Positioning devices and methods

Abstract

The present disclosure relates to devices and methods for group configuration of positioning reference signal (PRS) transmission, where a plurality of UEs may form a group and perform sidelink positioning. Instead of providing individual resource allocation to each UE separately, a group PRS transmit configuration is provided by a group leader or network to all of the UEs in the group. The group PRS transmit configuration may comprise PRS resource allocations of all UEs in the group. In this way, each UE can be aware of the RS configuration of all UEs in the group. Each UE can not only send its PRS according to the group PRS transmit configuration, but also receive PRS resources sent by other UE(s) based on the group PRS transmit configuration. In this way, signaling overhead can be reduced.(FIG. 9)

Description

[0001] POSITIONING DEVICES AND METHODS

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to the field of positioning in communications networks. Optionally, the present disclosure relates to devices and methods for a group configuration of a reference signal transmission for positioning.

[0004] BACKGROUND

[0005] In some communications networks, such as a cellular network or a vehicle-to-everything (V2X) network, a number of user equipment (UEs) may form a group. The UEs in the group may be required to determine the position(s) of other UE(s) in the group, or to obtain position information of other UE(s). The position of a UE may refer to an absolute location of the UE that may be represented by longitude and latitude, or may refer to a relative position of the UE with respect to an anchor UE that may be represented by distance and / or orientation.

[0006] A group of UEs normally comprises two or more UEs, for example, UEs within a platoon or UEs in a coordinated maneuver. The group of UEs may have one UE as a group leader configured to coordinate other UEs in the group. For example, the group leader may manage resources of member UEs. The group of UEs may be in network coverage, out of network coverage, or in partial network coverage. Partial network coverage refers to a scenario where only a part of the UEs in the group is in network coverage. In the present disclosure, the group of UEs (or devices) may be simply referred to as “a group”.

[0007] The position information may be determined via sidelink (SL) positioning between UEs. The SL positioning refers to the positioning of a UE based on sidelink measurements, e.g., based on measurements made by a UE of one or more positioning reference signals (PRSs) transmitted by one or more other UEs in sidelink.

[0008] For SL positioning, resources for PRS transmissions need to be selected. In a mode 1 operation of a new radio (NR) V2X communications network, resources for data transmissions of UEs in sidelink are managed by the network. That is, the network selects and assigns the resources for SL PRS transmission to the UEs. In a mode 2 operation of the NR V2X communications network, resources for data transmissions in sidelink are selected autonomously by a UE. Based on these two operation modes, the resources for the SL PRS transmissions within a group of UEs can be selected and assigned by the network (e.g. when the group is in network coverage) or can be selected autonomously by the UE(s) in the group (i.e. independent of the network coverage). In the latter case, one of the UEs in the group, e.g. the group leader, can select the resources for the SL PRS transmissions of other UEs in the group. Alternatively, each UE can select resources for its own SL PRS transmission.

[0009] After the resources have been selected, the transmission of the SL PRSs and measurement request of the SL PRSs among the UEs have to be configured. Such configuration comprises a configuration of a first UE to transmit PRS with certain parameters on a certain resource; an indication to a second UE about the SL PRS configuration of a first UE (i.e. to enable the second UE to make measurements of the PRS sent by the first UE); and the configuration of a second UE via a measurement request to make a measurement of an SL PRS.

[0010] SUMMARY

[0011] However, it is not efficient to communicate the configuration of each UE’s PRS transmission, the resources assigned to each UE’s PRS transmission, and an indication of PRS configurations of other UE(s) separately.

[0012] For example, assuming that the resources for the SL PRS transmissions within the group have already been selected, the configuration of the SL PRS transmissions and measurement requests within the group can be signaled in a dedicated manner per UE. Such a dedicated configuration can be performed in a similar way as the transmission of the configuration of sounding reference signal (SRS) for uplink (UL) positioning, or the measurement request configuration of downlink (DL) PRS for DL positioning. Similarly, the dedicated configuration for SL positioning can be done between pairs of UEs, e.g., in a unicast manner between one UE and another UE. For example, a UE that transmits SL PRS can indicate its SL PRS configuration to another UE that shall make measurements of the SL PRS. Such configuration between pairs of UEs can also be done by another configuring entity, e.g. by a network device or a group leader.

[0013] However, this can result in a large overhead when there are many UEs in a group and when multiple pairs of UEs need to be configured for the SL PRS transmissions and measurement requests. Based on the dedicated configuration, a UE is only aware of its SL PRS transmit configuration and not of the SL PRS configuration of other UEs, and thus the UE needs additional configuration or indication so as to measure an SL PRS of another UE.

[0014] In view of the above, this disclosure aims to provide an efficient manner for positioning within a group of UEs in a communications network. An objective of this disclosure is to reduce signaling overhead for communicating configurations of reference signals between UEs within the group.

[0015] These and other objectives are achieved by the solution of this disclosure as described in the independent claims. Advantageous implementations are further defined in the dependent claims.

[0016] A first aspect of this disclosure provides a first device configured to send, to one or more second devices, a configuration of one or more reference signal (RS) resources for transmitting one or more RSs by the one or more second devices for positioning.

[0017] In the present disclosure, the “configuration of one or more reference signal (RS) resources for transmitting one or more RSs by the one or more second devices for positioning” may be simply referred to as the group configuration or the group PRS transmit configuration.

[0018] Optionally, the one or more second devices may be in a group. Alternatively or additionally, the one or more second devices and the first device may be in a group, when the first device is a user device.

[0019] Optionally, with respect to one specific second device of a group, the group configuration sent by the first device to the specific second device may comprise an RS resource configuration of the specific second device, and a further RS resource configuration of a further device of the group. The further RS resource configuration may allow the specific device to measure the RS resource sent by the further device of the group without further indication. The same may apply to other second device(s). That is, the first device may be configured to send the group configuration, which is a common message, to all of the one or more second devices.

[0020] An advantage is that a signaling overhead can be reduced, since there is no need for dedicated signaling. For example, the specific second device can be aware of the RS resources of its own for RS transmission, and of the RS resources of other devices in the group to measure RS resources sent by other devices in the group. Therefore, there is no need to communicate by the first device to the specific second device additionally or separately about the RS resource configuration of other devices in the group. Signaling overhead can be reduced.

[0021] For instance, by transmitting the group configuration to the one or more second devices, each second device in the group may be aware of RS resource configuration of its own and RS resource configurations other device(s) in the group at the same time. There is no need to separately communicate by the first device to each second device in a dedicated manner. Therefore, signaling overhead may be reduced.

[0022] In an implementation form of the first aspect, the group configuration may comprise a resource allocation of the one or more RS resources to the one or more second devices, wherein each of the one or more RS resources may be associated with one identifier (ID) of one of the one or more second devices.

[0023] Optionally, the resource allocation may be represented by resource allocation information comprising a number of bits. For each second device, the allocated one or more RS resources may be used for RS transmission of the associated second device.

[0024] Optionally, the allocated one or more RS resources may be associated with the ID of the corresponding second device. The ID may comprise an identifier that can uniquely identify a second device at least within the group. For example, the ID may comprise a member ID of a second device in the group. The member ID may be provided by an application layer when establishing the group, e.g. for the link establishment for groupcast. The application may be a V2X application layer. The first device may be further configured to assign a member ID to each second device when forming the group. Alternatively, the ID may comprise a communication address or a hardware identifier of a second device. The communication address may comprise an IP address, or MAC address, or radio network temporary identifier (RNTI), or a phone number (e.g., mobile subscriber ISDN (MSISDN) number). The hardware identifier may comprise an international mobile equipment identity (IMEI), or international mobile subscriber identity (IMSI), or a serial number of a second device. By associating the allocated RS resources with the ID of a second device, all devices in the group can be aware of the whole RS resource allocation within the group based on a common group configuration. In this way, each second device can clearly identify the one or more RS resources that are assigned for its own RS transmission and the one or more RS resources that are assigned to other devices in the group. Then, each second device may be configured to measure the RS resources sent by other devices based on the group configuration. Therefore, signaling overhead may be significantly reduced.

[0025] In an implementation form of the first aspect, the one or more RS resources may be multiplexed in time and / or frequency domains.

[0026] Optionally, the one or more RS resources may comprise time and / or frequency radio resources. The time and / or frequency radio resources may comprise one or more resource blocks (RBs). Each RB may comprise one or more slots in the time domain (e.g., OFDM symbol(s)), and one or more subcarriers (or subchannels) in the frequency domain. In the present disclosure, an RB can also be referred to as a physical RB (PRB). A group of resources can also be seen as a single resource.

[0027] Optionally, the one or more RS resources may comprise RBs that are orthogonal in the time domain. Additionally or alternatively, the one or more RS resources may comprise RBs that are orthogonal in the frequency domain.

[0028] In an implementation form of the first aspect, the one or more RS resources may be multiplexed in the code domain.

[0029] In an implementation form of the first aspect, the one or more RSs may comprise a positioning reference signal (PRS) or a sounding reference signal (SRS).

[0030] Optionally, each reference signal is a signal that can be used for obtaining one or more parameters for positioning such as but not limited to roundtrip time (RTT), angle of arrival / departure (AoA / AoD), and time difference of arrival (TDOA). Optionally, the PRS may be an SL PRS (SL-PRS), e.g., in an application scenario of sidelink positioning. Alternatively, the PRS may be an SL SRS (SL-SRS), e.g., in an application scenario of sidelink positioning.

[0031] In an implementation form of the first aspect, the one or more RS resources may be of a resource pool.

[0032] Optionally, the resource pool may be a sidelink communication resource pool such as a physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH) resource pool.

[0033] In this way, RS resources signaling can be simplified within the resource pool. Therefore, the signaling overhead can be further reduced.

[0034] In an implementation form of the first aspect, the one or more RS resources are part of resources reserved for SL positioning.

[0035] Optionally, some resources (e.g., in a resource pool) may be pre-configured and reserved for the transmission of SL-PRS or SL-SRS.

[0036] In an implementation form of the first aspect, the group configuration further comprises configuration information of the one or more RS resources. The configuration information comprises one or more of: a type of sequence, a sequence identifier, and an initialization of the sequence for generating a sequence for the one or more RS resources, a periodicity of the one or more RS resources, a repetition of the one or more RS resources, a bandwidth of the one or more RS resources, a comb size of the one or more RS resources, a staggering pattern of the one or more RS resources, a quasi-colocation information of the one or more RS resources, and parameters for power control of the one or more RS resources.

[0037] Optionally, the configuration information may be common for some or all the devices in the group. Alternatively, the configuration information may be device-specific. That is, the configuration information may be associated with the ID of each second device and may comprise device-specific configuration(s).

[0038] In an implementation form of the first aspect, the first device may be further configured to send one or more measurement requests to the one or more second devices. Each measurement request may indicate the one or more second devices to perform one or more measurements based on the one or more RS resources.

[0039] Optionally, a part or all of the one or more second devices may be required to perform the measurement. That is, the first device may send a measurement request only to a second device that is required to perform the measurement.

[0040] Optionally, the first device may send one measurement request to all devices in the group. The measurement request may comprise one or more IDs of one or more second devices that are required to perform a measurement. The first device may be configured to send the measurement request in the group in a groupcast manner Such measurement request may be referred to as group measurement request. Alternatively, the first device may be configured to send the (group) measurement request in a unicast manner. Then, each second device in the group may be configured to determine whether it is requested to make a measurement by checking whether its identifier is included in the group measurement request.

[0041] In an implementation form of the first aspect, the one or more measurement requests may comprise one or more of a destination ID; an indication of an RS to be used as a reference for the measurement; a quantity of measurement results to be reported; and an expected range of values for the measurement.

[0042] Optionally, the destination ID may indicate an intended receiver of a result of the measurement (e.g. a measurement report). The destination ID may be an ID of the first device, or an ID of one second device of the one or more second devices. When the first device is a network device and receives a measurement report, the first device as the network device may be configured to estimate a location of a corresponding UE based on the measurement report, and may be configured to provide the estimated location to any UE that is interested in knowing the location of the corresponding UE.

[0043] Optionally, information comprised in the one or more measurement requests may be common or device-specific. Optionally, the device-specific information comprised in a measurement request may be associated with an ID of a second device of the one or more second devices.

[0044] In this way, a flexible measurement configuration may be achieved.

[0045] In an implementation form of the first aspect, wherein the first device may be a user device, which is configured to send the configuration by control information.

[0046] Optionally, the control information may comprise one or more of the following: sidelink control information (SCI); higher layer signaling on PC5 interface; and a transport block.

[0047] The sidelink control information may comprise a first stage SCI or a second stage SCI.

[0048] Optionally, when the first device is a user device, the first device may be a member of the group that comprises the one or more second devices. In this case, the first device may be adapted to function as a group leader. In the group, the first device and the one or more second devices may be adapted to communicate with each other through sidelink. Optionally, the first device may also be adapted to transmit one or more RSs for positioning. Accordingly, the group configuration may further comprise RS resource configuration of the first device, so that the one or more second devices can be aware of the RS resources transmitted by the first device. The first device may also be adapted to perform a measurement based on RS resources transmitted by the one or more second devices in the group.

[0049] In an implementation form of the first aspect, the first device may be further configured to send reservation information for reserving the one or more RS resources.

[0050] In the present disclosure, the reservation information for reserving the one or more RS resources may also be referred to as a group resource reservation. Optionally, the reservation information may be used for reserving group RS resources that are assigned for the whole group. The group RS resources may refer to a general resource area on a resource grid that covers one or more resources allocated to devices of the group.

[0051] In an implementation form of the first aspect, the first device may be further configured to send the reservation information through a first stage SCI.

[0052] Optionally, the first stage SCI may be transmitted on PSCCH.

[0053] By reserving the one or more RS resources, UEs not part of the group (non-group UEs) may sense this reservation and not occupy the reserved RS resources. Therefore, resource conflicts may be avoided. Moreover, by reserving the group resources via the group reservation information, the group PRS transmit configuration may only need to indicate a relative assignment to the one or more devices based on the resources reserved in the group resource reservation. This has the advantage that the resources of the PRS transmissions in the group configuration can be indicated more efficiently.

[0054] In an implementation form of the first aspect, the first device may be further configured to send, through the first stage SCI, indication information indicating that the reserved one or more RS resources are for positioning.

[0055] Optionally, the indication information may comprise one or more bits indicating that the one or more resources reserved by the first stage SCI are for positioning purposes only, and shall not be interpreted as resources for other purposes such as a user data transmission or retransmission.

[0056] It is noted that a reference signal for positioning may be seen as control data, which may be different from user data that are intended for a user operating a UE.

[0057] In an implementation form of the first aspect, the group configuration further indicates one of the one or more second devices to send reservation information for reserving the one or more RS resources.

[0058] In an implementation form of the first aspect, the first device may be a network device, which is configured to send the configuration by control information. Optionally, the control information may comprise one or more of the following: downlink control information (DCI); higher layer signaling; radio resource control (RRC) signaling; and a positioning protocol for a telecommunications network, such as LTE positioning protocol (LPP) and new radio positioning protocol (NRPP).

[0059] A second aspect of this disclosure provides a second device configured to receive, from a first device, a configuration of one or more RS resources for transmitting one or more RSs for positioning. Then, the second device is configured to transmit one or more RSs according to the configuration.

[0060] Optionally, the second device may be a user device, or a terminal device.

[0061] In an implementation form of the second aspect, the configuration may comprise a resource allocation of the one or more RS resources associated with one or more identifiers (IDs) of the one or more second devices. The second device may be further configured to determine one or more allocated RS resources for transmitting the one or more RSs based on an ID of the second device.

[0062] In an implementation form of the second aspect, the one or more RS resources may be multiplexed in time and / or frequency domains.

[0063] In an implementation form of the second aspect, the one or more RSs may comprise a PRS or an SRS.

[0064] In an implementation form of the second aspect, the second device may be further configured to receive a measurement request from the first device, and perform one or more measurements according to the measurement request.

[0065] In an implementation form of the second aspect, the measurement request may further comprise one or more of: a destination ID; an indication of an RS to be used as a reference for the measurement; a quantity of measurement results to be reported; and an expected range of values for the measurement.

[0066] In an implementation form of the second aspect, the second device may be configured to receive the resource allocation by control information.

[0067] In an implementation form of the second aspect, the second device may be further configured to send, through a first stage SCI, reservation information for reserving one or more RS resources.

[0068] Optionally, the reservation information may be used to reserve group resources, i.e., one or more RS resources of the devices in the group.

[0069] In an implementation form of the second aspect, the second device may be further configured to send, through the first stage SCI, indication information indicating that the reserved one or more RS resources are for positioning.

[0070] A third aspect of this disclosure provides a method comprising sending, by a first device to one or more second devices, a configuration of one or more RS resources for transmitting one or more RSs by the one or more second devices for positioning.

[0071] In an implementation form of the third aspect, the group configuration may comprise a resource allocation of the one or more RS resources to the one or more second devices, wherein each of the one or more RS resources may be associated with one identifier (ID) of one of the one or more second devices.

[0072] In an implementation form of the third aspect, the one or more RS resources may be multiplexed in time and / or frequency domains.

[0073] In an implementation form of the third aspect, the one or more RS resources may be multiplexed in code domain. In an implementation form of the third aspect, the one or more RSs may comprise a PRS or an SRS.

[0074] In an implementation form of the third aspect, the one or more RS resources may be of a resource pool.

[0075] In an implementation form of the third aspect, the one or more RS resources are part of resources reserved for SL positioning.

[0076] In an implementation form of the third aspect, the group configuration further comprises configuration information of the one or more RS resources. The configuration information comprises one or more of: a type of sequence, a sequence identifier, and an initialization of the sequence for generating a sequence for the one or more RS resources, a periodicity of the one or more RS resources, a repetition of the one or more RS resources, a bandwidth of the one or more RS resources, a comb size of the one or more RS resources, a staggering pattern of the one or more RS resources, a quasi-colocation information of the one or more RS resources, and parameters for power control of the one or more RS resources.

[0077] In an implementation form of the third aspect, the method may further comprise sending, by the first device, one or more measurement requests to the one or more second devices. Each measurement request may indicate the one or more second devices to perform one or more measurements based on the one or more RS resources.

[0078] In an implementation form of the third aspect, the one or more measurement requests may comprise one or more of: a destination ID; an indication of an RS to be used as a reference for the measurement; a quantity of measurement results to be reported; and an expected range of values for the measurement. In an implementation form of the third aspect, wherein the first device may be a user device, and the method may further comprise sending, by the first device, the configuration by control information.

[0079] In an implementation form of the third aspect, the method may further comprise sending, by the first device, reservation information for reserving the one or more RS resources.

[0080] In an implementation form of the third aspect, the method may further comprise sending, by the first device, the reservation information through a first stage SCI.

[0081] In an implementation form of the third aspect, the method may further comprise sending, by the first device through the first stage SCI, indication information indicating that the reserved one or more RS resources are for positioning.

[0082] In an implementation form of the third aspect, the group configuration further indicates one of the one or more second devices to send reservation information for reserving the one or more RS resources.

[0083] In an implementation form of the third aspect, the first device may be a network device, and the method may further comprise sending, by the first device, the configuration by control information.

[0084] The method of the third aspect and its implementation forms may achieve the same advantages and effects as described above for the first device of the first aspect and its implementation forms.

[0085] A fourth aspect of this disclosure provides a method comprising: receiving, by a second device from a first device, a configuration of one or more RS resources for transmitting one or more RSs for positioning; and transmitting, by the second device, one or more RSs according to the configuration.

[0086] In an implementation form of the fourth aspect, the configuration may comprise a resource allocation of the one or more RS resources associated with one or more IDs of the one or more second devices. The method may further comprise determining, by the second device, one or more allocated RS resources for transmitting the one or more RSs based on an ID of the second device.

[0087] In an implementation form of the fourth aspect, the one or more RS resources may be multiplexed in time and / or frequency domains.

[0088] In an implementation form of the fourth aspect, the one or more RSs may comprise a PRS or an SRS.

[0089] In an implementation form of the fourth aspect, the method may further comprise receiving, by the second device, a measurement request from the first device, and performing, by the second device, one or more measurements according to the measurement request.

[0090] In an implementation form of the fourth aspect, the measurement request may further comprise one or more of: a destination ID; an indication of an RS to be used as a reference for the measurement; a quantity of measurement results to be reported; and an expected range of values for the measurement.

[0091] In an implementation form of the fourth aspect, the method may further comprise receiving, by the second device, the resource allocation by control information.

[0092] In an implementation form of the fourth aspect, the method may further comprise sending, by the second device through a first stage SCI, reservation information for reserving the one or more RS resources.

[0093] In an implementation form of the fourth aspect, the method may further comprise sending, by the second device through the first stage SCI, indication information indicating that the reserved one or more RS resources are for positioning.

[0094] The method of the fourth aspect and its implementation forms may achieve the same advantages and effects as described above for the second device of the second aspect and its implementation forms. A fifth aspect of this disclosure provides a system comprising a first device according to the first aspect or any implementation form thereof, and one or more second devices according to the second aspect or any implementation form thereof.

[0095] A sixth aspect of this disclosure provides a computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method according to the third aspect or any of its implementation forms.

[0096] A seventh aspect of this disclosure provides a computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method according to the fourth aspect or any of its implementation forms.

[0097] An eighth aspect of this disclosure provides a storage medium storing executable program code which, when executed by a processor, causes the method according to the third aspect or any of its implementation forms to be performed.

[0098] A ninth aspect of this disclosure provides a storage medium storing executable program code which, when executed by a processor, causes the method according to the fourth aspect or any of its implementation forms to be performed.

[0099] It has to be noted that all devices, elements, units, and means described in the present application could be implemented in the software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof. BRIEF DESCRIPTION OF DRAWINGS

[0100] The above described aspects and implementation forms will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which

[0101] FIG. 1 shows a first device and one or more second devices according to this disclosure;

[0102] FIG. 2 shows a second device according to this disclosure;

[0103] FIG. 3 shows a further second device according to this disclosure;

[0104] FIG. 4 shows an example of PRS resource allocation according to this disclosure;

[0105] FIG. 5 shows a further example of PRS resource allocation according to this disclosure;

[0106] FIG. 6 shows a further example of PRS resource allocation according to this disclosure;

[0107] FIG. 7 shows a further example of PRS resource allocation according to this disclosure;

[0108] FIG. 8 shows an example of a signaling flow according to this disclosure;

[0109] FIG. 9 shows an example of a further signaling flow according to this disclosure;

[0110] FIG. 10 shows an example of a further signaling flow according to this disclosure;

[0111] FIG. 11 shows a diagram of a method of the present disclosure; and

[0112] FIG. 12 shows a diagram of a further method of the present disclosure.

[0113] DETAILED DESCRIPTION OF EMBODIMENTS

[0114] The present disclosure may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms "system" and "network" are often used interchangeably.

[0115] The present disclosure generally relates to configurations of resource allocation for reference signal transmission. The reference signals are for positioning. UE may need RS resource configuration so that the UE can transmit one or more reference signals accordingly. In the present disclosure, resources may be referred to as radio resources. Radio resources may comprise time-frequency resources, i.e., resources on time and / or frequency domains. Timefrequency resources may be partitioned into physical resource blocks (PRBs), which may also be referred to as resource blocks (RBs). The resources of the present disclosure may refer to the RBs. Each RB may cover a number of subcarriers (or sub-channels) in one time slot (or one subframe). The number of RBs in each slot may be dependent on system bandwidth. Each RB may comprise a number of resource elements. Each resource element may cover one subcarrier in one symbol period and may be used to transmit one modulation symbol (e.g. an OFDM symbol), which may be a real or complex value. As an example, in a fifth generation (5G) communications network, the number of subcarriers per PRB is 12, and the number of (OFDM) symbols per slot may be 14. It is noted that in the present disclosure, a group of resources can be seen as a single resource. Therefore, the term “resources” used in the present disclosure therefore can also be understood as a single resource.

[0116] Sidelink communication may refer to a device-to-device (D2D) communication through a sidelink channel, without relaying data through the network.

[0117] Sub-channels are used to transmit data and control information. In sidelink communication, the data may be organized in transport blocks (TBs) that may be carried in a physical sidelink shared channel (PSSCH). A TB may contain a full packet (e.g. a single complete message). A TB can occupy one or more sub-channels depending on the size of the packet, the number of RBs per sub-channel, and the utilized modulation and coding scheme (MCS). TBs can be transmitted using, such as but not limited to, QPSK, 16-QAM, 64-QAM or 256-QAM modulations, and turbo coding or LDPC coding.

[0118] V2X communications may be based on uplink / downlink and sidelink communications, and may include vehicle-to vehicle (V2V), vehicle-to-network (V2N) or vehicle-to-infrastructure (V2I), vehicle-to-road side unit (V2R), and vehicle-to-pedestrian (V2P). A 5G communication system may support V2X communications, which may be referred to as a 5G NR V2X system. Similarly, a legacy communication network may also support V2X communications, such as an LTE V2X system.

[0119] Transmitting one or more reference signals on allocated resources may be referred to as “transmitting RS resources”. Similarly, receiving one or more reference signals on corresponding resources may be referred to as “receiving RS resources”. Measuring one or more reference signals on corresponding resources may be referred to as “measuring RS resources”. For example, a device may need to measure time-frequency resources before it can measure a transmission sent on that time-frequency resource. After measuring the resource, the device can measure the transmission (e.g. PRS), i.e. by correlating a pilot sequence or extracting information from the measured resource. Therefore, transmitting / receiving a PRS may be referred to as “transmitting / receiving PRS resources”. FIG. 1 shows a first device and one or more second devices according to the present disclosure. The first device 110 on the left-hand side of FIG. 1 is configured to send group configuration 101 for RS transmission to the one or more second devices 120, 140, 160 on the right-hand side of FIG. 1. After receiving the group configuration 101, the one or more second devices 120, 140, 160 are configured to send one or more RSs 102, 104, 106 according to the group configuration.

[0120] There may be two exemplary scenarios in the present disclosure. A first scenario is that the first device may be a user device. The first device in this case may be a group leader of a group of user devices. There may be at least one second device as a user device in the same group. In the following, the first device as the group leader may be referred to as UE A; the at least one second device may be referred to as UE B (and UE C, D, E, F ... when applicable). It is noted that in the present disclosure, the terms “UE” and “second device” may be used interchangeably. Similarly, when the first device is a user device, the first device may also be referred to as a “UE”.

[0121] When there are two group members in the group, e.g. UE A and UE B, UE A as the group leader is configured to send the group configuration 101 to UE B. The group configuration 101 comprises RS resource configurations of UE A and UE B. In this way, UE B can transmit one or more RSs of its own based on the configuration of UE B comprised in the group configuration 101. Moreover, UE B can also retrieve one or more RSs sent by UE A based on the configuration of UE A comprised in the group configuration 101 when performing measurement for positioning at a later stage. The same applies to a case when there are three or more members in the group. For example, when there are three members, UE A, UE B and UE C, UE A as the group leader is configured to send the group configuration to both UE B and UE C. The group configuration is not device-specific and comprises RS resource configuration of all the members in the group, e.g. UE A, B and C in this case.

[0122] A second scenario is that the first device may be a network device, such as a base station or a road side unit (RSU). Each second device may be a user device, such as a terminal or a vehicle. In this scenario, a group of second devices may comprise at least two user devices. In this scenario, the first device is configured to send the group configuration 101 to the at least two second devices. The group configuration 101 comprises RS resource configurations of the at least two second devices. Generally, the group configuration 101 sent by the first device 110 to one second device 120 may comprise the RS resource configuration of the second device 120 and a further RS resource configuration of a further device. The further device may be the first device 110 if the first device 110 is a user device. Alternatively, the further device may be a further second device 140 or 160. The further device and the second device 120 may be in a same group. The further RS resource configuration may allow the second device 120 to retrieve the RS resource sent by the further device and perform a measurement based on the further RS resource for positioning. The RS resource configuration and the (at least one) further RS resource configuration may be associated with device IDs.

[0123] FIG. 2 shows an example of the second device 120 according to the present disclosure. It is noted that corresponding elements and devices in FIG. 1 and FIG. 2 may share the same functions and features likewise.

[0124] The second device 120 is configured to receive a group configuration 201 from a first device (not shown in FIG. 2). The second device 120 then may be configured to determine the configuration for its PRS transmission, which may be based on a PRS configuration associated with its UE ID. Afterwards, the second device 120 is configured to transmit the PRS 202 based on the PRS configuration. Optionally, the second device 120 may comprise a determination module 210 to determine the PRS configuration.

[0125] Optionally, the second device 120 may be further configured to receive a group resource reservation indication 203 from the first device. In response to the group resource reservation indication 203, the second device 120 may be further configured to send a group resource reservation information 204 in order to reserve PRS resources of the group, i.e., to reserve one or more PRS resources of the devices indicated in the group configuration 201. The group resource reservation information may not need to specifically indicate which resources are reserved for which second device, since this information is not relevant for non-group devices, i.e., devices outside the group. That is, optionally, the group resource reservation information in the present disclosure may be used to reserve a smallest resource group that covers the one or more PRS resources of the devices in the group. This may allow resource sensing by the nongroup devices. Alternatively, one of the one or more second devices may be pre-configured to send the group resource reservation information 204. For example, when forming the group, the group leader or the network device may designate one of the one or more second devices to send the group resource reservation 204, e.g., by indicating a corresponding ID. Optionally, the second device 120 may comprise a reservation module 230 adapted to perform the group resource reservation.

[0126] Optionally, when the group resource is reserved by the group resource reservation information 204, the group configuration 201 may only need to indicate a relative resource assignment to one or more second devices based on resources reserved by the group resource reservation information 204. This may have the advantage that the resources of the PRS transmissions in the group configuration can be indicated more efficiently. The signaling overhead may be further reduced.

[0127] Optionally, the group resource reservation information 204 can be sent through SCI, such as the first stage SCI (1st- stage- SCI).

[0128] FIG. 3 shows another example of the second device 120 according to the present disclosure. It is noted that corresponding elements and devices in FIGs. 1-3 may share the same functions and features likewise.

[0129] Similar to the second device 120 of FIG. 2, the second device 120 of FIG. 3 is configured to receive a group configuration 301 from a first device. Then, the second device 120 may be further configured to receive a measurement request 303 from the first device. The measurement request 303 may comprise one or more UE IDs, and / or one or more PRS IDs, which may indicate the second device 120 to receive the corresponding PRS resource for measurement. Then, the second device 120 may be further configured to receive the PRS for measurement 305, and perform the measurement. Then, the second device 120 may be further configured to send a measurement report 302. Optionally, the second device 120 may comprise a measurement module adapted to perform the measurement.

[0130] For example, the measurement request 303 may comprise UE ID X, then the second device 120 may be configured to receive PRS resources sent by UE X based on the PRS configuration of UE X comprised in the group configuration 301, which has been sent to the second device 120 previously. Therefore, this has the advantage that no additional signaling may be needed to notify the second device details of the PRS resources to be measured. Thus, signaling overhead can be further reduced.

[0131] It is noted that in the present disclosure, transmitting a PRS can be seen as transmitting PRS resources. Similarly, receiving a PRS can be seen as receiving PRS resources.

[0132] Optionally, the second device 120 in FIG. 2 and the second device 120 in FIG. 3 can be combined. That is, optionally, a second device according to the present disclosure may comprise three modules 210, 230 and 310 mentioned in FIG. 2 and FIG. 3, and may be adapted to perform the corresponding features.

[0133] FIG. 4 shows an example of PRS resource allocation according to this disclosure. In this example, there are four UEs in a group, UE A, UE B, UE C and UE D. In the group, each UE may be configured to receive PRSs from all other UEs. Generally, PRS resources may be multiplexed in the time domain. In this example, orthogonal resources in the time domain are configured for PRS transmissions due to the half-duplex constraint of the UEs.

[0134] In this example, UE A is the group leader, which may act as a first device as mentioned in either of FIGs. 1-3. UE B-D act as the one or more second devices in either of FIGs. 1-3. UE A is configured to send a group configuration to other UEs in a groupcast transmission via PSSCH in resource R0. UE A also may be configured to send in a control channel, e.g. physical sidelink control channel (PSCCH), at resource R0 resource reservation information for resource R1. The resource reservation information may serve as a group resource reservation for PRS transmissions within the group of UEs. In this example, the group resource reservation information may indicate that resource R1 is reserved for PRS transmission. The resource reservation allows non-group UEs to perform resource sensing in order to be aware that resource R1 is reserved. The assignment of the resources within the reserved resource R1 for the PRS transmissions within the group may be indicated through the group configuration sent by UE A. The group configuration configures and indicates which UE transmits PRS on which resources (e.g. symbol) of the next reserved group resource, i.e. resource Rl . As shown in the table with the group configuration in FIG. 4, UE A shall transmit PRS on symbols 2 and 3, UE B shall transmit PRS on symbol 6, UE C shall transmit PRS on symbol 9 and UE D shall transmit PRS on symbol 12 in resource Rl . It is noted that the transmitted PRS can be retrieved by any UE that is aware of the corresponding PRS resource configuration. Generally, as UEs need to switch from transmission to reception within the resource Rl, automatic gain control (AGC) symbols and guard symbols may be needed between the PRS transmissions of the UEs in the group. The AGC symbol may comprise a duplication of the symbol following the AGC symbol. The AGC and guard symbols are exemplarily illustrated in FIG. 4.

[0135] In FIG. 4, the PSCCH in resource Rl can be sent by a UE sending PRS on symbols 2 and 3, i.e. UE A in this case. The PSCCH may be used to reserve further resources for PRS transmissions within the group. It is noted that the PSCCH may consist of a plurality of symbols in the time domain, e.g. 2 symbols or 3 symbols. Optionally, a measurement request within the group may be sent by UE A in the groupcast transmission via the PSSCH in resource RO shown in FIG. 4. The measurement request can be based on UE ID for the configured PRS transmissions within the group. For example, the measurement request may comprise UE ID B and C, which indicates that UE B and C are configured to perform a measurement.

[0136] FIG. 5 shows another example of PRS resource allocation according to this disclosure. In this example, there are six UEs, UE A, UE B, UE C, UE D, UE E and UE F, in a group. A group PRS transmit configuration is sent by UE A as a group leader to the other UEs in a groupcast transmission via the PSSCH in resource RO. Thus, UE A in this example acts as a first device in either of FIGs. 1-3, and UE B-E act as the one or more second devices in either of FIGs. 1- 3. The group PRS transmit configuration may configure and indicate which UE transmits PRS on which resources as shown exemplarily in the table of FIG. 5, where resource R2-X refers to a portion of the resources (e.g. one or more symbols) within resource R2. The resources for the PRS transmissions in the group are spread over multiple slots. As shown in the table of FIG. 5, UE A, UE B and UE C send a PRS in resource Rl and another PRS in resource R3, while UE D, UE E and UE F send a PRS in resource R2 and another PRS in resource R4.

[0137] Generally, a plurality of resources for sending a plurality of PRSs can be assigned to a UE, e.g. for sending PRSs with different beams or antenna panels. Thus, the present disclosure can also be applied to a multiple-input-multiple-output (MIMO) system or to UEs with multiple antenna panels.

[0138] Optionally, the group resource reservation can be sent by multiple UEs in different slots. In this example, the group reservation for resources Rl, R2 and R4 is sent by UE A in the PSCCH sent in resources RO, Rl and R3, respectively, while the group reservation for resource R3 is sent by UE D in the PSCCH sent in resource R2. In FIG. 5, the measurement request within the group is also sent by UE A in the groupcast transmission via the PSSCH in resource RO. The measurement request can be based on the UE ID for the configured PRS transmissions within the group.

[0139] In FIG. 5, resources of PRS transmissions of multiple UEs are multiplexed in one sub-channel. Alternatively, multiple PRS transmissions from one UE can also be configured within one resource. Alternatively, multiple PRS transmissions from one or more UEs can be multiplexed in multiple sub-channels.

[0140] In FIG. 5, resources of PRS transmissions of multiple UEs are multiplexed in the time domain in one sub-channel. Alternatively, multiple PRS transmissions of multiple UEs can also be multiplexed in the frequency domain.

[0141] In FIG. 5, the PRS transmissions configured with the group PRS transmit configuration may span one sub-channel in the frequency domain. Alternatively or additionally, a PRS transmission configured with the group PRS transmit configuration can span multiple subchannels. Alternatively or additionally, a PRS transmission configured with the group PRS transmit configuration can span all the sub-channels within a resource pool.

[0142] FIG. 6 shows another example of PRS resource allocation according to this disclosure. In this example, there are eight UEs in a group, UE A, UE B, UE C, UE D, UE E, UE F, UE G and UE H.

[0143] Generally, there may be sub-groups in the group. UEs in a sub-group are configured to transmit and receive PRSs from UEs in another sub-group, while UEs in a same sub-group do not receive PRS from each other. In this example, UE A, UE B, UE C and UE D as a first sub-group shall receive PRS from UE E, UE F, UE G and UE H as a second sub-group and vice-versa. The PRS transmissions of the first sub-group can be multiplexed (e.g. orthogonal) in the time domain with the PRS transmissions of the second sub-group, due to the half-duplex constraint. As UE A, UE B, UE C and UE D (as well as UE E, UE F, UE G and UE H) do not need to receive PRS from one another, their PRS transmissions can be multiplexed in the frequency domain at the same symbol.

[0144] In FIG. 6, the group PRS transmit configuration is sent by UE A to other UEs (i.e., UE B-H) in a groupcast transmission via the PSSCH in resource RO. The group PRS transmit configuration configures and indicates which UE transmits PRS on which resources. The multiplexing of the PRS transmissions of the UEs is given by the patterns in the table of the group PRS transmit configuration in FIG. 6, where each PRS transmission may be spread over the frequency domain and over one or more symbols within a slot. UE A may send in the PSCCH at resource RO a resource reservation for resource Rl, which may serve as a group resource reservation for PRS transmissions within the group of UEs. In FIG. 6, the measurement request within the group may also be sent by UE A in the groupcast transmission via the PSSCH in resource RO. The measurement request can be based on UE ID for the configured PRS transmissions within the group.

[0145] FIG. 7 shows another example of PRS resource allocation according to this disclosure. In this example, a resource for a PRS transmission of a resource pool may be (pre-)configured with a corresponding PRS ID, as shown in the “table with (pre-)configured allocations for PRS resources” of FIG. 7. Each designated resource for a PRS may span a part or all of the subchannels in the resource pool. The designated resources for PRS may also be in another resource pool. In this example, there are six UEs in a group, UE A, UE B, UE C, UE D, UE E and UE F. UE A in this example acts as a first device in either of FIGs. 1-3, and UE B-F act as the one or more second devices in either of FIGs. 1-3. The group PRS transmit configuration is sent by UE A to the other UEs in a groupcast transmission via the PSSCH in resource RO. The group PRS transmit configuration configures and indicates which UE transmits which preconfigured PRS resource based on the PRS ID. As shown in FIG. 7, group PRS transmit configuration indicates an association between UE IDs and PRS IDs.

[0146] In FIG. 7, the measurement request within the group may be also sent by UE A in the groupcast transmission via the PSSCH in resource RO. The measurement request can be based on the UE ID for the configured PRS transmissions within the group or based on the index of the PRS (PRS ID). FIG. 8 shows an example of a signaling flow according to this disclosure. In this example, the group PRS transmit configuration may be provided by a first device being a network device to a group of second devices. The group PRS transmit configuration can be transmitted via a control message such as a downlink control information (DCI), or with a higher layer configuration such as radio resource configuration (RRC). The group may comprise at least two UEs. In FIG. 8, at least two UEs are shown, i.e. UE 1 and UE N. The network device in this example acts as a first device in either of FIGs. 1-3, while UE 1 and UE N act as the one or more second devices in either of FIGs. 1-3.

[0147] The group configuration configures and indicates which UE transmits PRS on which resources. For example, the group configuration may comprise information like: { (RS resource 1, UE 1), ..., (RS resource N, UE N) }. Optionally, the group configuration may also comprise one or more other parameters of the RS and / or the RS resources, such as a type of RS sequence, an RS sequence identifier, and an initialization of the RS sequence, a periodicity of the RS resources, a repetition of the RS resources, a bandwidth of the RS resources, a comb size of the RS resources, a staggering pattern of the RS resources, a quasi-colocation information of the RS resources, and parameters for power control of the RS resources. These configurations may be common for all the UEs in the group. Alternatively, these configurations may be dedicated to a specific UE in the group. In this case, these configurations may be associated with an ID of the specific UE.

[0148] Optionally, the network device may also be configured to send a measurement request based on UE ID for a measurement of the configured PRS transmissions within the group. Optionally, the network device may be further configured to indicate one of the UEs, e.g. UE 1, to send group resource reservation for reserving resources for PRS transmissions within the group, which may be received by a non-group UE outside the group for performing resource sensing. Afterwards, UEs in the group are configured to send the PRS according to the group configuration. The UEs may be further configured to make measurements of PRSs sent by the other UEs in the group.

[0149] FIG. 9 shows a further example of a signaling flow according to this disclosure. In this example, there are two UEs in a group, where the group PRS transmit configuration is provided by UE 1 as the group leader. UE 1 in this example acts as a first device in either of FIGs. 1-3, while UE 2 acts as the one or more second devices in either of FIGs. 1-3. In this example, the group PRS transmit configuration can be transmitted by the group leader via a PSSCH, with an SCI transmission (e.g. 2nd stage SCI), or with a higher layer configuration (e.g. PC5-RRC), or a TB of a PSSCH. The group configuration may be used to configure and indicate on which resources UE 1 and UE 2 shall transmit PRS, respectively. The group configuration may also comprise other parameters of the PRS or PRS resource as mentioned with respect to FIG. 8.

[0150] Optionally, UE 1 may be configured to send a measurement request to UE 2 as shown in FIG. 9. Alternatively, the measurement request may be sent by another device in the group, or from a network device, which is not shown in FIG. 9.

[0151] Optionally, UE 1 may be configured to indicate or configure UE 2 to send a group resource reservation for PRS transmissions of UE 1 and UE 2.

[0152] FIG. 10 shows a further example of a signaling flow according to this disclosure. In this example, there are at least three UEs in a group, UE 1, UE 2, and UE N. UE 1 in this example acts as a first device of FIGs. 1-3, while UE 2 and UE N act as the one or more second devices of FIGs. 1-3. Other aspects of FIG. 10 are similar to those of FIG. 9, which are not repeated herein for the sake of brevity. It is noted that in the present disclosure, any UE in the group may be configured to initiate a measurement request to one or more other UEs in the group. That is, in an alternative scenario of FIG. 10, UE 2 may send a measurement request to other UEs in the group, e.g., UE 1 and UE N. Then, UE 2 may be configured to receive measurement reports of PRS 2 sent by UE 2 from UE 1. Then, UE 2 may be configured to estimate the locations of UE 1 and UE N via the received measurement reports.

[0153] It is noted that each optional feature or function that is mentioned with respect to the examples in FIG. 4-10 can be separately applied to the first device and the second device of FIG. 1-3 accordingly.

[0154] FIG. 11 shows a diagram of a method 1100 of the present disclosure. The method 1100 is performed by a first device for positioning. The method 1100 comprises step 1101 : sending, by a first device to one or more second user devices, a configuration of one or more RS resources for transmitting one or more RSs by the one or more second devices for positioning. Optionally, the method 1100 may further comprise step 1102: sending, by the first device to the one or more second user devices, a measurement request.

[0155] The steps of the method 1100 may share the same functions and details from the perspective of FIG. 1-10 described above for the first device. Therefore, the corresponding method implementations are not described again at this point.

[0156] FIG. 12 shows a diagram of a method 1200 of the present disclosure. The method 1200 is performed by a second device for positioning. The method 1200 comprises the following steps: step 1201 : receiving, by the second device from a first device, a group configuration of one or more RS resources for transmitting one or more RSs for positioning; and step 1202: transmitting, by the second device, one or more RSs according to the configuration.

[0157] Optionally, the method 1200 may further comprise the following steps: step 1203: receiving, by the second device (from the first device), a measurement request; step 1204: measuring, by the second device, RS resources from other devices according to the measurement request and based on the group configuration.

[0158] The steps of the method 1200 may share the same functions and details from the perspective of FIG. 1-10 described above for the second device. Therefore, the corresponding method implementations are not described again at this point.

[0159] In the present disclosure, for facilitating positioning in a group of UEs, a group configuration of PRS transmissions, which may be simply referred to as a group PRS transmit configuration or group configuration, is sent to one or more UEs of the group. The one or more UEs comprise UE(s) that are to send one or more PRS transmissions and / or UE(s) that are to make a measurement of one or more PRS transmissions of other UE(s). For example, a group may comprise UE 1 and UE 2. UE 1 and UE 2 each may be configured to send one or more PRS transmissions in each resource assigned by the group configuration. Moreover, UE 1 may be configured to measure UE 2’s PRS transmission according to the resources assigned to UE 2 based on the group configuration. UE 2 may be configured to measure UE l’s PRS transmission according to the resources assigned to UE 1 based on the group configuration. The group PRS transmit configuration may comprise an indication of on which resources a PRS shall be transmitted and which UE shall transmit the PRS. For example, the resource assignment may comprise information such as: { (PRS resource 1, UE 1), (PRS resource 2, UE 2),. . (PRS resource N, UE N) }. In this way, each UE may be aware of the resources assigned for its own PRS transmission, e.g., based on UE ID of each own. Moreover, each UE may be aware of the resources assigned to other UE(s), e.g., based on ID of other UE(s), so that each UE may measure the PRS resources transmitted by other UE(s) accordingly. Therefore, signaling overhead may be reduced.

[0160] Optionally, the group PRS transmit configuration may further comprise one or more parameters of each PRS. For example, the group PRS transmit configuration may comprise information such as:{ (PRS resource 1, UE 1, parameter 1), (PRS resource 2, UE 2, parameter 2),. . ., (PRS resource N, UE N, parameter N) } . In this case, UE 1 , UE, 2 and UE N are configured to transmit PRS based on parameters 1, 2, and N, respectively. Optionally, a default parameter may be preconfigured and may not be explicitly comprised in the group PRS transmit configuration. As another example, the group PRS transmit configuration may be: { (PRS resource 1, UE 1, parameter(s) 1), (PRS resource 2, UE 2), ..., (PRS resource N, UE N, param eter(s) N) }. In this case, UE 1 and UE N are configured to transmit PRS based on parameter(s) 1 and parameter(s) N, respectively, while UE 2 is configured to transmit PRS based on a default parameter. The one or more parameters of the PRS may comprise the type of sequence used for the PRS (e.g. Zaduff-Chu sequence, Gold sequence, etc.), the sequence identifier, the initialization of the sequence, a periodicity of the PRS, the comb size, the staggering pattern, quasi-colocation information, parameters for power control of the PRS transmission, etc.

[0161] Optionally, the resources for the PRS transmissions may correspond to resources that are reserved or (pre-)configured only for PRS transmissions, e.g. in a resource pool. Optionally, the resource reservation may be carried on a first stage SCI. Optionally, the first stage SCI may be carried on PSCCH. That is, optionally, the group resource reservation may be indicated via PSCCH. Optionally, the first stage SCI may further include indication information comprising one or more indicator bits. The one or more indicator bits may be used to indicate that a resource reservation for data transmission or retransmission, sent through the first stage SCI, shall be interpreted in a different way, i.e., shall be interpreted as resources for positioning and not as resources for user data. By including the indication information, the first stage SCI can be configured to indicate that the resources assigned by a resource reservation in the first stage SCI can be either for a user data (re)transmission, or for positioning. For instance, the indicator bits having “00” may indicate resources are reserved for a new user data transmission. The indicator bits having “01” may indicate resources are reserved for a retransmission. The indicator bits having “11” may indicate resources are reserved for a PRS transmission. It is noted that the bit values herein are merely given as an example and any other bit values may be used. In this way, the present disclosure may re-use existing control information to convey the group PRS transmit configuration and may bring compatibility.

[0162] The reserved or (pre-)configured resources for SL PRS transmission can be configured by the network or (pre-)configured in a resource pool. Within the available PRS resources, resources for each PRS transmission can be specified or defined in a relative manner, e.g. with a table indicating an index for a PRS and the resources specified for that PRS. This has the advantage that a PRS resource can be specified more efficiently. The specification of PRS resources among designated resources for SL PRS can be done via configuration by the network or by a UE as a group leader.

[0163] Optionally, the UE that shall transmit a PRS is identified through an identifier of the UE, e.g. a member ID in the group, which is associated with a PRS transmit configuration. This has the advantage that the UEs in the group know which UE is transmitting a PRS. For example, in an NR V2X communication network, UEs in a group may be assigned a member ID, e.g. provided by a V2X application layer for the link establishment for groupcast.

[0164] The group PRS transmit configuration can be sent to the one or more UEs by the network or by a UE in the group. When the configuration is sent by the network, this has the advantage that the network can also manage the resources for the PRS transmissions in the group. The group configuration of the PRS transmissions can be sent by network via control information such as DCI, RRC, or any higher layer signaling. When the group configuration is sent by a UE, this has the advantage that the present disclosure is applicable for out-of-network coverage scenarios. The UE that sends the group configuration may be a group leader of the group, which has the advantage that the group leader can also manage or select the resources for the PRS transmissions for members in the group. The UE can send the group configuration via a groupcast transmission or groupcast configuration via sidelink to each member UE separately. This has the advantage that every UE in the group can be configured. The group PRS transmit configuration can be sent by a UE via control information such as SCI or a transport block of a PSSCH. Optionally, the SCI may be a second stage SCI. It is noted that when resource reservation is sent on the first stage SCI, the resource reservation may include one or more indicator bits indicating that the resources assigned through the second stage SCI are for SL positioning purposes. This provides the advantage of a more dynamic PRS configuration. The group configuration may also be sent via PC5-RRC as a groupcast manner, which allows for a more semi-static configuration.

[0165] Optionally, by sending resource reservation, it may allow for resource sensing, e.g. by nongroup UEs outside the group, for the one or more PRS transmissions within the group. This has the advantage that a UE can reserve multiple PRS transmissions of other UEs, without the need to specifically indicate the assignment of those resources, as the specific assignment is not needed by non-group UEs for performing only resource sensing. This configuration can be indicated by the network or by a UE in the group. The configuration of the UE sending the resource reservation can also be (pre-)configured, i.e. the resource reservation is performed by the UE with a given UE identifier. The resource reservation can be sent in the 1st stage SCI. Given the group resource reservation, the group PRS transmit configuration may only need to indicate the relative assignment to UEs based on the resources reserved in the group resource reservation. This has the advantage that the resources of the PRS transmissions in the group can be indicated more efficiently.

[0166] Optionally, a measurement request for measuring one or more PRS transmissions may be based on an identifier of the UE, i.e. a UE is configured to make measurements of the PRS sent by other UEs with a given UE identifier. Optionally, each UE in the group may be assigned with a member ID, which may be used as the identifier for the SL positioning configuration. This has the advantage that with the group PRS transmit configuration, where a PRS transmit configuration of a UE is associated with an identifier of the UE, a receiving UE knows which PRS transmissions it needs to measure and there is no need to indicate the resources on which to perform a measurement in the measurement request. In this way, the configuration of the measurement request does not need to be updated if a PRS transmit configuration is updated, i.e. a PRS is sent on another resource. The measurement can comprise a reference signal received power (RSRP), a receive-transmit time difference (Rx-Tx time difference), or a time difference of arrival (TDOA). The measurement request can be sent separately to each UE or jointly to multiple UEs. The measurement request can be sent by the network or by a UE in the group, e.g. a group leader.

[0167] When the group configuration is sent by a UE in the group, this has the advantage that the present disclosure is applicable for out-of-network coverage scenarios. The UE can send the measurement request via a groupcast transmission or groupcast configuration in the sidelink. This has the advantage that each UE in the group can be configured to make a measurement. Optionally, the measurement request can be sent by the UE via control information such as a second stage SCI, or in a transport block of a PSSCH. This provides the advantage of a more dynamic configuration of the measurement request. Optionally, the measurement request can also be sent via higher layer signaling or PC5-RRC signaling in a groupcast manner, which provides the advantage of a more semi- static configuration of the measurement request.

[0168] Optionally, the configuration of the measurement request can also include an identifier of the destination of a measurement, i.e. to whom a UE shall transmit its measurement result. Optionally, the measurement request can also include a reference to be used for measurement, i.e. a reference PRS, as well as the number of measurements to report. Optionally, the measurement request may also comprise other information that may help a UE to make a measurement, e.g. an expected range of values for a measurement.

[0169] In the present disclosure, the device (including the first device and the second device) may comprise a processor or processing circuitry (not shown) configured to perform, conduct or initiate the various operations of the device described herein. The processing circuitry may comprise hardware and / or the processing circuitry may be controlled by software. The hardware may comprise analog circuitry or digital circuitry, or both analog and digital circuitry. The digital circuitry may comprise components such as application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), digital signal processors (DSPs), or multipurpose processors. The device may further comprise memory circuitry, which stores one or more instruction(s) that can be executed by the processor or by the processing circuitry, for example, under control of the software. For instance, the memory circuitry may comprise a non- transitory storage medium storing executable software code which, when executed by the processor or the processing circuitry, causes the various operations of the device to be performed. In one embodiment, the processing circuitry comprises one or more processors and a non-transitory memory connected to the one or more processors. The non-transitory memory may carry executable program code which, when executed by the one or more processors, causes the device to perform, conduct or initiate the operations or methods described herein. When the first device is a network device, the first device may be a network access device, a base station, a router, a roadside unit (RSU) and the like. When the first device is a user device, the first device may be a mobile terminal, a tablet, a wearable device, a drone, a positioning module, a vehicle, an on-board unit (OBU) of a vehicle for V2X and the like. The second device may be a user device such as but not limited to a mobile terminal, a tablet, a drone, a wearable device, a positioning module, a vehicle, an OBU of a vehicle for V2X and the like. The present disclosure has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed matter, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

CLAIMS1. A first device (110) configured to send to one or more second devices (120), a configuration of one or more reference signal, RS, resources for transmitting one or more RSs by the one or more second devices (120) for positioning.

2. The first device (110) according to claim 1, wherein the configuration comprises a resource allocation of the one or more RS resources to the one or more second devices (120), wherein each of the one or more RS resources is associated with an identifier, ID, of one of the one or more second devices (120).

3. The first device (110) according to claim 1 or 2, wherein the one or more RS resources are multiplexed in time and / or frequency domains.

4. The first device (110) according to any one of claims 1 to 3, wherein the one or more RSs comprise a positioning reference signal, PRS, or a sounding reference signal, SRS.

5. The first device (110) according to any one of claims 1 to 4, wherein the one or more RS resources are of a resource pool.

6. The first device (110) according to any one of claims 1 to 5, wherein the one or more RS resources are part of resources reserved for sidelink, SL, positioning.

7. The first device (110) according to any one of claims 1 to 6, wherein the configuration further comprises configuration information of the one or more RS resources, wherein the configuration information comprises one or more of a type of sequence, a sequence identifier, and an initialization of the sequence for generating a sequence for the one or more RS resources, a periodicity of the one or more RS resources, a repetition of the one or more RS resources, a bandwidth of the one or more RS resources, a comb size of the one or more RS resources, a staggering pattern of the one or more RS resources,a quasi-colocation information of the one or more RS resources, and parameters for power control of the one or more RS resources.

8. The first device (110) according to any one of claims 1 to 7, further configured to send one or more measurement requests to the one or more second devices (120), wherein each measurement request indicates the one or more second devices (120) to perform one or more measurements based on the one or more RS resources.

9. The first device (110) according to claim 8, wherein the one or more measurement requests comprise one or more of: a destination ID; an indication of an RS to be used as a reference for the measurement; a quantity of measurement results to be reported; and an expected range of values for the measurement.

10. The first device (110) according to any one of claims 1 to 9, wherein the first device (110) is a network device, which is configured to send the configuration by control information.

11. The first device (110) according to any one of claims 1 to 9, wherein the first device (110) is a user device, which is configured to send the configuration by control information.

12. The first device (110) according to any one of claims 1 to 11, further configured to send reservation information for reserving the one or more RS resources.

13. The first device (110) according to claim 12, further configured to send the reservation information through a first stage sidelink control information, SCI.

14. The first device (110) according to claim 13, further configured to send, through the first stage SCI, indication information indicating that the reserved one or more RS resources are for positioning.

15. The first device (110) according to any one of claims 1 to 11, wherein the configuration further indicates one of the one or more second devices (120) to send reservation information for reserving the one or more RS resources.

16. A second device (120), configured to: receive, from a first device, a configuration (201) of one or more reference signal, RS, resources for transmitting one or more RSs for positioning; and transmit one or more RSs (202) according to the configuration.

17. The second device (120) according to claim 16, wherein the configuration (201) comprises a resource allocation of the one or more RS resources associated with one or more identifiers, IDs, of the one or more second devices, and the second device is further configured to determine one or more allocated RS resources for transmitting the one or more RSs (202) based on an ID of the second device.

18. The second device (120) according to claim 16 or 17, wherein the one or more RS resources are multiplexed in time and / or frequency domains.

19. The second device (120) according to any one of claims 16 to 18, wherein the one or more RSs (202) comprise a positioning reference signal, PRS, or a sounding reference signal, SRS.

20. The second device (120) according to any one of claims 16 to 19, further configured to: receive a measurement request (303) from the first device and perform one or more measurements according to the measurement request (303).

21. The second device (120) according to claim 20, wherein the measurement request (302) further comprises one or more of: a destination ID; an indication of an RS to be used as a reference for the measurement; a quantity of measurement results to be reported; and an expected range of values for the measurement.

22. The second device (120) according to any one of claims 16 to 21, configured to receive the resource allocation by control information.

23. The second device (120) according to any one of claims 16 to 22, further configured to send, through a first stage sidelink control information, SCI, reservation information (120) for reserving the one or more RS resources.

24. The second device (120) according to claim 23, further configured to send, through the first stage SCI, indication information indicating that the reserved one or more RS resources are for positioning.

25. A system (100) comprising a first device (110) according to any one of claims 1 to 15, and one or more second devices (120, 140, 160) according to any one of claims 16 to 24.

26. A method (1100) comprising: sending (1101), by a first device to one or more second devices, a configuration of one or more reference signal, RS, resources for transmitting one or more RSs by the one or more second devices for positioning.

27. A method (1200) comprising: receiving (1201), by a second device from a first device, a configuration of one or more reference signal, RS, resources for transmitting one or more RSs for positioning; and transmitting (1202), by the second device, one or more RSs according to the configuration.

28. A computer program comprising a program code for performing the method according to claim 26 or 27, when executed on a computer.

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