Non-uniform reconfigurable redirection device state for enhanced positioning

Abstract

Systems and methods are presented by which at least one reconfigurable redirection device is controlled to apply a non-uniform phase profile to enhance positioning of a target mobile device by creating a non-planar redirection pattern. Using and changing a non-uniform phase profile during a localization task allows for the use of fewer transmissions and / or fewer hardware components to discover information about the location of a target mobile device, such as the angle or orientation relative to a reconfigurable redirection device.

Description

Technical Field

[0001] This invention relates to the field of location services for terminal devices, including mobile access devices in wireless networks, such as, but not limited to, reconfigurable smart surfaces (RIS) or other reconfigurable redirection devices (RRDs). Background Technology

[0002] Various positioning technologies can be used within cellular networks such as 5G systems, employing combinations of timing, angle, signal strength, or other data to allow the location of a mobile terminal (e.g., user equipment (UE) in 5G terminology) to be determined by itself or by network entities such as base stations (e.g., gNB in ​​5G terminology) or other access points. Auxiliary components, such as reconfigurable redirection devices (RRDs), like RIS or network control repeaters (NCRs), can be provided to assist in the positioning of the mobile terminal.

[0003] While any technique with appropriate properties (e.g., the ability to redirect, i.e., to reflect or transmit radio waves in different configurations at the correct frequency) can be used to construct RIS, the mainstream technique is metamaterial surfaces, or simply "metasurfaces".

[0004] Switchable metasurfaces have recently been developed, offering numerous possibilities for improving wireless communication paths between access devices (e.g., base stations or access points) and terminal devices (e.g., user equipment (UEs)) in wireless networks. Various techniques can be employed to realize such switchable metasurfaces. Typically, electronically switched metasurfaces are used, but physically movable reflective patches are also feasible techniques. Metasurfaces can consist of an array of elements (“metaatoms”) comprising periodic subwavelength metallic / dielectric antennas resonantly coupled to an electrical or magnetic or both component of the incident electromagnetic field, exhibiting an inherently unseen effective electrical (represented by the dielectric constant ε) and / or magnetic (represented by the permeability µ) response.

[0005] Therefore, metasurfaces represent a general concept for manipulating electromagnetic waves. Due to the ease of fabrication using planar circuitry, they hold significant application potential in the microwave frequency range. Huygens metasurfaces have attracted considerable attention due to their near-unity transmittance and efficient suppression of reflection artifacts.

[0006] Metamaterials will be useful in many aspects, such as 6G wireless communication schemes. Syed S. Bukhari et al.'s " A Metasurfaces Review: Definitions and Applications "A review of metasurfaces is provided. Purely passive metasurfaces are useful, but only serve as a permanent alteration to the transport environment."

[0007] Kun Woo Cho and others' " mmWall: A Reconfigurable Metamaterial Surface for mmWave Networks A reconstructable metasurface for millimeter-wave networks (“mmWall”) has been proposed. This tunable smart surface, made of metamaterials, differs from conventional wireless relay systems in that it lacks transmit and receive antennas and amplifiers. Once an incident beam strikes the metasurface, it naturally redirects the beam to the desired direction, regardless of whether the transmitter and receiver are in the same room (“mirror” mode) or different rooms (“lens” mode). Furthermore, it can split the input signal into multiple beams and simultaneously guide multiple beams. The authors used Huygen's metasurface to realize their design.

[0008] In addition, in Yongxu Zhu et al.'s " Stochastic Geometry Analysis of Large Intelligent Surface-Assisted Millimeter Wave Networks The study has disclosed large-scale intelligent surfaces (LIS) and models for integrating base stations and LIS to determine the benefits of each in different proportions within a communication network. Their conclusion is that LIS contributes well in the presence of a limited number of base stations, but this is not the case where there are many base stations providing services to users.

[0009] In addition, among Jun Zhao and others "A Survey of Intelligent Reflecting Surfaces (IRSs): Towards 6G Wireless Communication Networks” The authors refer to these surfaces as “intelligent reflective surfaces” and their behavior is limited to reflection, rather than both reflection and transmission.

[0010] Low-capability and / or single-antenna device positioning technologies need improvement to achieve the desired level of positioning accuracy. This can be achieved by combining positioning technologies with RIS or other RRDs (such as NCR) to provide RRD-aware positioning. However, known RRD-aware positioning technologies may impose a higher processing burden on the user terminals involved. Summary of the Invention

[0011] The purpose of this invention is to enhance network control of wireless communication to improve the positioning of mobile devices.

[0012] This objective is achieved by the apparatus of claim 1, the access device of claim 7, the reconfigurable redirection device of claim 8, the system of claim 10, the method of claim 15, and the computer program product of claim 16.

[0013] According to a first aspect relating to a reconfigurable redirection device (e.g., RIS or NCR) or an access device (e.g., a base station (gNB) or access point), an apparatus for supporting the positioning of mobile devices in a wireless network is provided, the apparatus being configured to establish reflection and / or deflection profiles of array elements of at least one reconfigurable redirection device in the wireless network to create a non-planar spatial redirection pattern of at least one reconfigurable redirection device.

[0014] According to a second aspect relating to a reconfigurable redirection device (e.g., RIS or NCR) or an access device (e.g., a base station (gNB) or access point), a method for supporting the positioning of mobile devices in a wireless network is provided, the method comprising: establishing reflection and / or deflection profiles of array elements of at least one reconfigurable redirection device in the wireless network to create a non-planar spatial redirection pattern of at least one reconfigurable redirection device.

[0015] According to a third aspect, a reconfigurable redirection device (e.g., RIS or NCR) is provided, which includes the means of the first aspect.

[0016] According to the fourth aspect, an access device (e.g., a base station (gNB) or access point) is provided, which includes the means of the first aspect.

[0017] According to a fifth aspect, a positioning system for locating a mobile device in a wireless network is provided, the positioning system including means of the first aspect, a positioning function for determining the location of the mobile device, and a phase profile design system for converting a desired non-planar spatial redirection pattern into a spatially non-uniform phase profile that can be implemented by a reconfigurable redirection device.

[0018] Finally, according to the sixth aspect, a computer program product is provided, which includes code units for generating the steps of the method of the second aspect when run on a computer device.

[0019] Therefore, in order to guide the impact beam or signal along a non-planar redirection pattern, a reconfigurable redirection device is configured to display non-planar reflection and / or deflection profiles or characteristics by applying a non-uniform phase profile to support the localization of a nearby mobile device (e.g., a UE). The proposed use of a non-uniform phase profile enables the discovery of information about the location of the mobile device, such as its angle or orientation relative to the reconfigurable redirection device, using fewer transmissions and / or fewer hardware components (e.g., one reconfigurable redirection device instead of two). Furthermore, additional location information can be obtained by using changes in the phase profile during the localization task. Thus, in such scenarios, the processing burden can be relieved from the mobile device.

[0020] The reconfigurable redirection device can be implemented by a RIS configured to display reflection and / or deflection profiles that reflect or deflect impact beams from an access device (e.g., gNB) or a terminal device (e.g., UE) into a desired non-planar redirection pattern or characteristic.

[0021] Reconfigurable redirection devices can be implemented by an NCR equipped with an antenna array comprising multiple antenna elements having a beam profile that simulates (operates as, is used as, creates) a desired nonplanar redirection pattern or characteristic (reflection or deflection profile). The NCR can not only reflect / redirect beams received from access or terminal devices, but can also have signals with omnidirectional propagation paths (e.g., transmitted using an omnidirectional antenna).

[0022] Therefore, designing and applying non-uniform spatial phase profiles at reconfigurable redirection devices is a useful enhancement for positioning tasks. Positioning methods can be used advantageously to address the problems of conventional positioning systems in the presence of one or more reconfigurable redirection devices with controllable non-uniform spatial phase profiles.

[0023] According to the first option, which can be combined with any of the first to sixth aspects described above, the reflection and / or deflection profiles of the array elements can be set by controlling the spatial phase shift profiles of the array elements to obtain non-uniform spatial phase shift profiles. Therefore, individual phase profiles can be provided (stored) for different desired non-planar redirection modes.

[0024] According to the second option, which can be combined with the first option or any of the first to sixth aspects described above, the spatial phase shift profile of the array elements can be controlled to obtain at least one of a continuous nonlinear phase profile and a stacked linear phase profile. Thus, by changing the specific parameters of the continuous nonlinear profile or the stacked linear phase profile, different redirection modes can be obtained directly.

[0025] According to a third option, which can be combined with the first or second option or any of the first to sixth aspects described above, the spatial phase shift profile of the array elements can be controlled to obtain a non-uniform phase profile, which exhibits a reflection and / or deflection profile having a center point or one or more center lines. The center point or center lines facilitate and improve specific positioning tasks.

[0026] According to the fourth option, which can be combined with any of the first to third options or any of the first to sixth aspects, the reflection and / or deflection profiles of the array elements can be changed during the positioning of the mobile device. This allows for the acquisition of additional valuable information for the positioning task.

[0027] According to the fifth option, which can be combined with any of the first to fourth options or any of the first to sixth aspects, the reflection and / or deflection profiles of the array elements can be dynamically created in response to positioning measurements and feedback from the mobile device. Therefore, the non-planar redirection mode can dynamically adapt to the current environmental conditions.

[0028] According to the sixth option, which can be combined with any one of the first to fifth options or any one of the first to sixth aspects, the reconfigurable redirection device may include a reconfigurable smart surface or a network-controlled repeater equipped with an antenna array. Thus, a flexible approach for implementing a positioning system can be provided.

[0029] According to a seventh option, which can be combined with any of the first to sixth options or any of the first to sixth aspects, the mobile device can be configured to use uplink positioning and send pilot signals to a reconfigurable redirection device for reflection to an access device in the wireless network. The means of the first aspect can be configured to use feedback information from the access device to control the reconfigurable redirection device by applying a series of nonlinear phase profiles until the received signal strength at the access device is maximized or minimized. This requires relatively fewer signaling rounds from the mobile device, saving time and resources.

[0030] According to an eighth option, which can be combined with any of the first to seventh options or any of the first to sixth aspects, the means of the first aspect can be configured to approximately locate the mobile device by applying a stacked linear phase profile consisting of small regions of linear phase profiles at a center point surrounded by divergent or randomly oriented phase profiles. This requires relatively fewer signaling rounds from the mobile device, saving time and resources.

[0031] According to the ninth option, which can be combined with any of the first to eighth options or any of the first to sixth aspects, the means of the first aspect can be configured to apply two stacked linear phase profiles with different center points and determine the intersection of two reflection or deflection angles that result in the maximum received signal strength at the mobile device to locate the mobile device. Therefore, relatively fewer hardware components are required (i.e., one RIS or NCR, rather than two), which extends applicability to a wider range of situations.

[0032] According to a tenth option, which can be combined with any of the first to ninth options or any of the first to sixth aspects, the apparatus of the first aspect can be configured to control a reconfigurable redirection device to reflect or deflect incident beams from an access device in two directions, such that a null value is created between the two reflected beams, and the two reflected beams are guided through the mobile device, wherein the point of minimum received signal strength at the access device represents the angle at which the null value points towards the mobile device. This measurement allows for more accurate determination of azimuth and elevation angles.

[0033] Note that the above-described device may be implemented based on a discrete hardware circuit having an arrangement of discrete hardware components, integrated chips, or chip modules, or based on a signal processing device or chip controlled by software routines or programs stored in memory, written on a computer-readable medium, or downloaded from a network (e.g., the Internet).

[0034] It should be understood that the apparatus of claim 1, the access device of claim 7, the reconfigurable redirection device of claim 8, the system of claim 10, the method of claim 15, and the computer program product of claim 16 may have similar and / or identical preferred embodiments, particularly as defined in the dependent claims.

[0035] It should be understood that preferred embodiments of the present invention may also be any combination of dependent claims or the above embodiments with corresponding independent claims.

[0036] These and other aspects of the invention will be apparent from the embodiments described below and will be illustrated with reference to the embodiments described below. Attached Figure Description

[0037] In the following figures:

[0038] Figure 1 The general architecture of an RRD sensing and positioning system according to various embodiments is illustrated schematically;

[0039] Figure 2 The use is illustrated schematically. Figure 1 The flowchart of the RRD perception and localization process in the architecture;

[0040] Figure 3 A flowchart illustrating the common initial portion of the RIS-aware localization process according to various embodiments is shown schematically;

[0041] Figure 4 A flowchart illustrating a subsequent single part of the RIS-aware uplink localization process with terminal beamforming according to the first embodiment is shown schematically.

[0042] Figure 5A flowchart illustrating a subsequent single part of the RIS-aware uplink localization process without terminal beamforming according to the second embodiment is shown schematically.

[0043] Figure 6 A flowchart illustrating a subsequent single part of the downlink localization process based on RIS sensing angle according to the third embodiment is shown schematically.

[0044] Figure 7 The spatially uniform phase profile used to find the strongest localization path from the terminal device to the access point is schematically illustrated.

[0045] Figure 8 The spatially non-uniform phase profile used to position the terminal device relative to the centerline is schematically shown.

[0046] Figure 9 The stacked linear phase profile used to provide a movable centerline is schematically shown;

[0047] Figure 10 This schematically illustrates how non-parallel light rays are reflected from a convex mirror;

[0048] Figure 11 The different phase profiles of the deflection angle and the associated rate of change are schematically shown;

[0049] Figure 12 The diagram schematically illustrates divergent beam guidance through the moving center of curvature;

[0050] Figure 13 The diagram schematically illustrates convergent beam guidance through a moving center of curvature; and

[0051] Figure 14 The basic geometry of a base station, target terminal equipment, and reconfigurable redirection equipment with relevant distances is schematically shown. Detailed Implementation

[0052] Embodiments of the invention are now described in the context of cellular network environments such as 5G. However, the invention may also be used in conjunction with other wireless technologies in which reconfigurable redirection devices can be introduced, such as IEEE 802.11 / Wi-Fi or IEEE 802.15.4 / Ultra-Wideband (UWB) communication.

[0053] Throughout this disclosure, the abbreviation "gNB" (5G term) or "BS" (base station) is intended to refer to an access device / point, such as a cellular base station, a WiFi access point, or a UWB PAN coordinator. A gNB can consist of a centralized control plane unit (gNB-CU-CP), multiple centralized user plane units (gNB-CU-UP), and / or multiple distributed units (gNB-DU). The gNB is part of the radio access network (RAN), which provides an interface to functions in the core network (CN). The RAN is part of a wireless communication network. It implements radio access technology (RAT). Conceptually, it resides between communication devices such as mobile phones, computers, or any remotely controlled machine and provides connectivity to their CN. The CN is the core part of the communication network, providing numerous services to customers interconnected via the RAN. More specifically, it directs communication flows through the communication network and possibly other networks.

[0054] Furthermore, the terms "base station" (BS) and "network" are generally used as synonyms in this disclosure. This means, for example, that when a "network" is written to perform an operation, it can be performed by the CN function of a cellular network or by one or more base stations that are part of such a cellular network, and vice versa. It can also mean that some functions are performed by the CN function of a cellular network and some functions are performed by a base station.

[0055] A wide range of names have been given to (large area) surfaces that can passively alter the direction of radio waves striking them, but these reflection or transmission properties can be altered and / or switched and / or reconfigured to produce different passive behaviors depending on their established "states". These names include Intelligent Reflective Surfaces (IRS), Reconfigurable Intelligent Surfaces (RIS), Large Intelligent Surfaces (LIS), Reconfigurable Metasurfaces (RM), Programmable Metasurfaces (PM), Large Intelligent Metasurfaces (LIM), Intelligent Reflective Arrays (SRA), Software-Defined Metasurfaces (SDM), Software-Defined Surfaces (SDS), Passive Intelligent Surfaces (PIS), and Passive Intelligent Mirrors (PIM). These surfaces can switch between different states, each reflecting or transmitting radio waves in a different manner. The differences among these types of surfaces lie in the fact that some surfaces have an inherent ability to determine signal strength; for example, they can incorporate both a receiver and a reflector / transmitter, and thus can act as independent "relay-like" systems, performing their own beam path searches (albeit with reflected / transmitted signals originating elsewhere). Their similarity to relays allows them to be integrated into communication standards (e.g., cellular standards). Such switchable metamaterial surfaces offer numerous possibilities for improving communication paths between base stations or other types of access devices and terminal devices (e.g., UEs).

[0056] In the following text, the term "reconfigurable smart surface" or "RIS" will be used to refer to any of the above-described surface types. It should be understood as a surface used to control radio wave propagation, containing multiple individual electronic components (e.g., "superatoms") through which a phase delay can be applied to an input radio frequency (RF) signal or other electromagnetic (EM) signal reflected from the surface.

[0057] In the embodiments, it may be assumed that the RIS arrays are completely passive, i.e., they do not have inherent radio sensing capabilities and therefore cannot perform beam searching or the like on their own, but can be defined by switching states when commanded by an external controller, and it is the responsibility of the external controller to determine the appropriate state for the RIS.

[0058] The phase delay level, overall surface control, and network communication of the RIS can be handled by a controller (“RIS controller”), which may also include standardized communication hardware for communicating on the network (e.g., the RIS controller can act as a UE on a 5G network), local processing, and memory hardware.

[0059] The RIS controller can operate in response to instructions received from its associated network, for example, via a control plane link, or autonomously, for example, according to scheduling configured by a base station (e.g., gNB) or in response to changes in channel conditions. Optionally, the RIS can also respond to signals from a target UE or third-party device, wherein these signals can be messages directed to the RIS (e.g., commands, requests, notifications, etc.) or other relevant signals monitored or detected by the RIS controller.

[0060] By comparing the angle ρ that the RIS at that node faces with respect to the beamwidth used at that node, the RIS can be classified as "large" or "small" relative to that node (i.e., UE or base station). When ρ is less than the beamwidth, the RIS can be called "small." When ρ is greater than the beamwidth, the RIS can be called "large." This classification affects the options used for beam control. That is, when the RIS is "large," the node can direct its own beam through the RIS to illuminate different parts of the RIS surface. When the RIS is "small," this is practically impossible.

[0061] Note that the effective size of the RIS is a function of the physical size of the RIS, the angle of the RIS surface relative to the centerline between the corresponding node and the RIS, the distance between the corresponding node and the RIS, and the beamwidth of the corresponding node.

[0062] In addition to reflecting incident EM radiation (i.e., acting as a reflector), the RIS can also alternatively or additionally refract or deflect radiation through it according to its profile (i.e., acting as a lens). Therefore, the RIS can be placed directly in front of the antenna to act as a lens. In this case, the RIS can be used to perform beamforming of signals to and from the antenna. In the following embodiments, the term "reflection" should be understood to also include such transmission operations.

[0063] Although it is assumed that the signal is in the RF frequency range, the same principles disclosed can also be applied to other parts of the electromagnetic spectrum, including optical (IR, visible, UV) signals or signals in the terahertz region.

[0064] Throughout the disclosed embodiments, "reflection profile" or "reflection and / or deflection profile" will be understood as a description (which may be expressed as a matrix, function, or other form of description) of how incident light rays are reflected or deflected (refracted) from each point on the RIS surface (some examples are below). Figures 7 to 13 (Illustrated schematically).

[0065] Throughout the disclosed embodiments, "redirection pattern" will be understood as a description of the pattern of the beam leaving the RIS surface. The redirection pattern is a function of the reflection and / or deflection profile and the characteristics of the striking beam or signal, wherein said characteristics may include the beam coverage area on the RIS, coverage location, effective focal length, angle of incidence, and, in some cases, frequency or wavelength. In the disclosed embodiments, the redirection pattern is typically considered in the downlink direction, i.e., from the base station to the UE via a reconfigurable redirection device. The redirection pattern acts as the received beam in the uplink direction via reciprocity. In some cases, the redirection pattern may be considered in the uplink direction based on the reflection and / or deflection profile and the beam from the UE.

[0066] Throughout the disclosed embodiments, the "phase profile" will be understood as a matrix or other representation expressing the relationship between the physical location of a superatom on the RIS and the degree of phase delay or advance applied by that superatom to the incoming light, in order to achieve a desired reflection profile that induces the corresponding reorientation mode. The RIS controller can be configured to set and / or adjust the phase profile by controlling the superatom according to parameters given in the matrix.

[0067] For convenience, the manual typically describes operation based on phase profiles. While there is a close relationship between phase profiles and reflection profiles, it should be remembered that the phase profile required to implement a specific reflection profile is a function of the RIS implementation. In contrast, reflection profiles provide an implementation-independent description of the RIS configuration, which can be transferred to other RIS implementations, including the RIS implementation, based on different methods of implementing reflection profiles.

[0068] The phase profile can be a "spatially uniform" profile, where the relationship between the superatomic position and the phase delay is a linear function or a constant (i.e., a "linear phase profile"). By applying such a linear phase profile, where all elements apply the same phase shift, the RIS behaves like a plane mirror, which can tilt around an imaginary center point by changing the applied phase shift. In this way, the incident EM signal can be guided over a certain angular range.

[0069] Figure 7 An example of a spatially uniform phase profile for finding the strongest localization path (shortest path) from a terminal device to an access point (e.g., gNB) is illustrated schematically, as will be described in more detail later. Figure 7 The left portion of the diagram shows different spatial uniform phase profiles with different dashed line patterns in the x-axis direction relative to the reflection angle Φ from the RIS surface plane. Figure 7 The right side shows the beam (solid line) of the impact from the target UE on a certain x-coordinate of the RIS surface plane, and the resulting reflected beams with different reflection angles obtained from the phase profile (dashed line pattern corresponding to the spatial uniform phase profile).

[0070] In embodiments, the phase profile can be a “continuously nonlinear” profile, where the relationship between the superatomic position on the RIS and the assigned phase delay is a continuously nonlinear function. Using such a phase profile, the width of the reflected beam can be varied, thereby providing improved search capability and / or providing path gain on linear profiles. Examples of continuously nonlinear functions with maximum or minimum values ​​(including functions with a centrally symmetric point (or principal axis)) are quadratic functions, parabolic functions, etc. These can be used to enable the reflection of incident rays or beams into diverging or converging beams and to guide the beam in different directions.

[0071] As an example, the phase delay imparted by the radially symmetric phase profile can be given by the following formula:

[0072]

[0073] Where φ is the degree of phase delay (or advance), r is the distance from the defined center point, and k is a scaling constant, which is similar to the coordinates of the center point and can be regarded as a variable parameter.

[0074] Figure 8 An example of such a continuous nonlinear phase profile for positioning a terminal device relative to a centerline is illustrated schematically, as will be described in more detail later. Figure 8 The left portion of the diagram shows different parabolic continuous non-uniform phase profiles with different dashed patterns in the x-axis direction relative to the reflection angle Φ from the RIS surface plane. Figure 8 The right side shows two different examples: a beam (solid line) striking the RIS surface plane from a target UE at a certain x-coordinate, and the resulting reflected beams with different reflection angles obtained from the phase profile (corresponding to the dashed pattern of a continuous non-uniform phase profile). In the first example on the left, the target UE is located far from the vertical centerline of the RIS (dashed line), which results in a larger difference in deflection angle. In the second example on the right, the target UE is located near the vertical centerline of the RIS, which results in a smaller difference in deflection angle.

[0075] In other embodiments, the phase profile may be a “stacked linear phase” profile with discontinuities between two regions or segments of different linear functions or between a region or segment of a single linear function and some nonlinear or pseudo-random functions. By applying a stacked linear phase profile, sharp discontinuities in the reflection angle from the RIS can be applied to a signal arriving from a direction that may be known to the RIS controller and can be altered by changing the phase profile. The angle of arrival (AoA) can be estimated by detecting points where the signal experiences significant intensity changes. Additional advantages are gained if one of the regions or segments uses a nonlinear profile to allow for coarser or finer AoA estimation as part of the localization algorithm. The concept can be further extended by applying more than one discontinuity and applying discontinuities in two dimensions. Furthermore, the discontinuity is not limited to straight lines but can take the form of, for example, curves or line segments depending on the intended application. All of the above concepts should be understood to be covered by the term “stacked linear phase”.

[0076] It is evident that contours with other properties can be readily defined by extrapolation from the above definitions. For example, a class of nonlinear phase contours may include those using different functions on orthogonal axes, including functions that are asymmetric about the center point or linear on an orthogonal axis (cylindrical contours). Categories of stacked linear phase contours may include multiple discontinuous lines that do not require parallelism. Depending on the requirements of the target application, the region defined by the discontinuity can be linear, nonlinear, or (pseudo)random.

[0077] The aforementioned phase profile can be configured to have a "center point" or one or more "centerlines," as defined below:

[0078] For nonlinear phase profiles, the center point can be a stationary point (i.e., the maximum or minimum value) of the nonlinear function. This may or may not correspond to the geometric center of the RIS (or the region of the RIS) to which the phase profile is applied, and in some cases, it can be a point beyond the physical boundary of the RIS.

[0079] For stacked linear phase profiles, the centerline can be a discontinuity line between two linear regions (or a single linear region and a nonlinear region).

[0080] For a linear phase profile, the center point can be the point at the geometric center of the region on the RIS where the linear phase profile is applied, or the center line can be a line that intersects the geometric center.

[0081] Throughout the disclosed embodiments, the “phase profile design function” will be understood as a function for designing a phase profile that can design a suitable phase matrix, when implemented by a RIS, such that a specified reflection profile is applied to the incident beam (e.g., divergent reflection). Conceptually, a Phase Profile Design System (PPDS) transforms a desired reflection profile into a phase profile that can be implemented by a RIS. A reflection profile may include one or more functions and associated parameters. Similarly, a corresponding phase profile may also represent corresponding parameters, or a set of phase profiles may be created to match the parameters. Transformation can be performed using methods such as zero-forcing, minimum mean square error, etc. Machine learning methods (e.g., genetic algorithms or neural networks) can be used when a deterministic translation cannot be performed. Such methods can also be used to design or optimize reflection profiles for specific use cases.

[0082] There are several possible locations for PPDS. When PPDS is implemented by RIS, the base station and the RIS controller can exchange reflection profiles, and the corresponding phase profile implementation can be within the RIS. Otherwise, when PPDS is implemented in the base station or network, the RIS controller can report the RIS's hardware capabilities (such as RIS size and the number and spacing of superatoms) to the network entity (such as gNB) to implement an external design for a suitable phase profile. The RIS controller and the base station can then exchange phase profiles.

[0083] Several possible scenarios exist for defining reflection and phase profiles. The RIS can be pre-programmed with reflection and phase profiles during manufacturing, installation, or deployment, and can indicate available reflection profiles for the base station to choose from. Alternatively, the RIS can be pre-programmed with phase profiles during operation. When the base station requests a reflection profile, the RIS selects the phase profile that best corresponds to it (or, if no such phase profile is found within a specified error tolerance, it can indicate a fault). Alternatively, the RIS controller can indicate available phase profiles to the base station, and can perform the desired mapping between reflection and phase profiles on the network side. As another option, the base station or network can be pre-programmed with a set of reflection profiles that can be optimized for a specific use case and can be converted into phase profiles by the PPDS (e.g., in a one-time step). If needed, reflection profile parameters can change dynamically as the corresponding phase profile parameters transmitted to the RIS controller change. Alternatively, reflection profiles can be dynamically created by the base station or RIS controller in response to positioning measurements and feedback from the target UE. The PPDS maps these to phase profiles directly implemented by the RIS controller.

[0084] Throughout the disclosed embodiments, a “Network Control Repeater” (NCR) will be understood as a network element under the control of a base station that amplifies and relays transmissions between the base station and the UE. A multi-element antenna array (referred to as an “access link”) provided at the NCR (e.g., adapted to the NCR) to handle the link between the NCR and the UE can be configured with a beam profile that matches the effect of a RIS reflection profile and allows the NCR to be used as an alternative to the RIS. The NCR can be designed not only to amplify / repeat / redirect the beam from the access device or terminal device (e.g., directed to the NCR), but also to amplify / repeat / redirect signals that can have an omnidirectional propagation path (e.g., transmitted using an omnidirectional antenna).

[0085] Throughout the disclosed embodiments, the “location function” will be understood as a function for calculating the location of a target UE (or RIS during an optional setup phase) based on measurements taken by nodes involved in the location process. These may include gNB, RIS, the target UE, and may also include third-party nodes arranged to measure their own location signals. The location function may include known algorithms, including those based on arrival or departure angles (AoA or AoD) and timing (such as time of arrival (ToA), time difference of arrival (TDoA), etc.), and those with specific modifications (described later) to optimally utilize the non-uniform phase profile applied by the RIS (“shown”). The location function may be provided in the network, in the UE, or in some cases in a third-party device. The locations of fixed nodes (such as gNB, RIS, and other available third-party nodes) may be known a priori and stored in a location database configured to be accessible by the location function.

[0086] Throughout the disclosed embodiments, "target device" will be understood as a device whose location or location will be determined, such as a 5G UE or other mobile device.

[0087] Note that throughout this disclosure, only those blocks, components, and / or devices related to the proposed data distribution function are shown in the accompanying drawings. Other boxes have been omitted for brevity. Furthermore, boxes designated by the same reference numerals are intended to have the same or at least similar functions, so their functions will not be described further later.

[0088] The following embodiments allow for enhanced network control for wireless communications involving at least one access point / device (e.g., a base station (BS)), at least one reconfigurable reflective device (e.g., a RIS), and at least one terminal device (e.g., a UE).

[0089] More specifically, RIS are seamlessly integrated into the 5G network, for example, by a BS (e.g., a gNB in ​​5G terminology) via a transport database that maintains a local area (which may include both buildings and objects). The transport database may include all known RIS and their properties (including the means by which RIS operate and control them). The resulting 3D radio propagation model can be used, along with some limited local searches, to select communication channels that include the BS beam direction and the state of the RIS controlled by the network and / or the BS.

[0090] The 3GPP specification TR 38.867 for 5G Release 18 defines the Network Control Repeater (NCR), which allows for extensive control over the behavior of the NCR by the base station. Specifically, it allows the base station to control the antenna beamforming of the NCR (“access channel”) on the UE side. This functionality allows the base station to adjust the beam direction and beamwidth of the NCR to optimize the link between the NCR and the UE. Since modern antenna panels can support arrays of tens or hundreds of antenna elements, the NCR access channel can be configured with a beam profile that mimics, operates as, or creates the RIS nonlinear phase profile described in the following embodiments.

[0091] Therefore, the described embodiments can be implemented instead of the RIS using an NCR that includes such an antenna array. Therefore, for the purposes of this disclosure, the term "reflection profile" should be understood to include the NCR beam profile. Therefore, for the purposes of this disclosure, the term Reconfigurable Redirecting Device (RRD) is used where a RIS or NCR can be deployed.

[0092] The transport database can be enhanced by automatically discovering user-installed RIS (metasurfaces) within the coverage area. RIS can be automatically discovered based on unexpected measured signal strength between the BS and UE (or between two or more BSs), where such strength would not be expected based on previous iterations of the transport database (e.g., 3D area maps) and the location reported and / or estimated by the UE. This can be marked as reconfigurable if the surface's properties are allowed to differ at different times. When a BS suspects that a new RIS may have been discovered, it can look up the surface and its properties (and possible usage prices) in the registration database, and if found there, the BS can (e.g., request control capabilities from the RIS owner) and integrate it (along with its properties and control) into the 3D transport database (e.g., an updated 3D area map). RIS can also be discovered if the RIS controller has, for example, communication capabilities registered with the network.

[0093] During use, the BS can perform analyses of the desired communication, the user's location, and / or predictions from its 3D radio propagation model. The BS can then use its beamforming capabilities and, under its control, actively switch the behavior of the RIS (e.g., phase profile) to maximize communication quality and / or throughput while minimizing the transmission power level.

[0094] Figure 1 The general architecture of an RRD sensing and positioning system according to various embodiments is illustrated schematically.

[0095] The reconfigurable redirection device (RRD) 10 includes a reconfigurable smart surface (RIS) or a network control repeater (NCR). Control and network communication of the reconfigurable redirection device 10 are handled by an RRD controller (RRD-CTRL) 110, which may include standardized communication hardware (e.g., the controller may act as a UE on a 5G network) for receiving control commands from the network or for bidirectional communication with the network, local processing, and memory hardware. Furthermore, the reconfigurable redirection device 10 includes a superatom (MA) 120 for controlling the reflection and / or refraction of the incident beam or light.

[0096] For the following combination Figures 2 to 6 The described method requires RRD metadata, which may include the RRD location, RIS direction or NCR access antenna direction, and (optionally) the straight-line distance to at least one access point (e.g., base station (BS) 20), which may alternatively be calculated based on the RRD and BS locations. This metadata 120 may be manually entered by the installer during RRD 10 installation, or discovered during a one-time setup phase using known positioning techniques after RRD 10 installation, to allow BS 20 to locate RRD 10.

[0097] The BS 20 (e.g., gNB) is configured to support network communications and perform local computing tasks. In addition to its normal functions, the BS 20 includes or is able to access the UE location database (UEL-DB) 210 and / or the RRD location database (RDL-DB) 220, which store the orientation / location of the mobile device (UE) and the RRD, respectively.

[0098] One or more mobile devices (e.g., mobile terminals or UEs) 30 include the necessary antennas and / or other components for communicating via a communication network such as a 5G system. The UE 30 may include one or more antennas and may or may not be capable of beamforming. In an embodiment, at least one UE is a target UE, and one or more UEs may provide access to the BS 20 to other UEs. In out-of-coverage scenarios, the role of the BS 20 and the network for positioning purposes may be performed by another UE referred to as the anchor UE.

[0099] In addition, the RRD sensing positioning system includes a positioning function (LF) 40 as described above, a phase profile design system (PPDS) 60 for providing non-uniform reflection / refractive profiles (such as nonlinear phase profiles (NL-PP) 610 and / or stacked linear phase profiles (SL-PP) 620 as described above), and a phase profile database (PP-DB) 50 in which the phase profiles of the RRD can be stored.

[0100] exist Figure 14 In the schematically illustrated basic arrangement, the base station (BS) and the target UE (T-UE) are separated by a first distance (D1). The RRD is located at a second distance (D2) from the base station and a third distance (D3) from the target UE, with sufficient angular spacing to allow the base station to distinguish between direct beams to / from the target UE and beams reflected via the RRD. The locations of the base station and the RRD are known and stored in the location database 220, such that the length of the second distance is known, and the line between the base station and the RRD can be used as a baseline for further measurements.

[0101] The proposed positioning method aims to determine at least the third distance and azimuth angle between the base station and the UE facing each other at the RRD, and, if necessary, the elevation angle and a reference line such as the horizon facing the target UE facing the RRD. In the embodiments below, a method for determining the azimuth angle is disclosed. The third distance can be obtained directly via the time of flight between the RRD and the target UE or a similar method, or indirectly by measuring the angle between the RRD and the target UE facing each other at the base station, by performing, for example, a ToF measurement between the base station and the target UE, or by changing the focal length or equivalent of the RRD beam facing the target UE, to maximize signal strength. The target UE can perform a received signal strength (RSS) measurement per beam index (e.g., synchronization signal block (SSB)) and report, for example, the RSS per SSB to the base station or network, and / or can perform other measurements (e.g., AoA, TDOA, time of arrival) and report these measurements to the base station or network. Furthermore, the RRD can perform measurements such as signal strength (e.g., RSS per beam), signal departure time (after redirection / reflection) and / or signal arrival time, RRD state information (e.g., which phase profile has been applied, angle information, state / or orientation of RIS atoms or NCR antenna array elements), timing information (e.g., timing advance compared to gNB timing), and can report these measurements to the base station or network. The base station can use the received measurements to adjust the beam control of the RRD (e.g., by adjusting the phase profile or changing the state of the RRD or its atoms / elements), and / or the positioning function 40 can use the received measurements to determine the angle and / or distance between the base station and / or the RRD and / or the target UE.

[0102] Other measurements can be performed with the help of other UEs, RRDs, and base stations to reduce uncertainty and eliminate ambiguity.

[0103] In a favorable arrangement, the RRD is located relatively close to the target UE. For example, the target UE and the RRD can be located within 5 to 10 meters of each other and approximately 50 to 100 meters from the base station. In this arrangement, the signal from the base station can be considered as arriving as an approximately parallel beam, such as... Figure 12 and Figure 13 It is shown schematically in the diagram.

[0104] Figure 10 The diagram schematically illustrates how a non-parallel ray emitted from an object (O) is reflected from a convex mirror (CM) at the principal focal point (F) and principal axis (Ax). The principal focal point is located where a ray or beam parallel to the principal axis appears to intersect the principal axis behind the mirror. This parallel ray or beam reflected by the convex mirror can be projected behind the mirror. The non-parallel ray or beam is reflected such that the angle of reflection relative to the normal to the surface of the convex mirror is equal to the angle of incidence relative to the normal.

[0105] During a search operation, RRD can be configured to simulate, for example... Figure 12 The convex spherical mirror shown causes the incident parallel beam (solid arrow) from the base station to be reflected as diverging beams in different directions (dashed arrows) based on the focal point (F) and depending on the position of the center of curvature (C).

[0106] In normal operation, the RRD can be configured as a concave spherical mirror, such as... Figure 13 As shown, the reflected beam is focused onto the target UE at any position (dashed arrow), and guidance is achieved again by changing the position of the curvature center (C).

[0107] Significant gains can be achieved compared to the “abnormal specular reflection” method, in which the RRD is arranged as a plane mirror with an anomalous reflection angle.

[0108] Although Figure 12 and Figure 13 The example presents a spherical profile, but other profiles, such as parabolic or offset parabolic, can be used.

[0109] Other geometries can be used for positioning purposes, which may affect the achievable accuracy. Specifically, similar channel gain can be achieved when the RRD is located relatively close to the base station rather than the UE, this time treating the beam from the UE as a parallel beam and focusing it on the base station. The additional length of the third distance may result in a loss of accuracy for positioning purposes, but leads to sufficiently accurate beam steering for channel gain.

[0110] Figure 2 The illustration schematically shows the use of non-uniform reflection profiles to describe the application. Figure 1 The flowchart shows the process of RIS-aware localization with enhanced localization in the presence of RRD10.

[0111] RRD controller 110, target UE 30, and BS 20 are configured to transmit data via control plane data (CP-D) of a network system (e.g., a 5G system). Additionally, target UE 30 sends uplink pilot signals (UL-PL) or other beacons to RRD 10. The reflection or refraction characteristics of RRD 10 are controlled by RRD controller 110 by setting a corresponding phase delay (PD) at superatom 120 based on a suitable phase profile (PP) retrieved from phase profile database 50.

[0112] The resulting reflected / refracted pilot signal (R-PL) is received by base station 20 from RRD 10. Additionally, the current phase profile (e.g., retrieved from phase profile database 50) is transmitted from RRD controller 110 to base station 20. At least one of the signal strength (SS), timing (T), and phase profile (PP) data is compared with RRD location and orientation data (L) retrieved from RRD location database 220. RIS O RIS The information is forwarded from base station 20 to positioning algorithm 40. Based on the received information, positioning function 40 calculates the location (L) of target UE 30. UE ).

[0113] The proposed enhanced positioning can be used to extend existing positioning methods by providing additional information about the location of the target node, and is therefore generally applicable to methods used in 3GPP 4G, 5G, 6G, and other wireless standards. In this embodiment, a 5G system is assumed, where the target UE is connected to the 5G network via a gNB acting as a base station. It is assumed that the base station can guide a beam substantially toward the RRD or the target UE, such that reception of the beam by another device is negligible.

[0114] In this embodiment, the ability of RRD 10 to provide a non-uniform phase profile is utilized to alter how the RF signal is reflected and thereby improve the quality of position estimation. Alternatively, NCR can be configured with an equivalent beam profile at RRD 10.

[0115] The following embodiments can be implemented based on different UE capabilities and different use case scenarios. These may involve at least one of the following different types of non-uniform profiles: 1. Use non-linear profiles for positioning with RRD; 2. Use UE beamforming for positioning near the large RIS; 3. Positioning without UE beamforming; 4. Use stacked linear contours for RIS positioning; and 5. Use null-valued imported references for RIS positioning.

[0116] Figure 3A flowchart illustrating the common initial part of the RRD sensing and localization process according to various embodiments is shown schematically.

[0117] For all embodiments, there are some common startup steps:

[0118] In the initial step S301, before using the positioning system, a set of reflection profiles and / or corresponding phase profiles (PPs) to be configured at the RIS / NCR can be created. RIS This information is stored (e.g., by a phase profile design system) in a phase profile database. Optionally, the phase profile design system can operate dynamically during the use of the positioning system.

[0119] Then, in an optional or alternative step S302, the one-time setup phase (RIS-SU) can be run on the RIS / NCR installer to find parameters including location, angle, and distance to the base station. Alternatively, such data can be manually entered by the RIS / NCR installer.

[0120] In step S303, the target UE is near the RIS / NCR and initiates a location request (L-REQ). The location step can be initiated by the target UE or a base station (e.g., gNB) to which the target UE is connected and which wants to obtain the location of the target UE, or by a location function (LF), such as based on an application or service request received via / from another network service (e.g., Network Open Function (NEF) or Gateway Mobility Center (GMLC)).

[0121] The base station determines that the target UE is near the RIS / NCR with suitable phase profile capability and a suitable RRD controller. If not already established, the base station can initiate contact with the RRD controller. More specifically, the target UE or the base station can determine that it (i.e., the UE or the base station) is near the RIS / NCR by at least one of the following options:

[0122] i. Approximate positioning techniques (such as Received Signal Strength (RSS) or cell-based positioning) or non-network-based positioning (such as Global Navigation Satellite System (GNSS)) that allow prior location knowledge;

[0123] ii. The target UE or RRD controller receives a signal with a signal strength higher than a threshold from the RRD controller or the target UE;

[0124] iii. The base station is able to send signals to or receive signals from the target UE in the direction of RIS / NCR, especially when the direction is inconsistent with the approximate location determined for the target UE;

[0125] iv. Received signal strength and quality are functions of the RIS / NCR state; and

[0126] v. When the RRD is in different states, the base station detects significant changes in the received signal strength of the signal from the target UE.

[0127] In addition, in some cases, the base station or the target UE may assume that the target UE is always near the RIS / NCR (e.g., where the target UE is industrial equipment in a factory or other building containing the RIS / NCR, and it never leaves the factory / building).

[0128] In the example, RIS / NCR can be directly controlled by the base station using a control plane link, or it can be controlled locally via an RRD controller.

[0129] In step S304, the type and / or capability (UE-C) of the UE can be transmitted to the entity performing logical control (e.g., base station or RRD controller).

[0130] Finally, in step S305, the base station or RRD controller selects an appropriate embodiment (E1 / E2 / E3) from the embodiments described below based on the UE's type and capabilities (e.g., beamforming capability and broadband vs. narrowband communication capability and / or desired use case). The base station or LF can then calculate the approximate location of the target UE and determine the nearest RIS / NCR. Alternatively, the target UE can identify the appropriate RIS / NCR itself and notify the base station.

[0131] In the following text, see references Figures 4 to 6 Available embodiments for selection in step S305 are described.

[0132] The embodiments include: embodiments for target UEs capable of beamforming and suitable for UEs capable of broadband communication (because they depend on timing); embodiments suitable for target UEs without beamforming but still suitable for broadband communication (again due to timing measurement); embodiments suitable for broadband or narrowband target UEs regardless of whether they are capable of beamforming (however, the position accuracy is related to the physical size of RIS / NCR); and embodiments using nulls to provide accurate angle measurements based on the trend that the null value of the antenna radiation pattern is narrower than the main lobe.

[0133] The embodiments described below assume that the RIS / NCR is relatively close to the target UE and relatively far from the base station, such that the beam from the base station to the RIS / NCR can be considered as a parallel beam. In this configuration, the path from the base station to the RIS / NCR is similar to the backhaul path from the base station to the RIS / NCR.

[0134] For simplicity, the following embodiments assume RIS; however, it should be understood that in practice, NCR can operate in a similar manner in terms of beamforming capabilities. Other geometric arrangements are also possible and are not excluded from the embodiments below.

[0135] Figure 4 A flowchart illustrating a subsequent single part of the RIS-aware uplink localization process with terminal beamforming according to the first embodiment is shown schematically.

[0136] In this embodiment, the RIS application has a nonlinear profile with a known principal axis or center of curvature or other reference point, which extends the incident parallel beam from the base station (e.g., gNB) over a wide angle sufficient to capture signals from the target UE. The width and direction of the reflected beam can be controlled by changing parameters. For example, if the RIS is arranged to simulate (operate / use as, create) a spherical reflector, the width of the reflected beam can be controlled by changing the focal length (e.g., by changing the parameter k), and the beam can be guided by changing the x and y coordinates of the position of the center of curvature in the plane of the RIS surface when projected along the z-axis (perpendicular to the RIS surface) onto the plane of the RIS surface. Modeling the profile of a convex spherical reflector will produce a diverging beam (see...). Figure 12 Modeling the contour of a concave spherical reflector will produce a converging beam (see...). Figure 13 The converging beam will bring the impact beam to the focal point. In between, the planar profile will allow the RIS to behave as a guided specular mirror.

[0137] The RIS can also be arranged to behave as an aspherical reflector (e.g., to display a parabolic profile) or a reflector with deformable or other asymmetrical profiles, while retaining the ability to change the beamwidth and orientation. Such a profile can also present other adjustable parameters. For example, a parabolic profile can also allow the orientation of the principal axis to be adjusted away from the z-axis.

[0138] Practical implementations can support discrete rather than continuous settings. Such implementations can implement changes in guidance and / or focus by altering the phase profile. Parameters k, x, and y can be varied from a simple list or alternatively from a parameter or measurement derived from the use case (e.g., they can vary depending on the frequency of the signaling used).

[0139] In step S401, uplink positioning (UL-L) is used, where the target UE to be located transmits a pilot signal or other signal that can be beamformed toward the RIS and reflected by the RIS toward the base station. Using feedback from the base station, the RIS can apply a series of nonlinear profiles, each guided to maximize the received signal strength (RSS) at the base station. Once the azimuth of the target UE relative to the RIS has been determined with sufficient accuracy, the distance between the RIS and the target UE (D(UE-RIS)) can be determined in step S402. Alternatively, the target UE can send a measurement report to the base station via the RIS or through a direct communication path between the target UE and the base station. In this case, using feedback from the base station, the RIS can apply a series of nonlinear profiles, each guided to maximize the received signal strength (RSS) at the target UE. Once the azimuth of the target UE relative to the RIS has been determined with sufficient accuracy, the distance between the RIS and the target UE (D(UE-RIS)) can be determined in step S402.

[0140] In the example, the azimuth search process can be performed as follows:

[0141] The positioning function determines the range of azimuth angles for guiding the search beam. It can use auxiliary information that gives the approximate location of the target UE to limit the required search range.

[0142] The positioning function, via the base station, instructs the RIS application to have a wide-beam nonlinear phase profile and guides it within the azimuth range, aiming to maximize the received signal strength (RSS) at the base station and / or the target UE.

[0143] The base station accurately tracks RSS measurements over time, and thus tracks RSS measurements over azimuth angle, and reports the results to the positioning function. Similarly, the target UE can accurately track RSS measurements over time, and thus track RSS measurements over azimuth angle, and can report the results to the base station and / or the positioning function.

[0144] The positioning algorithm correlates the RSS value with the phase profile or azimuth angle by matching the receiving timing with the timing used for the phase profile at the RIS.

[0145] Based on the RSS measurement, the positioning function determines the second azimuth range to be scanned, corresponding to, for example, a 3 dB point that defines the maximum RSS range.

[0146] Then, the positioning function selects a second phase profile with a narrower beam and guides it within a second angle range, aiming again to maximize the received signal strength at the base station and / or the target UE.

[0147] Repeat this process until the narrowest beamwidth has been used or the positioning function has obtained a result with sufficient accuracy.

[0148] In this step, the positioning algorithm can strictly use the first arrival signal for its calculations.

[0149] If the phase profile is frequency-dependent, such that the precise values ​​of parameters k, x, and y vary with frequency, then an embodiment allows the UE or base station to transmit on multiple frequencies simultaneously, each dispersed by a different amount. The base station, targeting the UE separately, can then determine the strongest frequency, thereby determining the correct azimuth angle without explicit guidance operations. This can be advantageous in terms of processing time if suitable RIS hardware is available.

[0150] The subsequent determination of the distance corresponding to the shortest path between the target UE and the RIS in step S402 can be based on timing or angle measurements. (To be continued later...) Figure 6 The latter is described in the embodiments. Some exemplary timing-based methods are described below:

[0151] It can measure the Time-of-Flight (ToF) of the signal on the strongest path from the target UE to the base station via the RIS or vice versa, and subtract the known path length from the RIS to the base station from the result.

[0152] If there is good synchronization between the target UE and the base station, the base station can report the ToA of the path with the highest RSS to the positioning function in step S403. The UE reports the departure time (ToD) so that ToF can be calculated as the difference between ToD and ToA. Alternatively, the base station can report ToD to the positioning function, and the target UE can report the ToA of the path with the highest RSS to the positioning function.

[0153] When good synchronization is unavailable, a two-way ranging method between the UE and the base station may be appropriate.

[0154] When multiple signals are encountered at the RIS, it can be assumed that the signal with the shortest path delay is the most direct path between the RIS and the target UE. Therefore, performing Time-of-Flight (ToF) measurements during angle search may be valuable.

[0155] If a direct path exists between the base station and the target UE, the base station can use signals from the target UE to determine the angular distance between itself and the RIS. Alternatively or additionally, the base station can perform a ToF measurement directly with the target UE to determine the distance between itself and the target UE. Knowing at least any three of the two distances BS-RIS and BS-UE, and the two angles BS-RIS-UE and RIS-BS-UE, the positioning function can calculate the distance between the RIS and the target UE.

[0156] Auxiliary information from other nodes that receive signals from the target UE can also be used to help locate it.

[0157] With the target UE located to optimize the BS-RIS-UE path, the aforementioned azimuth search process can be extended by including a convergence profile that reflects the beam from the base station onto the focal point. The base station then adjusts the focal length for maximum RSS (e.g., by changing the aforementioned parameter k). If necessary, the beam azimuth can be adjusted as part of an iterative process to find the optimal channel.

[0158] In cases where the base station can resolve multiple instances of a signal from a target UE (e.g., when multiple peaks in the RSS are detected due to multipath signals arriving at the base station via a strong static reflector or a strong line-of-sight (LoS) path), the RIS or the base station can attempt to resolve the ambiguity by alternating between two (or more) different phase profiles at a known time, one being the signal with the maximized RSS and the other a signal with a known lower RSS at the base station. The base station can then identify a set of received (pilot) signals in the time domain whose intensity and ToA vary synchronously with the changes in the RIS phase profile, and can infer that this corresponds to a signal arriving via a reflection path from the RIS. The signal from this set with the highest RSS can then be identified as the initial signal of interest for ranging.

[0159] Optionally, in step S404, if ambiguity exists (e.g., due to multipath reception), the RIS can change its phase profile (CH(P)) to identify the signal reflected at the RIS in the ToA domain (because it will be the signal whose RSS changes along with the RIS state). The decrease in RSS when the RIS applies a series of altered linear phase profiles can also be used as a calibration check to find out whether the RSS decreases faster or slower than in the linear case (e.g.).

[0160] In step S405, the obtained range (distance) data can be stored in the UE location database.

[0161] Then, in step S406, the RIS can apply several divergent phase profiles, and the base station and / or the target UE can measure the RSS. By reducing the RSS relative to the base station and / or the target UE for each phase profile, the base station or LF (e.g., based on measurements received from the base station and / or the target UE) can calculate the UE angle with respect to the RIS.

[0162] More specifically, when a beamforming UE is relatively close to a “large” RIS, it can selectively illuminate different portions of the RIS surface. Information about which portion of the RIS is illuminated can be valuable when seeking to refine measurements or further optimize the UE’s beam.

[0163] The gain of the propagation path between the RIS and the UE will be the product of the beams of the RIS and the UE. In principle, the direction of the UE beam can be determined by considering the rate of change (decrease) of the RSS at the base station during the application of various nonlinear phase profiles, and thus the point where it strikes the RIS surface. Using this information, the localization function calculates the distance from the signal from the UE to the center point of the RIS.

[0164] For example, if the decrease in RSS decreases relatively slowly with the change in azimuth and is symmetrical about the maximum RSS point, the positioning function can determine that the UE signal is closer to the center point impact. Conversely, if it changes more rapidly and asymmetrically about the maximum RSS point, the positioning function can determine that the signal is farther from the center point impact. In this way, the positioning function can estimate the UE's beam angle.

[0165] The precise point distance can be estimated by comparing the trend of the RSS with the equation used to generate the phase profile and (if available) the characteristics of the beam used by the UE.

[0166] Similar considerations apply to beams received from base stations.

[0167] In step S407, the distance data (RD) and angle data (AD) are used to calculate the position of the target UE.

[0168] For better communication, the UE beam and the RIS reflected beam should be aligned; that is, the centerlines of the two beams should be the same. To correct for errors, the positioning function can allow the UE to update its beam to align it in the direction of the RIS's center point. Optionally, the RIS can also move the center point of its phase profile to match the impact point of the UE beam.

[0169] This may be beneficial for further refining angle estimation and, in specific scenarios (e.g., locating UEs with very large RIS by maintaining an operating mode in which the phase profile is not too strongly divergent in the region close to the UE direction, so that the RSS at the base station is maintained at the desired level).

[0170] In this case, the center point location and the phase profile applied at each time step are transmitted to the localization algorithm.

[0171] In a variant of this embodiment, if the RIS presents a “large” signal to the receiver (i.e., the receiver beamwidth at the RIS is smaller than the effective surface area of ​​the RIS), beam steering can be shared between the receiver-to-RIS beam and the beam deflected by the RIS.

[0172] The RIS can perform "coarse" guidance, while the receiver performs "fine" guidance, and vice versa.

[0173] The RIS can employ segmented contours, and the receiver can choose which "side" to use (this can also depend on the "side" of the RIS where the base station is located).

[0174] Figure 11 Different phase profiles 1 to 3 and the corresponding rates of change of the deflection angle are schematically shown. Figure 11 In the diagram, phase profiles 1 through 3 are exaggerated and deviated from the surface of the RIS. In reality, they would be positioned on the surface of the RIS. Furthermore, the linear offset (LOS) between each of phase profiles 1 through 3 does not exist. This LOS is provided merely for better understanding the teachings of the diagram.

[0175] The numbers in the rectangular box indicate UE locations (UEL) 1 to 3, where the solid line from the UE location to the phase profile or RIS indicates the shortest path (SP) between the RIS and the corresponding UE, which can be initially determined as described above, thereby removing the AoA uncertainty at the RIS before subsequently measuring the distance on the shortest path.

[0176] The UE can be in position 1 or 2, but should not move during the measurement. For a UE in position 3, the RIS principal axis will need to be moved toward the UE, or the phase profile will need to be changed to allow for proper reflection.

[0177] By measuring the rate of change of RSS at the base station (e.g., gNB) and / or the target UE as the RIS changes through phase profiles 1 to 3, the base station can calculate the distance of the UE from the main axis (i.e., the position along line AB within the field of view of the RIS).

[0178] As determined by the continuous nonlinear phase profiles 1 to 3, the rate of change (NC) of the reflection angle is smaller when switching between different phase profiles 1 to 3, where the shortest path between the UE and the RIS approaches the principal axis (Ax), compared to UE position 2 where the shortest path is closest to the edge of the RIS. This is given in UE position 1.

[0179] Figure 5 A flowchart illustrating a subsequent single part of the RIS-aware uplink localization process without terminal beamforming according to the second embodiment is shown schematically.

[0180] In cases where there is insufficient UE beamforming (where the adequacy of UE beamforming may depend on whether the RIS is "large" for the UE), additional steps can be taken to refine the measurement of the path length from the UE to the RIS. In this scenario, which can be addressed alternatively through angle measurement, refer to... Figure 6 The described embodiments may optionally replace the following steps to calculate the UE-RIS range.

[0181] In step S501, the RIS applies a hybrid phase profile (MP-P) with a small beamforming region, which attempts to maximize the RSS at the base station surrounded by a highly divergent region. Therefore, the RIS attempts to approximate the UE by using a stacked linear phase profile, which consists of the minimum feasible region of the linear phase profile at the center point, surrounded by a highly divergent (or even randomly oriented) phase profile.

[0182] Therefore, a scenario is created in which (pilot) signals from the UE are received only by the base station (or signals from the base station are received only by the UE) when they are reflected from a small area in the RIS at a known location corresponding to a reference point used for distance measurement, or when an area corresponding to the shortest ToA is determined, which can then be identified as the approximate origin of the shortest path from the target UE to the RIS.

[0183] In step S502, the (pilot) signal from the target UE at the base station is primarily received from the signal path on the RIS impacting the beamforming region. This region moves around the RIS to determine the location of the signal impact from the target UE with the shortest ToA (ToAmin) via ToA measurement at the base station. Similarly, the signal from the base station at the target UE can be primarily received from the signal path on the RIS impacting the beamforming region. This region moves around the RIS to determine the location of the signal impact from the base station with the shortest ToA (ToAmin) via ToA measurement at the target UE.

[0184] As already mentioned, an example of a suitable phase profile may include a small region of a linear phase profile surrounded by a random phase profile. The size of the small region can be determined by the number of superatoms required to ensure good reception of the signal, and will therefore be implementation-dependent (but can be defined for the specific RIS at the time of manufacture).

[0185] ToF can be measured using feedback from the base station combined with the known center point location on the RIS of the current application's phase profile, as in the first embodiment above.

[0186] Phase profiles with different center points can be applied by RIS covering the entire surface region until ToF is minimized.

[0187] In step S503, given the approximate location of the signal with the shortest ToF from the UE on the RIS, the range or distance (R(RIS-UE)) between the target UE and the RIS can be determined using the previously described technique, where the known distance between the base station and the origin of the RIS beam is used to eliminate this portion of the propagation delay.

[0188] Alternatively, the beam reflected from the center point region can be guided to optimize the RSS at the base station or the target UE. The Time of Flight (ToF) can then be measured using the previously described techniques, and the distance from the target UE to the RIS center point can be determined by subtracting the known distance between the base station and the RIS center point.

[0189] Finally, in step S504, the distance or range between the target UE and the RIS can be stored in the UE location database, and the process can continue. Figure 4 Steps S406 and S407 determine the angle data used for position calculation.

[0190] Several methods for angle-based localization are expected to be enhanced by using stacked linear phase profiles.

[0191] In the third embodiment described below, the stacked linear phase profile essentially allows the RIS to simulate two RIS with a spatial offset between them, and thus performs known positioning techniques applicable to both RIS, but with the advantage of requiring only one RIS. Advantages of the third embodiment include the elimination of the need for broadband signaling or beamforming from the UE.

[0192] Figure 6 A flowchart illustrating a subsequent single part of the downlink localization process based on RIS sensing angle according to the third embodiment is shown schematically.

[0193] In step S601, downlink positioning (DL-L) can be used, and the base station (e.g., gNB) or an external static UE using device-to-device (D2D) communication transmits a pilot signal reflected by RIS (which may be omnidirectional or beamforming).

[0194] In step S602, RIS applies stacked linear phase profiles (SL-P) with known center points and deflection angles. Examples of suitable phase profiles may include two linear phase profiles with known center points but different deflection angles.

[0195] Figure 9 Three different stacked linear phase profiles are schematically shown for providing a movable centerline. Figure 9 The left side of the diagram shows a two-dimensional plot of the deflection angle Φ on the x-axis for three different profiles. Figure 9 The right side shows the resulting shift of the centerline, which can therefore be matched with obstacles, etc.

[0196] In step S603, the receiver (i.e., the target UE for uplink positioning or the base station for downlink positioning) reports the received RSS. The RIS can be configured to modify the deflection angle of one of the linear regions while keeping the other static, in an attempt to maximize the reported RSS.

[0197] Alternatively, the phase profile can consist of a single linear region that is separated from the region of highly divergent or pseudo-random phase at its center point.

[0198] In both cases, the effect of the phase profile means that the RSS optimization in step S603 is applied only to the signal hitting the RIS within the (optimizable) linear region, and not elsewhere.

[0199] In step S604, the RIS applies another (modified) stacked linear phase profile (CH(SL-P)), where the linear region causes a different deflection angle, and the receiver again reports the received signal strength (RSS) to the RIS. The modified stacked linear phase profile can be similar to the first step, but with a modified deflection angle within the linear phase profile region.

[0200] In step S605, previous steps S601 to S604 are iterated until the deflection angle corresponding to the strongest RSS from a first linear phase profile region with a fixed center point is found. Then, the steps and iterations are repeated again, but using a linear phase profile region with a second center point, such that the angle corresponding to the strongest RSS at the UE is found from at least two separate regions of the RIS with a known center point.

[0201] The center points to be used can be chosen as far away as possible from the RIS surface, with the constraint that the corresponding region still contains enough superatoms to support the display of a robust linear phase profile. The number of superatoms required, and therefore the maximum spacing of the center points, depends on the specific RIS hardware and is taken into account by the phase profile design system. It should be noted that this differs from techniques that use a single RIS to combine phase profiles to induce multiple simultaneous deflection angles, because here the two deflection angles are constrained to originate from regions on the RIS that are offset by a known amount in space along the RIS surface.

[0202] In step S606, the two half-lines corresponding to the two angles from different center points on the RIS that result in the maximum RSS at the UE (as determined in step S605) intersect to find the position (L) of the UE in two-dimensional (2D) space. UE-2D ), which is stored in the UE location database.

[0203] Optionally, in step S607, the entire process of steps S601 to S606 can be repeated on the orthogonal axis to find the position (L) of the UE in three-dimensional (3D) space. UE-3D ).

[0204] Optional additional steps or modifications to the third embodiment may include:

[0205] In step S601, the UE to be localized is used as both a transmitter and receiver of the pilot signal. This enables the UE to perform self-localization using RIS.

[0206] The RIS uses prior settings (e.g., using a UE with a well-known ground location) to associate a given phase profile applied by the RIS with some known geographic location (e.g., inside a room). This allows the RIS to continuously apply phase profiles that result in predictable differences in signal strength within certain areas of the room. An example of such a phase profile could be a stacked linear phase profile where the difference in deflection angle between two linear regions is very small. This can result in a narrow region in the space from which reflected signals are received from the two linear regions, and thus be maximized.

[0207] The center point and deflection angle of the linear region can be correlated with the desired boundary using feedback from the installer during the installation phase. Therefore, the UE can easily determine whether it is close to (or has crossed) a boundary without actually acquiring its position (and thus expected to be faster than full localization).

[0208] In a fourth embodiment, a null-based RIS is provided, such that the RIS's directional pattern has a null value (zero reflection) in at least one specific direction. In this embodiment, the ability of the RIS to reflect the incident beam into two or more paths is utilized. In the basic example, the RIS can be configured to reflect the beam in two directions, creating a null value (zero reflection) between the two beams. During the azimuth search process, the beam is guided on the target UE, where the base station seeks a minimum signal point representing the angle at which the null value directly points to the target UE.

[0209] The initial beam can be wide to ensure that any decrease in signal strength is due to null values ​​in one of the beams rather than edges. The width and depth of the null values ​​are functions of the beamwidth and angular beam divergence. These can be varied for subsequent azimuth searches to create narrower null values ​​and more accurate detection results.

[0210] The following variations can be applied to all of the above embodiments:

[0211] The RRD controller can communicate not only with the BS (e.g., gNB), but also, in some scenarios, with the target UE, either alternatively or additionally.

[0212] In scenarios where the network (and thus the BS (e.g., gNB)) is inaccessible, the second UE may act as both the BS and the network for location / location purposes.

[0213] The positioning function can be tuned and take into account additional positioning / location information provided from or via other UEs, RRDs or other components.

[0214] The location signal is described as being transmitted by the target UE and received by the BS (e.g., gNB). The target UE may also receive signals transmitted by the BS. Taking into account auxiliary information provided by the BS or known to the target UE, the target UE can then make its own assessment of its location. Alternatively, it can report the signals it has received to the BS, and the BS will then perform location calculations.

[0215] The signals used for positioning / location can be purposefully designed or intended for other purposes. In some cases, specially designed signals can exhibit certain characteristics that are advantageous for certain positioning methods.

[0216] RRDs can be shared between location / location operations and other services (e.g., normal data transmission) at least on a time-division basis. If an RRD has this capability, it can also be shared on a spatial or frequency-division basis.

[0217] The target UE can use beamforming to further enhance positioning performance. Assume that the beam training required for UE-RRD beamforming is handled separately, for example, using known conventional techniques.

[0218] In summary, a system and method have been described in which at least one reconfigurable redirection device is controlled to apply a non-uniform phase profile to array elements to enhance the localization of a target mobile device by creating a non-planar redirection pattern. Using and altering the non-uniform phase profile during a localization task allows for the discovery of information about the target mobile device's location, such as its angle or orientation relative to the reconfigurable redirection device, with fewer transmissions and / or fewer hardware components.

[0219] While the invention has been detailed and described in the accompanying drawings and the foregoing description, such description is to be considered illustrative or exemplary rather than limiting. The invention is not limited to the disclosed embodiments. It can be applied to various types of UEs or terminal devices, such as mobile phones, vital sign monitoring / telemetry devices, smartwatches, detectors, vehicles (for vehicle-to-vehicle (V2V) communication or more generally vehicle-to-everything (V2X) communication), V2X devices, Internet of Things (IoT) hubs, IoT devices (including low-power medical sensors for health monitoring), medical (emergency) diagnostic and treatment devices, devices for hospital use or first responder use, virtual reality (VR) headsets, etc.

[0220] A BS can be any network access device (such as a base station, node B (eNB, eNodeB, gNB, gNodeB, ng-eNB, etc.), access point, etc.) that provides geographic services to a region.

[0221] RIS can be created using smart devices (e.g., smart TVs or smart infrared panels) with hardware components that can be considered good reflectors (e.g., large glass screens or panels). RIS can also be embedded in objects such as billboards, building facades, posters, floor tiles, roofs, walls, etc. Furthermore, in the above embodiments, the RIS can be replaced by a smart repeater or RF repeater, or any repeater device with controllable relay or reflection capabilities.

[0222] In addition, at least some of the embodiments described above can be implemented to provide a new product category of network equipment or (low-cost / mid-cost) reconfigurable smart surfaces for 5G / 6G / xG cellular networks to improve the coverage, reliability and speed of cellular networks.

[0223] By studying the accompanying drawings, disclosure, and appended claims, those skilled in the art can understand and implement other variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. Throughout the specification and claims, the expressions "at least one of A, B, and C" or "at least one of A, B, or C" should generally be understood to mean "A and / or B and / or C." A single processor or other unit can implement the functionality of several items recited in the claims. The fact that certain measures are recited in mutually different dependent claims does not mean that combinations of these measures cannot be used advantageously. The foregoing description details certain embodiments of the invention. However, it should be understood that the invention can be practiced in many ways, regardless of how detailed the foregoing is in the text, and is therefore not limited to the disclosed embodiments. It should be noted that the use of specific terms in describing certain features or aspects of the invention should not be construed as implying that such terms are redefined herein as limited to any particular characteristic of the invention including the feature or aspect of the invention associated with that term.

[0224] The described operation (similar to) Figures 2 to 6 Those (as indicated in the text) can be implemented as program code units of a computer program and / or dedicated hardware for related network devices or functions. Computer programs can be stored and / or distributed on suitable media, such as optical or solid-state media, provided with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

Claims

1. An apparatus (110) for supporting the positioning of a mobile device (30) in a wireless network, the apparatus (110) being configured to establish reflection and / or deflection profiles of an array element (120) of at least one reconfigurable redirection device (10) in the wireless network to create a non-planar spatial redirection pattern of the at least one reconfigurable redirection device (10).

2. The apparatus (110) according to claim 1, wherein, The device is configured to establish the reflection and / or deflection profile of the array element (120) by controlling the spatial phase shift profile of the array element (120) to obtain a non-uniform spatial phase shift profile.

3. The apparatus (110) according to claim 2, wherein, The device (110) is configured to control the spatial phase shift profile of the array element (120) to obtain at least one of a continuous nonlinear phase profile and a stacked linear phase profile.

4. The apparatus (110) according to claim 2 or 3, wherein, The device (110) is configured to control the spatial phase shift profile of the array element (120) to obtain a non-uniform phase profile having a center point or one or more center lines.

5. The apparatus (110) according to any one of the preceding claims, wherein, The device (110) is configured to change the reflection and / or deflection profile of the array element (120) during the positioning of the mobile device (30).

6. The apparatus (110) according to any one of the preceding claims, wherein, The device (110) is configured to dynamically create the reflection and / or deflection profile of the array element (120) in response to positioning measurements and feedback from the mobile device (30).

7. An access device (20) comprising means according to any one of the preceding claims.

8. A reconfigurable redirection device (10) comprising means according to any one of the preceding claims.

9. The reconfigurable redirection device (10) according to claim 8, comprising a reconfigurable smart surface or network control repeater equipped with an antenna array.

10. A positioning system for locating a mobile device (30) in a wireless network, the system comprising means according to any one of claims 1-7, a positioning function (40) for determining the location of the mobile device (30), and a phase profile design system (60) for converting a desired non-planar spatial redirection pattern into a spatially non-uniform phase profile that can be implemented by the reconfigurable redirection device (10).

11. The positioning system according to claim 10, wherein, The mobile device (30) is configured to use uplink positioning and send pilot signals to the reconfigurable redirection device (10) for reflection to the access device (20) of the wireless network, wherein the device (110) is configured to use feedback information from the access device (20) to control the reconfigurable redirection device (10) by applying a series of nonlinear phase profiles until the received signal strength at the access device (20) is maximized or minimized.

12. The positioning system according to claim 10, wherein, The device (110) is configured to approximately position the mobile device (30) by applying a stacked linear phase profile consisting of small regions of linear phase profiles at a center point surrounded by divergent or randomly oriented phase profiles.

13. The positioning system according to claim 10, wherein, The device (110) is configured to apply two stacked linear phase profiles with different center points and determine the intersection of two reflection or deflection angles that result in the maximum received signal strength at the mobile device (30) to locate the position of the mobile device (30).

14. The positioning system according to claim 10, wherein, The device (110) is configured to control the reconfigurable redirection device (10) to reflect or deflect incident beams from the access device (20) of the wireless network in two directions, such that a null value is created between the two beams and the null value is guided across the mobile device (30), wherein the point of minimum received signal strength at the access device (20) represents the angle at which the null value points toward the mobile device (30).

15. A method for supporting the positioning of a mobile device (30) in a wireless network, the method comprising establishing a reflection and / or deflection profile of an array element (120) of at least one reconfigurable redirection device (10) in the wireless network to create a non-planar spatial redirection pattern of the at least one reconfigurable redirection device (20).

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