METHOD FOR SIDELINK BEAM MANAGEMENT IN WIRELESS NETWORKS

Abstract

A method for sidelink beam management in a wireless network is provided, comprising the following steps: periodically transmitting channel state information reference signals (CSI-RS) over one or more beams and performing a beam failure detection (BFD) procedure or a candidate beam determination (CBD) procedure for the one or more beams based on the reception of the reference signals. The periodicity of the transmission is adjusted based on one or more criteria, which may relate to a congestion level, a priority level, and / or a mobility level. The method may further include the step of determining the congestion level in a channel, preferably in all directions, or at a beam level, preferably using one or more wide beams.

Description

BACKGROUND

[0001] Next-generation wireless networks, such as 5G New Radio (NR), may use millimeter wave (mmW) communication between a base station and a user equipment (UE). Radio waves with wavelengths between 1 millimeter and 10 millimeters can be referred to as millimeter waves. More specifically, next-generation wireless networks can use the so-called frequency range 2, i.e., 25-52 GHz. Wireless communications using a mmW high frequency band generally have higher path loss and shorter range than those using lower frequencies. In 5G NR, the base station (which can be referred to as a gNB (next-generation NodeB)) and the UE (user equipment) can use beamforming techniques to compensate for the high path loss and short range of mmW communications.This approach can also be used for communication between two UEs, such as vehicle-to-vehicle or vehicle-to-infrastructure communication. A communication link between two UEs can be referred to as a sidelink.

[0002] Beamforming is a signal processing technique that can be used with an antenna array for directional signal transmission and / or reception. Each antenna in the antenna array transmits a signal, which is combined with other signals from other antennas in the same array in such a way that signals at certain angles experience constructive interference, while others experience destructive interference. Constructive interference can produce one or more signal beams.

[0003] In beamforming signal transmission, the amplitude and phase of the signal transmitted by each antenna in an antenna array can be controlled (e.g., pre-coded, weighted) to create a predetermined (e.g., directional) pattern of constructive and destructive interference in the wavefront. Thus, a signal beam (referred to as a "beam") can provide more energy or range to the receiver in a particular direction.

[0004] As the demand for mobile broadband access continues to grow, research and development are pushing communications using beamforming techniques to mitigate the high path loss and short range of mmW wireless communications.

[0005] According to the definition provided for the NR-Uu (Radio Interface) in 3GPP's TR 38.802, SL (Sidelink) beam management is intended to "acquire and maintain a coherent set of [UE] beams that can be used for [SL] transmission / reception." The general concept of SL beam management includes procedures for (i) initial beam pairing, (ii) beam reporting and maintenance, and (iii) sidelink beam failure indication.

[0006] The object of this application is to further improve the procedure for (ii) beam reporting and maintenance as well as (iii) display of sidelink beam errors. SUMMARY

[0007] The object of the invention is achieved by providing a method according to claim 1 and a user device according to claim 13.

[0008] According to a first aspect, a method for sidelink beam management in a wireless network is provided, the method comprising the following steps - periodic transmission of channel state information reference signals (CSI-RS) over one or more beams - performing a beam failure detection (BFD) procedure or a candidate beam determination (CBD) procedure for the one or more beams based on the reception of the reference signals; wherein the periodicity of the transmission is adjusted based on one or more criteria.

[0009] The term "wireless network" may refer to 5G and New Radio Access technology, which is subject to definition and standardization by 3GPP in Release 15. The term may also refer to other systems defined by 3GPP, such as Long-Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunication System (UMTS), and / or Global System for Mobile (GSM). The term may also refer to systems defined by the 3rd Generation Partnership Project 2 (3GPP2), such as CDMA2000 and / or Evolution-Data Optimized (EV-DO), or to systems using IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth, and / or other appropriate systems.

[0010] For continuous beam failure detection (BFD) or to determine suitable beams, reference signals can be continuously transmitted in different beams, even when there is no traffic on a given data channel. This can be a potential waste of the energy used to transmit and receive the reference signals, as well as a source of reference signal contamination. Furthermore, transmitting more reference signals (more frequently, i.e., with smaller periodicity) provides the advantage that the UE can monitor the quality of the beams more frequently, but at the same time potentially generates more interference with other users. The trade-off between these advantages and disadvantages is the subject of this invention.

[0011] It is therefore advantageous to adjust the number of slots with reference signals transmitted per unit time (i.e., the periodicity of transmitting the reference signal) based on one or more (a combination of) criteria. In this case, fewer reference signals are transmitted if BFD or CBD can be executed later or less frequently.

[0012] Beam Failure Detection (BFD) and Candidate Beam Determination (CBD) procedures can be used in sidelink beam management, particularly in beam reporting and maintenance and the indication of sidelink beam failures.

[0013] According to the invention, the reference signals are channel state information reference signals (CSI-RS). Alternatively, S-SSBs (sidelink synchronization signal blocks) can be used as reference signals.

[0014] According to one or more embodiments, the one or more criteria relate to a congestion level, a priority level, and / or a mobility level. Indeed, it may be advantageous to execute the BFD and / or CBD procedures more frequently when a congestion level in the network is high, as new channels or beams may be needed to reduce the congestion or quickly compensate for beam errors.

[0015] Furthermore, it may be advantageous to execute the BFD and / or CBD procedures more frequently if the data to be transmitted has a high priority (i.e., requires low packet loss, low latency, and / or low jitter) or if the UE has a high priority. Furthermore, if one or both UEs are moving relative to each other, the availability and quality of the beams may vary. A higher mobility level, indicating more or faster movements, may require more frequent execution of the BFD and / or CBD procedures. In general, more frequent execution of the BFD and / or CBD procedures may require transmitting more reference signals per unit time or per data frame, i.e., higher periodicity.

[0016] According to one or more embodiments, the method further comprises the step of determining the congestion level in a channel, preferably in all directions, or at a beam level, preferably using one or more wide beams. Furthermore, according to one or more embodiments, the congestion level is determined based on a channel busy ratio (CBR) and / or a channel occupancy ratio (CR).

[0017] When using CR, congestion is measured based on how much the channel is used by the measuring unit itself. In the case of CBR, congestion is measured based on how much the channel is used by other units.

[0018] According to one or more embodiments, a mapping between the one or more criteria and a predetermined periodicity is stored in a table. It may be advantageous to quickly look up the required periodicity in a particular situation in a table that stores a mapping between criteria and periodicity values. For example, congestion above a predefined level X (e.g., 30%) may indicate that the periodicity needs to be adjusted to Y slots for reference signals.

[0019] In one or more embodiments, the table may include a default mapping that specifies the periodicity of transmitting reference signals when another mapping is unavailable. For example, when the UE is not within range of an entity providing another mapping, such as a gNB.

[0020] According to one or more embodiments, the assignment is based on system information provided by a base station of the wireless network, i.e., the base station determines a specific periodicity or that a specific situation requires a specific periodicity. The assignment may also be based on pre-coded information in the specification and / or negotiated during connection setup. According to one or more embodiments, the assignment may also be adjusted over time.

[0021] In one or more embodiments, multiple mappings may be stored in the tables, each mapping identified by a respective reference. In one or more embodiments, one of the respective reference characters is transmitted to indicate the mapping to be used.

[0022] It may be advantageous to have a table of mappings in a UE and transfer only one reference to change the mapping to be used. In this case, only one reference needs to be transferred instead of all the information required for a completely new mapping.

[0023] According to one or more embodiments, each assignment relates to one or more beams. Since the congestion level can be measured for one or more beams, it may be advantageous to provide different assignments independently for different beams.

[0024] According to further aspects of the invention, a computer program is provided comprising instructions that, when executed by a computer processor, cause the computer processor to perform the steps of any method as described in this document. Furthermore, a computer-readable medium on which this computer program is stored is provided.

[0025] According to yet another aspect of the invention, a user equipment (UE) is provided, comprising a processor and a computer-readable medium according to claim 9, wherein the user equipment (UE) is configured to perform the steps of any method as described herein. According to another aspect of the invention, a vehicle comprising such a UE is provided.

[0026] Furthermore, a wireless communication system comprising network devices is provided, wherein the network devices are configured to be interconnected using a wireless network and comprise at least one base station and at least two UEs as described in this document.

[0027] The functionality, advantages, and embodiments of the UE, the vehicle, and the system, as well as the functionality, advantages, and embodiments of the computer program and the computer-readable medium, correspond to the functionality, advantages, and embodiments of the method as described in this document, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] For a more complete understanding of the present invention, reference is made to the accompanying drawings in the following description. In the drawings: Fig.1 a schematic representation of a wireless communication system; Fig. 2a and Fig. 2b schematic representation of the data transmission scenario between UE1 and UE2; Fig. 3 a schematic overview of a method according to one or more embodiments of the invention; and, Fig. 4 a schematic overview of a vehicle according to one or more embodiments of the invention. DETAILED DESCRIPTION

[0029] Fig. 1 shows a schematic representation of a wireless communication system 100 comprising a base station (gNB) 110, a first user equipment (UE1) 120 and a second user equipment (UE2) 130.

[0030] Regarding the wireless communication system 100, it can be said that it comprises three interacting areas: a core network, a radio access network (RAN), and a user equipment (UE1 or UE2). The user equipment (UE) can be a standalone device or integrated into a vehicle, as in Fig. 4. Using the wireless communication system 100, a UE may be enabled to perform data communication with an external data network, such as (but not limited to) the Internet.

[0031] For communication between the gNB and the UE1 and UE2, multiple beams 140 may be available. Pairing beam t2 may enable communication between the gNB and the UE1, and pairing beam t1 may enable communication between the gNB and the UE2. Similarly, beam technology may be used for communication between the UE1 and the UE2, using sidelink beams 150.

[0032] Fig. 2a and Fig. 2b shows a schematic representation of the data transmission scenario between the UE1 and the UE2. In Fig. 2a and Fig. 2b, the UE1 and the UE2 are present in a first vehicle 210 and a second vehicle 220, respectively. In Fig. 2a, data is transmitted between UE1 and UE2 using a sidelink with paired beams. In Fig.2b, no data is transmitted between UE1 and UE2, even though many beams are available. In one or more embodiments, the periodicity of transmitting channel state information reference signals (CSI-RS) is not the same for all beams.

[0033] In some embodiments, the non-limiting term user equipment (UE) or wireless device may be used to refer to any type of wireless device that communicates with a network node and / or with another UE in a cellular or mobile communication system. Examples of a UE include a target device, a device-to-device (D2D) UE, a machine UE, or a UE capable of machine-to-machine (M2M) communication, a PDA, a PAD, a tablet, mobile devices, a smartphone, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles, a Category M1 UE, a Category M2 UE, a ProSe UE, a V2V UE, a V2X UE, etc.

[0034] Fig.Figure 3 shows a schematic overview of a method 300 according to one or more embodiments of the invention. The method 300 comprises the following steps:

[310] periodically transmitting channel state information reference signals (CSI-RS) over one or more beams; and

[320] Performing a beam failure detection (BFD) procedure or a candidate beam determination (CBD) procedure for the one or more beams based on the reception of the reference signals; wherein the periodicity of the transmission is adjusted based on one or more criteria. The one or more criteria relate to a congestion level, a priority level, and / or a mobility level.

[0035] The method 300 may further include a step 330 of determining the congestion level in a channel, preferably in all directions, or at a beam level, preferably using one or more wide beams, the priority level, and / or the mobility level. The congestion level may be determined based on a channel busy ratio (CBR) and / or a channel occupancy ratio (CR).

[0036] A mapping between one or more criteria and a periodicity can be stored in a table. Each mapping table can be labeled with a reference. Examples of such mapping tables are provided below. Reference: M1 (Assignment 1) Criteria Periodicity [slots / ms] A X B Y C Z

[0037] The table above shows a general single-criteria assignment table with reference M1. Such a table is provided below with an overload level as a criterion. Reference: M1 (Assignment 1) Overload level Periodicity [slots / ms] < 20 % 2 < 50 % 6 >= 50 % 10

[0038] The mapping table M2 below has the same structure as the mapping table M1, but with different periodicities. Therefore, it can be said that the mapping is different. Reference: M2 (Assignment 2) Overload level Periodicity [slots / ms] <20% 2 < 50 % 6 >= 50 % 10

[0039] In two further examples, the assignments M3 and M4 are based on several criteria, as shown in the tables below: Reference: M3 (Assignment 3) UE Priority + Mobility Periodicity [slots / ms] Priority 1 and speed < 50 km / h 2 Priority 1 and v > 50 km / h 10 Priority 2 and speed < 70 km / h 5 Priority 2 and v > 70 km / h 12 Reference: M4 (Assignment 4) UE Priority + Mobility Periodicity [slots / ms] Priority 1 and speed < 50 km / h 10 Priority 1 and v > 50 km / h 15 Priority 2 and speed < 70 km / h 12 Priority 2 and v > 70 km / h 24

[0040] Mappings 3 and 4 take into account the priority of the data to be transmitted (which may, for example, have a priority 1 or a priority 2) and the mobility of the UE (which may, for example, be expressed as a speed of the UE).

[0041] In one or more embodiments, the allocation is defined by a formula. For example, for an allocation of 5, the periodicity in slots may be defined by the measured congestion percentage divided by 10. For an allocation of 6, the periodicity in slots may be defined by the measured congestion percentage divided by 4.

[0042] In one or more embodiments, data is transmitted in data frames between UEs. Each frame may comprise multiple slots (or blocks). A channel state information reference signal (CSI-RS) may be included in a slot or in a block. A high periodicity may then indicate that more slots with a CSI-RS are transmitted per unit of time. A mapping can be created based on system information provided by a wireless network base station; and / or pre-coded information in the specification; and / or negotiation or settings during connection setup. The mapping can be adjusted over time.

[0043] In one or more embodiments, a mapping table may be present in the UE. If a mapping needs to be changed (e.g., from mapping 1 to mapping 3, as indicated in the table above), only the reference of the new mapping may need to be transmitted. In this example, only the number "3."

[0044] Fig.Figure 4 shows a schematic overview of a vehicle 400 according to one or more embodiments of the invention, including a UE 410. The UE 410 is configured to perform the steps according to any of the methods described herein. In general, a vehicle may be a car, a motorcycle, a van, a truck, a bicycle, or a scooter.

[0045] Furthermore, embodiments may take the form of a program product embodied in one or more computer-readable storage devices storing machine-readable code, computer-readable code, and / or program code, hereinafter referred to as code. The storage devices may be tangible, non-transitory, and / or non-transferable. The storage devices may not embody signals. In a particular embodiment, the storage devices use signals only for accessing code.

[0046] Any combination of one or more computer-readable media may be used. The computer-readable medium may be a computer-readable storage medium. The computer-readable storage medium may be a storage device that stores the code. The storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, device, or apparatus, or any suitable combination of the foregoing.

[0047] More specific examples (non-exhaustive list) of the storage device would include: an electrical connection with one or more wires, a portable computer diskette, a hard disk, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM) or flash memory, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, device, or apparatus.

[0048] Code for performing operations for embodiments may have any number of lines and be written in any combination of one or more programming languages, including an object-oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages ​​such as the "C" programming language or the like, and / or machine languages ​​such as assembly languages. The code may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server.In the latter scenario, the remote computer may be connected to the user's computer over any type of network, including a local area network (“LAN”), a wireless LAN (“WLAN”), or a wide area network (“WAN”), or it may be connected to an external computer (for example, over the Internet using an Internet Service Provider (“ISP”)).

[0049] Applications DE 10 2023 207 566 and DE 10 2023 207 565 are deemed to be incorporated into this application by reference.

[0050] Aspects of the invention are explained in the detailed description. Further aspects, features, and embodiments of the present invention will become apparent to those of ordinary skill in the art upon reviewing the following description of specific embodiments of the present invention in conjunction with the accompanying figures. Although features of the present invention may be discussed with reference to specific embodiments and figures below, all embodiments of the present invention may include one or more of the advantageous features discussed therein. In other words, although one or more embodiments may be discussed as having certain advantageous features, one or more of these features may also be used according to the various embodiments of the invention discussed herein.Similarly, although embodiments may be discussed below as apparatus, system, or method embodiments, it should be understood that these embodiments may be implemented in various apparatus, systems, and methods.

[0051] The steps of all methods disclosed herein need not be performed exactly in the order disclosed, unless a step is expressly described as following or preceding another step and / or where it is in the nature of the matter that one step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment wherever appropriate. Likewise, any advantage of any of the embodiments may apply to all other embodiments, and vice versa. Other objects, features, and advantages of the included embodiments will become apparent from the following description.

[0052] Those skilled in the art will appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether this functionality is implemented in hardware or software depends on the specific application and design constraints of the overall system.Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as causing a departure from the scope of the present invention.

[0053] The foregoing description of the disclosed embodiments is provided to enable those skilled in the art to make or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0054] The beneficial effects and advantages that may be provided by the present invention have been described above with reference to specific embodiments. These beneficial effects and advantages, and any elements or limitations that may cause them to occur or be enhanced, are not to be construed as critical, required, or essential features of any or all of the claims. As used herein, the terms "comprises," "comprising," or any other variations thereof, are intended to be construed as including, not exclusively, the elements or limitations that follow those terms. Accordingly, a system, method, or other embodiment that includes an associated set of elements is not limited to only those elements, but may include other elements not expressly listed or inherent in the claimed embodiment.

[0055] Although the present invention has been described with reference to specific embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions, and improvements to the above-described embodiments are possible. These variations, modifications, additions, and improvements are intended to fall within the scope of the invention, as detailed in the following claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2023 207 566

[0049] DE 10 2023 207 565

[0049]

Claims

[1] A method for sidelink beam management in a wireless network, comprising the following steps: - periodic transmission of channel state information reference signals (CSI-RS) over one or more beams; - performing a beam failure detection (BFD) procedure or a candidate beam determination (CBD) procedure for the one or more beams based on the reception of the reference signals; wherein the periodicity of the transmission is adjusted based on one or more criteria. [2] The method of claim 1, wherein the one or more criteria relate to a congestion level, a priority level and / or a mobility level. [3] A method according to claim 2, further comprising the step of determining the congestion level in a channel, preferably in all directions, or at a beam level, preferably using one or more wide beams. [4] The method of claim 2 or 3, wherein the congestion level is determined based on a channel busy ratio (CBR) and / or a channel occupancy ratio (CR). [5] Method according to one of claims 1 to 4, wherein an association between the one or more criteria and a periodicity is stored in a table. [6] The method of claim 5, wherein the assignment is based on: - System information provided by a wireless network base station; and / or - pre-coded information in the specification; and / or - Negotiation or settings during connection establishment. [7] The method of claim 5 or 6, wherein a plurality of mappings are stored in the table, and wherein each mapping further comprises a respective reference. [8] A method according to claim 7, wherein one of the respective reference characters is transmitted to indicate the assignment to be used. [9] A method according to any one of claims 5-8, wherein each assignment relates to one or more beams. [10] Method according to one of claims 5-9, wherein the allocation is adjusted over time. [11] A computer program comprising instructions which, when executed by a computer processor, cause the computer processor to carry out the steps of the method according to any one of claims 1-10. [12] A computer-readable medium on which the computer program according to claim 11 is stored. [13] A user equipment (UE) comprising a processor and a computer-readable medium according to claim 12, wherein the user equipment (UE) is configured to perform the steps of any one of claims 1-10. [14] A vehicle comprising a user device according to claim 13. [15] A wireless communication system comprising network devices, wherein the network devices are arranged to be interconnected using a wireless network and comprise at least one base station and at least two UEs according to claim 13.

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