060] S108: The network node 110 transmits at least one second localization signal for the downlink localization of the UE 130.

[0061] S110: The network node 110 receives a second indication from the UE 130 about a second localization result based on measurements made by the UE 130 on the at least one second localization signal.

[0062] Determining that the first localization result is based on the at least one first localization signal as forwarded by the repeater device 120a, 120b, as in step S112, can then be based on comparing the first indication to the second indication.

[0063] There could be different ways of reconfiguring the repeater device 120a, 120b for the second localization process in step s106. In some non-limiting examples, reconfiguring the repeater device 120a, 120b comprises at least one of: adapting directional beams and / or beam types used by the repeater device 120a, 120b, adapting reflection coefficients of the repeater device 120a, 120b, adapting amplification gain of the repeater device 120a, 120b, adapting operation frequency of the repeater device 120a, 120b, turning off at least one antenna panel in the repeater device 120a, 120b, changing polarization, or antenna panels, in the repeater device 120a, 120b.

[0064] There could be different ways for the network node 110 to compare the first localization result and the second localization result. In some embodiments, the first localization result is determined to be based on the at least one first localization signal as forwarded by the repeater device 120a, 120b in case at least one condition holds. In some non-limiting examples, the at least one condition holds when the first indication indicates that the UE 130 is capable of localization while the second indication indicates that the UE 130 is incapable of localization, and / or when the first localization result and the second localization result differ more than a pre-defined threshold from each other.

[0065] In some aspects, the determination in step S112 is based on the moving trajectory of the UE 130. In particular, in some embodiments, determining that the first localization result is determined to be based on the at least one first localization signal as forwarded by the repeater device 120a, 120b based on a moving trajectory of the UE 130 as derived from a difference between the first indication and the second indication.

[0066] There could be different examples of auxiliary information that the UE 130 can use to localize itself accurately. In some non-limiting examples, the auxiliary information pertains to at least one of: a new reference position point that is based on a location of the repeater device 120a, 120b as facing the UE 130, a new reference time value, information about type of directional beams in which the at least one first localization signal is transmitted, information about a power compensation value. In some aspects, the network node 110 transmits one or multiple third localization signals to be received by the UE 130, possibly via the repeater device 120a, 120b, for a third localization process. Particularly, in some embodiments, the UE 130 is configured with localization parameters for calculating the first localization result, and the network node 110 is configured to perform (optional) steps S116, S118, and S210.

[0067] S116: The network node 110 reconfigures the repeater device 120a, 120b after having transmitted the auxiliary information.

[0068] S118: The network node 110 transmits, after having reconfigured the repeater device 120a, 120b, reconfiguration to the UE 130 of the localization parameters for calculating a third localization result.

[0069] S120: The network node 110 transmits at least one third localization signal for the refined downlink localization of the UE 130.

[0070] There could be different examples of reconfigurations transmitted in step S118. In some non-limiting examples, the reconfiguration pertains to at least one of: combining the at least one first localization signal with the at least one third localization signal, ignoring the first localization result, ignoring any of the at least one first localization signal and the at least one third localization signal when estimated to be of a non-line-of-sight link, or of low accuracy. The same as for the first localization signal applies also for the at least one second localization signal (if transmitted in step S108).

[0071] Reference is now made to Fig. 3 illustrating a method for downlink localization of a UE 130 in a repeater device 120a, 120b-assisted network 100a, 100b as performed by the UE 130 according to an embodiment. The UE 130 is served by a network node 110 in the repeater-assisted network 100a, 100b. As disclosed above, the network node 110 serves the UE 130 via a repeater device 120a, 120b in the repeater-assisted network 100a, 100b. However, since the repeater device 120a, 120b is transparent to the UE 130, the UE 130 is in unaware of the existence of the repeater device 120a, 120b.

[0072] S202: The UE 130 receives at least one first localization signal, originating from the network node 110, for downlink localization of the UE 130.

[0073] S204: The UE 130 calculates a first localization result based on measurements made by the UE 130 on the at least one first localization signal.

[0074] S206: The UE 130 sends a first indication to the network node 110 about the first localization result.

[0075] S214: The UE 130 receives auxiliary information, originating from the network node 110, for refined downlink localization of the UE 130.

[0076] S216: The UE 130 updates the first localization result based on the auxiliary information. Embodiments relating to further details of downlink localization of a UE 130 in a repeater device 120a, ^Ob- assisted network 100a, 100b as performed by the UE 130 will now be disclosed with continued reference to Fig. 3.

[0077] As disclosed above, with an explicit indication the network node 110 is provided with the localization results obtained at the UE 130. That is, in some embodiments, the first indication is the first localization result itself and specifies a location of the UE 130 in relation to the network node 110 or another reference point known to the network node 110 and the UE 130.

[0078] As disclosed above, with an implicit indication the network node 110 can be provided with different types of information. In particularly, in some embodiments, the first indication comprises information of at least one of: angle of arrival, or direction, of the at least one first localization signal as received by the UE 130, beam indicator associated with the at least one first localization signal, received signal power and / or received signal quality of the at least one first localization signal, a line-of-sight or no-line-of-sight link estimation made by the UE 130 based on measurements on the at least one first localization signal, estimated signal travel time for the at least one first localization signal.

[0079] As disclosed above, in some aspects, the determination in step S112 is based on considering different configurations for the repeater device 120a, 120b and comparing corresponding first and the second localization results. Therefore, in some embodiments, the UE 130 is configured to perform (optional) steps S208, S210, and S212.

[0080] S208: The UE 130 receives at least one second localization signal, originating from the network node 110, for the downlink localization of the UE 130.

[0081] S210: The UE 130 calculates a second localization result based on measurements made by the UE 130 on the at least one second localization signal.

[0082] S212: The UE 130 sends a second indication to the network node 110 about the second localization result.

[0083] As disclosed above, there could be different examples of auxiliary information that the UE 130 can use to localize itself accurately. In some non-limiting examples, the auxiliary information pertains to at least one of: a new reference position point that is based on a location of the repeater device 120a, 120b as facing the UE 130, a new reference time value, information about type of directional beams in which the at least one first localization signal is transmitted, information about a power compensation value.

[0084] As disclosed above, in some aspects, the network node 110 transmits one or multiple third localization signals to be received by the UE 130, possibly via the repeater device 120a, 120b, for a third localization process. Particularly, in some embodiments, the UE 130 is configured with localization parameters for calculating the first localization result, and the UE 130 is configured to perform (optional) steps S218, S220, and S222. S218: The UE 130 receives, after having received the auxiliary information, reconfiguration from the network node 110 of the localization parameters.

[0085] S220: The UE 130 receives at least one third localization signal for the refined downlink localization of the UE 130.

[0086] S222: The UE 130 calculates a third localization result based on measurements made by the UE 130 on the at least one third localization signal and using the localization parameters as reconfigured according to the reconfiguration.

[0087] There could be different examples of reconfigurations transmitted in step S118, and thus received in step S218. In some non-limiting examples, the reconfiguration pertains to at least one of: combining the at least one first localization signal with the at least one third localization signal, ignoring the first localization result, ignoring any of the at least one first localization signal and the at least one third localization signal when estimated to be of a non- line-of-sight link, or of low accuracy. Here, the UE 130 may utilize the received auxiliary information to perform some pre-processing before combining the received localization signals. Alternatively, the localization results are combined (instead of the localization signals). For instance, the first localization may yield a first location X1 of the UE 130 and the second localization might yield a second location X2 of the UE 130. Then, the UE 130 may consider (X1 +X2J / 2 as the location of the UE 130. Another option is for the UE 130 to perform triangulation based on all received localization signals.

[0088] Further details of the above embodiments, aspects, and examples of the methods for downlink localization of a UE 130 as performed by the network node 110 and the UE 130 will now be disclosed.

[0089] In some aspects, the network node 110 receives a report about the capabilities of the repeater device 120a, 120b. Some non-limiting examples of capabilities of the repeater device 120a, 120b that might be reported are: the repeater device’s 120a, 120b position at the network-side and / or UE-sides, different repeater device 120a, 120b panels positions, beam arrangement, power ON / OFF capability, maximum output power, latency requirements for dynamic indication, internal switching delay, power amplification capability, number and types (wide / semi-wide / narrow) of beams, antenna polarizations, array, or panel, directions, etc. In some examples, the capability report is received either directly from the repeater device 120a, 120b or from other network nodes, higher layer signaling, an Operations, Administration and Maintenance (OAM) system, etc.

[0090] As disclosed above, in step S102, the network node 110 transmits one or multiple first localization signals to be used by the UE 130 for localization. Accordingly, the UE 130 receives the localization signals in step S202, and runs a localization algorithm to calculate a first localization result, as in step S204. Here, in one example, the network node 110 sweeps through different beams and sequentially transmit multiple first localization signals. These localization signals might be either forwarded by the repeater device 120a, 120b or directly received by the UE 130. Particularly, the network node 110 might transmit multiple first localization signals in the beam(s) towards the repeater device 120a, 120b in different time resources (symbols, slots, etc.) and the repeater device 120a, 120b forwards the reference signals in different beams, directions for eventual reception at the UE 130.

[0091] As disclosed above, in step S206 the UE 130 sends an indication to the network node 110 and informs the network node 110 about its first localization result. The indication is received by the network node 110 in step S104. The indication may be either explicit or implicit. With an explicit indication, the UE 130 informs the network node 110 about its determined location. With an implicit indication, however, the UE 130 provides the network node 110 with some information related to its determined location. In any case, the indication is based on measurements made by the UE 130 on the received localization signals.

[0092] In step S112, the network node 110 determines whether the UE 130 has localized itself either based on a localization signal forwarded by the repeater device 120a, 120b or based on a localization signal received directly from the network node 110. Hereinafter it will be assumed that the UE 130 has performed the localization based on a localization signal received via the repeater device 120a, 120b. In this respect, there can be different ways for the network node 110 to make the determination in step S112.

[0093] With an implicit indication in step S206 the UE 130, the UE 130 might provide the network node 110 with one or more of the following pieces of information: the direction of the signal received by the UE 130, the beam index (or, other beam indicators, such as TCI state) received by the UE 130, received signal power or quality, such as Reference Signal Received Power (RSRP) or Reference Signal Received Quality (RSRQ), LOS / NLOS link estimation, estimated signal travel time such as Reference Signal Time Difference (RSTD), or time difference of arrival (TDOA), etc. Then, based on the received information, the network node 110 can estimate if the UE 130 has received the localization signal via the repeater device 120a, 120b or not.

[0094] With an explicit indication in step S206 the UE 130 provides the network node 110 with its localization results. Corresponding, if the UE 130 has localized itself in the coverage area of the repeater device 120a, 120b (or, close to it), the network node 110 can assume that the localization signals have been received via the repeater device 120a, 120b and, thereby, that the localization results are not reliable. Alternatively, the network node 110 can determine that the UE 130 has localized itself based on the localization signals forwarded by the repeater device 120a, 120b based on the moving trajectory of the UE 130 (e.g., when the UE 130 is estimated to move towards the repeater device’s 120a, 120b coverage area).

[0095] In some aspects, the network node 110 transmits one or more second localization signals for the UE 130 and with different configurations for the repeater device 120a, 120b to use, as in optional steps S106 and S108. Examples of such configurations will be disclosed below. The UE 130 thus receives the one or more second localization signals as in step S208 and calculates a second localization result based on the one or more second localization signals in step S210. The UE 130 then sends an indication, as in step S212, to inform the network node 110 about its second localization result. This indication is by the network node 110 received in step S110 and used in step S112 to determine whether the one or more first localization signals were received via the repeater device 120a, 120b or not.

[0096] In this respect, if a different repeater device configuration is used for the second localization signals than for the first localization signals and the UE 130 still obtains the same localization result, it can be concluded that the UE 130 did not receive the first localization signals via the repeater device 120a, 120b. On the other hand, if the localization results change considerably by considering a different configuration for the repeater device 120a, 120b, it can be concluded that the UE 130 was receiving the first localization signals via the repeater device 120a, 120b.

[0097] Further, in some examples, the network node 110 determines that the UE 130 has been initially localized based on the first localization signals as forwarded by the repeater device 120a, 120b, in case one or a combination of the following conditions hold. Condition 1 : The UE 130 is incapable of establishing its localization based on the second localization signals whilst the UE 130 was indeed capable of establishing its localization based on the first localization signals. Condition 2: The localization results for the first localization signals and the second localization signals are very different from each other, for example by the difference being larger than a predefined threshold for some pre-defined metric. Condition 3: The directions, the travel time and / or the power of the received first localizations signals are considerably different from the directions, the travel time and / or the power of the received second localizations signals.

[0098] In some examples, the repeater device 120a, 120b is configured for the second localization signals according to any, or any combination of: adaptation of the repeater device’s 120a, 120b beams and / or beam types, adaptation of the reflection coefficients of the repeater device 120a, 120b (e.g., when the repeater device 120b is an IRS), adaptation of the repeater device’s 120a, 120b amplification gain, adaptation of the repeater device’s 120a, 120b operation frequency, turning the repeater device 120a, 120b OFF (completely or in some sub-arrays, or panels), using different polarizations, panels, etc. compared to during the transmission of the first localization signal.

[0099] As disclosed above, the network node 110 in step S114 transmits auxiliary information that is received by the UE 130 in step S214 and that is used by the UE 130 in step S216 to update the first localization result. There can be different examples of such auxiliary information. In some non-limiting examples, the auxiliary information comprises a new reference position point (based on the repeater device’s 120a, 120b UE-side position), a new reference time (by removing the network-repeater transmission delay plus any internal repeater device delay), information about the type of the beams for the location signals received by the UE 130 (i.e., without mentioning the presence of the repeater device 120a, 120b, the network node 110 informs that the UE 130 that it is receiving, e.g., wide or narrow beams), information about a power compensation value (removing the effect of networkrepeater link and the power amplification gain of the repeater device 120a, 120b). For example, the network node 110 can, by means of the auxiliary information, inform the UE 130 that the UE 130 should consider the position of the UE-side of the repeater device 120a, 120b as the reference point. Also, the network node 110 may inform the UE 130 about the sum of the network-repeater transmission delay and the internal repeater device delay. Moreover, the network node 110 may inform the UE 130 about a power compensation value (taking the power loss of the network-repeater link and the additional power amplification, if any, of the repeater device 120a, 120b into account). In this way, the effects of the network-repeater device and the power amplification as well as internal repeater device delay can be compensated for, and the UE 130 can thus localize itself more accurately by also considering the position of the UE-side of the repeater device 120a, 120b as the reference point.

[0100] In this respect, the repeater devices 120a, 120b are assumed to be stationary with known geographical locations. As a result, the network node 110 can be assumed to have access to accurate information about the repeater device’s 120a, 120b position, the power loss in the network-repeater link, the beams used by the repeater device 120a, 120b, and the signal travel delay in the network-repeater link, the repeater device’s 120a, 120b amplification gain, as well as the internal repeater device 120a, 120b delay. As a result, the network node 110 can properly inform the UE 130 to compensate the effect of these parameters.

[0101] There could be different ways for the UE 130 to update the first localization result, as in step S216.

[0102] In one example, the UE 130 considers the received auxiliary information and re-uses the first localization signal to re-compute the first localization result.

[0103] In another example, in an optional step S120 the network node 110 transmits one or more third localization signals to be received by the UE 130 (possibly via the repeater device 120a, 120b) for a third localization. Accordingly, the UE 130 receives the one or more third localization signals, as in step S220, and calculates a third localization result, as in step S222. The UE 130 might then inform the network node 110 accordingly. For this purpose, the network node 110 might reconfigure the repeater device 120a, 120b before the one or more third localization signals are transmitted, as in step S116. The reconfiguration might here, for example, pertain to the beam types, the number of beams, the amplification gain, the frequency, polarization, etc., to be used by the repeater device 120a, 120b when the one or more third localization signals are transmitted. Further, in one example, the network node 110 reconfigure the localization algorithm to be used by the UE 130 for the third localization process, as in steps S118 and S222. Here, reconfiguring the localization algorithm at the UE 130 might pertain to any, or any combination of: combining the localization signals received in different rounds (i.e., in steps S202, S208, and S220), ignoring the localization result in the first round (i.e., in step S204), ignoring any localization signals estimated to be NLOS, of low accuracy, etc. For calculation of the localizations as in any of steps S204, S210, and S222, the localization algorithm in the UE 130 may be based on any, or any combination, of: received beam / direction, received power (e.g., RSRP, RSRQ), received travel time (e.g., RSTD, TDOA), etc.)

[0104] Fig. 4 schematically illustrates, in terms of a number of structural units, the components of a network node 400 according to an embodiment. Processing circuitry 410 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 810a (as in Fig. 8), e.g. in the form of a storage medium 430. The processing circuitry 410 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

[0105] Particularly, the processing circuitry 410 is configured to cause the network node 400 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 430 may store the set of operations, and the processing circuitry 410 may be configured to retrieve the set of operations from the storage medium 430 to cause the network node 400 to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry 410 is thereby arranged to execute methods as herein disclosed.

[0106] The storage medium 430 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

[0107] The network node 400 may further comprise a communications (comm.) interface 420 for communications with other entities, functions, nodes, and devices in the repeater-assisted networks 100a, 100b. As such the communications interface 420 may comprise one or more transmitters and receivers, comprising analogue and digital components.

[0108] The processing circuitry 410 controls the general operation of the network node 400 e.g. by sending data and control signals to the communications interface 420 and the storage medium 430, by receiving data and reports from the communications interface 420, and by retrieving data and instructions from the storage medium 430. Other components, as well as the related functionality, of the network node 400 are omitted in order not to obscure the concepts presented herein.

[0109] Fig. 5 schematically illustrates, in terms of a number of functional modules, the components of a network node 500 according to an embodiment. The network node 500 of Fig. 5 comprises a number of functional modules; a first transmit module 505 configured to perform step S102, a first receive module 510 configured to perform step S104, a determine module 530 configured to perform step S112, and a second transmit module 535 configured to perform step S114. The network node 500 of Fig. 5 may further comprise a number of optional functional modules, such as any of a first reconfigure module 515 configured to perform step S106, a third transmit module 520 configured to perform step S108, a second receive module 525 configured to perform step S110, a second reconfigure module 540 configured to perform step S116, a fourth transmit module 545 configured to perform step S118, and a fifth transmit module 550 configured to perform step S120.

[0110] In general terms, each functional module 505:550 may be implemented in hardware or in software. Preferably, one or more or all functional modules 505:550 may be implemented by the processing circuitry 410, possibly in cooperation with the communications interface 420 and / or the storage medium 430. The processing circuitry 410 may thus be arranged to from the storage medium 430 fetch instructions as provided by a functional module 505:550 and to execute these instructions, thereby performing any steps of the network node 400 as disclosed herein.

[0111] The network node 110, 400, 500 may be provided as a standalone device or as a part of at least one further device. For example, the network node 110, 400, 500 may be provided in a node of the radio access network or in a node of the core network. Alternatively, functionality of the network node 110, 400, 500 may be distributed between at least two devices, or nodes. These at least two nodes, or devices, may either be part of the same network part (such as the radio access network or the core network) or may be spread between at least two such network parts. In general terms, instructions that are required to be performed in real time may be performed in a device, or node, operatively closer to the cell than instructions that are not required to be performed in real time. Thus, a first portion of the instructions performed by the network node 110, 400, 500 may be executed in a first device, and a second portion of the instructions performed by the network node 110, 400, 500 may be executed in a second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the network node 110, 400, 500 may be executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by a network node 110, 400, 500 residing in a cloud computational environment. Therefore, although a single processing circuitry 410 is illustrated in Fig. 4 the processing circuitry 410 may be distributed among a plurality of devices, or nodes. The same applies to the functional modules 505:550 of Fig. 5 and the computer program 820a of Fig. 8.

[0112] Some (radio) access network architectures define network nodes (or gNBs) comprising multiple component parts or nodes: a central unit (CU), one or more distributed units (DUs), and one or more radio units (RUs). The protocol layer stack of the network node is divided between the CU, the DUs and the RUs, with one or more lower layers of the stack implemented in the RUs, and one or more higher layers of the stack implemented in the CU and / or DUs. The CU is coupled to the DUs via a fronthaul higher layer split (HLS) network; the CU / DUs are connected to the RUs via a fronthaul lower-layer split (LLS) network. The DU may be combined with the CU in some embodiments, where a combined DU / CU may be referred to as a CU or simply a baseband unit. A communication link for communication of user data messages or packets between the RU and the baseband unit, CU, or DU is referred to as a fronthaul network or interface. Messages or packets may be transmitted from the network node 110, 600, 700 in the downlink (i.e., from the CU to the RU) or received by the network node 110, 600, 700 in the uplink (i.e., from the RU to the CU).

[0113] Fig. 6 schematically illustrates, in terms of a number of structural units, the components of a UE 600 according to an embodiment. Processing circuitry 610 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 810b (as in Fig. 8), e.g. in the form of a storage medium 630. The processing circuitry 610 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA). Particularly, the processing circuitry 610 is configured to cause the UE 600 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 630 may store the set of operations, and the processing circuitry 610 may be configured to retrieve the set of operations from the storage medium 630 to cause the UE 600 to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry 610 is thereby arranged to execute methods as herein disclosed.

[0114] The storage medium 630 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

[0115] The UE 600 may further comprise a communications interface 620 for communications with other entities, functions, nodes, and devices in the repeater-assisted networks 100a, 100b. As such the communications interface 620 may comprise one or more transmitters and receivers, comprising analogue and digital components.

[0116] The processing circuitry 610 controls the general operation of the UE 600 e.g. by sending data and control signals to the communications interface 620 and the storage medium 630, by receiving data and reports from the communications interface 620, and by retrieving data and instructions from the storage medium 630. Other components, as well as the related functionality, of the UE 600 are omitted in order not to obscure the concepts presented herein.

[0117] Fig. 7 schematically illustrates, in terms of a number of functional modules, the components of a UE 700 according to an embodiment. The UE 700 of Fig. 7 comprises a number of functional modules; a first receive module 705 configured to perform step S202, a first calculate module 710 configured to perform step S204, a first send module 715 configured to perform step S206, a second receive module 735 configured to perform step S214, and an update module 740 configured to perform step S216. The UE 700 of Fig. 7 may further comprise a number of optional functional modules, such as any of a third receive module 720 configured to perform step S208, a second calculate module 725 configured to perform step S210, a second send module 730 configured to perform step S212, a fourth receive module 745 configured to perform step S218, a fifth receive module 750 configured to perform step S220, and a third calculate module 755 configured to perform step S222.

[0118] In general terms, each functional module 705:755may be implemented in hardware or in software. Preferably, one or more or all functional modules 705:755may be implemented by the processing circuitry 610, possibly in cooperation with the communications interface 620 and / or the storage medium 630. The processing circuitry 610 may thus be arranged to from the storage medium 630 fetch instructions as provided by a functional module 705:755 and to execute these instructions, thereby performing any steps of the UE 600 as disclosed herein.

[0119] Fig. 8 shows one example of a computer program product 810a, 810b comprising computer readable means 830. On this computer readable means 830, a computer program 820a can be stored, which computer program 820a can cause the processing circuitry 410 and thereto operatively coupled entities and devices, such as the communications interface 420 and the storage medium 430, to execute methods according to embodiments described herein. The computer program 820a and / or computer program product 810a may thus provide means for performing any steps of the network node 400, 500 as herein disclosed. On this computer readable means 830, a computer program 820b can be stored, which computer program 820b can cause the processing circuitry 610 and thereto operatively coupled entities and devices, such as the communications interface 620 and the storage medium 630, to execute methods according to embodiments described herein. The computer program 820b and / or computer program product 810b may thus provide means for performing any steps of the UE 600, 700 as herein disclosed.

[0120] In the example of Fig. 8, the computer program product 810a, 810b is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product 810a, 810b could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program 820a, 820b is here schematically shown as a track on the depicted optical disk, the computer program 820a, 820b can be stored in any way which is suitable for the computer program product 810a, 810b.

[0121] The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.

Claims

CLAIMS1. A method for downlink localization of a user equipment, UE (130), in a repeater-assisted network (100a, 100b), wherein the method is performed by a network node (110), wherein the network node (110) serves the UE (130) via a repeater device (120a, 120b) in the repeater-assisted network (100a, 100b), and wherein the method comprises: transmitting (S102) at least one first localization signal for downlink localization of the UE (130); receiving (S104) a first indication from the UE (130) about a first localization result based on measurements made by the UE (130) on the at least one first localization signal; determining (S112), based on the first indication from the UE (130) about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device (120a, 120b); and transmitting (S114) auxiliary information to the UE (130) for refined downlink localization of the UE (130).

2. The method according to claim 1, wherein the at least one first localization signal is transmitted in different time resources of at least two directional beams, wherein one of the directional beams is directed towards the repeater device (120a, 120b).

3. The method according to claim 1, wherein the first indication from the UE (130) is the first localization result itself and specifies a location of the UE (130) in relation to the network node (110) or another reference point known to the network node (110) and the UE (130).

4. The method according to claim 1, wherein the first indication from the UE (130) comprises information of at least one of: angle of arrival, or direction, of the at least one first localization signal as received by the UE (130), beam indicator associated with the at least one first localization signal, received signal power and / or received signal quality of the at least one first localization signal, a line-of-sight or non-line-of-sight link estimation made by the UE (130) based on measurements on the at least one first localization signal, estimated signal travel time for the at least one first localization signal.

5. The method according to claim 1, wherein the method further comprises: reconfiguring (S106) the repeater device (120a, 120b) after having transmitted the at least one first localization signal; transmitting (S 108) at least one second localization signal for the downlink localization of the UE (130);receiving (S110) a second indication from the UE (130) about a second localization result based on measurements made by the UE (130) on the at least one second localization signal; and wherein determining that the first localization result is based on the at least one first localization signal as forwarded by the repeater device (120a, 120b) is based on comparing the first indication to the second indication.

6. The method according to claim 1, wherein reconfiguring the repeater device (120a, 120b) comprises at least one of: adapting directional beams and / or beam types used by the repeater device (120a, 120b), adapting reflection coefficients of the repeater device (120a, 120b), adapting amplification gain of the repeater device (120a, 120b), adapting operation frequency of the repeater n device (120a, 120b) ode, turning off at least one antenna panel in the repeater device (120a, 120b), changing polarization, or antenna panels, in the repeater device (120a, 120b).

7. The method according to claim 1, wherein the first localization result is determined to be based on the at least one first localization signal as forwarded by the repeater device (120a, 120b) in case at least one condition holds, wherein the at least one condition holds when: the first indication indicates that the UE (130) is capable of localization while the second indication indicates that the UE (130) is incapable of localization, and / or the first localization result and the second localization result differ more than a pre-defined threshold from each other.

8. The method according to claim 5, wherein determining that the first localization result is determined to be based on the at least one first localization signal as forwarded by the repeater device (120a, 120b) based on a moving trajectory of the UE (130) as derived from a difference between the first indication and the second indication.

9. The method according to claim 1, wherein the auxiliary information pertains to at least one of: a new reference position point that is based on a location of the repeater device (120a, 120b) as facing the UE (130), a new reference time value, information about type of directional beams in which the at least one first localization signal is transmitted, information about a power compensation value.

10. The method according to claim 1, wherein the UE (130) is configured with localization parameters for calculating the first localization result, and wherein the method further comprises: reconfiguring (S116) the repeater device (120a, 120b) after having transmitted the auxiliary information; transmitting (S118), after having reconfigured the repeater device (120a, 120b), reconfiguration to the UE (130) of the localization parameters for calculating a third localization result; and transmitting (S120) at least one third localization signal for the refined downlink localization of the UE (130).11 . The method according to claim 10, wherein the reconfiguration pertains to at least one of: combining the at least one first localization signal with the at least one third localization signal, ignoring the first localization result, ignoring any of the at least one first localization signal and the at least one third localization signal when estimated to be of a non-line-of-sight link, or of low accuracy.

12. A method for downlink localization of a user equipment, UE (130), in a repeater-assisted network (100a, 100b), wherein the UE (130) is served by a network node (110) in the repeater-assisted network (100a, 100b), wherein the method is performed by the UE (130), and wherein the method comprises: receiving (S202) at least one first localization signal, originating from the network node (110), for downlink localization of the UE (130); calculating (S204) a first localization result based on measurements made by the UE (130) on the at least one first localization signal; sending (S206) a first indication to the network node (110) about the first localization result; receiving (S214) auxiliary information, originating from the network node (110), for refined downlink localization of the UE (130); and updating (S216) the first localization result based on the auxiliary information.

13. The method according to claim 12, wherein the first indication is the first localization result itself and specifies a location of the UE (130) in relation to the network node (110) or another reference point known to the network node (110) and the UE (130).

14. The method according to claim 12, wherein the first indication comprises information of at least one of: angle of arrival, or direction, of the at least one first localization signal as received by the UE (130), beamindicator associated with the at least one first localization signal, received signal power and / or received signal quality of the at least one first localization signal, a line-of-sight or no-line-of-sight link estimation made by the UE (130) based on measurements on the at least one first localization signal, estimated signal travel time for the at least one first localization signal.

15. The method according to claim 12, wherein the method further comprises: receiving (S208) at least one second localization signal, originating from the network node (110), for the downlink localization of the UE (130); calculating (S210) a second localization result based on measurements made by the UE (130) on the at least one second localization signal; and sending (S212) a second indication to the network node (110) about the second localization result.

16. The method according to claim 12, wherein the auxiliary information pertains to at least one of: a new reference position point that is based on a location of the repeater device (120a, 120b) as facing the UE (130), a new reference time value, information about type of directional beams in which the at least one first localization signal is transmitted, information about a power compensation value.

17. The method according to claim 12, wherein the UE (130) is configured with localization parameters for calculating the first localization result, and wherein the method further comprises: receiving (S218), after having received the auxiliary information, reconfiguration from the network node (110) of the localization parameters; receiving (S220) at least one third localization signal for the refined downlink localization of the UE (130); and calculating (S222) a third localization result based on measurements made by the UE (130) on the at least one third localization signal and using the localization parameters as reconfigured according to the reconfiguration.

18. The method according to claim 17, wherein the reconfiguration pertains to at least one of: combining the at least one first localization signal with the at least one third localization signal, ignoring the first localization result,ignoring any of the at least one first localization signal and the at least one third localization signal when estimated to be of a non-line-of-sight link, or of low accuracy.

19. A network node (400) for downlink localization of a user equipment, UE (130), in a repeater-assisted network (100a, 100b), the network node (400) being configured to server the UE (130) via a repeater device (120a, 120b) in the repeater-assisted network (100a, 100b), the network node (400) comprising processing circuitry (410), the processing circuitry being configured to cause the network node (400) to: transmit at least one first localization signal for downlink localization of the UE (130); receive a first indication from the UE (130) about a first localization result based on measurements made by the UE (130) on the at least one first localization signal; determine, based on the first indication from the UE (130) about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device (120a, 120b); and transmit auxiliary information to the UE (130) for refined downlink localization of the UE (130).

20. A network node (500) for downlink localization of a user equipment, UE (130), in a repeater-assisted network (100a, 100b), the network node (500) being configured to serve the UE (130) via a repeater device (120a, 120b) in the repeater-assisted network (100a, 100b), the network node (500) comprising: a first transmit module (505) configured to transmit at least one first localization signal for downlink localization of the UE (130); a receive module (510) configured to receive a first indication from the UE (130) about a first localization result based on measurements made by the UE (130) on the at least one first localization signal; a determine module (530) configured to determine, based on the first indication from the UE (130) about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device (120a, 120b); and a second transmit module (535) configured to transmit auxiliary information to the UE (130) for refined downlink localization of the UE (130).21 . The network node (400, 500) according to claim 19 or 20, further being configured to perform the method according to any of claims 2 to 11.

22. A user equipment, UE (600), for downlink localization of the UE (600) in a repeater-assisted network (100a, 100b), the UE (130) being configured to be served by a network node (110) in the repeater-assistednetwork (100a, 100b), the UE (600) comprising processing circuitry (610), the processing circuitry being configured to cause the UE (600) to: receive at least one first localization signal, originating from the network node (110), for downlink localization of the UE (600); calculate a first localization result based on measurements made by the UE (600) on the at least one first localization signal; send a first indication to the network node (110) about the first localization result; receive auxiliary information, originating from the network node (110), for refined downlink localization of the UE (600); and update the first localization result based on the auxiliary information.

23. A user equipment, UE (700), for downlink localization of the UE (700) in a repeater-assisted network (100a, 100b), the UE (700) being configured to be served by a network node (110) in the repeater-assisted network (100a, 100b), the UE (700) comprising: a first receive module (705) configured to receive at least one first localization signal, originating from the network node (110), for downlink localization of the UE (700); a calculate module (710) configured to calculate a first localization result based on measurements made by the UE (700) on the at least one first localization signal; a send module (715) configured to send a first indication to the network node (110) about the first localization result; a second receive module (735) configured to receive auxiliary information, originating from the network node (110), for refined downlink localization of the UE (700); and an update module (740) configured to update the first localization result based on the auxiliary information.

24. The UE (600, 700) according to claim 22 or 23, further being configured to perform the method according to any of claims 13 to 18.

25. A computer program (820a) for downlink localization of a user equipment, UE (130), in a repeater-assisted network (100a, 100b), the computer program comprising computer code which, when run on processing circuitry (410) of a network node (400) configured to serve the UE (130) via a repeater device (120a, 120b) in the repeater-assisted network (100a, 100b), causes the network node (400) to:"2-1 transmit (S 102) at least one first localization signal for downlink localization of the UE (130); receive (S104) a first indication from the UE (130) about a first localization result based on measurements made by the UE (130) on the at least one first localization signal; determine (S112), based on the first indication from the UE (130) about the first localization result, that the first localization result is based on the at least one first localization signal as forwarded by the repeater device (120a, 120b); and transmit (S 114) auxiliary information to the UE (130) for refined downlink localization of the UE (130).

26. A computer program (820b) for downlink localization of a user equipment, UE (600), in a repeater-assisted network (100a, 100b), the computer program comprising computer code which, when run on processing circuitry (610) of the UE (600) configured to be served by a network node (110) in the repeater-assisted network (100a, 100b), causes the UE (600) to: receive (S202) at least one first localization signal, originating from the network node (110), for downlink localization of the UE (600); calculate (S204) a first localization result based on measurements made by the UE (600) on the at least one first localization signal; send (S206) a first indication to the network node (110) about the first localization result; receive (S214) auxiliary information, originating from the network node (110), for refined downlink localization of the UE (600); and update (S216) the first localization result based on the auxiliary information.

27. A computer program product (810a, 810b) comprising a computer program (820a, 820b) according to at least one of claims 25 and 26, and a computer readable storage medium (830) on which the computer program is stored.

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