Method for transmitting sidelink positioning reference signal using radio resources of dedicated resource pool

Abstract

A method of transmitting a sidelink positioning reference signal (SL-PRS) using radio resources of a dedicated resource pool (PRS-RP) of a radio access network, in which the dedicated resource pool (PRS-RP) for transmitting the sidelink positioning reference signal (SL-PRS) excludes radio resources for transmitting sidelink communication data in the radio access network, the method comprises:-transmitting sidelink control information (SCI) from the first radio node (UE1) to the second radio node (UE2) using radio resources of a dedicated resource pool (PRS-RP), wherein the sidelink control information (SCI) indicates radio resources selected for transmitting sidelink positioning reference signals (SL-PRS) in the dedicated resource pool (PRS-RP); and-transmitting a sidelink positioning reference signal (SL-PRS) from the first radio node (UE1) to the second radio node (UE2) using the selected radio resources of the dedicated resource pool (PRS-RP).

Description

[0001] The present invention relates to two associated methods for transmitting and receiving sidelink positioning reference signals, respectively, using radio resources of a dedicated resource pool of a radio access network, associated radio nodes, a system for radio communication, a computer program and a non-transitory computer-readable medium. Background Art

[0002] In 3GPP Release 18, enhancements to positioning determination with both higher accuracy and lower latency were studied to meet the requirements of new applications in vertical industries for cellular communications with higher integrity and better reliability. The enhancements studied particularly concern Sidelink Positioning Reference Signals (SL-PRS) and their allocation possibilities for radio resource pools used for sidelink communication and / or sidelink positioning.

[0003] In a shared radio resource pool, sidelink communications and sidelink positioning reference signals are transmitted using the same radio resources. The transmitting user equipment (UE) must select available radio resources for the SL-PRS in a time instant and frequency subcarrier that avoids overlap with other communication / positioning resource allocations. This also allows the receiving UE to perform a joint sensing process for the communication signal and the SL-PRS. Summary of the Invention

[0004] According to a first aspect, a method for transmitting a sidelink positioning reference signal using radio resources of a dedicated resource pool of a radio access network is provided, wherein the dedicated resource pool for transmitting the sidelink positioning reference signal excludes radio resources used for transmitting sidelink communication data in the radio access network.

[0005] The method according to the first aspect comprises:

[0006] - transmitting sidelink control information from the first radio node to the second radio node using radio resources of a dedicated resource pool,

[0007] wherein the sidelink control information indicates a radio resource in a dedicated resource pool selected for transmitting a sidelink positioning reference signal; and

[0008] - Transmitting a sidelink positioning reference signal from the first radio node to the second radio node using the selected radio resources from the dedicated resource pool.

[0009] A resource pool includes one or more contiguous or non-contiguous (preferably Orthogonal Frequency Division Multiplexing (OFDM)) symbols or time slots in the time domain, and one or more preferably contiguous or non-contiguous subcarriers or subchannels in the frequency domain. In other words, a resource pool is a set of radio resource elements. A dedicated resource pool includes radio resources used to transmit sidelink positioning reference signals and sidelink control information (particularly associated with the corresponding sidelink positioning reference signals).

[0010] The dedicated resource pool excludes, or more precisely, does not include, radio resources used for transmitting sidelink communication data in the radio access network. When sidelink communication data is transmitted from a first radio node to a second radio node, radio resources from a resource pool used for transmitting sidelink communication data in the radio access network are used instead. The dedicated resource pool used for transmitting sidelink positioning reference signals and sidelink control data and the resource pool used for transmitting sidelink data are separated in the frequency domain and preferably non-interleaved, with or without frequency gaps between different resource pools, and / or separated in the time domain and preferably non-interleaved, preferably allocated to different time slots, i.e., consecutive or non-consecutive time slots. In particular, the dedicated resource pool used for transmitting sidelink positioning reference signals and the resource pool used for transmitting sidelink communication data are non-overlapping in the frequency and / or time domains. In other words, the frequency range and / or time range comprising the dedicated resource pool do not overlap with the frequency range and / or time range comprising the resource pool used for transmitting sidelink communication data.

[0011] Compared to transmitting sidelink positioning reference signals and sidelink communication data in a shared resource pool, where each radio node is required to perform channel sensing on any existing possible occupied means (both communication data and positioning reference signals), the concept of a dedicated resource pool for sidelink positioning reference signals requires radio nodes to perform channel sensing only on positioning reference signals (and corresponding sidelink control information, if transmitted using radio resources of a dedicated resource pool). Additionally, multiple radio nodes can select coexisting radio resources of a dedicated resource pool for concurrent transmission of sidelink positioning reference signals.

[0012] The sidelink positioning reference signal can be considered as the primary reference signal for supporting sidelink-based positioning and / or ranging methods of a radio node. Specifically, the sidelink positioning reference signal can be used to estimate positioning and / or ranging information of the (anchor) radio node receiving the sidelink positioning reference signal.

[0013] The transmitted sidelink control information is used to indicate or identify the radio resources in the dedicated resource pool selected for transmitting the sidelink positioning reference signal. The sidelink control information is transmitted using radio resources of the same radio resource pool as the radio resource pool used for transmitting the sidelink positioning reference signal.

[0014] The radio resources of the dedicated resource pool are selected by the radio node that transmits the sidelink control information and the sidelink positioning reference signal. The radio resources may be selected from a plurality of (pre-)configured sets of contiguous or non-contiguous physical resource elements of the dedicated resource pool. The selection of the radio resources for transmitting the sidelink positioning reference signal by the first radio node may be communicated to the second radio node via the transmitted sidelink control information to reserve the selected radio resources, thereby reducing or avoiding interference or collisions between sidelink transmissions of different radio nodes in the radio access network. The term "(pre-)configured" mode / radio resources may be understood to cover "configured" and / or "preconfigured" mode / radio resources, where "preconfigured" refers to an offline configuration of the mode / radio resources and "configured" refers to a network-initiated configuration of the mode / radio resources.

[0015] According to a second aspect, a method for receiving a sidelink positioning reference signal using radio resources of a dedicated resource pool of a radio access network is provided, wherein the dedicated resource pool for transmitting the sidelink positioning reference signal excludes radio resources used for transmitting sidelink communication data in the radio access network.

[0016] The method according to the second aspect comprises:

[0017] - receiving sidelink control information transmitted from the first radio node to the second radio node using radio resources of the dedicated resource pool,

[0018] wherein the sidelink control information indicates a radio resource in a dedicated resource pool selected for transmitting a sidelink positioning reference signal; and

[0019] - Receiving a sidelink positioning reference signal transmitted from the first radio node to the second radio node using the selected radio resource in the dedicated resource pool.

[0020] According to a third aspect, a first radio node is provided. The first radio node comprises a radio modem, a non-transitory computer-readable medium comprising machine-readable instructions, and a processor configured to load and execute the machine-readable instructions to cause the first radio node to perform the method according to the first aspect or an embodiment thereof, and thereby transmit a sidelink positioning reference signal using radio resources of a dedicated resource pool of a radio access network.

[0021] According to a fourth aspect, a second radio node is provided. The second radio node comprises a radio modem, a non-transitory computer-readable medium comprising machine-readable instructions, and a processor configured to load and execute the machine-readable instructions to cause the second radio node to perform the method according to the second aspect or an embodiment thereof, and thereby receive a sidelink positioning reference signal using radio resources of a dedicated resource pool of a radio access network.

[0022] According to a fifth aspect, there is provided a system for radio communication comprising a first radio node as defined by the third aspect and a second radio node as defined by the fourth aspect.

[0023] According to a sixth aspect, there is provided a computer program comprising machine-readable instructions to cause

[0024] - a first radio node as defined by the third aspect performs the steps of the method according to the first aspect and / or

[0025] - The second radio node as defined by the fourth aspect performs the steps of the method according to the second aspect.

[0026] According to a seventh aspect, there is provided a non-transitory computer readable medium having stored thereon a computer program as defined by the sixth aspect.

[0027] The described method of using radio resources of a dedicated resource pool of a radio access network to transmit and receive sidelink positioning reference signals and associated sidelink control information, respectively, allows avoiding interference or collision between the transmission of sidelink positioning reference signals and the transmission of sidelink communication data by different radio nodes. The method also allows the design of a dedicated resource pool independently of the resource pool used for sidelink communication data, and optimizes the design by taking advantage of specific sidelink positioning requirements (e.g., a short response time to request positioning reference signal transmission). In addition, the independence of the resource pool is beneficial because radio resources can be allocated for both licensed and unlicensed radio bands, thereby further increasing the flexibility of sidelink positioning. In addition, by requiring the transmitting radio node to transmit the sidelink positioning reference signal in an uplink channel and requiring the receiving radio node to receive the transmitted sidelink positioning reference signal in the corresponding uplink channel, the proposed solution also allows network-based allocation of the dedicated resource pool.

[0028] According to an embodiment of the first aspect, the method further comprises transmitting a reference signal associated with the sidelink control information from the first radio node to the second radio node using radio resources of a dedicated resource pool, wherein the reference signal and the sidelink control information are preferably transmitted using the same one or more symbols of the radio resources. Similarly, according to an embodiment of the second aspect, the method further comprises receiving a reference signal associated with the sidelink control information from the first radio node to the second radio node using radio resources of a dedicated resource pool, wherein the reference signal and the sidelink control information are preferably transmitted using the same one or more symbols of the radio resources. As an example, two OFDM symbols of a time slot may be reserved for transmitting both the sidelink control information and the reference signal. The reference signal may be any kind of sidelink reference signal, for example, a demodulation reference signal, a sounding reference signal, a reference signal for phase or time tracking.

[0029] According to the embodiments of the first aspect and / or the embodiments of the second aspect

[0030] - transmitting sidelink control information using one or more consecutive resource elements of the radio resources, and

[0031] - Transmitting a reference signal using reference signal groups of multiple separated blocks of at least one or more consecutive resource elements, wherein the reference signal groups are distributed across a predetermined proportion of the bandwidth or bandwidth portion of the dedicated resource pool, preferably spanning the full bandwidth or full bandwidth portion of the dedicated resource pool.

[0032] Resource elements may be contiguous in the time and / or frequency domains. Blocks of reference signal groups may be separated in the frequency and / or time domains. Sidelink control information is preferably transmitted using one or more contiguous subcarriers of a radio resource. Reference signal groups preferably use multiple separated blocks of at least one or more contiguous subcarriers to transmit reference signals.

[0033] According to the embodiments of the first aspect and / or the second aspect, the multiple separated blocks of the reference signal group are separated by at least one radio resource element used to transmit sidelink control information. The blocks of the reference signal group can be separated in the frequency domain and / or the time domain. Preferably, the multiple separated blocks of the reference signal group are separated by at least one subcarrier used to transmit sidelink control information.

[0034] According to an embodiment of the first aspect, the method further comprises transmitting further sidelink control information and further reference signals from the first radio node or the further first radio node to the second radio node or the further second radio node, preferably using the same one or more symbols of the radio resources of the dedicated resource pool.

[0035] - transmitting further sidelink control information using one or more further contiguous resource elements of the radio resources,

[0036] - transmitting a further reference signal using a further reference signal group of at least a plurality of further separated blocks of one or more consecutive resource elements,

[0037] - a plurality of separate blocks of the further reference signal group are separated by at least one radio resource element used for transmitting sidelink control information, and

[0038] - A plurality of separated blocks of a reference signal group are further separated by at least blocks of a further reference signal group.

[0039] Similarly, according to an embodiment of the second aspect, the method further comprises receiving further sidelink control information and further reference signals transmitted from the first radio node or the further first radio node to the second radio node or the further second radio node, preferably using the same one or more symbols of the radio resources of the dedicated resource pool. Here,

[0040] - transmitting further sidelink control information using one or more further contiguous resource elements of the radio resources,

[0041] - transmitting a further reference signal using a further reference signal group of at least a plurality of further separated blocks of one or more consecutive resource elements,

[0042] - a plurality of separate blocks of the further reference signal group are separated by at least one radio resource element used for transmitting sidelink control information, and

[0043] - A plurality of separated blocks of a reference signal group are further separated by at least blocks of a further reference signal group.

[0044] The additional resource elements may be contiguous in the time domain and / or frequency domain. The blocks of the additional reference signal groups may be separated in the frequency domain and / or time domain. Preferably, the additional sidelink control information is transmitted using one or more contiguous subcarriers of the radio resources. Preferably, the additional reference signal groups are transmitted using multiple separated blocks of at least one or more contiguous subcarriers. In other words, the radio resources are contiguous or separated in at least the frequency domain (optionally also in the time domain or alternatively only in the frequency domain). This design allows multiplexing of transmissions of SCI and associated reference signals transmitted concurrently from different radio nodes.

[0045] According to the embodiments of the first aspect and / or the embodiments of the second aspect

[0046] - transmitting sidelink control information and reference signals using a control resource set consisting of multiple separate blocks of consecutive resource elements, and

[0047] - Controlling a distribution of a predetermined proportion of the resource set across the bandwidth or bandwidth portion of the dedicated resource pool, preferably across the full bandwidth or the full bandwidth portion of the dedicated resource pool.

[0048] In other words, a control resource set includes both sidelink control information and reference signals, where multiple separate blocks of consecutive resource elements represent a control resource set. As an example, a control resource set can consist of twelve or multiples of twelve resource elements in the frequency domain and one, two, three, or more OFDM symbols in the time domain. This alternative design also allows for multiplexing of transmissions of SCI and associated reference signals transmitted in parallel from different radio nodes.

[0049] According to an embodiment of the first aspect and / or an embodiment of the second aspect, each of the consecutive resource element blocks includes both resource elements for transmitting sidelink control information and resource elements for transmitting reference signals. Therefore, both the sidelink control information and the reference signals are distributed across (parts of) the bandwidth.

[0050] According to an embodiment of the first aspect and / or an embodiment of the second aspect, each block includes a reference signal group comprising multiple separated blocks of at least one or more contiguous resource elements, wherein the reference signal group is distributed across each block, wherein the multiple separated blocks of the reference signal group are separated by at least one radio resource element used to transmit sidelink control information. Thus, both the sidelink control information and the reference signal are distributed across the resource elements of each block.

[0051] According to the embodiments of the first aspect and / or the second aspect

[0052] - transmitting sidelink control information and a reference signal using one or more symbols of a first portion of a time slot of a radio resource, wherein an associated sidelink positioning reference signal is transmitted using one or more different symbols of the first portion of the time slot, and

[0053] - using one or more symbols of the second part of the time slot of the radio resource to transmit further sidelink control information and a further reference signal from the first radio node to the second radio node, wherein one or more different symbols of the second part of the time slot are used to transmit the associated further sidelink positioning reference signal from the first radio node to the second radio node.

[0054] The first and second parts can be of equal or different lengths or sizes, represented by multiple OFDM symbols. Preferably, the first and second parts are non-overlapping and constitute a complete time slot. This reduces the temporal distance between two opportunities for transmitting the sidelink positioning signal, which is very beneficial for time-critical sidelink positioning applications.

[0055] According to the embodiments of the first aspect and / or the embodiments of the second aspect

[0056] - a dedicated resource pool comprising a plurality of (pre-)configured radio resource patterns for transmitting sidelink positioning reference signals,

[0057] - a predetermined proportional distribution of the bandwidth or bandwidth portion across the dedicated resource pool for each of a plurality of (pre-)configured modes, and

[0058] - The selected radio resources include at least one of a plurality of preconfigured patterns.

[0059] Each of the plurality of (pre-)configured patterns includes a plurality of radio resource elements consisting of one (OFDM) symbol in the time domain and one subcarrier in the frequency domain. For each of the plurality of (pre-)configured patterns, the plurality of radio resource elements represents a defined arrangement or pattern in the time domain and the frequency domain. The plurality of radio resource elements of each pattern may be non-contiguous, partially contiguous, or fully contiguous in the time domain and / or the frequency domain. A pattern of partially contiguous radio resource elements represents a pattern in which at least two resource elements are contiguous and at least two resource elements are discontinuous in the time domain and / or the frequency domain.

[0060] A (pre-)configured pattern distributed across a predetermined proportion of a bandwidth (portion) is a pattern that includes at least one radio resource element from all N segments of a predetermined proportion of the bandwidth (portion), wherein the N segments preferably constitute the predetermined portion of the bandwidth (portion) equally, and N is equal to or greater than 2. Specifically, a (pre-)configured pattern distributed across a predetermined proportion of a bandwidth (portion) is a pattern that includes at least one radio resource element from all resource blocks of a predetermined proportion of the bandwidth (portion). The predetermined proportion of the bandwidth (portion) may include the full bandwidth (portion), or only a portion of the full bandwidth (portion), for example 80%.

[0061] Each radio node may select a different (pre-)configured pattern to transmit positioning reference signals.The transmissions of multiple radio nodes may multiplex themselves on the same dedicated resource pool, thus avoiding collisions between simultaneous transmissions of different radio nodes.

[0062] According to an embodiment of the first aspect and / or an embodiment of the second aspect, each of the plurality of (pre)configuration patterns includes at least partially different, preferably dedicated, non-contiguous subcarriers for each of the at least two symbols, such that all subcarriers of a predetermined proportion of the bandwidth or bandwidth portion are included by each of the plurality of pre-configuration patterns, so that the plurality of (pre)configuration patterns preferably form an interleaved structure across a predetermined proportion of the bandwidth or bandwidth portion. As an example, each of the plurality of (pre)configuration patterns may include a first subset of all subcarriers for a first symbol and at least a second subset of all subcarriers for at least one second symbol, wherein the joint set of the first subset and the at least one second subset includes all subcarriers of a predetermined proportion of the bandwidth (portion). Here, with respect to the included subcarriers, the first subset and the at least one second subset may partially overlap or be disjoint. Specifically, the first subset and the at least one second subset may include only non-contiguous subcarriers, or at least non-contiguous segments of continuous subcarriers. Thus, for each symbol of the time slot, each of the plurality of (pre)configuration patterns has a comb-like structure.

[0063] In other words, an interleaving structure can be understood as a structured allocation of radio resources from a dedicated resource pool to multiple transmission modes. Here, the dedicated resource pool can be divided, distributed, or allocated to multiple transmission modes such that the multiple transmission modes are interleaved across a predetermined proportion of the bandwidth (portion). In other words, the interleaving structure consists of multiple interleaved interleaving patterns, each of which represents a transmission resource. By forming an interleaving structure for the sidelink channel across a predetermined proportion of the dedicated resource pool, each of the multiple patterns allows for a single transmission of a sidelink positioning reference signal to be distributed across a frequency range that is a predetermined proportion of the bandwidth (portion).

[0064] This design of a dedicated resource pool allows for simultaneous transmission of sidelink positioning reference signals for different radio nodes, thereby further increasing efficiency in transmitting sidelink positioning reference signals and reducing delays in responding to sidelink positioning reference signal requests.

[0065] According to an embodiment of the first aspect and / or an embodiment of the second aspect, the indication of the selected radio resource in the transmitted sidelink control information includes information about at least one of the following:

[0066] - at least one selected (pre-)configuration mode,

[0067] - repetition information of at least one selected (pre-)configured pattern, in particular periodic information,

[0068] - a start time for transmitting a sidelink positioning reference signal using at least one selected (pre-)configured pattern,

[0069] - The offset between the transmission of the sidelink control information and the start of the transmission of the associated sidelink positioning reference signal.

[0070] At least one selected (pre-)configured mode may be indicated by including a mode identifier in the sidelink control information. Repetition information, particularly periodicity information, may be the same or different for different (pre-)configured modes. An offset may refer to the time difference between the start of transmission of the sidelink control information and the start of transmission of the corresponding sidelink positioning reference signal.

[0071] According to the embodiment of the first aspect and / or the embodiment of the second aspect, the selected radio resource indicated by the sidelink control information is reserved for transmitting the sidelink positioning reference signal within the reserved time, the reserved time being

[0072] - equal to the (pre-)configured maximum reservation time, or

[0073] - shorter than a (pre-)configured maximum reservation time, wherein the shorter reservation time is indicated by the transmitted sidelink control information.

[0074] For each of the multiple (pre-)configured modes, the same or different maximum reservation time may be (pre-)configured.

[0075] According to an embodiment of the first aspect and / or an embodiment of the second aspect, if no positioning reference signal is transmitted from the first radio node to the second radio node for a time greater than a defined maximum discard time, the selected radio resources reserved for transmitting the sidelink positioning reference signal are released. For each of a plurality of (pre-)configured modes, the same or different maximum discard time may be (pre-)configured.

[0076] According to an embodiment of the first aspect, the method further comprises:

[0077] transmitting further sidelink control information from the first radio node to the second radio node using radio resources of the dedicated resource pool, wherein the further sidelink control information indicates releasing at least part of the selected radio resources reserved for transmission of a sidelink positioning reference signal, or

[0078] - Extending the reservation time, preferably by an extension time configured or indicated by further sidelink control information transmitted.

[0079] Similarly, according to an embodiment of the second aspect, the method further comprises:

[0080] receiving, using radio resources of the dedicated resource pool, further sidelink control information transmitted from the first radio node to the second radio node, wherein the further sidelink control information indicates

[0081] - releasing at least part of the selected radio resources reserved for transmission of a sidelink positioning reference signal, or

[0082] - Extending the reservation time, preferably by an extension time configured or indicated by received further sidelink control information.

[0083] Therefore, by making the reserved radio resources available again for the transmission of further sidelink positioning reference signals in the future, the efficiency of using the radio resources of the dedicated resource pool can be further increased. At the same time, the option to extend the reservation time allows for flexible responses to further positioning requests from the target radio node by re-updating the reservation.

[0084] According to an embodiment of the first aspect, the method further comprises receiving, by the first radio node, sidelink control information transmitted from the second radio node using radio resources of the dedicated resource pool, wherein

[0085] - the received sidelink control information indicates a request to transmit a sidelink positioning reference signal from the first radio node to the second radio node, and

[0086] - in response to the received sidelink control information, transmitting sidelink control information and / or a sidelink positioning reference signal from the first radio node to the second radio node.

[0087] Similarly, according to an embodiment of the second aspect, the method further comprises transmitting sidelink control information from the second radio node to the first radio node using radio resources of the dedicated resource pool, wherein

[0088] - the transmitted sidelink control information indicates a request to transmit a sidelink positioning reference signal from the first radio node to the second radio node, and

[0089] - in response to the sidelink control information transmitted from the second radio node to the first radio node, transmitting the received sidelink control information and / or the received sidelink positioning reference signal from the first radio node to the second radio node.

[0090] Hence, the second radio node may trigger the transmission of a sidelink positioning reference signal, in particular for positioning and / or ranging determination purposes.

[0091] According to an embodiment, the first radio node and the second radio node are members of a 5G NR network. The first radio node and / or the second radio node may be a user equipment. The first radio node and / or the second radio node may include an input interface configured to obtain input data, such as a command from a higher layer, to perform sidelink communication. The first radio node and / or the second radio node may include a power supply and / or an antenna coupled to a radio modem of the respective radio node. The first radio node and / or the second radio node may support device-to-device, Internet of Things, and / or V2X communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Exemplary embodiments of the present invention are depicted in the drawings, which should not be construed as limiting the claims, and are explained in more detail below.

[0093] Figure 1 A resource diagram is schematically shown to illustrate the transmission of a sidelink positioning reference signal and corresponding sidelink control information according to a first embodiment;

[0094] Figure 2 A resource diagram is schematically shown to illustrate the transmission of a sidelink positioning reference signal and corresponding sidelink control information according to a second embodiment;

[0095] Figure 3 schematically illustrates a portion of a resource map according to a third embodiment;

[0096] Figure 4 Schematically illustrates a signaling protocol for transmitting a sidelink positioning reference signal and sidelink control information according to an embodiment of the present invention; and

[0097] Figure 5A 、 Figure 5B The methods according to the first aspect and the second aspect are schematically illustrated.

[0098] Figure 1 A resource diagram is schematically shown to illustrate the transmission of a Sidelink Positioning Reference Signal (SL-PRS) and corresponding Sidelink Control Information (SCI) according to the first embodiment. Here, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain.

[0099] The SL-PRS and the SCI are transmitted using radio resources of a dedicated resource pool PRS-RP of the radio access network. The dedicated resource pool PRS-RP includes a plurality of consecutive time slots in the time domain and a plurality of consecutive subchannels in the frequency domain.

[0100] To transmit the SL-PRS, the dedicated resource pool PRS-RP includes (pre-)configured patterns of radio resources. Each of the (pre-)configured patterns includes multiple consecutive symbols and all subcarriers of the dedicated resource pool PRS-RP. Specifically, each of the (pre-)configured patterns includes radio resource elements distributed across all symbols of the time slot and all subcarriers of the dedicated resource pool PRS-RP. Multiple (pre-)configured patterns coexist within each OFDM symbol of the time slot.

[0101] Here, each of the multiple (pre)configuration patterns SL-PRS-pat1, SL-PRS pat 2 includes at least partially different, preferably dedicated, non-contiguous subcarriers for each symbol of the time slot, so that all subcarriers of the dedicated resource pool PRS-RP are included by each of the multiple pre-configuration patterns. Therefore, the multiple (pre)configuration patterns form an interleaved structure across the bandwidth of the dedicated resource pool PRS-RP. In particular, for each symbol of the time slot, each of the multiple (pre)configuration patterns has a comb-like structure. The multiple (pre)configuration patterns can be selected and reserved by different radio nodes, for example, the first (pre)configuration pattern can be selected and reserved by the first radio node (UE1), and the second (pre)configuration pattern can be selected and reserved by the second radio node (UE2), wherein the first radio node and the second radio node (UE2) can be part of a defined radio node group.

[0102] The group of radio nodes may share time slots, with each of the radio nodes dedicated to (at least) one SL-PRS pattern. Thus, the group of radio nodes may be a group of anchor (i.e., auxiliary) radio nodes that perform sidelink positioning in response to a request from a so-called target radio node UE. Additionally, the group of radio nodes may be a group to which resources for multicast communication are allocated (e.g., within communication range or within a group with a group member ID). Additionally or alternatively, the group of radio nodes may be considered geographically or allocated by the network. Once a group of radio nodes is formed or identified, it is assumed that there may be one or more radio nodes that contribute or transmit SL-PRS in (one or more) specific patterns. The group's patterns may be orthogonal (non-overlapping SL-PRS symbols between group members) or quasi-orthogonal (allowing partial overlap of SL-PRS symbols between group members with specific criteria). Specifically, for time slots that include more than one pattern for transmitting SL-PRS, each radio node of the group may select a pattern in the same time slot, as defined in the time-frequency resource grid.

[0103] Each pattern is repetitive in the time domain, wherein the pattern preferably repeats periodically.

[0104] Each pattern can be selected by a radio node (e.g., user equipment) as a radio resource for transmitting SL-PRS. In order to convey the selection of one of the patterns to one or more other radio nodes (e.g., user equipment) and to reserve the selected pattern for transmission of SL-PRS, SCI is transmitted from the first radio node (UE1) to the one or more other radio nodes using radio resources of a dedicated resource pool PRS-RP for transmission of SCI.

[0105] Furthermore, a reference signal associated with the SCI is transmitted from the first radio node (UE1) to the second radio node (UE2) using radio resources of the dedicated resource pool PRS-RP. Here, the reference signal and the SCI are transmitted using the same one or more symbols of the radio resources (in accordance with Figure 1 in the first time slot of the embodiment shown).

[0106] The SCI is transmitted using contiguous resource elements of the radio resources. Conversely, the associated reference signal is transmitted using a reference signal group consisting of multiple separate blocks of contiguous resource elements of contiguous subcarriers. In this embodiment, the reference signal group is distributed across the full bandwidth of the dedicated resource pool PRS-RP, thus spanning the full bandwidth of the dedicated resource pool PRS-RP.

[0107] The plurality of separated blocks of the reference signal group are separated by at least one radio resource element used to transmit SCI. Specifically, every two blocks of the reference signal group (each of which includes consecutive subcarriers) are separated by at least one subcarrier used to transmit SCI.

[0108] The design of the dedicated resource pool PRS-RP allows multiplexing the transmission of SCIs transmitted from different radio nodes to concurrently reserve radio resources of the dedicated resource pool PRS-RP for transmission of SL-PRS.

[0109] exist Figure 1 In an embodiment, the additional SCI and the additional reference signal are preferably transmitted from the additional first radio node (UE1) to the second radio node (UE2) using the same symbols of radio resources of the dedicated resource pool PRS-RP. In particular, the additional SCI is transmitted using additional contiguous resource elements of the radio resources. The additional reference signal groups are transmitted using multiple additional separated blocks of contiguous resource elements. The multiple separated blocks of the additional reference signal groups are separated by at least one radio resource element used to transmit the SCI. The multiple separated blocks of the reference signal groups are further separated by at least one block of the additional reference signal groups.

[0110] Each SCI comprises information allowing identification of the selected radio resources for transmission of the SL-PRS, in particular the selected (pre-)configured mode, eg an identification number of the selected mode.

[0111] The start of transmitting the SL-PRS may be signaled by including start time information in the SCI. Alternatively, the SCI may include an offset between the start of transmitting the SCI and the start of transmitting the corresponding SL-PRS.

[0112] The offset between the start of transmitting the SCI and the start of transmitting the corresponding SL-PRS may preferably be (pre)configured for the selected mode. Alternatively, the offset may be selected from at least two (pre)configured offsets, wherein the selected offset is indicated by the SCI.

[0113] The selected radio resource indicated by the sidelink control information is reserved for transmitting a sidelink positioning reference signal within a specific reservation time. The reservation time may be equal to a (pre)configured maximum reservation time, which may be allocated to the selected radio resource, in particular the selected (pre)configured patterns SL-PRS-pat1 and SL-PRS-pat2. The maximum reservation time may be the same or different for different (pre)configured patterns SL-PRS-pat1 and SL-PRS-pat2. Alternatively, the reservation time may be shorter than the (pre)configured maximum reservation time. Here, the shorter reservation time is indicated by the transmitted sidelink control information.

[0114] In order to release at least part of the selected radio resources reserved for transmitting the sidelink positioning reference signal, or to extend the reservation time, further SCI is transmitted from the first radio node (UE1) to the second radio node (UE2) using radio resources of the dedicated resource pool PRS-RP.

[0115] Figure 1 The basic concept of the illustrated design is to provide subchannels for transmitting SCIs that are punctured for subchannels used to transmit reference signals, where the subchannels used to transmit reference signals span the entire dedicated resource pool (PRS-RP) in the frequency domain. In other words, a reference signal group spanning the full (partial) bandwidth of the dedicated resource pool (PRS-RP) is provided, while also leaving enough room for intermittent short SCIs. One or more users can use each SCI to indicate and reserve radio resources of the dedicated resource pool (PRS-RP) for transmitting SL-PRSs. Thus, SL-PRSs from multiple users are multiplexed by transmitting SL-PRSs in a (pre-)configured comb-based pattern.

[0116] As an example, the reference signal groups provided may be dense within the physical shared control channel (PSSSC) corresponding to the short SCI associated with the SL-PRS and relaxed over frequency outside the short SCI. Furthermore, a specific set of sidelink control channel elements (SL-CCEs) may be provided, with a preferred set of demodulation reference signals (DMRS) provided for each SL-CCE. Each DMRS group associated with the corresponding SL-CCE may have its own specific, in particular unique, DMRS pattern.

[0117] The second radio node (UE2) may be configured to monitor a specific set of time symbols (e.g., two symbols in an SL slot) to identify a specific (pre-)configured set of PSCCH resource elements indicating an associated SL-PRS pattern. Here, the specific comb-based SL-PRS pattern is guaranteed not to overlap with concurrently transmitting radio nodes.

[0118] Figure 2 A resource diagram is schematically shown to illustrate the transmission of a sidelink positioning reference signal and corresponding sidelink control information according to the second embodiment. Again, the horizontal axis represents the time domain and the vertical axis represents the frequency domain.

[0119] The design of the radio resources for transmitting the SL-PRS using the radio resources of the dedicated resource pool PRS-RP and the transmission of the SL-PRS are the same as those in the first embodiment, see above.

[0120] In contrast to the first embodiment, the SCI and associated reference signals are transmitted using a control resource set consisting of multiple separate blocks of consecutive resource elements. Furthermore, the control resource set is distributed across a predetermined proportion of the bandwidth (portion) of the dedicated resource pool PRS-RP, preferably across the full bandwidth (portion) of the dedicated resource pool PRS-RP.

[0121] Each block of contiguous resource elements includes both resource elements for transmitting SCI and resource elements for transmitting reference signals. More specifically, each block includes reference signal groups of multiple separated blocks of contiguous resource elements. Reference signal groups are distributed across each block. The multiple separated blocks of reference signal groups are separated by at least one radio resource element for transmitting SCI. Figure 2 In

[0014] , the reference signal groups are distributed across each block in the frequency domain. Multiple blocks are separated by at least subcarriers used to transmit SCI in the frequency domain.

[0122] like Figure 1 As shown, the design of the dedicated resource pool PRS-RP allows multiplexing the transmission of SCIs transmitted from different radio nodes to concurrently reserve radio resources of the dedicated resource pool PRS-RP for transmission of SL-PRS.

[0123] For information included in the SCI, reservation of SL-PRS and release or extension of radio resources for transmitting SL-PRS using radio resources of a dedicated resource pool PRS-RP, see Figure 1 Description of the first embodiment illustrated in FIG.

[0124] Figure 1 The basic idea of ​​the design shown is to provide a pattern for interleaving control channel blocks to span the entire bandwidth, where the pattern or interleaving structure can be fixed (with a fixed offset) or have a (pre-)configured structure to allow minimal (partial) overlap. To this end, dedicated (multiple) sidelink configured control resource sets (SL-CORESET) are provided that interleave the entire bandwidth (portion), thus allowing SL transmission over the entire dedicated bandwidth (portion) of the dedicated resource pool PRS-RP. Therefore, no switching time is required between transmitting SCI and transmitting SL-PRS.

[0125] In other words, interleaving here can be thought of as dividing the SCI into multiple slices (preferably of equal or nearly equal size in the frequency domain) spanning the entire bandwidth (parts) in an interleaving structure (also called pattern), such as Figure 2 As shown. Here, an interleaving or (pre)configured pattern is provided so that SCIs from multiple radio nodes can be interleaved with equal interleaving size. Each SCI indicates the configured SL-PRS associated with the SCI and its corresponding interleaving structure. In particular, the comb-based interleaving or pattern is non-overlapping in the frequency domain.

[0126] Each interlace or pattern may include a specific DMRS group that is repeated (or present) in each slice of the interlaced SCI. The location of the DMRS group(s) within the slice may be preconfigured. A single radio node may be configured to reserve all interlaces, only one interlace, or no interlaces. In the case where a radio node reserves only one interlace or pattern without any multiplexing with other radio nodes, the other interlaces are left empty.

[0127] Figure 3 Schematically shows a part of a resource map according to the third embodiment.Here, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain.

[0128] Compared with the first and second embodiments, the time slot of the dedicated resource pool PRS-RP is divided into two parts to allow two consecutive moments to transmit SCI and associated SL-PRS in one time slot. These parts can have equal or different sizes, that is, the number of symbols.

[0129] like Figure 3As shown, a first SCI and a first reference signal are transmitted using, for example, the first two symbols of a first portion of a time slot. An associated SL-PRS is transmitted using, for example, the next five symbols of the first portion of the time slot. An additional SCI and an additional reference signal are transmitted from a first radio node (UE1) to a second radio node (UE2) using, for example, the first two symbols of a second portion of the time slot. An associated additional SL-PRS is transmitted from a first radio node (UE1) to a second radio node (UE2) using, for example, the next five symbols of the second portion of the time slot.

[0130] For each portion of a time slot, the design of radio resources for transmitting SCI and SL-PRS using radio resources of a dedicated resource pool PRS-RP and the transmission of SL-PRS and SCI are similar to Figure 1 and Figure 2 In particular, both control information and SL-PRS are distributed across the entire bandwidth (part) of the corresponding symbol, while allowing multiplexing of transmissions from different radio nodes.

[0131] for Figure 1 、 Figure 2 、 Figure 3 In each of the embodiments illustrated in , a radio node receiving an SCI and / or SL-PRS may consider the first symbol of the SCI and / or SL-PRS for automatically adapting its receive gain control (automatic gain control).

[0132] Figure 4 The figure schematically illustrates a signaling protocol for transmitting SL-PRS and SCI from a first radio node UE1 to a second radio node UE2 according to an embodiment of the present invention.

[0133] The second radio node UE2 is configured to transmit an SCI-REQ from the second radio UE2 to the first radio UE1, and preferably to the at least one further radio node UEn, using radio resources of a dedicated resource pool for transmitting SL-PRS. Here, the transmitted SCI-REQ indicates a request to transmit SL-PRS from the first radio node UE1, and preferably from the at least one further radio node UEn, to the second radio node UE2.

[0134] The first radio node UE1 and preferably at least one further radio node UEn are configured to receive the SCI-REL transmitted from the second radio node UE2. In addition, the first radio node UE1 and preferably at least one further radio node UEn are configured to generate an SL-PRS in response to the received SCI-REQ and select resources for transmitting the SL-PRS.

[0135] Furthermore, the first radio node UE1 and preferably at least one further radio node UEn are configured to transmit SCI to the second radio node UE2 using radio resources of a dedicated resource pool in response to SCI received from the second radio node UE2. Here, the transmitted SCI indicates radio resources of the dedicated resource pool selected by the respective UE1, UEn for transmitting the SL-PRS. The second radio node UE2 is configured to receive the transmitted SCI from the respective radio node(s) UE1, UEn using radio resources of the dedicated resource pool.

[0136] Furthermore, the first radio node UE1 and preferably at least one further radio node UEn are configured to transmit SL-PRS to the second radio node UE2 using selected radio resources of the dedicated resource pool. Here, since the (pre-)configured patterns are (quasi-)orthogonal in the frequency domain, the SL-PRS transmitted by the first radio node UE1 and the SL-PRS transmitted by the at least one further radio node UEn can coexist without interference or collision.

[0137] The second radio node UE2 is configured to receive the transmitted SL-PRS from the respective radio node(s) UE1, UEn using the selected radio resources of the dedicated resource pool as indicated in the SCI received by the second radio node UE2.

[0138] Furthermore, the second radio node UE2 is configured to implement an algorithm for positioning and / or ranging determination based on the received SL-PRS, wherein the algorithm for positioning and / or ranging is an algorithm known to those skilled in the art. In other words, the second radio node UE2 is configured to obtain a position and / or information about its position and / or its distance to a reference point / system based on measuring one or more SL-PRS.

[0139] To this end, the second radio node UE2 may be configured to perform measurements based on detecting SL-PRS including, for example, time of arrival (ToA), time delay of arrival (TDoA), angle of arrival (AoA), round trip time (RTT) or a combination thereof to determine its position and / or distance.

[0140] Optionally, the first radio node UE1 and preferably at least one further radio node UEn are configured to transmit further SL-PRS to the second radio node UE2 using selected radio resources of the dedicated resource pool, wherein the further SL-PRS is transmitted according to repetition information of a (pre-)configured pattern. Here, the repetition information may be (pre-)configured for the selected (pre-)configured pattern and / or included in an SCI transmitted from the respective radio node UE1, UEn to the second radio node UE2. The second radio node UE2 is configured to receive the transmitted further SL-PRS from the respective radio node(s) UE1, UEn using the selected radio resources of the dedicated resource pool.

[0141] Furthermore, the first radio node UE1 and preferably at least one further radio node UEn are configured to transmit a further SCI-REL to the second radio node UE2 using radio resources of the dedicated resource pool. Here, the further SCI-REL indicates the release of a portion of the selected radio resources reserved for the transmission of the SL-PRS, e.g., the release of future reserved radio resources in the event that the second radio node UE2 does not request further transmission of the SL-PRS.

[0142] Figure 5a schematically illustrates a method according to the first aspect.According to the first aspect, there is provided a method 100 of transmitting a sidelink positioning reference signal using radio resources of a dedicated resource pool of a radio access network.

[0143] Here, the dedicated resource pool for transmitting the sidelink positioning reference signal excludes the radio resources used to transmit the sidelink communication data in the radio access network. Specifically, the dedicated resource pool and the resource pool used to transmit the sidelink communication data in the radio access network are separated in the frequency domain and / or time domain.

[0144] The method 100 comprises a step 110 of transmitting sidelink control information from the first radio node to the second radio node using radio resources of a dedicated resource pool, wherein the sidelink control information indicates radio resources in the dedicated resource pool selected for transmitting a sidelink positioning reference signal.

[0145] Further, the method 100 comprises a step 120 of transmitting a sidelink positioning reference signal from the first radio node to the second radio node using the selected radio resources in the dedicated resource pool.

[0146] Figure 5b schematically illustrates a method according to the second aspect.According to the second aspect, there is provided a method 200 of receiving a sidelink positioning reference signal using radio resources of a dedicated resource pool of a radio access network.

[0147] Here, the dedicated resource pool for transmitting the sidelink positioning reference signal excludes the radio resources used to transmit the sidelink communication data in the radio access network. Specifically, the dedicated resource pool and the resource pool used to transmit the sidelink communication data in the radio access network are separated in the frequency domain and / or time domain.

[0148] The method 200 comprises a step 210 of receiving sidelink control information transmitted from a first radio node to a second radio node using radio resources of a dedicated resource pool, wherein the sidelink control information indicates radio resources in the dedicated resource pool selected for transmitting a sidelink positioning reference signal.

[0149] Further, the method 200 comprises a step 220 of receiving a sidelink positioning reference signal transmitted from the first radio node to the second radio node using the selected radio resources in the dedicated resource pool.

[0150] The examples provided in the drawings and described in the preceding written description are intended to provide an understanding of the principles of this specification. They are not intended to limit the scope of the appended claims. This specification describes variations and modifications to the illustrated examples. Only preferred examples are presented, and protection is intended for all changes, modifications, and further applications of these examples that come within the scope of this specification.

[0151] The examples provided in the drawings and described in the preceding written description are intended to provide an understanding of the principles of this specification. They are not intended to limit the scope of the appended claims. This specification describes variations and modifications to the illustrated examples. Only preferred examples are presented, and protection is intended for all changes, modifications, and further applications of these examples that come within the scope of this specification.

Claims

1. A method (100) for transmitting a sidelink positioning reference signal (SL-PRS) using radio resources of a dedicated resource pool (PRS-RP) of a radio access network, wherein said dedicated resource pool (PRS-RP) for transmission of a sidelink positioning reference signal (SL-PRS) excludes radio resources used for transmission of sidelink communication data in said radio access network, The method (100) comprises: - transmitting (110) sidelink control information (SCI) from the first radio node (UE1) to the second radio node (UE2) using radio resources of the dedicated resource pool (PRS-RP), wherein the sidelink control information (SCI) indicates a radio resource in the dedicated resource pool (PRS-RP) selected for transmitting the sidelink positioning reference signal (SL-PRS); as well as - transmitting (120) the sidelink positioning reference signal (SL-PRS) from the first radio node (UE1) to the second radio node (UE2) using the selected radio resources of the dedicated resource pool (PRS-RP).

2. The method (100) according to claim 1, further comprising: A reference signal (DMRS) associated with the sidelink control information (SCI) is transmitted from a first radio node (UE1) to a second radio node (UE2) using radio resources of the dedicated resource pool (PRS-RP), wherein the reference signal (DMRS) and the sidelink control information (SCI) are preferably transmitted using the same one or more symbols of the radio resources.

3. The method (100) according to claim 2, wherein - transmitting the sidelink control information (SCI) using one or more consecutive resource elements of the radio resources, and - Transmitting the reference signal using a reference signal (DMRS) group of multiple separated blocks of at least one or more consecutive resource elements, wherein the reference signal (DMRS) group is distributed across a predetermined proportion of the bandwidth or bandwidth portion of the dedicated resource pool (PRS-RP), preferably across the full bandwidth or full bandwidth portion of the dedicated resource pool (PRS-RP).

4. The method (100) of claim 3, wherein the plurality of separate blocks of the reference signal (DMRS) group are separated by at least one radio resource element used for transmitting sidelink control information (SCI).

5. The method (100) according to claim 4, further comprising: Further sidelink control information (SCI) and further reference signals (DMRS) are preferably transmitted from the first radio node (UE1) or the further first radio node (UE1) to the second radio node (UE2) or the further second radio node (UE2) using the same one or more symbols of the radio resources of the dedicated resource pool (PRS-RP), wherein - transmitting said further sidelink control information (SCI) using one or more further contiguous resource elements of said radio resources, - transmitting the further reference signal using a further reference signal (DMRS) group of a plurality of further separate blocks of at least one or more consecutive resource elements, - said plurality of separate blocks of said further reference signal (DMRS) group are separated by at least one radio resource element for transmitting sidelink control information (SCI), and - said plurality of separated blocks of said set of reference signals (DRMS) are further separated by at least a block of said further set of reference signals (DRMS).

6. The method (100) of claim 2, wherein - the sidelink control information (SCI) and the reference signal (DMRS) are transmitted using a control resource set consisting of multiple separate blocks of consecutive resource elements, and - The set of control resources is distributed across a predetermined proportion of the bandwidth or bandwidth portion of the dedicated resource pool (PRS-RP), preferably across the full bandwidth or the full bandwidth portion of the dedicated resource pool (PRS-RP).

7. The method (100) of claim 6, wherein each of the blocks of consecutive resource elements comprises both resource elements for transmitting the sidelink control information (SCI) and resource elements for transmitting the reference signal (DMRS).

8. The method (100) of claim 7, wherein each of the blocks comprises a reference signal (DMRS) group of at least a plurality of separated blocks of one or more consecutive resource elements, wherein the reference signal (DMRS) groups are distributed across each block, and wherein the plurality of separated blocks of the reference signal (DMRS) groups are separated by at least one radio resource element for transmitting the sidelink control information (SCI).

9. The method (100) according to one of claims 2 to 8, wherein - transmitting the sidelink control information (SCI) and the reference signal (DMRS) using one or more symbols of a first part of a time slot of the radio resource, wherein an associated sidelink positioning reference signal (SL-PRS) is transmitted using one or more different symbols of the first part of the time slot, and - Transmitting further sidelink control information (SCI) and a further reference signal (DMRS) from the first radio node (UE1) to the second radio node (UE2) using one or more symbols of the second part of the time slot of the radio resource, wherein an associated further sidelink positioning reference signal (SL-PRS) is transmitted from the first radio node (UE1) to the second radio node (UE2) using one or more different symbols of the second part of the time slot.

10. The method (100) according to one of the preceding claims, wherein - the dedicated resource pool (PRS-RP) comprises a plurality of (pre-)configured patterns of radio resources for transmitting the sidelink positioning reference signal (SL-PRS), - a predetermined proportional distribution of each of said plurality of (pre-)configured modes across the bandwidth or bandwidth portion of said dedicated resource pool (PRS-RP), and - said selected radio resources comprising at least one of said plurality of preconfigured patterns.

11. The method (100) of claim 10, wherein the indication of the selected radio resource in the transmitted Sidelink Control Information (SCI) comprises information about at least one of: - at least one selected (pre-)configuration mode, - repetition information of at least one selected (pre-)configured pattern, in particular periodic information, - a start time of said transmission of said Sidelink Positioning Reference Signal (SL-PRS) using said at least one selected (pre-)configured pattern, - The offset between the transmission of the Sidelink Control Information (SCI) and the start of transmission of the associated Sidelink Positioning Reference Signal (SL-PRS).

12. A method (200) for receiving a sidelink positioning reference signal (SL-PRS) using radio resources of a dedicated resource pool (PRS-RP) of a radio access network, wherein said dedicated resource pool (PRS-RP) for transmission of a sidelink positioning reference signal (SL-PRS) excludes radio resources used for transmission of sidelink communication data in said radio access network, The method (200) comprises: - receiving (210) sidelink control information (SCI) transmitted from the first radio node (UE1) to the second radio node (UE2) using radio resources of the dedicated resource pool (PRS-RP), wherein the sidelink control information (SCI) indicates a radio resource in the dedicated resource pool (PRS-RP) selected for transmitting the sidelink positioning reference signal (SL-PRS); as well as - receiving (220) said sidelink positioning reference signal (SL-PRS) transmitted from a first radio node (UE1) to a second radio node (UE2) using selected radio resources of said dedicated resource pool (PRS-RP).

13. A first radio node (UE1), comprising: - radio modems, - a non-transitory computer-readable medium comprising machine-readable instructions, and - a processor configured to load and execute the machine-readable instructions to cause the first radio node (UE1) to perform the method (100) according to one of claims 1 to 11.

14. A second radio node (UE2), comprising: - radio modems, - a non-transitory computer-readable medium comprising machine-readable instructions, and - a processor configured to load and execute the machine-readable instructions to cause the second radio device to perform the method (200) according to claim 12.

15. A system for radio communication, comprising: - a first radio node (UE1) as defined by claim 13, and - A second radio node (UE2) as defined by claim 14.

16. A computer program comprising machine-readable instructions to cause - the first radio node (UE1) according to claim 13 performs the steps of the method (100) according to one of claims 1 to 11, and / or - The second radio node (UE2) of claim 14 performs the steps of the method (200) according to claim 12.

17. A non-transitory computer-readable medium having stored thereon the computer program of claim 16.

Images