WO2025032445A1 - Sequence-based sidelink positioning reference signal conflict indication in sidelink positioning - Google Patents

Abstract

Sequence-based sidelink positioning reference signal conflict indication in sidelink positioning is provided. A method for sequence-based sidelink positioning reference signal conflict indication may include receiving sidelink positioning reference signal transmissions from at least two anchor user equipment and associating each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter. The method may also include determining whether the sidelink positioning reference signal transmissions are conflicted.

Description

TITLE:

SEQUENCE-BASED SIDELINK POSITIONING REFERENCE SIGNAL CONFLICT INDICATION IN SIDELINK POSITIONING

TECHNICAL FIELD:

[0001] Some example embodiments may generally relate to mobile or wireless telecommunication systems, such as Long Term Evolution (LTE) or fifth generation (5G) new radio (NR) access technology, or 5G beyond, or other communications systems. For example, certain example embodiments may relate to sequence-based sidelink (SL) positioning reference signal (PRS) conflict indication in SL positioning.

BACKGROUND:

[0002] Examples of mobile or wireless telecommunication systems may include the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN), LTE-Advanced (LTE-A), MulteFire, LTE-A Pro, and/or fifth generation (5G) radio access technology or new radio (NR) access technology. Fifth generation (5G) wireless systems refer to the next generation (NG) of radio systems and network architecture. 5G network technology is mostly based on new radio (NR) technology, but the 5G (or NG) network can also build on E-UTRAN radio. It is estimated that NR may provide bitrates on the order of 10-20 Gbit/s or higher, and may support at least enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC) as well as massive machine-type communication (mMTC). NR is expected to deliver extreme broadband and ultra-robust, low- latency connectivity and massive networking to support the Internet of Things (loT). SUMMARY:

[0003] Various exemplary embodiments may provide an apparatus including 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 receive sidelink positioning reference signal transmissions from at least two anchor user equipment. The apparatus may also be caused to associate each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter, and determine whether the sidelink positioning reference signal transmissions are conflicted. [0004] Certain exemplary embodiments may provide an apparatus including 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 transmit a sidelink positioning reference signal transmission to a target user equipment. The apparatus may also be caused to receive, from the target user equipment, an indication of a sidelink positioning reference signal conflict and determine whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

[0005] Some exemplary embodiments may provide an apparatus including 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 receive, from a user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions. The apparatus may also be caused to determine whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

[0006] Certain exemplary embodiments may provide a method including receiving sidelink positioning reference signal transmissions from at least two anchor user equipment and associating each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter. The method may also include determining whether the sidelink positioning reference signal transmissions are conflicted.

[0007] Various exemplary embodiments may provide a method including transmitting a sidelink positioning reference signal transmission to a target user equipment and receiving, from the target user equipment, an indication of a sidelink positioning reference signal conflict. The method may also include determining whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

[0008] Some exemplary embodiments may provide a method including receiving, from a user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions and determining whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

[0009] Certain exemplary embodiments may provide an apparatus including means for receiving sidelink positioning reference signal transmissions from at least two anchor user equipment and means for associating each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter. The apparatus may also include means for determining whether the sidelink positioning reference signal transmissions are conflicted.

[0010] Various exemplary embodiments may provide an apparatus including means for transmitting a sidelink positioning reference signal transmission to a target user equipment and means for receiving, from the target user equipment, an indication of a sidelink positioning reference signal conflict. The apparatus may include means for determining whether to reselect a resource or sequence of the sidelink positioning reference signal transmission. [0011] Certain exemplary embodiments may provide an apparatus including means for receiving, from a user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions and means for determining whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

[0012] Some exemplary embodiments may provide a non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus at least to receive sidelink positioning reference signal transmissions from at least two anchor user equipment. The non- transitory computer readable medium may also cause the apparatus to associate each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter, and determine whether the sidelink positioning reference signal transmissions are conflicted.

[0013] Various exemplary embodiments may provide a non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus at least to transmit a sidelink positioning reference signal transmission to a target user equipment. The non- transitory computer readable medium may also cause the apparatus to receive, from the target user equipment, an indication of a sidelink positioning reference signal conflict, and determine whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

[0014] Certain exemplary embodiments may provide a non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus at least to receive, from a user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions, and determine whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions. [0015] Some exemplary embodiments may provide one or more computer programs including instructions stored thereon for performing one or more of the methods described herein. Some exemplary embodiments may also provide one or more apparatuses including one or more circuitry configured to perform one or more of the methods described herein.

BRIEF DESCRIPTION OF THE DRAWINGS:

[0016] For proper understanding of example embodiments, reference should be made to the accompanying drawings, as follows:

[0017] FIG. 1 illustrates an example of a configuration of UEs to perform SL positioning;

[0018] FIG. 2 illustrates an example of a signal diagram for SL PRS conflict mitigation, according to certain exemplary embodiments;

[0019] FIG. 3 illustrates an example of a flow diagram of a method, according to various exemplary embodiments;

[0020] FIG. 4 illustrates an example of a flow diagram of another method, according to certain exemplary embodiments;

[0021] FIG. 5 illustrates an example of a flow diagram of a further method, according to some exemplary embodiments; and

[0022] FIG. 6 illustrates a set of apparatuses, according to various exemplary embodiments.

DETAILED DESCRIPTION:

[0023] It will be readily understood that the components of certain example embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. The following is a detailed description of some exemplary embodiments of systems, methods, apparatuses, and non-transitory computer program products for sequence-based sidelink (SL) positioning reference signal (PRS) conflict indication in SL positioning. Although the devices discussed below and shown in the figures refer to 5 G or Next Generation NodeB (gNB) devices and user equipment (UE) devices, this disclosure is not limited to only gNBs and UEs.

[0024] It may be readily understood that the components of certain example embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Different reference designations from multiple figures may be used out of sequence in the description, to refer to a same element to illustrate their features or functions. If desired, the different functions or procedures discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the described functions or procedures may be optional or may be combined. As such, the following description should be considered as illustrative of the principles and teachings of certain example embodiments, and not in limitation thereof.

[0025] In 5G/NR technology, direct device-to-device communications, such as UE to UE, vehicle-to- vehicle (V2V), vehicle-to-everything (V2X), and the like, may be referred to as sidelink (SL) communications. NR SL communications may be performed by unicast, groupcast, and broadcast. In unicast, a device, such as a UE, may target communications directly to a specific receiving device to receive the communications. In groupcast, the UE may target a group of receiving devices to receive the communications. In broadcast, the UE may target any and all devices that may be within a range of transmission relative to the UE.

[0026] As part of sidelink transmissions, the devices, such as UEs, may intercoordinate with each other to determine resource information and allocation for the sidelink transmission. This procedure may be referred to as inter-UE- Coordination (IUC). As part of the IUC procedure, a first UE may transmit a request, referred to as lUCRequest, to a second UE by unicast communication. The second UE may provide a response, which may be in the form of an lUCInformation message, to the first UE. The response from the second UE may include information related to resource allocation and/or channel information. Alternatively, the second UE may ignore the lUCRequest from the first UE. For example, the second UE may ignore the lUCRequest when the second UE does not have any sensing results.

[0027] 3^rd Generation Partnership Project (3GPP) specifications may define certain performance requirements for different positioning service levels. The requirements may include, for example, horizontal and vertical accuracy, positioning service availability, and positioning service latency. For example, the requirements may be particularly strict for a positioning service level 4, requiring 99.9 % availability and 15ms latency, and a positioning service level 6, requiring 99.9 % availability and 10ms latency. These examples may apply to, for example, vehicle platooning, cooperative lane merge, lane change warning, emergency break warning, intersection movement assist, high definition sensor sharing, vulnerable road user (VRU) collision risk warning, cooperative maneuvers in emergency situations, real-time situation awareness, high-definition maps, and the like. Further examples may be for factories of the future scenarios, such as augmented reality in smart factories, mobile control panels with safety functions in smart factories, inbound logistics for manufacturing, such as for driving trajectories of indoor autonomous driving systems. These are mere examples and the exemplary embodiments discussed herein are not limited to these examples.

[0028] SL positioning may be used to position a target UE using SL radio interface with one or more anchor UEs. The target UE may be a UE to be positioned using, for example, a PC5 interface. The anchor UE may be a UE supporting positioning of the target UE, such as, for example, by transmitting and/or receiving reference signals for positioning, providing positioning- related information, and the like, over the SL interface. SL positioning may use reference signals transmitted over SL, such as a PC5 interface, to obtain absolute position, relative position, or ranging information. The ranging information may be a determination of the distance and/or the direction between the target UE and another entity, such as the anchor UE.

[0029] FIG. 1 illustrates an example of a configuration of UEs to perform SL positioning. SL positioning is based on transmissions of SL PRS by multiple anchor UEs to be received by the target UE. The SL PRS may be a reference signal transmitted over SL for positioning purposes, and an SL PRS configuration may be parameters, which may be pre-configured, of SL PRS, such as time-frequency resources including bandwidth and periodicity. SL positioning using transmissions of SL PRS by multiple anchor UEs may be based on SL time difference of arrival (TDOA) procedures or SL PRS exchange between the anchor UEs and the target UE in, for example, SL round trip time (RTT), or multi-RTT, to enable localization of the target UE and/or ranging of target UE relative to a reference UE, which may be an anchor UE. The localization of the target UE and/or ranging of target UE relative to the reference UE may be within certain latency and accuracy requirements of the corresponding SL positioning.

[0030] In FIG. 1, the SL positioning configuration may include a target UE (UE-T) 101 performing SL positioning by receiving SL PRS from multiple, e.g., three anchor UEs (UE-A1 102, UE-A2 103 and UE-A3 104). The target UE 101 may determine the location of the target UE 101 using SL TDOA. The anchor UEs 102/103/104 may be considered as providing SL PRS assistance, such as by providing the SL PRS, to the target UE 101. An incoverage procedure may provide that a location management function (LMF) may coordinate the SL positioning in which the SL PRS transmissions from the anchor UEs 102/103/104 may be configured by the LMF.

[0031] The SL PRS sequence may be generated based on the following Equation (1):

where c(2n) and c(2n + 1) represent a pseudo-random sequence.

[0032] The SL PRS sequence may be generated using a pseudo-random sequence c(i) initialization equation as a function of at least a slot number, a symbol number, and a parameter

The pseudo-random sequence c(i) initialization equation may be based on an initialization equation as for DL PRS.

[0033] For a shared resource pool, an existing IUC signaling of both Scheme 1 (similar to mode 1 in legacy SL communication) and Scheme 2 (similar to mode 2 in legacy SL communication) may be reused. SL-PRS transmissions may be treated as any other legacy transmission for SL communication when considering IUC information exchanges. An SL PRS resource may refer to a time-frequency resource within a slot of a dedicated SL PRS resource pool that is used for SL PRS transmission. Characteristics associated with a SL PRS resource may include at least a resource ID, a comb offset and associated SL PRS comb size, a starting symbol and number of SL PRS symbols, and/or frequency domain allocation. An SL PRS resource may be identified by a SL PRS resource ID that is unique within a slot of a dedicated SL PRS resource pool. For a shared resource pool, the SL PRS resource may be a timefrequency resource within a slot that is used for SL PRS transmission.

[0034] In IUC scheme-2, a UE may monitor sidelink control information (SCIs), which include time-frequency resource info, transmitted from two or more other UEs and may detect a time-frequency resource conflict. The UE may send a resource conflict indication to one or more of the two or more transmitting UEs to make the two or more transmitting UEs aware of the sidelink transmission conflict. SL PRS transmissions on the same or different resource, may be able to perform PRS transmissions. Each SL PRS transmission may be based on a SL PRS sequence, such that two SL PRSs may reliably use the same time-frequency resource when the SL PRS sequences are orthogonal, or substantially orthogonal, in code-domain.

[0035] Various exemplary embodiments may advantageously provide one or more procedures for adopting an IUC scheme-2 to improve reliability performance of SL PRS transmissions while avoiding false alarms on SL PRS conflicts using the legacy procedures since legacy procedures only consider conflict in time-frequency and may impact the channel utilization. Certain exemplary embodiments may improve channel utilization, reliability performance of SL PRS transmissions, and accuracy performance of positioning.

[0036] Certain exemplary embodiments may provide an assistance UE that detects a SL PRS resource conflict between SL PRS resources of two or more SL PRS transmissions and associates an SL PRS sequence for each of the SL PRS transmissions. The association of the SL PRS sequence may be based on an actual SL PRS sequence generation parameter used, or to be used, in the SL PRS, if known. The assistance UE may be aware of the SL PRS sequence generation parameter

which may be either provided by higher layers, or based on a cyclic redundancy check (CRC) of a physical shared control channel (PSCCH) associated with the SL PRS. For example, the SL PRS sequence may be generated based on, for example, 12 least significant bits (LSB) CRC of PSCCH associated with the SL PRS.

[0037] The assistance UE may determine whether the SL PRS are conflicted in terms of SL PRS resources and/or SL PRS sequence based on at least the associated SL PRS sequences of the SL PRS transmissions. Determining whether a conflict exists may be based on detecting that the associated SL PRS sequences are not orthogonal or substantially orthogonal.

[0038] The assistance UE may transmit or otherwise provide an SL PRS conflict indication when the SL PRS conflict is determined. The SL PRS conflict indication may contain information on the conflicting SL PRS resource, such as SL PRS resource IDs of the conflicted SL PRS resources, and/or information on SL PRS sequence association for conflict determination. As an example of the information on the SL PRS association, the SL PRS sequence generation parameter may be used, if known, for one or more of the SL PRS transmissions. As another example, the information may be an indication of whether the SL PRS sequence generation parameter ⁿi^SD,seq^S i^s known at the assistance UE for one or more of the SL PRS transmissions. As a further example, the information may indicate whether the assistance UE for one or more SL PRS transmissions may have assumed that the SL PRS sequence is generated based on 12 LSB bits CRC of PSCCH associated with the SL PRS.

[0039] Some exemplary embodiments may provide that the UE, which may transmit the SL PRS, which may be referred to as an SL PRS transmitting UE, may receive the SL PRS conflict indication and determine whether to reselect the SL PRS resource and/or SL PRS sequence for the SL PRS transmission. In addition, or as an alternative, the UE may determine whether to retransmit the SL PRS based on at least the SL PRS conflict information and the SL PRS sequence generation used at the UE which transmitted the SL PRS. An LMF or a server UE may receive an indication on SL positioning measurements characterized by SL PRS conflict and/or the LMF or the server UE may determine whether to change the associated positioning process. At least a portion of the SL positioning measurements performed in a SL PRS resource may be discarded based on at least the SL PRS conflict information.

[0040] The SL PRS resource may refer to a time-frequency resource within a slot that is used for SL PRS transmission. For SL PRS sequence generation, the SL PRS transmitting UE may define the parameter n⁸D_;'_Seq^S by either setting the parameter

to be a higher layer configured parameter or by setting the parameter

based on a 12 bits CRC of PSCCH associated with the SL PRS transmission. When the parameter n⁸D_;'_Seq^S is a higher layer configured parameter, the receiver UE may provide the SL PRS sequence generation parameter. When the parameter n^’^q⁸ is based on the CRC of the PSCCH, the received UE may obtain the SL PRS sequence generation parameter based on the CRC of the PSCCH associated with the SL PRS transmission. A slot number, a symbol number, and the parameter n^’^q⁸ may be used to define the SL PRS sequence based the above-mentioned Equation (1).

[0041] Various exemplary embodiments may include a UE-A 202, which is an assistance UE. The UE-A 202 may monitor an SL PRS and associated SCI transmissions from UE-Bs 203/204, which are SL PRS transmitting UEs. The UE-A 202 may identify an SL PRS resource conflict between transmissions from the UE-Bs 203/204. For example, the UE-A 202 may monitor the transmission for a partial or complete overlap of SL PRS combs based on the monitored SCIs. The UE-A 202 may associate an SL PRS sequence for each of the SL PRS transmissions based on either (i) a known SL PRS sequence generation based on a known parameter n^ ^q⁸ and an actual SL PRS sequence ID, or (ii) an assumption that the SL PRS sequence is generated based on 12 LSB bits CRC of PSCCH associated with the SL PRS and an assumed SL PRS sequence ID.

[0042] The UE-A 202 may determine whether the SL PRS are conflicted based on at least the associated SL PRS sequences of the SL PRS transmissions. When the SL PRS conflict is determined, the UE-A 202 may transmit or otherwise provide an SL PRS indication to one or more of the UE-Bs 203/204. The SL PRS conflict indication may include information on the SL PRS sequence association for determining the SL PRS conflict.

[0043] Certain exemplary embodiments may provide that the one or more UE- Bs 203/204, which may function as SL PRS transmitting UEs, may receive the SL PRS conflict indication from the UE-A 202. The UE-B 203/204 may determine whether to select or reselect a SL PRS resource and/or SL PRS sequence for the SL PRS transmission. In addition, or as an alternative, the UE-B 203/204 may determine whether to retransmit the SL PRS based on at least the information on the SL PRS conflict and the generated SL PRS sequence used by the UE-A 202 functioning as the SL PRS transmitting UE. [0044] Some exemplary embodiments may provide that the UE-A 202 communicates with an LME or server UE 201. The LME (or server UE) 201 may receive the SL PRS conflict indication from the UE-A 202. upon receiving a notification on conflict determination, such as via the SL PRS conflict indication, the LMF (or server UE) 201 may determine whether to discard at least a portion of SL positioning measurements made in a SL PRS resource based on at least the SL PRS conflict information and the generated SL PRS sequence used at the UE-A 202, functioning as the SL PRS transmitting UE.

[0045] FIG. 2 illustrates an example of a signal diagram for SL PRS conflict mitigation in a network, according to certain exemplary embodiments. The network may include the LMF (or server UE) 201, UE-A 202, UE-B 203, and UE-B 204. At 210, the UE-B 203 may provide SCI and an SL PRS to the UE- A 202, and at 215, the UE-B 204 may also provide SCI and an SL PRS to the UE-A 202. The UE-B 203 and UE-B 204 may serve as anchor UEs. UE-A 202 may be referred to as the assistance UE and may monitor SL resource pools. The UE-A 202 may or may not be the intended recipient of SL-PRSs from UE-B 203 and UE-B 204. The LMF or server UE 201 may collect SL PRS measurements from a target UE, for example, for SL-TDOA-based positioning. The target UE may be UE-A 202 or may be another UE not shown in the figures.

[0046] At 220, the UE-A 202 may monitor for and identify an SL PRS resource conflict using the SL PRSs and associated SCI transmissions from the UE-Bs 203/204. The resource conflict between SL PRS resources of two or more SL PRS transmissions may be identified or detected when the SL PRS resources at least partially overlap in the time-frequency domain. At 230, the UE-A 202 may associate an SL PRS sequence for each of the SL PRS transmissions. The SL PRS sequence association may be based on an actual SL PRS sequence generation parameter nf^’seq⁸ used in the SL PRS, if known. The actual SL PRS sequence generation parameter n^g^⁸ may be provided to UE-A 202 by either higher layers or UE-A 202 may obtain the parameter ⁿi^SD,seq^S based on, for example, 12 LSB bits CRC of PSCCH associated with the SL PRS. The UE-A 202 may be aware of the actual SL PRS sequence generation procedures using either a higher layer configured parameter or a CRC of the PSCCH with the SL PRS transmission. Alternatively, the SL PRS sequence association may be based on assuming that the SL PRS sequence is generated based on 12 LSB bits CRC of PSCCH associated with the SL PRS. [0047] At 240, the UE-A 202 may determine whether the SL PRSs are conflicted based on at least the associated SL PRS sequences of the SP PRS transmissions. The UE-A 202 may account for reference signal received power (RSRP) measurements and/or mobility characteristics (e.g., velocity) in determining the SL PRS conflict. Lor example, if RSRP of one conflicting SL PRS transmission is lower than the RSRP of another SL PRS transmission(s), the UE-A 202 may not determine there to be an SL PRS conflict and the target UE may be assumed to be at a close proximity to the UE-A 202 (assistance UE). SL PRS conflict determination may be based on whether or not the SL PRSs can be successively received given the distance between SL PRSs in code-domain, even when overlapping in time-frequency resource. Lor example, two SL PRSs may use the same time-frequency resource and be considered reliable when the SL PRS sequences are orthogonal, or substantially orthogonal, in code-domain. When the associated SL PRS are orthogonal, or substantially orthogonal, the SL PRSs may be determined to be not conflicted.

[0048] At 250, the UE-A 202 may transmit an SL PRS conflict indication to one or both of UE-B 203 and UE-B 204 at least when the SL PRS conflict is determined. At 255, the UE-A 202 may alternatively or additionally transmit the SL PRS conflict indication to the LMF (server UE) 201. The SL PRS conflict indication may include information on the SL PRS sequence association for determining the conflict. The SL PRS conflict indication may include additional information, such as an indication or information on generating the SL PRS sequence, if known, for one or more of the SL PRS transmissions, information on whether the SL PRS sequence generation parameter n⁸D_;'_Seq^S is known at the UE-A 202 (assistance UE) for one or more of the SL PRS transmissions, and/or information on whether the UE-A 202 (assistance UE) has assumed for one or more SL PRS transmissions that an SL PRS sequence may be generated based on, for example, 12 LSB bits CRC of PSCCH associated with the SL PRS. The SL PRS conflict indication may be transmitted over sidelink positioning protocol (SLPP) to another UE, LTE positioning protocol (LPP) to the LMF (server UE) 201, and/or physical sidelink feedback channel (PSFCH) to another UE.

[0049] At 260, one or both of UE-B 203 and/or UE-B 204 may determine whether to reselect the SL PRS resource and/or SL PRS sequence for the respective SL PRS transmission and/or whether to retransmit the SL PRS based on at least the SL PRS conflict information and how the SL PRS sequence was generated at the UE-A 202 (e.g., SL PRS transmitting UE). As an example, UE-B 203 may reselect the SL PRS resources or SL PRS sequence for the next transmission if the SL PRS conflict is determined at UE-A 202 based on actual SL PRS sequence information and the sequence generation of the conflicted SL PRS is based on a higher layer configured parameter for at least two of the conflicting UE-Bs 203/204. Alternatively, the conflicted SL PRS sequence may be generated using the parameter

as 12 bits CRC of PSCCH associated with the SL PRS transmission. As another example, if the SL PRS sequence is generated using a higher layer configured parameter at, for example, UE-B 203 and the SL PRS sequence is assumed to be generated using the parameter n⁸D_;'_Seq^S as 12 bits CRC of PSCCH associated with the SL PRS transmission for another conflicting UE- B, such as UE-B 204, at UE-A, and a quality of service (QoS) requirement (e.g., positioning accuracy) is higher than a threshold, the UE-B 203 may reselect the SL PRS resources or SL PRS sequence for the next transmission. Due to the higher QoS requirement, UE-B 203 may consider the conflicting UE-B 204 as a persistently conflicting UE.

[0050] Some exemplary embodiments may provide a UE-B, such as UE-B 203, may retransmit the SL PRS to allow for additional measurement at target UE(s) if the SL PRS conflict is determined at UE-A 202 based on actual SL PRS sequence information and the SL PRS sequence of the conflicted SL PRS is generated based on a higher layer configured parameter for at least two of the conflicting UE-Bs 203/204. The UE-B 203 may retransmit the SL PRS if the SL PRS sequence of the conflicted SL PRS generated based on a higher layer configured parameter is used at the UE-B 203 and the SL PRS sequence of the conflicted SL PRS is generated based on an assumption that the parameter n⁸D_;'_Seq^S may be 12 bits CRC of PSCCH associated with the SL PRS transmission for another conflicting UE-B, such as UE-B 204, and the QoS requirement (e.g. positioning accuracy) is higher than a threshold. The discussion of step 260 may apply equally to either or both of UE-B 203 and UE-B 204.

[0051] At 265, the LMF or server UE 201 may determine whether to discard the SL positioning measurements made at the target UE (not shown) or at the UE-A 202 in an SL PRS resource based on at least the SL PRS conflict information. The LMF or server UE 201 may discard the SL positioning measurements in the conflicted SL PRS resource (time-frequency resource) if, for example, the SL PRS conflict is determined at UE-A 202 based on actual SL PRS sequence information. In this situation, if the SL PRS sequence of the conflicted SL PRS is generated using the parameter nf^’seq^{8 as} 12 bits CRC of PSCCH associated with the SL PRS transmission, the SL PRS sequence generation may be random and the SL PRS conflict may not persist in the future. Alternatively, if the SL PRS sequence generated based on a higher layer configured parameter is assumed to be correct at UE-A 202, the LME or server UE 201 may discard the SL positioning measurements in the conflicted SL PRS resource.

[0052] At 270, the LML or server UE 201 may trigger additional SL PRS measurement(s) at the target UE, such as UE-A 202, and/or additional SL PRS transmission(s) at UE-B 203 and/or UE-B 204 in case of positive determination at step 265. At 280, the UE-B 203 and UE-B 204 may transmit SL PRS with reselected resource(s) and/or SL PRS sequence(s), or may perform additional SL PRS transmission(s) in case of positioning determination at step 260.

[0053] Various exemplary embodiments may provide technological advantages for improved channel utilization and improved reliability of SL PRS transmission(s) and SL positioning performance, such as improved accuracy.

[0054] EIG. 3 illustrates an example flow diagram of a method, according to certain exemplary embodiments. In an example embodiment, the method of EIG. 3 may be performed by a network element, or a group of multiple network elements in a 3GPP system, such as LTE or 5G-NR. Lor instance, in an exemplary embodiment, the method of EIG. 3 may be performed by a user device, mobile device, etc., such as an ambient loT UE, similar to apparatus 610 illustrated in EIG. 6. [0055] According to various exemplary embodiments, the method of FIG. 3 may include, at 310, receiving SL PRS transmissions from at least two anchor UEs, and at 320, associating each SL PRS transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter. The method may also include, at 330, determining whether the SL PRS transmissions are conflicted.

[0056] Certain exemplary embodiments may provide that the method may further include indicating, to the at least two anchor UE or a server, a SL PRS conflict with the association of the SL PRS transmission with the SL PRS sequence. The conflict may be determined between the SL PRS transmissions based on the associated SL PRS sequences. The SL PRS transmissions may include sidelink control information.

[0057] Some exemplary embodiments may provide that the conflict is determined between the SL PRS transmissions when at least a partial overlap of resources exist in a time-frequency domain. The parameter may be a higher layer configured parameter or a CRC of a shared control channel associated with the SL PRS transmissions.

[0058] FIG. 4 illustrates an example flow diagram of a method, according to certain exemplary embodiments. In an example embodiment, the method of FIG. 4 may be performed by a network element, or a group of multiple network elements in a 3GPP system, such as LTE or 5G-NR. For instance, in an exemplary embodiment, the method of FIG. 4 may be performed by another user device, mobile device, etc., such as a relay UE, similar to apparatus 620 illustrated in FIG. 6.

[0059] According to various exemplary embodiments, the method of FIG. 4 may include, at 410, transmitting an SL PRS transmission to a target UE, and at 420, 420, receiving, from the target UE, an indication of a SL PRS conflict. At 430, the method may further include determining whether to reselect a resource or sequence of the SL PRS transmission. [0060] Certain exemplary embodiments may provide that the indication includes information on an association of the SL PRS transmission with the sequence of the SL PRS. The method may further include retransmitting, to the target UE, an SL PRS transmission using the reselected resource, when the resource of the SL PRS transmission is determined to be reselected. The method may also include retransmitting, to the target UE, an SL PRS transmission using the reselected sequence, when the sequence of the SL PRS transmission is determined to be reselected.

[0061] PIG. 5 illustrates an example flow diagram of a method, according to certain exemplary embodiments. In an example embodiment, the method of PIG. 5 may be performed by a network element, or a group of multiple network elements in a 3GPP system, such as LTE or 5G-NR. Lor instance, in an exemplary embodiment, the method of PIG. 5 may be performed by a network device or network entity, such as a base station or gNB, similar to apparatus 630 illustrated in PIG. 6.

[0062] According to various exemplary embodiments, the method of PIG. 5 may include, at 510, receiving, from a target UE, an indication of an SL PRS conflict in SL PRS transmissions. The method may also include, at 520, determining whether to discard one or more SL positioning measurements in a resource of the SL PRS transmissions.

[0063] Some exemplary embodiments may further provide that the method may include triggering additional SL positioning measurements. The indication may include information on an association of the SL PRS transmission with a sequence of the SL PRS.

[0064] PIG. 6 illustrates apparatuses 610, 620, and 630 according to various exemplary embodiments. In the various exemplary embodiments, apparatus 610 may be an element in a communications network or associated with such a network, such as a UE, RedCap UE, ambient loT UE, SL UE, mobile equipment (ME), mobile station, mobile device, stationary device, ambient loT device, or other device. UE-A 202 may be an example of apparatus 610 according to various exemplary embodiments as discussed above. It should be noted that one of ordinary skill in the art would understand that apparatus 610 may include components or features not shown in FIG. 6. Further, the apparatus 620 may be an element in a communications network or associated with such a network, such as a UE, RedCap UE, relay UE, SL UE, mobile equipment (ME), mobile station, mobile device, stationary device, ambient loT device, or other device. UE-B 203 and UE-B 204 may be examples of apparatus 620 according to various exemplary embodiments as discussed above. It should be noted that one of ordinary skill in the art would understand that apparatus 620 may include components or features not shown in FIG. 6. In addition, an apparatus 630 may be a network entity, element of the core network, or element in a communications network or associated with such a network, such as a UE server, a base station, an NE, or a gNB. For example, LMF or server UE 201 may be an example of apparatus 630 according to various exemplary embodiments as discussed above. It should be noted that one of ordinary skill in the art would understand that apparatus 630 may include components or features not shown in FIG. 6.

[0065] According to various exemplary embodiments, the apparatuses 610, 620, and/or 630 may include one or more processors, one or more computer- readable storage medium (for example, memory, storage, or the like), one or more radio access components (for example, a modem, a transceiver, or the like), and/or a user interface. In some exemplary embodiments, apparatuses 610, 620, and/or 630 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB- loT, Bluetooth, NFC, MulteFire, and/or any other radio access technologies.

[0066] As illustrated in the example of FIG. 6, apparatuses 610, 620, and/or 630 may include or be coupled to processors 612, 622, and 632, respectively, for processing information and executing instructions or operations. Processors 612, 622, and 632 may be any type of general or specific purpose processor. In fact, processors 612, 622, and 632 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application- specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples. While a single processor 612 (622 and 632) for each of apparatuses 610, 620, and/or 630 is shown in FIG. 6, multiple processors may be utilized according to other example embodiments. For example, it should be understood that, in certain example embodiments, apparatuses 610, 620, and/or 630 may include two or more processors that may form a multiprocessor system (for example, in this case processors 612, 622, and 632 may represent a multiprocessor) that may support multiprocessing. According to certain example embodiments, the multiprocessor system may be tightly coupled or loosely coupled to, for example, form a computer cluster).

[0067] Processors 612, 622, and 632 may perform functions associated with the operation of apparatuses 610, 620, and/or 630, respectively, including, as some examples, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatuses 610, 620, and/or 630, including processes illustrated in FIGs. 2-5.

[0068] Apparatuses 610, 620, and/or 630 may further include or be coupled to memory 614, 624, and/or 634 (internal or external), respectively, which may be coupled to processors 612, 622, and 632, respectively, for storing information and instructions that may be executed by processors 612, 622, and 632. Memory 614 (memory 624 and 634) may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and/or removable memory. For example, memory 614 (memory 624 and 634) can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, hard disk drive (HDD), or any other type of non-transitory machine or computer readable media. The instructions stored in memory 614, memory 624, and memory 634 may include program instructions or computer program code that, when executed by processors 612, 622, and 632, enable the apparatuses 610, 620, and/or 630 to perform tasks as described herein.

[0069] In certain example embodiments, apparatuses 610, 620, and/or 630 may further include or be coupled to (internal or external) a drive or port that is configured to accept and read an external computer readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer readable storage medium may store a computer program or software for execution by processors 612, 622, and 632 and/or apparatuses 610, 620, and/or 630 to perform any of the methods illustrated in FIGs. 2-5.

[0070] In some exemplary embodiments, apparatuses 610, 620, and/or 630 may also include or be coupled to one or more antennas 615, 625, and 635, respectively, for receiving a downlink signal and for transmitting via an uplink from apparatuses 610, 620, and/or 630. Apparatuses 610, 620, and/or 630 may further include transceivers 616, 626, and 636, respectively, configured to transmit and receive information. The transceivers 616, 626, and 636 may also include a radio interface (for example, a modem) respectively coupled to the antennas 615, 625, and 635. The radio interface may correspond to a plurality of radio access technologies including one or more of GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, or the like. The radio interface may include other components, such as filters, converters (for example, digital-to-analog converters or the like), symbol demappers, signal shaping components, an Inverse Fast Fourier Transform (IFFT) module, or the like, to process symbols, such as OFDMA symbols, carried by a downlink or an uplink.

[0071] For instance, transceivers 616, 626, and 636 may be respectively configured to modulate information on to a carrier waveform for transmission by the antenna(s) 615, 625, and 635, and demodulate information received via the antenna(s) 615, 625, and 635 for further processing by other elements of apparatuses 610, 620, and/or 630. In other example embodiments, transceivers 616, 626, and 636 may be capable of transmitting and receiving signals or data directly. Additionally or alternatively, in some example embodiments, apparatuses 610, 620, and/or 630 may include an input and/or output device (I/O device). In certain example embodiments, apparatuses 610, 620, and/or 630 may further include a user interface, such as a graphical user interface or touchscreen.

[0072] In certain example embodiments, memory 614, memory 624, and memory 634 store software modules that provide functionality when executed by processors 612, 622, and 632, respectively. The modules may include, for example, an operating system that provides operating system functionality for apparatuses 610, 620, and/or 630. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatuses 610, 620, and/or 630. The components of apparatuses 610, 620, and/or 630 may be implemented in hardware, or as any suitable combination of hardware and software. According to certain example embodiments, apparatus 610 may optionally be configured to communicate with apparatus 620 and/or 630 via a wireless or wired communications links 640, 650, and/or 660 according to any radio access technology, such as NR.

[0073] According to certain example embodiments, processors 612, 622, and 632, and memory 614, 624, and 634 may be included in or may form a part of processing circuitry or control circuitry. In addition, in some example embodiments, transceivers 616, 626, and 636 may be included in or may form a part of transceiving circuitry.

[0074] For instance, in certain exemplary embodiments, the apparatus 610 may be controlled by the memory 614 and the processor 612 to receive sidelink positioning reference signal transmissions from at least two anchor user equipment and associate each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter. The apparatus 610 may also be controlled to determine whether the sidelink positioning reference signal transmissions are conflicted.

[0075] In various exemplary embodiments, the apparatus 620 may be controlled by the memory 624 and the processor 622 to transmit a sidelink positioning reference signal transmission to a target user equipment and receive, from the target user equipment, an indication of a sidelink positioning reference signal conflict. The apparatus 620 may also be controlled to determine whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

[0076] In various exemplary embodiments, the apparatus 630 may be controlled by the memory 634 and the processor 632 to receive, from a target user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions and determine whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

[0077] In some exemplary embodiments, an apparatus (e.g., apparatus 610, apparatus 620, and/or apparatus 630) may include means for performing a method, a process, or any of the variants discussed herein. Examples of the means may include one or more processors, memory, controllers, transmitters, receivers, and/or computer program code for causing the performance of the operations. [0078] Various exemplary embodiments may be directed to an apparatus, such as apparatus 610, that includes means for receiving sidelink positioning reference signal transmissions from at least two anchor user equipment and means for associating each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter. The apparatus 610 may also include means for determining whether the sidelink positioning reference signal transmissions are conflicted.

[0079] Various exemplary embodiments may be directed to an apparatus, such as apparatus 620, that includes means for transmitting a sidelink positioning reference signal transmission to a target user equipment, and means for receiving, from the target user equipment, an indication of a sidelink positioning reference signal conflict. The apparatus 620 may also include means for determining whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

[0080] Various exemplary embodiments may be directed to an apparatus, such as apparatus 630, that includes means for receiving, from a target user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions and means for determining whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

[0081] As used herein, the term “circuitry” may refer to hardware-only circuitry implementations (for example, analog and/or digital circuitry), combinations of hardware circuits and software, combinations of analog and/or digital hardware circuits with software/firmware, any portions of hardware processor(s) with software, including digital signal processors, that work together to cause an apparatus (for example, apparatus 610, 620, and/or 630) to perform various functions, and/or hardware circuit(s) and/or processor(s), or portions thereof, that use software for operation but where the software may not be present when it is not needed for operation. As a further example, as used herein, the term “circuitry” may also cover an implementation of merely a hardware circuit or processor or multiple processors, or portion of a hardware circuit or processor, and the accompanying software and/or firmware. The term circuitry may also cover, for example, a baseband integrated circuit in a server, cellular network node or device, or other computing or network device.

[0082] A computer program product may include one or more computerexecutable components which, when the program is run, are configured to carry out some example embodiments. The one or more computer-executable components may be at least one software code or portions of it. Modifications and configurations required for implementing functionality of certain example embodiments may be performed as routine(s), which may be implemented as added or updated software routine(s). Software routine(s) may be downloaded into the apparatus.

[0083] As an example, software or a computer program code or portions of it may be in a source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers may include a record medium, computer memory, read-only memory, photoelectrical and/or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers. The computer readable medium or computer readable storage medium may be a non-transitory medium.

[0084] In other example embodiments, the functionality may be performed by hardware or circuitry included in an apparatus (for example, apparatuses 610, 620, and/or 630), for example through the use of an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another example embodiment, the functionality may be implemented as a signal, a non-tangible means that can be carried by an electromagnetic signal downloaded from the Internet or other network.

[0085] According to certain example embodiments, an apparatus, such as a node, device, or a corresponding component, may be configured as circuitry, a computer or a microprocessor, such as single-chip computer element, or as a chipset, including at least a memory for providing storage capacity used for arithmetic operation and an operation processor for executing the arithmetic operation.

[0086] The features, structures, or characteristics of example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, the usage of the phrases “certain embodiments,” “an example embodiment,” “some embodiments,” or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment. Thus, appearances of the phrases “in certain embodiments,” “an example embodiment,” “in some embodiments,” “in other embodiments,” or other similar language, throughout this specification do not necessarily refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments. Further, the terms “cell”, “node”, “gNB”, or other similar language throughout this specification may be used interchangeably.

[0087] As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or,” mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0088] One having ordinary skill in the art will readily understand that the disclosure as discussed above may be practiced with procedures in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the disclosure has been described based upon these example embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of example embodiments. Although the above embodiments refer to 5G NR and LTE technology, the above embodiments may also apply to any other present or future 3GPP technology, such as LTE-advanced, and/or fourth generation (4G) technology.

[0089] Partial Glossary:

[0090] 3GPP 3rd Generation Partnership Project

[0091] 5G 5th Generation

[0092] CRC Cyclic Redundancy Check

[0093] DL Downlink

[0094] EMBB Enhanced Mobile Broadband

[0095] gNB 5G or Next Generation NodeB

[0096] ID Identifier

[0097] loT Internet of Things

[0098] IUC Inter-UE Coordination

[0099] LMF Location Management Function

[0100] LPP LTE Positioning Protocol

[0101] LTE Long Term Evolution

[0102] NR New Radio

[0103] PRS Positioning Reference Signal

[0104] PSFCH Physical Sidelink Feedback Channel [0105] RAN Radio Access Network

[0106] RSRP Reference Signal Received Power

[0107] RTT Round Trip Time

[0108] SL Sidelink

[0109] SLPP Sidelink Positioning Protocol

[0110] UE User Equipment

[0111] UL Uplink

[0112] VTV Vehicle to Vehicle

[0113] VTX Vehicle to Anything

Claims

WE CLAIM:

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: receive sidelink positioning reference signal transmissions from at least two anchor user equipment; associate each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter; and determine whether the sidelink positioning reference signal transmissions are conflicted.

2. The apparatus according to claim 1, wherein the at least one memory and the instructions, when executed by the at least one processor, further cause the apparatus at least to: indicate, to the at least two anchor user equipment or a server, a sidelink positioning reference signal conflict with information on the association of the sidelink positioning reference signal transmission with the sidelink positioning reference signal sequence.

3. The apparatus according to claim 1 or claim 2, wherein the conflict is determined between the sidelink positioning reference signal transmissions based on the associated sidelink positioning reference signal sequences.

4. The apparatus according to any one of claims 1-3, wherein the sidelink positioning reference signal transmissions comprise sidelink control information.

5. The apparatus according to any one of claims 1-4, wherein the conflict is determined between the sidelink positioning reference signal transmissions when at least a partial overlap of resources exist in a timefrequency domain.

6. The apparatus according to any one of claims 1-5, wherein the parameter is a higher layer configured parameter or a cyclic redundancy check of a shared control channel associated with the sidelink positioning reference signal transmissions.

7. 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: transmit a sidelink positioning reference signal transmission to a target user equipment; receive, from the target user equipment, an indication of a sidelink positioning reference signal conflict; and determine whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

8. The apparatus according to claim 7, wherein the indication comprises information on an association of the sidelink positioning reference signal transmission with the sequence of the sidelink positioning reference signal.

9. The apparatus according to claim 7 or claim 8, wherein the at least one memory and the instructions, when executed by the at least one processor, further cause the apparatus at least to: retransmit, to the target user equipment, sidelink positioning reference signal transmission using the reselected resource, when the resource of the sidelink positioning reference signal transmission is determined to be reselected.

10. The apparatus according to claim 7 or claim 8, wherein the at least one memory and the instructions, when executed by the at least one processor, further cause the apparatus at least to: retransmit, to the target user equipment, sidelink positioning reference signal transmission using the reselected sequence, when the sequence of the sidelink positioning reference signal transmission is determined to be reselected.

11. 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: receive, from a user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions; and determine whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

12. The apparatus according to claim 11, wherein the at least one memory and the instructions, when executed by the at least one processor, further cause the apparatus at least to: trigger additional sidelink positioning measurements.

13. The apparatus according to claim 11 or claim 12, wherein the indication comprises information on an association of the sidelink positioning reference signal transmission with a sequence of the sidelink positioning reference signal.

14. A method, comprising: receiving sidelink positioning reference signal transmissions from at least two anchor user equipment; associating each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter; and determining whether the sidelink positioning reference signal transmissions are conflicted.

15. The method according to claim 14, further comprising: indicating, to the at least two anchor user equipment or a server, a sidelink positioning reference signal conflict with information on the association of the sidelink positioning reference signal transmission with the sidelink positioning reference signal sequence.

16. The method according to claim 14 or claim 15, wherein the conflict is determined between the sidelink positioning reference signal transmissions based on the associated sidelink positioning reference signal sequences.

17. The method according to any one of claims 14-16, wherein the sidelink positioning reference signal transmissions comprise sidelink control information.

18. The method according to any one of claims 14-17, wherein the conflict is determined between the sidelink positioning reference signal transmissions when at least a partial overlap of resources exist in a timefrequency domain.

19. The method according to any one of claims 14-18, wherein the parameter is a higher layer configured parameter or a cyclic redundancy check of a shared control channel associated with the sidelink positioning reference signal transmissions.

20. A method, comprising: transmitting a sidelink positioning reference signal transmission to a target user equipment; receiving, from the target user equipment, an indication of a sidelink positioning reference signal conflict; and determining whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

21. The method according to claim 20, wherein the indication comprises information on an association of the sidelink positioning reference signal transmission with the sequence of the sidelink positioning reference signal.

22. The method according to claim 20 or claim 21, further comprising: retransmitting, to the target user equipment, sidelink positioning reference signal transmission using the reselected resource, when the resource of the sidelink positioning reference signal transmission is determined to be reselected.

23. The method according to claim 20 or claim 21, further comprising: retransmitting, to the target user equipment, sidelink positioning reference signal transmission using the reselected sequence, when the sequence of the sidelink positioning reference signal transmission is determined to be reselected.

24. A method, comprising: receiving, from a user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions; and determining whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

25. The method according to claim 24, further comprising: triggering additional sidelink positioning measurements.

26. The method according to claim 24 or claim 25, wherein the indication comprises information on an association of the sidelink positioning reference signal transmission with a sequence of the sidelink positioning reference signal.

27. An apparatus, comprising: means for receiving sidelink positioning reference signal transmissions from at least two anchor user equipment; means for associating each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter; and means for determining whether the sidelink positioning reference signal transmissions are conflicted.

28. The apparatus according to claim 27, further comprising: means for indicating, to the at least two anchor user equipment or a server, a sidelink positioning reference signal conflict with information on the association of the sidelink positioning reference signal transmission with the sidelink positioning reference signal sequence.

29. The apparatus according to claim 27 or claim 28, wherein the conflict is determined between the sidelink positioning reference signal transmissions based on the associated sidelink positioning reference signal sequences.

30. The apparatus according to any one of claims 27-29, wherein the sidelink positioning reference signal transmissions comprise sidelink control information.

31. The apparatus according to any one of claims 27-30, wherein the conflict is determined between the sidelink positioning reference signal transmissions when at least a partial overlap of resources exist in a timefrequency domain.

32. The apparatus according to any one of claims 27-31, wherein the parameter is a higher layer configured parameter or a cyclic redundancy check of a shared control channel associated with the sidelink positioning reference signal transmissions.

33. An apparatus, comprising: means for transmitting a sidelink positioning reference signal transmission to a target user equipment; means for receiving, from the target user equipment, an indication of a sidelink positioning reference signal conflict; and means for determining whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

34. The apparatus according to claim 33, wherein the indication comprises information on an association of the sidelink positioning reference signal transmission with the sequence of the sidelink positioning reference signal.

35. The apparatus according to claim 33 or claim 34, further comprising: means for retransmitting, to the target user equipment, sidelink positioning reference signal transmission using the reselected resource, when the resource of the sidelink positioning reference signal transmission is determined to be reselected.

36. The apparatus according to claim 33 or claim 34, further comprising: means for retransmitting, to the target user equipment, sidelink positioning reference signal transmission using the reselected sequence, when the sequence of the sidelink positioning reference signal transmission is determined to be reselected.

37. An apparatus, comprising: means for receiving, from a user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions; and means for determining whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

38. The apparatus according to claim 37, further comprising: means for triggering additional sidelink positioning measurements.

39. The apparatus according to claim 37 or claim 38, wherein the indication comprises information on an association of the sidelink positioning reference signal transmission with a sequence of the sidelink positioning reference signal.

40. A non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus at least to: receive sidelink positioning reference signal transmissions from at least two anchor user equipment; associate each sidelink positioning reference signal transmission with a sidelink positioning reference signal sequence, which is generated based on a parameter; and determine whether the sidelink positioning reference signal transmissions are conflicted.

41. The non-transitory computer readable medium according to claim 40, wherein the program instructions, when executed by the apparatus, cause the apparatus at least to: indicate, to the at least two anchor user equipment or a server, a sidelink positioning reference signal conflict with information on the association of the sidelink positioning reference signal transmission with the sidelink positioning reference signal sequence.

42. The non-transitory computer readable medium according to claim 40 or claim 41, wherein the conflict is determined between the sidelink positioning reference signal transmissions based on the associated sidelink positioning reference signal sequences.

43. The non-transitory computer readable medium according to any one of claims 40-42, wherein the sidelink positioning reference signal transmissions comprise sidelink control information.

44. The non-transitory computer readable medium according to any one of claims 40-43, wherein the conflict is determined between the sidelink positioning reference signal transmissions when at least a partial overlap of resources exist in a time-frequency domain.

45. The non-transitory computer readable medium according to any one of claims 40-44, wherein the parameter is a higher layer configured parameter or a cyclic redundancy check of a shared control channel associated with the sidelink positioning reference signal transmissions.

46. A non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus at least to: transmit a sidelink positioning reference signal transmission to a target user equipment; receive, from the target user equipment, an indication of a sidelink positioning reference signal conflict; and determine whether to reselect a resource or sequence of the sidelink positioning reference signal transmission.

47. The non-transitory computer readable medium according to claim 46, wherein the indication comprises information on an association of the sidelink positioning reference signal transmission with the sequence of the sidelink positioning reference signal.

48. The non-transitory computer readable medium according to claim 46 or claim 47, wherein the program instructions, when executed by the apparatus, cause the apparatus at least to: retransmit, to the target user equipment, sidelink positioning reference signal transmission using the reselected resource, when the resource of the sidelink positioning reference signal transmission is determined to be reselected.

49. The non-transitory computer readable medium according to claim 46 or claim 47, wherein the program instructions, when executed by the apparatus, cause the apparatus at least to: retransmit, to the target user equipment, sidelink positioning reference signal transmission using the reselected sequence, when the sequence of the sidelink positioning reference signal transmission is determined to be reselected.

50. A non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus at least to: receive, from a user equipment, an indication of a sidelink positioning reference signal conflict in sidelink positioning reference signal transmissions; and determine whether to discard one or more sidelink positioning measurements in a resource of the sidelink positioning reference signal transmissions.

51. The non-transitory computer readable medium according to claim 50, wherein the program instructions, when executed by the apparatus, cause the apparatus at least to: trigger additional sidelink positioning measurements.

52. The non-transitory computer readable medium according to claim 50 or claim 51, wherein the indication comprises information on an association of the sidelink positioning reference signal transmission with a sequence of the sidelink positioning reference signal.

53. A computer program comprising instructions stored thereon for performing at least the method of claim 14.

54. A computer program comprising instructions stored thereon for performing at least the method of claim 20.

55. A computer program comprising instructions stored thereon for performing at least the method of claim 24.

56. An apparatus comprising one or more circuitry configured to perform the method of claim 14.

57. An apparatus comprising one or more circuitry configured to perform the method of claim 20.

58. An apparatus comprising one or more circuitry configured to perform the method of claim 24.