Angle of departure estimation based on channel impulse response

Abstract

A method of operating a wireless communication device (102) connectable to a communication network is provided. The communication network comprises an access node (101, 101-1, 101-2, 101-3). The method comprises monitoring a plurality of reference signals (121, 122, 123) transmitted (351) in a plurality of resources, the transmissions being provided by the access node (101, 101-1, 101-2, 101-3); and based on the monitoring: participating in a positioning of the wireless communication device (102) in dependence on an indicator indicative of at least one of a size or a phase of at least one first path component (810) of an impulse response (800, 801) of a radio channel, the at least one first path component being associated with at least one reference signal (121, 122, 123) of the plurality of reference signals (121, 122, 123) transmitted (351).

Description

Technical Field

[0001] Various aspects of this disclosure generally relate to using a positioning reference signal to locate a wireless communication device. Various examples of this disclosure specifically relate to estimating the departure angle for transmission toward a UE based on one or more characteristics of the channel impulse response, said one or more characteristics being determined based on the positioning reference signal (e.g., a first path component of the channel impulse response). Background Technology

[0002] Various positioning technologies are known for locating mobile devices, such as wireless communication devices (sometimes also called user equipment). Generally, positioning technologies include cellular and non-cellular positioning technologies. Examples of non-cellular positioning technologies include, for example, satellite-based positioning or the use of gyroscopes. Cellular positioning technologies may rely on a dedicated positioning reference signal (PRS) transmitted by a first node and received by a second node, using cell identity tracking. One or more of the following can then be determined: Time of Arrival (ToA), more specifically, Time Difference of Arrival (TDoA) or Multi-Round-Trip Time (Multi-RTT), Angle of Arrival (AOA), and / or Angle of Departure (AOD).

[0003] There is a general trend toward more accurate positioning. For example, according to the 3GPP (3rd Generation Partnership Project), Release 17, in RAN1 Working Group #101e in May 2020, enhancements were made to improve positioning accuracy. See 3GPP RP-193237 (New SIDon NR Positioning Enhancements). To address the higher accuracy requirements for positioning arising from new applications and industrial verticals, enhancements in existing positioning technologies are considered to meet the following exemplary performance targets: decimeter-level positioning accuracy for general commercial use cases as specified in 3GPP Technical Specification (TS) 22.261; and positioning accuracy of no more than 0.2m for Industrial Internet of Things (IIoT) use cases. Summary of the Invention

[0004] Therefore, advanced positioning is needed. In particular, positioning that can estimate the location of mobile devices (e.g., UEs) with a fairly high degree of accuracy is required.

[0005] The features of the independent claims satisfy this need. The features of the dependent claims define further examples.

[0006] The techniques used to locate the UE will be described below. This location can be based on AOD estimation. A reference signal (e.g., PRS) that includes transmissions of multiple resources (e.g., multi-beam transmission) can be used. Based on monitoring the reference signal at the UE, one or more characteristics of the channel impulse response (CIR) of the channel between the transmitting node (e.g., base station (BS) or another access node) and the UE can be determined. The location can then be based on these one or more characteristics of the CIR.

[0007] One example feature that can be used to perform UE positioning is the use of the first path component of the CIR. It has been found that estimating AOD by using the first path component of the CIR can be particularly accurate, for example, compared to existing techniques that rely on, for example, the reference signal received power (RSRP) (and then integrate across multiple paths of the channel) to estimate AOD.

[0008] According to the examples described herein, the CIR of a radio channel can be characterized by determining a plurality of first path components using reference signals transmitted in different resources of a plurality of resources (i.e., using different transmit spatial filters, i.e., different transmit beams). A CIR indicator indicating at least one of these first path components can be determined.

[0009] A method for operating a UE is provided. The UE may be connected to a communication network. The communication network includes an access node. The method includes monitoring a plurality of transmitted reference signals. Transmission occurs in a plurality of resources. Transmission is provided by the access node. The method also includes positioning the UE based on the monitoring. The positioning depends on an indicator of at least one of the magnitude or phase of at least one first path component indicating the impulse response of a radio channel. The at least one first path component is associated with at least one of the transmitted plurality of reference signals.

[0010] This transmission can be multi-beam transmission. Different resources can be associated with different transmission beams.

[0011] A computer program, computer program product, or computer-readable storage medium includes program code. The program code can be loaded and executed by at least one processor. When executing the program code, at least one processor performs a method of operating a UE. The UE may be connected to a communication network. The communication network includes an access node. The method includes monitoring a plurality of transmitted reference signals. Transmission is performed in multiple resources. Transmission is provided by the access node. The method also includes positioning of the UE based on the monitoring. The positioning depends on an indicator of at least one of the magnitude or phase of at least one first path component indicating the impulse response of a radio channel. The at least one first path component is associated with at least one of the transmitted plurality of reference signals.

[0012] The UE includes control circuitry. The control circuitry is configured to perform a method of operating the UE. The UE may be connected to a communication network. The communication network includes an access node. The method includes monitoring multiple transmitted reference signals. Transmission is performed on multiple resources. Transmission is provided by the access node. The method also includes positioning the UE based on the monitoring. The positioning depends on an indicator of at least one of the magnitude or phase of at least one first path component indicating the impulse response of a radio channel. The at least one first path component is associated with at least one of the transmitted multiple reference signals.

[0013] A method for operating a network node in a communication network is provided. The method includes receiving a message representing at least one of the magnitude or phase of at least one first path component indicating a pulse response of a radio channel. The indicator is received from a UE. The at least one first path component is associated with at least one of a plurality of transmitted reference signals from a plurality of resources. Transmission is provided by an access node of the communication network. The method further includes estimating the AOD of at least one reference signal based on the indicator indicating at least one of the magnitude or phase of the at least one first path component.

[0014] A computer program, computer program product, or computer-readable storage medium includes program code. The program code can be loaded and executed by at least one processor. When executing the program code, at least one processor performs a method of operating an access node of a communication network. The method includes receiving a message representing at least one of the magnitude or phase of at least one first path component indicating a pulse response of a radio channel. The indicator is received from a UE. The at least one first path component is associated with at least one of a plurality of transmitted reference signals from a plurality of resources. Transmission is provided by the access node of the communication network. The method also includes estimating the AOD of at least one reference signal based on the indicator indicating at least one of the magnitude or phase of the at least one first path component.

[0015] An access node of a communication network includes control circuitry. The control circuitry is configured to perform a method of operating the access node. The method includes receiving a message representing an indicator indicating at least one of the magnitude or phase of at least one first path component indicative of a pulse response of a radio channel. The indicator is received from a UE. The at least one first path component is associated with at least one of a plurality of transmitted reference signals from a plurality of resources. Transmission is provided by the access node of the communication network. The method also includes estimating the AOD of at least one reference signal based on the indicator indicating at least one of the magnitude or phase of the at least one first path component.

[0016] It should be understood that, without departing from the scope of this disclosure, the above features and the features to be explained below can be used not only in the corresponding combinations shown, but also in other combinations or individually. Attached Figure Description

[0017] Figure 1 Communication systems including BS and UE are illustrated schematically according to various examples.

[0018] Figure 2 An illustrative example Figure 1 Details of the communication system.

[0019] Figure 3 Multi-beam transmission is illustrated schematically according to various examples.

[0020] Figure 4 The power density distribution (PDP) of CIRs according to various examples is illustrated, and the first path component of the CIR is specifically shown.

[0021] Figure 5 The location of the UE is illustrated schematically according to various examples.

[0022] Figure 6 It is a flowchart based on various examples of methods.

[0023] Figure 7 It is a flowchart based on various examples of methods.

[0024] Figure 8 It is a signaling diagram based on various examples. Detailed Implementation

[0025] Some examples of this disclosure generally provide multiple circuits or other electrical devices. All references to circuits and other electrical devices, and the functions provided by each, are not intended to limit the scope to what is shown and described herein. While specific labels may be assigned to the various circuits or other electrical devices disclosed, such labels are not intended to limit the scope of operation of the circuits and other electrical devices. Such circuits and other electrical devices may be combined and / or separated from each other in any way, based on the desired specific type of electrical implementation. It should be appreciated that any circuit or other electrical device disclosed herein may contain any number of microcontrollers, graphics processing units (GPUs), integrated circuits, memory devices (e.g., flash memory, random access memory (RAM), read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or other operating software that cooperate with each other to perform the operations disclosed herein. Furthermore, any one or more electrical devices may be configured to execute program code contained in a non-transient computer-readable medium programmed to perform any number of the functions disclosed.

[0026] In the following, examples of this disclosure will be described in detail with reference to the accompanying drawings. It should be understood that the following description of embodiments should not be construed as limiting. The scope of this disclosure is not intended to be limited to the examples or drawings described below, which are considered illustrative only.

[0027] The following describes location estimation (sometimes also called positioning) techniques for mobile devices. In particular, positioning within a communication network (e.g., a cellular network) is described. Here, a reference signal, such as a PRS, is transmitted by an access node of the communication network, wherein the reference signal is transmitted on resources allocated in the time-frequency resource grid of the communication network, which are also used for data transmission.

[0028] The technique is described in the context of PRS for illustrative purposes below, but similar techniques can be implemented based on other types of RS (e.g., sounding reference signal (SRS)).

[0029] In the following text, various technologies will be described in the context of implementations of communication networks as 3GPP cellular networks, such as those based on the Long Term Evolution (LTE) protocol or the New Radio (NR) protocol. These are examples, and other implementations are conceivable.

[0030] As a general rule, downlink (DL) transmission of the PRS can be used, i.e., transmission from the access node to the UE. Alternatively or additionally, the positioning can rely on uplink (UL) transmission of the PRS. It can also rely on sidelink PRS transmission between two UEs. In the following description, the technique is used in conjunction with DL transmission of the PRS for illustrative purposes; however, similar techniques can be readily applied to, for example, UL transmission or sidelink transmission.

[0031] In the following text, positioning is described based on the estimation of AOD. AOD describes the direction in which a signal can be sent to reach the UE to be positioned on the direct path.

[0032] PRS transmission can utilize multiple resources. PRS transmission can be implemented on a plurality of beams (i.e., using transmit beamforming). Multi-beam transmission can take the form of beam-scanning DL transmission. Different beams are associated with different spatial precoding / spatial transmit filters, and thus address different spatial paths of radio channels associated with different AODs from the access node. The transmission of a PRS for a spatial transmit filter occupies resources called PRS resources. PRS multi-beam transmission can employ a set of PRS resources comprising a plurality of PRS resources, for example, each PRS resource being associated with a corresponding spatial transmit filter. An example implementation of a PRS resource set is provided in Section 5.1.6.5 of 3GPP TS 38.214 V16.1.0 (2020-03).

[0033] As a general rule, a UE may receive one or more configuration messages indicating the time-frequency resource allocation of a PRS resource set, such as subcarrier spacing, frequency reference, etc. Using such configuration messages, the UE can monitor multiple PRS transmitted by a multi-beam PRS.

[0034] Based on one or more reception attributes of the PRS at the UE, it is possible to infer which spatial channel points to the UE. Based on this, AOD can be estimated.

[0035] Therefore, AOD represents the relative position / location of the UE with respect to the BS. Typically, the position of the BS is known in the global coordinate system; therefore, the position of the UE in the global coordinate system can be inferred.

[0036] Based on the various examples described in this paper, this positioning is based on the CIR of the radio channel. The CIR can be determined based on a channel model. A channel model is designed to provide a mathematical representation of the propagation of a wireless signal along a wireless channel. Typically, it is assumed that the wireless channel affects signal transmission in a linear manner, for example, using a multipath model that includes fading. Therefore, it can be described by an impulse response. In signal processing, the impulse response, or impulse response function (IRF), of a dynamic and linear system (here, a radio channel) is its output when given a short input signal (called an impulse). Mathematically, an impulse can be modeled as a Dirac function for a continuous-time system or as a Kronecker function for a discrete-time system. Given the impulse response of the radio channel, this CIR can be used to predict the effect of the radio channel on any shape of input signal. There are various options available for representing the CIR mathematically. The CIR can be represented as a channel matrix. Another option is to represent the CIR using the PDP, which is the signal delay relative to zero delay or the first detectable signal measurement.

[0037] Various techniques are based on the finding that, within the context of Time of Arrival (TOA) measurements as part of the Relative Signal Time Difference (RSTD) measurement in DL (3GPP TS 38.215 V16.0.1 (2020-01), Section 5.1.28), according to existing techniques, the delay of the first spatial path component of the CIR (hereinafter referred to as the first path component (FPC)) can be determined, and the time difference of arrival can be estimated based on it. The CIR can be derived from prior art reference signal time difference (RSTD) measurements. According to various examples, such TOA-based positioning techniques for determining the CIR can be used again to estimate the AOD in AOD-based positioning.

[0038] More specifically, the positioning described in this paper can be based on the FPC of the CIR. The FPC is generally defined as the fraction of the CIR when the size of the PDP of the CIR first crosses a predetermined threshold (starting from zero latency). Therefore, the FPC corresponds to the shortest effective path between the transmitting node and the receiving node.

[0039] This contrasts with existing technologies, where location (particularly the determination of AOD) is based on the RSRP of the received PRS (3GPP TS 37.355 V16.0.0 (2020-03) Section 6.5.11.4). Therefore, it essentially accumulates over the entire CIR. By limiting the location process to the first path using the CIR, more accurate AOD-based location becomes possible.

[0040] According to various examples, a UE monitors a plurality of PRS across a plurality of PRS resources of a multi-beam transmission (e.g., a beam-swept PRS transmission) provided by a BS. Then, the UE participates in the positioning of the UE. Such participation is based on said monitoring, and relies on an indicator that indicates at least one of the magnitude or phase of one or more FPCs of the CIR of a radio channel. The one or more FPCs may be determined based on said monitoring across different resources (e.g., sets of PRS resources) of the multi-beam transmission. That is, different FPCs may be determined based on different PRS received at the UE.

[0041] This indicator that indicates at least one FPC of the CIR associated with at least one PRS resource is hereinafter referred to as a CIR indicator.

[0042] As a general rule, the CIR indicator may indicate the FPCs for all resources of a set of PRS resources, or only a subset thereof.

[0043] As a general rule, the CIR indicator may be expressed / represented as a complex value, which describes both magnitude and phase; or as a scalar value, which describes magnitude or phase.

[0044] As another general rule, the UE may also participate in said positioning by reporting the CIR indicator to a cellular network, for example, to a positioning server node (LS node) of the cellular network.

[0045] Such reporting may be implemented as follows: the UE may transmit a respective message indicating the CIR indicator. For example, the message may comprise the CIR indicator. The message may also comprise only a portion of the CIR indicator: for example, the CIR indicator may indicate a plurality of FPCs determined based on PRS from all N resources of the set of PRS resources of the multi-beam transmission; and the message may comprise only a portion of the CIR indicator, which portion is associated, for example, with M<N resources of the set of PRS resources that correspond to the best FPCs (e.g., the strongest or relatively strongest FPCs).

[0046] Then, the LS node of the communication network may estimate the AOD based on the received message indicating the CIR indicator, that is, based on the CIR indicator. Alternatively or additionally, the UE participates in said positioning by estimating the AOD locally based on the CIR indicator, and then reporting the AOD to the LS node.

[0047] These two options are summarized in Table 1 below.

[0048]

[0049] Table 1: Different variants for assigning said logic to estimate said AOD.

[0050] The aforementioned scheme for estimating AOD based on one or more CIR characteristics can be used to supplement existing techniques for estimating AOD based on PRS-based RSRP. For example, if the quality of the FPC in the CIR is poor or it does not meet the required threshold, the UE can report only the RSRP (instead of the CIR indicator) for AOD estimation. Otherwise, for example, when the FPC is good, i.e., meeting one or more quality requirements, the UE can report the value (complex or absolute) of the CIR indicator. Alternatively, the LS can require the UE to provide both the RSRP and the CIR indicator for AOD estimation. Therefore, in general, whether the UE participates in CIR indicator-based AOD positioning can depend on one or more triggering criteria to be checked at the UE.

[0051] Figure 1 A communication system 100 is schematically illustrated. The communication system 100 includes two nodes 101, 102 configured to communicate with each other over a radio channel 111. The radio channel 111 may include one or more paths (sometimes referred to as spatial streams), which may be used individually or in combination to transmit data, for example, when relying on multiple-input multiple-output (MIMO) technology.

[0052] exist Figure 1 In the example, node 101 is implemented by an access node, more specifically, by a BS (Browser / Base Station) in the cellular network. In 5G NR, it is called a gNB (Garden Node Block). Node 102 is implemented by a UE (User Equipment).

[0053] The technology described in this article is not limited to this cellular network scenario. Other types of communication networks, such as Wi-Fi mesh networks, can also be used.

[0054] Figure 2 Aspects relating to BS 101 are illustrated schematically. BS 101 includes control circuitry implemented by processor 1011 and non-volatile memory 1015. Processor 1011 can load program code stored in memory 1015. Processor 1011 can then execute the program code. Executing the program code causes the processor to perform the techniques described herein, such as participating in the positioning of UE 102, for example by transmitting PRS and / or by receiving PRS from UE 102; performing PRS transmission in a plurality of resources, such as multiple resources of a PRS resource set; performing PRS multi-beam transmission, such as beam scanning transmission; applying analog beamforming or spatial precoding at specific azimuth and elevation angles to signals transmitted via radio interface 1012 using antenna 1014, i.e., using transmit beamforming, for example by transmitting PRS or implementing beam scanning transmission; and so on.

[0055] Figure 2Aspects relating to UE 102 are also illustrated. UE 102 includes control circuitry implemented by processor 1021 and non-volatile memory 1025. The processor can load program code from memory 1025 and execute the program code. Executing the program code causes the processor to perform the techniques described herein, such as: monitoring the PRS, which is transmitted, for example, by access node 101 or another UE on a side walkway using a PRS resource set and / or multi-beam transmission; transmitting the PRS; measuring one or more reception characteristics of the PRS, such as reception amplitude and / or reception phase; applying transmit beamforming and / or receive beamforming; determining the CIR based on one or more reception characteristics of the PRS; determining a CIR indicator for the FPC indicating the CIR; participating in UE localization, for example by determining the CIR indicator and / or establishing an AOD reaching the UE's PRS according to the FPC of the CIR; participating in UE localization by reporting the CIR indicator to the cellular network, for example, to an LS node; participating in UE localization by reporting an AOD estimated based on RSRP and / or the CIR indicator; and so on.

[0056] Figure 2 An aspect relating to communication between BS 101 and UE 102 on radio channel 111 is also illustrated. BS 101 includes an interface 1012 that can access and control a plurality of antennas 1014. Similarly, UE 102 includes an interface 1022 that can access and control a plurality of antennas 1024.

[0057] Interfaces 1012 and 1022 may each include one or more transmit chains and / or one or more receive chains. For example, such a receive chain may include a low-noise amplifier, an analog-to-digital converter, a mixer, etc. Analog and / or digital beamforming is possible. Transmit beamforming and receive beamforming can be applied; that is, the signal can be pre-coded. A MIMO communication system 100 can be implemented.

[0058] When multiple different spatial filters are applied (usually in sequence) to transmit a signal, this is called multi-beam transmission.

[0059] Figure 3 A multi-beam transmitter 351, comprising spatial filters 301 to 309, is schematically illustrated, all characterized by different AODs, thereby addressing different paths of radio channel 111. These spatial filters are also referred to as beams 301 to 309.

[0060] Different beams 301 to 309 can be associated with different time-frequency resource elements of a time-frequency resource grid defined for the corresponding signal, for example, by orthogonal frequency division multiplexing (OFDM) modulation. These resources of multi-beam transmission 351 form a resource set. The smallest granularity of the time-frequency resource grid can be related to the frequency of the OFDM subcarrier and the OFDM symbol duration. By transmitting on different beams 301 to 309 according to a predetermined time-frequency resource allocation, it is possible to infer which beam is used to transmit the signal received by UE 102 based on the time-frequency resource identifier. The time-frequency resource element of PRS transmission in one of the beams 301 to 309 is called a PRS resource. The PRS resources for all different beams 301 to 309 are called a PRS resource set.

[0061] As a general rule, the receiver receives the signal y obtained by multiplying the input signal x by the transmission matrix H of radio channel 111. Figure 2 Including the components h for the transmission matrix H 11 and h 13 Two example labels. The transmission matrix H observed over the system's bandwidth defines the CIR of radio channel 111. The rank of the transmission matrix corresponds to the number of linearly independent rows or columns, and thus indicates how many independent data streams on different paths can be used simultaneously; this is sometimes referred to as the number of layers.

[0062] CIR can be quantized using various indicators other than the transfer matrix H. One example of the various techniques described in this paper that can be relied upon is an indicator (CIR indicator) that indicates the size and / or phase of one or more FPCs in the CIR: in the cross-correlation R... l (τ FP In FPC delay τ FP The complex value at that point (thus representing the magnitude and phase of the FPC) can be expressed as:

[0063] R l (τ FP )=g( τ FP ,φ UE )P l (τ FP )+v l (1)

[0064] Where l is the index of the beam / resource for multi-beam transmission, g is a complex coefficient dependent on channel fading and receive antenna gain (i.e., associated with the channel matrix H), and φ UE Represents AOD, P l (φ) is the beam pattern (space transmission filter) of the l-th beam of the multi-beam transmission 351 (usually predefined and known), v l It is the UE received noise and Rl Measurement errors include, for example, the sum of Gaussian noise.

[0065] For example, for l=1, the CIR indicator will indicate a single FPC of the CIR associated with a single PRS. For l>1, the CIR indicator will indicate multiple FPCs of the CIR associated with multiple PRS transmitted on different beams in multi-beam transmission.

[0066] Figure 4 The CIR 800 according to the PDP 801 is illustrated schematically, for example, obtained by using the square of the CIR. Power is plotted as a function of delay time (shown here in arbitrary units). Power is normalized to 1 over the individual delays. The vertical arrows highlight the FPC delay τ. FP 811 is defined as a PDP that exceeds a predetermined threshold 812. The corresponding size of FPC 810 is indicated.

[0067] For a specific case of OFDM-based time-frequency resource grids including PRS, the cross-correlation of the CIR indicator used to calculate equation (1) can be achieved as follows:

[0068]

[0069] Where k is the index of the OFDM symbol of the resource element carrying the PRS, and n τ It is R k Sample index, L τ is the length of the cyclic prefix, x is the copy of the transmitted PRS (i.e., the shape of the input signal for the corresponding PRS, which is known by definition), M is the FFT size or a multiple thereof, and y is the received resource element carrying the PRS (i.e., the shape of the received signal for the corresponding PRS). Equation (2) corresponds to index n. τ The discrete value of corresponds to the delay τ of formula (1).

[0070] The CIR indicator is determined based on a plurality of PRS resources or all PRS resources within the PRS resource set (i.e., different index values ​​l in formula (1)).

[0071] When monitoring PRS transmitted on multiple beams, equation (2) can be re-executed for multiple PRS received by the UE (transmitted on different beams). For simplicity, index l is omitted from equation (2).

[0072] Formula (2) implements PRS-based measurements. These measurements can be standardized. They can be activated / deactivated by the cellular network. For example, UE 102 can perform this measurement upon receiving a corresponding activation request from the communication network. This is typically sent to the UE by the LS using the LPP protocol.

[0073] The CIR indicator can be used to locate the UE, and more specifically, to estimate AOD. Details regarding this location are in... Figure 5 Example in.

[0074] Figure 5 The location aspect of UE 102 is illustrated schematically. In the illustrated scenario, both UE 102 and LS node 120 participate in the location of UE 102. UE 102 and LS node 120 can communicate using location protocol 119 (e.g., the LTE Location Protocol (LPP) as specified in 3GPP TS 37.355 V16.0.0 (2020-03)). Figure 5 The example illustrates one-way communication, but as a general rule, two-way communication can be performed according to the positioning protocol.

[0075] exist Figure 5 In this case, multiple BSs 101-1 to 101-3 send PRS 121 to 123 to facilitate the positioning.

[0076] As a general rule, each BS in BS 101-1 to 101-3 can use multi-beam transmission 351 (see [link]). Figure 3 ;exist Figure 5 In this example, only those beams 311 to 313 that address the strongest paths are illustrated, thus defining AOD 191 to 193. Figure 5 As illustrated, BS 101-1 transmits PRS 121 in the direction of UE 102 using transmit beam 311 in the PRS resource (e.g., repeatedly according to the timing schedule defined in the PRS configuration); similarly, BS 101-2 transmits PRS 122 in the direction of UE 102 in the PRS resource on transmit beam 312; and BS 101-3 transmits PRS 123 to UE 102 in the PRS resource on transmit beam 313.

[0077] Although Figure 5 In such cases, as a general rule, three BSs 101-1 to 101-3 participate in the positioning of UE 102, but it is possible for only a single BS, two BSs, or four or more BSs to participate in the positioning.

[0078] UE 102 can identify, or at least reference, the corresponding transmit beam used by BS 101 using the associated PRS resource ID. In existing implementations of DL-AOD-based positioning, AOD 191 to 193 is measured by reporting the beams 311 to 313 (i.e., the associated PRS resource ID) used by BS 101-1 to 101-3 when transmitting PRS 121 to 123 to UE 102 with the highest RSRP. Identification of the “correct” beam is important for the accuracy of AOD-based positioning. In 3GPP LTE Release 16, identification is based on RSRP; furthermore, this document discloses techniques that facilitate the determination of the “correct” beam based on CIR 800. This provides increased accuracy. It is important to note that the accuracy of AOD estimated based on RSRP of PRS 121 to 123 according to existing techniques critically depends on the beamwidth of beams 311 to 313: as the beamwidth increases, the estimation error increases. As an example, for a gNB or transmit-receive-point (TRP) antenna in the frequency range (FR2) specification (i.e., 24.25 GHz to 52.6 GHz), eight horizontal antenna elements in a sector provide a resolution of 15 degrees, which leads to significant errors in the estimation of AOD 191 to 193. By using a technique for estimating AOD based on CIR, higher accuracy can be achieved in this estimation, even beyond the beamwidth. This is because AOD is based on CIR estimation and is not correlated with the transmit curve of TX beam 311. AOD-based positioning can be improved.

[0079] Location may include determining the AOD 191 of PRS 121 and / or the AODs 192 to 193 of PRS 122 to 123. For example, if location is based solely on the AOD 191 of PRS 121 transmitted by BS 101-1 using transmit beam 311, a coarse estimate of the location of UE 102 can already be performed, for example, by taking into account the path loss of PRS 121 for determining the distance between BS 101-1 and UE 102. In other examples, location may be based on the AODs 191 to 193 of all PRS 121 to 123 transmitted by a plurality of BS 101-1 to 101-3; in this case, triangulation or more generally polygonal measurements may be employed.

[0080] As a general rule, the location of UE 102 can be estimated at LS node 120 (see Table 1, Variation B); in some cases, the location of UE 102, or at least AODs 191 to 193, may also be estimated at UE 102 (see Table 1, Variation A). This could mean that LS node 120 estimates the location of AOD and / or UE 102; or UE 102 estimates the location of AOD and / or UE 102.

[0081] Combination Figure 6 This illustrates the details of determining the location of UE 102 and AOD.

[0082] Figure 6 It is a flowchart based on various examples of methods. For example, Figure 6 The method can be executed by the processor 1021 of UE 102, for example, when loading program code from memory 1025. Figure 6 The aspects related to the positioning of UE 102 are shown. Optional boxes are marked with dashed lines.

[0083] At optional box 3005, the UE reports to the cellular network its ability to participate in the positioning process using a CIR indicator. For example, UE 102 may report whether it is able to determine the CIR indicator to be used for AoD. For example, UE 102 may report whether it prefers to use RSRP to estimate AOD, or whether it prefers to determine a CIR indicator to estimate AOD.

[0084] The report can be requested from the cellular network, and the UE responds to the request with the appropriate capability message.

[0085] As part of box 3005, the UE can receive a configuration message from the network based on its ability to participate in the location based on a CIR indicator. For example, if the UE indicates that it is capable of participating in the location based on a CIR indicator, the cellular network can activate or deactivate CIR indicator-based location.

[0086] This capability can be reported to LS node 120 using Location Protocol 119 (see [link]). Figure 5 Configuration can be received from LS node 120 using positioning protocol 119.

[0087] Next, at box 3010, the UE attempts to receive the PRS transmitted by one or more BSs; that is, the UE monitors the PRS (see...). Figure 5 (PRS 121 to 123). UEs typically use positioning protocol 119 (see...). Figure 5 ) Receive PRS configurations from one or more BSs from LS.

[0088] This monitoring can be based on network configuration. Network configuration can indicate the time-frequency resources for transmitting PRS in the time-frequency resource grid. It can indicate the timing of corresponding DL multi-beam transmissions. Time-frequency resources can be distinguished between different beams in multi-beam transmissions. The time-frequency resources for PRS transmission using spatial transmission filters are called PRS resources, and they have an identifier (ID). Multiple PRS resources for multi-beam transmission using multiple spatial transmission filters are called a PRS resource set. Both PRS resources and PRS resource sets can be parts of the PRS configuration.

[0089] The UE has already received PRS configurations from one or more BSs. The UE can receive one or more PRSs from multiple beam transmissions or multiple multi-beam transmissions (if multiple BSs transmit PRSs).

[0090] Then, in box 3020, the UE checks whether one or more triggering criteria are met. One or more triggering criteria can specify whether the UE is configured / allowed to use CIR indicators when participating in positioning. One or more triggering criteria can specify whether CIR measurements for obtaining the FPC are activated or deactivated. One or more triggering criteria can be predefined.

[0091] As a general rule, various triggering criteria can be considered. Several examples are summarized in Table 2 below.

[0092]

[0093]

[0094] Table 2: Examples of triggering criteria used by the UE to determine whether to participate in the positioning based on CIR indicators. For example, multiple such triggering criteria can be used. Cumulative triggering criteria can be defined.

[0095] As can be understood from Table 2, some of the illustrated triggering criteria (Examples B and C) depend on one or more characteristics of the CIR itself. Therefore, before checking whether one or more triggering criteria are met at block 3020, UE 102 is configured to determine the CIR, specifically, one or more such characteristics used in combination at block 3020. For example, the UE can execute formula (2), i.e., perform a correlation between the received signal shape of the corresponding PRS and the input or pre-stored signal shape of the corresponding PRS, to determine the CIR indicator. The CIR indicator can then be compared with predefined metrics to check whether one or more CIR-based triggering criteria are met.

[0096] In other examples, such as Example A in Table 2, the determination of the CIR indicator may be subject to a positive result of satisfying one or more triggering criteria at box 3020.

[0097] When one or more triggering criteria are met at box 3020, the CIR indicator is reported to the cellular network at box 3025 (see Table 1, Variant B). For example, UE 102 may send a corresponding report message indicating the CIR indicator, such as including the CIR indicator, a representation of the CIR indicator, or a sub-part of the CIR indicator.

[0098] More specifically, the CIR indicator can be reported to the LS node 120 using the positioning protocol 119.

[0099] A CIR indicator represents one or more FPCs of a CIR determined by monitoring one or more PRS resources (e.g., in multi-beam transmission). As a general rule, a CIR indicator can represent the FPC of a CIR determined using multiple PRS resources in a multi-beam transmission. For example, in the case of a multi-beam transmission involving N beams, M ≤ N PRSs can be received on different beams, and the CIR indicator can represent the FPC determined based on the CIR derived from each of these M PRSs. It can be assumed that no unreported PRSs are received, i.e., there is no corresponding component of the available CIR indicator or a zero CIR indicator.

[0100] As a general rule, a UE can report either a scalar representation or a complex representation of the CIR indicator. This means that a UE can report both the size and phase of the FPC of the CIR indicator; or it can report only the size or only the phase. Reporting only the size or only the phase can have the positive effect of reducing the required reporting size (e.g., the number of bits). As a general rule, AOD can also be estimated based solely on the size of the FPC of the CIR in the absence of phase information.

[0101] As a general rule, such messages reporting CIR indicators can indicate the FPC by referencing a predefined codebook and / or PRS resource ID. For example, the predefined codebook and / or PRS resource ID can define different ranges of values, and can then be used to signal the index of a specific range of values, including the size and / or phase of the FPC, via messages.

[0102] In yet another example, the message may include a normalized representation of the FPC of the CIR indicator. This normalization may be relative to the strongest FPC observed for multiple PRS transmitted on different beams (cross-PRS normalization); or, for each received PRS, the corresponding FPC of the corresponding determined CIR may be normalized relative to the remaining path of that particular CIR.

[0103] As a general rule, additional information may be reported to the cellular network at block 3025. For example, the UE may further report other indicators indicative of the relative quality of the FPC of the CIR relative to one or more other path components of the CIR and / or relative to the noise floor, see Example C in Table 2. Alternatively or additionally, the UE may also optionally report the delay of the FPC of the CIR. For example, the relative quality and / or delay and / or other characteristics may be reported for such PRS resources of multi-beam transmission for which the FPC has been reported. Such and other characteristics of the CIR may further facilitate accurate positioning, i.e., a relatively accurate determination of the AOD. Such additional information may be used to estimate the AOD more accurately.

[0104] In the foregoing, a scenario has been described in which the CIR indicator (and optionally, other characteristics of the CIR as described above) is reported to the LS node 120 (see Variant B of Table 1), that is, the UE 102 participates in the positioning by sending a message representing the CIR indicator to the network. Then, for example, the LS node 120 may estimate the AOD based on the message, or more specifically, based on the CIR indicator and optionally one or more additional CIR-related indicators represented by the message.

[0105] In other scenarios (see Variant A of Table 1), the UE 102 may participate in the positioning by locally estimating the AOD based on the CIR indicator (and optionally, based on other characteristics of the CIR, such as the relative quality of the FPC of the CIR and / or the delay of the FPC of the CIR, as described above). Further, such estimation of the AOD may be based on a scalar representation or a complex representation of the CIR indicator.

[0106] As a general rule, when estimating the AOD based on the CIR indicator, the FPC of the CIR indicator derived from measurements on some or all of the transmit beams of PRS transmissions (e.g., multi-beam transmissions) in the plurality of PRS resources (R l (τ FP )) are summed. This yields the estimated channel coefficients in the spatial domain:

[0107]

[0108] where N is the number of beams or PRS resources, and M ≤ N (e.g., only M < N FPCs may be signaled, as will be explained in detail with respect to Tables 4 and 5 below). Thus, the summation may span PRS resources (e.g., within a set of PRS resources) or, for example, the "best" M < N PRS resources that the UE has been configured by the LS (here, an appropriate metric for defining what "best" means may be used, e.g., the quality of the FPC of the CIR). P l(φ) is the beam pattern of each beam, τ FP It is the estimated FPC delay from the PDP, R l (τ FP ) is in the delay τ FP The cross-correlated complex amplitude at the point is shown in equation (2).

[0109] Based on formula (3), AOD can be estimated as:

[0110]

[0111] Assuming beam pattern P l (φ) is known in advance by the LS or the UE. For example, the LS knows the PRS beam configuration by receiving it from the gNB through the NR PPa protocol, while the UE knows it by receiving the corresponding PRS beam configuration from the LS through the LPP protocol.

[0112] The above is a method for estimating AOD based on equations (3) and (4); other methods / variants based on the same parameters as shown above exist. For example, the denominator of equation (3) can be reversed.

[0113] In optional block 3030, RSRP is reported or RSRP is used to estimate AOD based on a reference technique (e.g., by selecting the direction of the PRS with the strongest RSRP observed for multiple PRSs transmitted in a multi-beam configuration). Therefore, block 3030 can be equivalent to a fallback to a conventional implementation, which in the illustrated example is conditional on the non-compliance of one or more triggering criteria at block 3020. In other examples, reporting RSRP and / or locally estimating AOD based on RSRP (i.e., UE-based positioning) may not be conditional on the non-compliance of one or more triggering criteria at block 3020; instead, such RSRP-based positioning can be statically activated. For illustration, if both CIR and RSRP are measured, the average between the RSRP-based estimate of AOD and the CIR-based estimate of AOD can be determined when positioning the UE.

[0114] Figure 7 It is a flowchart based on various examples of methods. For example, Figure 7 The method can be executed by LS node 120, for example, by its processor when loading program code.

[0115] The method includes receiving a report about the CIR indicator in box 3100. Thus, box 3100 is associated with box 3025 (see [link]). Figure 6As described above, this message can indicate the complex or scalar representation of one or more FPCs of the CIR indicator. This message can indicate one or more FPCs of the CIR indicator by referring to a predefined codebook. This message can include one or more FPCs of the CIR indicator in a normalized manner or in absolute value.

[0116] At optional box 3105, RSRP reports for one or more PRSs are received. Therefore, box 3105 is related to box 3030 (see...). Figure 6 They are interconnected.

[0117] In box 3110, estimate AOD. This is based on the messages in box 3100 and box 3105 (if available). For example, formulas (2), (3), and (4) can be used.

[0118] Figure 8 It is a signaling diagram based on various examples. Figure 8 The communication between one or more BSs 101-1 to 101-3, UE 102, and LS node 120 is illustrated. The communication between UE 102 and LS node 120 may be based on positioning protocol 119.

[0119] At 5001, UE 102 sends message 4001 indicating its ability to participate in its positioning based on a CIR indicator (which indicates the size and / or phase of the FPC of the CIR). 5001 thus implements... Figure 6 Box 3005.

[0120] At 5002, each of the BSs 101-1 to 101-3 sends a corresponding control message 4051 to LS 120, which includes the PRS configuration, including the PRS beam configuration (i.e., the spatial filter for multi-beam transmission, such as P in equation (3)). l (φ)) and PRS resource configuration (i.e., time-frequency resources used for UE monitoring). At 5003, LS 120 can further use message 4052 to forward some or all of the PRS configuration to the UE using the LPP protocol. For example, in UE-based positioning (see Table 1, Variant A), message 4052 may include a PRS configuration that includes both PRS beam configuration and PRS resource configuration; while in network-based positioning (see Table 1, Variant B), message 4052 may include a PRS configuration that includes PRS resource configuration but not PRS beam configuration (in which case the UE may not need the PRS beam configuration because the calculation according to equation (3) is performed at LS 120).

[0121] At 5005, LS node 120 sends a location measurement request 4005 to UE 102. Location measurement request 4005 indicates the AOD to be measured. Optionally, location measurement request 4005 may include a command requesting UE 102 to participate in location based on a CIR indicator. This may be consistent with the capability indicated by message 4001.

[0122] Then, in 5010, BS 101-1 to 101-3 transmit PRS 121 to 123 on their respective multi-beam transmissions (e.g., PRS in multiple resources to form a beam scan). This is consistent with the PRS configuration of 5002 and 5003. UE 102 monitors these PRS 121 to 123 (see...). Figure 6 (Box 3010).

[0123] Based on at least one received positioning reference being 121 to 123, UE 102 can participate in the positioning in block 5015 by determining RSRP and / or RSTD. UE 102 can determine this characteristic of one or more received attributes of PRS 121 to 123. Optionally, UE 102 can determine AOD based on this characteristic.

[0124] In box 5020, the UE can determine the CIR indicator. This may include performing a correlation between the input signal shape of the PRS and the received signal shape of the PRS according to formula (2).

[0125] Optionally, at box 5020, the UE can also estimate AOD based on the CIR indicator. This may include executing formulas (3) and (4). In other examples, the task of estimating AOD based on the CIR indicator can be offloaded to LS node 120.

[0126] At option 5025, choose between RSRP-based and / or CIR indicator-based engagement. This can include checking if one or more triggering criteria are met, as described above. Figure 6 As explained in box 3020. Depending on the result, location measurement report messages 4015 and / or 4020 are sent. Location measurement report messages 4015 and 4020 can be standardized in the LPP protocol TS 37.355.

[0127] First, consider the case where the selection at box 5025 results in positioning not being based on the CIR indicator. Then, a positioning measurement report message 4015 indicating RSRP can be sent at 5030 to facilitate AOD estimation at LS node 120. Alternatively, in such a case, measurement report message 4015 may already be included in the AOD locally estimated at UE 102 based on RSRP at box 5015.

[0128] Next, consider the case where the selection at box 5025 results in positioning based on the CIR indicator. Then, at 5035, a positioning measurement report message 4020 can be sent, indicating the CIR indicator (see Table 1, Variant B).

[0129] For example, a complex or scalar representation of one or more FPCs of the CIR indicator can be included in the location measurement report message 4020. The location measurement report message 4020 can include the absolute values ​​of one or more FPCs of the CIR indicator, or by referring to a predefined codebook. The location measurement report message 4020 can include one or more FPCs of the CIR indicator in a normalized representation. The LS node 120 can then estimate the AOD based on this information about the CIR. Alternatively, in such a case, at block 5020, the measurement report message 4020 can be sent with the AOD already included in the locally estimated AOD at UE 102 based on the CIR indicator (see Table 1, Variant A).

[0130] Table 3 below summarizes example information content for location measurement report message 4020.

[0131]

[0132]

[0133] Table 3: Example implementation of Position Measurement Report Message 4015 indicates the CIR indicator, which represents the FPC for the CIR determined by the PRS transmitted on a plurality of beams 301 to 309 (see [link]). Figure 3 ).

[0134] In the example in Table 3, the size of the FPC of the CIR determined based on the PRS transmitted on different beams 301 to 309 of the multi-beam transmission 351 is normalized to "1" relative to the size of all paths observed for each individual PRS resource measurement (which corresponds to the combined...). Figure 4 (Normalization discussed); as an alternative, normalization can be performed between FPCs determined based on PRS transmitted on different beams (i.e., cross-PRS normalization), which can be limited to those reported beams. This is illustrated in Table 4, where the fourth beam is used as the normalization reference, and therefore takes a size of "1" (there can be another normalization reference, such as the sum of all reported FPCs, etc.).

[0135]

[0136] Table 4: An example implementation of the positioning measurement report message 4015 indicates a CIR indicator that indicates the FPC of the CIR determined for PRSs transmitted on a plurality of beams 301 to 309 (see Figure 3 ).

[0137] In the example of Table 4, the positioning measurement report message 4015 includes a CIR indicator indicating the FPC of the CIR determined for all PRS resource IDs of the PRS resource set, that is, including all N FPCs, see equation (3).

[0138] In other examples, only M<N FPCs may be reported. This is illustrated in Table 5 based on the scenario of Table 4.

[0139]

[0140] Table 5: An example implementation of the positioning measurement report message 4015 indicates a CIR indicator that indicates the FPC of the CIR determined for PRSs transmitted on a plurality of beams 301 to 309 (see Figure 3 ). In the example of Table 5, only M=5<N=9 best FPCs are reported. That is, the count M of the reported FPCs is smaller than the count N of the PRS resources / beams for multi-beam transmission, but the count is greater than 1; M>1.

[0141] The metric for determining the (e.g., best) FPCs to be reported may vary depending on different implementations. For example, the metric may be network-defined. The number M of FPCs to be reported may be network-defined. For example, the M strongest FPCs may be reported. As described above, only those FPCs whose relative quality is higher than a certain threshold may be reported. Therefore, the count M of FPCs to be reported may be network-defined. As described above, the count may be defined by (e.g., network-configured) parameterization that depends on the quality of the FPCs.

[0142] Note that although in the scenarios of Table 3 to Table 5, the magnitudes of the FPCs of the CIR determined based on PRSs transmitted with different spatial transmit filters via multiple beams are reported, alternatively or additionally, the phases of the FPCs may be reported. For illustrative purposes, the phases may also be reported in a normalized manner. For example, in the scenario of Table 4, the fourth beam may by definition have a phase of 0°.

[0143] In summary, techniques that facilitate accurate positioning of a UE have been described. In particular, the AOD of one or more PRSs transmitted by one or more BSs to the UE may be estimated. According to the techniques described herein, one or more characteristics of the CIR are used to estimate the AOD. This is different from reference implementations that rely on RSRP to estimate the AOD.

[0144] One specific characteristic of the CIR that can be used to estimate AOD is the FPC. Here, the corresponding CIR indicator for the FPC that indicates the CIR can be used to estimate AOD.

[0145] For example, a message indicating a CIR indicator can be sent. This message could include, for example, a scalar or complex representation of the CIR indicator.

[0146] As a general rule, the message indicating the CIR indicator, or one or more other messages, may indicate additional characteristics of the CIR. For example, the message or one or more other messages may indicate at least one additional indicator that indicates the quality of the CIR's FPC and / or the delay of the CIR's FPC.

[0147] Techniques have been described to facilitate the determination of the CIR indicator based on measurements of one or more receive characteristics of the PRS. The FPC of the CIR can be derived by performing a correlation between the received signal shape of the PRS and the input signal shape.

[0148] This method of estimating AOD based on one or more characteristics of the CIR can replace or supplement the method of estimating AOD based on the RSRP. For example, a specific location mode can be activated based on one or more triggering criteria, i.e., (i) estimating AOD based on one or more characteristics of the CIR (such as the CIR indicator of the FPC that indicates the CIR), or (ii) estimating AOD based on the RSRP. An example triggering criterion includes network configuration. For example, the LS node of the communication network can indicate which location mode to use, i.e., (i) and / or (ii).

[0149] The above describes techniques to facilitate AOD estimation at the communication network (e.g., at the LS node). Alternatively or additionally, AOD can also be estimated at the UE based on UE location, see Table 1.

[0150] In addition, techniques have been described to facilitate the corresponding measurement capabilities of reporting UEs to determine one or more characteristics of the general impulse response.

[0151] Simulations were performed to compare the AOD estimation accuracy between existing techniques based on PRS-based RSRP (i.e., the sum across all paths) and the CIR indicator-based AOD estimation technique described herein. It was found that an improvement of 5% to 10% in accuracy can be achieved for AOD expressed in degrees, for example in an “open office” channel environment. The results of the comparative study are shown in Table 6 below.

[0152]

[0153] Table 6: Average estimated AOD error obtained from simulations assuming an open-plan office environment. The open-plan office in the simulation is assumed to have the following parameters: 120 meters long, 50 meters wide, and 3 meters high. The non-line-of-sight probability in the open-plan office environment is 13%.

[0154] While this disclosure has been shown and described with reference to certain preferred embodiments, equivalents and modifications will occur to those skilled in the art upon reading and understanding this specification. This disclosure includes all such equivalents and modifications and is limited only by the scope of the appended claims.

[0155] For illustration, various techniques are described in the context of corresponding estimations of DL PRS and AOD. Similar techniques can be readily applied to other PRSs, such as uplink PRS and / or lateral PRS. For further illustration, various examples of implementing PRS-based positioning have been described. In other examples, other types of reference signals, such as SRS, including lateral SRS, UL SRS, etc., can be employed. Furthermore, various techniques are described in the context of cellular networks. Other kinds and types of networks can follow the techniques described herein.

[0156] For further illustration, various techniques for estimating AOD based on the FPC of CIR have been described. Alternatively or additionally, one or more other characteristics of CIR, such as the second path component of CIR, may be considered in the estimation of AOD. This can be helpful, for example, when the magnitude of the second path component is significantly larger than the FPC of CIR. The CIR indicator as described throughout this disclosure can then be used to indicate one or more characteristics of CIR, for example, as a supplement to or alternative to the indication of the FPC of CIR.

[0157] Furthermore, various techniques for estimating AOD based on one or more characteristics of CIR as part of positioning have been described. As a general rule, one or more characteristics of CIR (e.g., FPC of CIR) can be used in the estimation of other location indicators (e.g., TOA, TDOA, and / or AOA, etc.).

Claims

1. A method for operating a wireless communication device (102) capable of connecting to a communication network, the communication network including access nodes (101, 101-1, 101-2, 101-3), the method comprising the steps of: Monitoring multiple reference signals (121, 122, 123) transmitted (351) in multiple resources, the transmissions being provided by the access nodes (101, 101-1, 101-2, 101-3), and Based on the monitoring, the location of the wireless communication device (102) is determined by an indicator of at least one of the magnitude or phase of at least one first path component (810) of an impulse response (800, 801) indicating the radio channel, said at least one first path component being associated with at least one of a plurality of reference signals (121, 122, 123) transmitted (351). The step of participating in the positioning of the wireless communication device (102) includes: sending a message (4020) to the communication network representing an indicator indicating at least one of the magnitude or phase of the at least one first path component (810) for estimating the departure angle (191, 192, 193) of the at least one of the plurality of reference signals (121, 122, 123).

2. The method according to claim 1, in, The step of participating in the positioning of the wireless communication device (102) includes: estimating the departure angle (191, 192, 193) of at least one of the reference signals (121, 122, 123) based on the indicator indicating the magnitude or phase of at least one of the at least one first path component (810).

3. The method according to claim 1 or 2, in, The wireless communication device (102) participates in the positioning based on the complex representation or the scalar representation of the indicator.

4. The method according to claim 1, in, The message (4020) indicates at least one of the magnitude or phase of the at least one first path component (810) by including a reference to a predefined codebook, or wherein the message (4020) includes a normalized representation of at least one of the magnitude or phase of the at least one first path component (810).

5. The method according to claim 1, in, The step of participating in the positioning is also based on at least one additional indicator, which indicates the relative quality of the at least one first path component (810) of the impulse response (800, 801) relative to one or more other path components of the impulse response (800, 801) and / or indicates the noise floor of the impulse response (800, 801).

6. The method according to claim 1, in, The steps involved in the positioning selectively depend on the indicator indicating at least one of the magnitude or phase of the at least one first path component (810) satisfying at least one trigger criterion.

7. The method according to claim 6, in, The at least one triggering criterion includes network configuration.

8. The method according to claim 6, in, The at least one trigger criterion includes a comparison between the size of the at least one first path component (810) and a baseline threshold.

9. The method according to claim 8, in, The baseline threshold is configured by the communication network.

10. The method according to claim 6, in, The at least one trigger criterion includes a comparison between the relative quality of the at least one first path component (810) defined relative to one or more other path components of the impulse response (800, 801) or the noise floor of the impulse response (800, 801) and a reference threshold.

11. The method according to claim 10, in, The baseline threshold is configured by the communication network.

12. The method according to claim 6, further comprising: Depending on the at least one triggering criterion, a message (4020) is selectively sent to the communication network, the message (4020) indicating an additional indicator indicating the received signal power of at least one of the plurality of reference signals (121, 122, 123).

13. The method according to claim 1, further comprising: The ability to report (3005) to participate in the positioning is based on the indicator that indicates the magnitude or phase of the at least one first path component (810).

14. The method according to claim 1, in, The steps involved in the positioning are also based on at least one additional indicator indicating the delay of at least one first path component (810) of the impulse response (800, 801).

15. The method according to claim 1, further comprising: Perform reference signal measurements to determine an indicator that indicates the magnitude or phase of the at least one first path component, the reference signal measurements including cross-correlation between the received signal shape of the at least one reference signal (121, 122, 123) and the input signal shape of the at least one reference signal (121, 122, 123).

16. The method according to claim 15, in, The reference signal measurement is performed in response to a corresponding activation request received from the communication network.

17. The method according to claim 1, in, The indicator indicates at least one of the magnitudes or phases of the plurality of first path components associated with the plurality of reference signals in the impulse response of the radio channel.

18. The method according to claim 17, in, The count of the plurality of reference signals is less than the count of the reference signals included in the plurality of reference signals.

19. The method according to claim 18, in, The count is defined by network configuration and / or by parameterization that depends on the quality of the first path component.

20. The method according to claim 1, in, The step of participating in the positioning of the wireless communication device (102) includes: estimating the departure angle (191, 192, 193) of at least one of the reference signals (121, 122, 123) based on the indicator indicating at least one of the magnitude or phase of the at least one first path component (810). The method further includes: Receive a message (4052) from the communication network indicating a spatial filter associated with the plurality of resources being transmitted. The departure angle is estimated based on the spatial filter.

21. A method for operating a network node in a communication network, the method comprising the following steps: A message is received from a wireless communication device (102) as an indicator of at least one of the magnitude or phase of at least one first path component (810) representing an impulse response (800, 801) indicative of a radio channel, said at least one first path component (810) being associated with at least one reference signal (121, 122, 123) of a plurality of resources for transmission (351) provided by access nodes (101, 101-1, 101-2, 101-3) of the communication network. The departure angles (191, 192, 193) of the at least one reference signal (121, 122, 123) are estimated based on the indicator indicating at least one of the magnitudes or phases of the at least one first path component (810).

22. The method according to claim 21, further comprising: Receive messages from the access nodes (101, 101-1, 101-2, 102-3) indicating spatial filters associated with the transmitted plurality of resources. The departure angle is estimated based on the spatial filter.

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