Method for sidelink beam management in wireless network

Abstract

A method for sidelink beam management in a wireless network is provided, the method comprising the steps of: periodically transmitting a channel state information reference signal (CSI-RS) through one or more beams; and performing a beam failure detection (BFD) or candidate beam determination (CBD) process for the one or more beams based on receiving the reference signal. The period of transmission is adjusted based on one or more criteria, which may be related to a congestion level, a priority level, and / or a mobility level. The method may further comprise the step of determining the congestion level in the channel, preferably in all directions or at the beam level, preferably using one or more wide beams.

Description

Methods for sidelink beam management in wireless networks Background Technology

[0001] Next-generation wireless networks (such as 5G New Radio (NR)) can use millimeter-wave (mmW) communication between base stations and user equipment (UEs). Radio waves with wavelengths between 1 millimeter and 10 millimeters can be called millimeter waves. More specifically, next-generation wireless networks can use the so-called frequency range 2, namely, 25-52 GHz. Wireless communication using the mmW radio frequency band typically has higher path loss and shorter range than those using lower frequencies.

[0002] In 5G NR, base stations (which can be called gNBs (next-generation NodeBs)) and UEs (user equipment) can use beamforming technology to compensate for the high path loss and short range of mmW communication. This method can also be used for communication between two UEs, such as vehicle-to-vehicle or vehicle-to-infrastructure communication. The communication link between two UEs can be called a sidelink.

[0003] Beamforming is a signal processing technique used in conjunction with antenna arrays for directional signal transmission and / or reception. Each antenna in the array transmits a signal, which is combined in a way that causes signals at a specific angle to undergo constructive interference, while other signals undergo destructive interference. Constructive interference can produce one or more signal beams.

[0004] In beamforming signal transmission, the amplitude and phase of the signal transmitted from each antenna in an antenna array can be controlled (e.g., pre-coded, weighted) to produce constructive and destructive interference in a predetermined (e.g., directional) pattern in the wavefront. Thus, the signal beam (called a “beam”) can deliver more energy or a longer distance to the receiver in a specific direction.

[0005] With the increasing demand for mobile broadband access, research and development are constantly advancing the use of beamforming technology to mitigate the high path loss and short-range communication of mmW wireless communications.

[0006] According to the definition provided for NR Uu (Radio Interface) in 3GPP TR 38.802, SL (Side Link) beam management is "acquiring and maintaining a set of [UE] beams that can be used for [SL] transmit / receive". The general framework of SL beam management includes the following processes: (i) initial beam pairing, (ii) beam reporting and maintenance, and (iii) side link beam fault indication.

[0007] The purpose of this application is to further improve the following processes: (ii) beam reporting and maintenance and (iii) side link beam fault indication. Summary of the Invention

[0008] The object of the present invention is achieved by providing the method according to claim 1 and the user equipment according to claim 13.

[0009] According to a first aspect, a method for sidelink beam management in a wireless network is provided, the method comprising the following steps:

[0010] Channel State Information Reference Signal (CSI-RS) is transmitted periodically through one or more beams;

[0011] Based on the received reference signal, perform beam fault detection (BFD) or candidate beam determination (CBD) procedures for the one or more beams;

[0012] The transmission period is adjusted based on one or more criteria.

[0013] The term "wireless network" may refer to 5G and new radio access technologies defined and standardized by 3GPP in Release 15. It may also refer to other systems defined by 3GPP, such as Long Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunications System (UMTS), and / or Global System for Mobile Communications (GSM). Furthermore, it may refer to systems defined by 3GPP2, such as CDMA2000 and / or Evolved Data Optimized (EV-DO), or systems employing IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra Wideband (UWB), Bluetooth, and / or other suitable systems.

[0014] For continuous beam fault detection (BFD) or candidate beam determination, reference signals can always be transmitted in different beams, even when there is no traffic on the corresponding data channel. This can be a potential source of wasted power for transmitting and receiving reference signals, as well as reference signal contamination. Furthermore, transmitting more reference signals (more frequently, i.e., with shorter periods) offers the advantage that the UE can monitor beam quality more frequently, but at the same time, this potentially causes more interference to other users. This invention addresses the trade-off between these advantages and disadvantages.

[0015] Therefore, it is advantageous to adjust the number of time slots (i.e., the period of reference signal transmission) per time unit based on one or more criteria (a combination of criteria). In that case, fewer reference signals are transmitted when BFD or CBD can be performed later or less frequently.

[0016] Beam Failure Detection (BFD) and Candidate Beam Determination (CBD) processes can be used for sidelink beam management, particularly for beam reporting and maintenance, and for sidelink beam failure indication.

[0017] According to the present invention, the reference signal is the Channel State Information Reference Signal (CSI-RS). Alternatively, the S-SSB (Side Link Synchronization Block) can be used as the reference signal.

[0018] According to one or more embodiments, the one or more criteria are related to congestion level, priority level, and / or mobility level. In practice, it may be advantageous to perform BFD and / or CBD procedures more frequently when congestion levels are high in the network, as new channels or beams may be needed to reduce congestion or quickly compensate for beam failures.

[0019] Furthermore, it may be advantageous to perform BFD and / or CBD procedures more frequently when the data to be transmitted has high priority (i.e., requires low packet loss, low latency, and / or low jitter) or when the UE has high priority. Additionally, beam availability and quality may vary when one or two UEs are moving relative to each other. Higher mobility levels indicating more or faster movement may require more frequent BFD and / or CBD procedures. Generally, more frequent BFD and / or CBD procedures may require transmitting more reference signals per time unit or per data frame, i.e., a higher period.

[0020] According to one or more embodiments, the method further includes the steps of: determining the congestion level in the channel, preferably in all directions or at the beam level, preferably using one or more wide beams. And, according to one or more embodiments, the congestion level is determined based on the channel busy rate (CBR) and / or channel occupancy rate (CR).

[0021] When using CR (Congestion Response), congestion is measured based on how many channels the measuring entity itself uses. In the case of CBR (Congestion Response), congestion is measured based on how many channels other entities use.

[0022] According to one or more embodiments, the mapping between the one or more criteria and predetermined periods is stored in a table. It may be advantageous to be able to quickly look up the desired period in a table where the mapping between criteria and period values ​​is stored, in specific situations. For example, congestion above a predetermined level X (e.g., 30%) may indicate that the period should be adjusted to Y time slots for a reference signal.

[0023] In one or more embodiments, the table may include a default mapping that indicates the period for transmitting a reference signal when no other mapping is available. For example, when the UE is not within the reach of an entity (such as a gNB) that provides another mapping.

[0024] According to one or more embodiments, the mapping is based on system information provided by the base station of the wireless network, i.e., the base station determines a specific period, or a specific period is required for a specific situation. The mapping may also be based on pre-coded information in the specification and / or negotiated during connection establishment. According to one or more embodiments, the mapping may also be adjusted over time.

[0025] In one or more embodiments, multiple mappings may be stored in the table, and each mapping is identified by a corresponding reference flag. In one or more further embodiments, one of the corresponding reference flags is transmitted to indicate the mapping to be used.

[0026] It may be advantageous to have a table with mappings existing in the UE, and to change the mapping to be used simply by transmitting the reference. In that case, only the reference flag needs to be transmitted, rather than all the information required for a completely new mapping.

[0027] According to one or more embodiments, each mapping is associated with one or more beams. Since the congestion level can be measured for one or more beams, it may be advantageous to provide different mappings independently for different beams.

[0028] According to other aspects of the invention, a computer program includes instructions that, when executed by a computer processor, cause the computer processor to perform the steps of any of the methods described herein. Furthermore, a computer-readable medium on which the computer program is stored.

[0029] According to another aspect of the invention, a user equipment (UE) is provided, the user equipment including a processor and a computer-readable medium according to claim 9, wherein the user equipment (UE) is configured to perform the steps of any of the methods described herein. According to another aspect of the invention, a vehicle is provided, the vehicle including such a UE.

[0030] Furthermore, a wireless communication system with network devices is provided, wherein the network devices are arranged to connect to each other using a wireless network, and includes at least one base station and at least two UEs as described in this document.

[0031] With necessary modifications, the operation, advantages, and embodiments of the UE, vehicle, and system, as well as the operation, advantages, and embodiments of the computer program and computer-readable medium, correspond to the operation, advantages, and embodiments of the methods described in this document. Attached Figure Description

[0032] To provide a more complete understanding of the invention, reference is made to the accompanying drawings, in which:

[0033] Figure 1 shows a schematic diagram of a wireless communication system;

[0034] Figures 2a and 2b illustrate schematic diagrams of data transmission scenarios between UE1 and UE2;

[0035] Figure 3 illustrates a schematic overview of a method according to one or more embodiments of the present invention; and

[0036] Figure 4 shows a schematic overview of a vehicle according to one or more embodiments of the present invention. Detailed Implementation

[0037] Figure 1 shows a schematic diagram of a wireless communication system 100, which includes a base station (gNB) 110, a first user equipment (UE1) 120, and a second user equipment (UE2) 130.

[0038] The wireless communication system 100 may be described as comprising three interacting domains: a core network, a radio access network (RAN), and user equipment (UE1 or UE2). The user equipment (UE) may be a stand-alone device or may be integrated into a vehicle as shown in Figure 4. The wireless communication system 100 enables the UE to perform data communication with external data networks (such as, but not limited to, the Internet).

[0039] For communication between gNB and UE1 and UE2, several beams 140 may be available. Beam pairing t2 enables communication between gNB and UE1, and beam pairing t1 enables communication between gNB and UE2. Similarly, beaming technology can use sidelink beams 150 for communication between UE1 and UE2.

[0040] Figures 2a and 2b illustrate schematic diagrams of data transmission scenarios between UE1 and UE2. In Figures 2a and 2b, UE1 and UE2 are represented in a first vehicle 210 and a second vehicle 220, respectively. In Figure 2a, data is being transmitted between UE1 and UE2 using a side link with paired beams. In Figure 2b, although many beams are available, no data is being transmitted between UE1 and UE2. In one or more embodiments, the period for transmitting the Channel State Information Reference Signal (CSI-RS) is not the same for all beams.

[0041] In some embodiments, the non-limiting terms User Equipment (UE) or Wireless Device may be used, and the term may 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 UEs include target devices, device-to-device (D2D) UEs, machine-type UEs or UEs capable of machine-to-machine (M2M) communication, PDAs, PADs, tablet computers, mobile terminals, smartphones, laptop embedded devices (LEE), laptop mounted devices (LME), USB dongles, UE class M1, UE class M2, ProSe UE, V2V UE, V2X UE, etc.

[0042] Figure 3 illustrates a schematic overview of a method 300 according to one or more embodiments of the present invention. Method 300 includes the following steps:

[0043] Step 310: Periodically transmit Channel State Information Reference Signal (CSI-RS) through one or more beams; and

[0044] Step 320: Based on the received reference signal, perform a beam fault detection (BFD) or candidate beam determination (CBD) procedure for the one or more beams; wherein the transmission period is adjusted based on one or more criteria. The one or more criteria may be related to congestion level, priority level, and / or mobility level.

[0045] Method 300 may further include step 330: determining the congestion level in the channel, preferably in all directions or at the 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 the channel busy rate (CBR) and / or channel occupancy rate (CR).

[0046] A mapping between one or more criteria and cycles can be stored in a table. Each mapping table can be referred to by a reference. An example of such a mapping table is provided below.

[0047]

[0048] The table above shows a general single-criterion mapping table using reference M1. The following tables will use congestion level as the criterion to provide such tables.

[0049]

[0050] The mapping table M2 below has the same structure as mapping table M1, but has a different period. Therefore, the mappings are different.

[0051]

[0052] In two further examples, mappings M3 and M4 are based on multiple criteria, as shown in the table below:

[0053]

[0054]

[0055] Mappings 3 and 4 take into account the priority of the data to be transmitted (e.g., having priority 1 or priority 2) and the mobility of the UE (which is expressed as, for example, the speed of the UE).

[0056] In one or more embodiments, the mapping is defined by a formula. For example, in mapping 5, the period in a time slot can be defined by dividing the measured percentage congestion by 10. In mapping 6, the period in a time slot can be defined by dividing the measured percentage congestion by 4.

[0057] In one or more embodiments, data is transmitted between UEs in data frames. Each frame may include multiple time slots (or blocks). Channel State Information Reference Signal (CSI-RS) may be included in a time slot or a block. High periodicity may indicate that more time slots of CSI-RS are transmitted per time unit.

[0058] Mapping can be established based on system information provided by the base station of the wireless network; and / or based on pre-coded information in the specification; and / or based on negotiation or settings during the connection establishment process. Mapping can be adjusted over time.

[0059] In one or more embodiments, the mapping table may exist in the UE. When a mapping needs to be changed (e.g., from mapping 1 to mapping 3, as indicated in the table above), it may only be necessary to transmit a reference to the new mapping. In this example, therefore only the number "3".

[0060] Figure 4 illustrates a schematic overview of a vehicle 400 according to one or more embodiments of the present invention, the vehicle including a UE 410. The UE 410 is configured to perform the steps of any of the methods described in this document. Generally, the vehicle may be an automobile, motorcycle, van, truck, bicycle, or scooter.

[0061] Furthermore, embodiments may take the form of a program product embodied in one or more computer-readable storage devices, which store machine-readable code, computer-readable code, and / or program code, hereinafter referred to as code. The storage device may be tangible, non-transitory, and / or non-transferable. The storage device may not contain signals. In one embodiment, the storage device uses only signals to access the code.

[0062] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable storage medium. A computer-readable storage medium may be a storage device for storing code. A storage device may be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor systems, apparatuses, or any suitable combination thereof.

[0063] Further specific examples of storage devices (a non-exhaustive list) will include the following: electrical connections having one or more wires; portable computer floppy disks; hard disks; random access memory (“RAM”); read-only memory (“ROM”); erasable programmable read-only memory (“EPROM” or flash memory); portable optical disc read-only memory (“CD-ROM”); optical storage devices; magnetic storage devices; or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium can be any tangible medium that can contain or store programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0064] The code used to perform the operations of the embodiments can be any number of lines and can be written in any combination of one or more programming languages, including object-oriented programming languages ​​(such as Python, Ruby, Java, Smalltalk, C++, etc.), as well as conventional procedural programming languages ​​(such as the "C" programming language, etc.) and / or machine languages ​​(such as assembly language). The code can be executed 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 a remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer via any type of network (including a local area network ("LAN"), a wireless LAN ("WLAN"), or a wide area network ("WAN"), or can be connected to an external computer (e.g., via the Internet through an Internet Service Provider ("ISP").

[0065] Applications DE 10 2023 207 566 and DE 10 2023 207 565 are incorporated herein by reference.

[0066] Various aspects of the invention have been set forth in the detailed description. Other aspects, features, and embodiments of the invention will become apparent to those skilled in the art upon review of the following description of specific exemplary embodiments of the invention in conjunction with the accompanying drawings. While features of the invention may be discussed below with respect to certain embodiments and drawings, all embodiments of the invention may include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used according to the various embodiments of the invention discussed herein. Similarly, while exemplary embodiments may be discussed below as apparatus, system, or method embodiments, it should be understood that such exemplary embodiments may be implemented in various apparatuses, systems, and methods.

[0067] The steps of any method disclosed herein need not be performed in the exact order disclosed, unless the steps are explicitly described as occurring after or before another step and / or where there is an implicit requirement that a step must occur after or before another step. Where appropriate, any feature of any embodiment of the embodiments disclosed herein may be applied to any other embodiment. Similarly, any advantage of any embodiment of the embodiments may be applied to any other embodiment, and vice versa. Other objects, features, and advantages of the appended embodiments will become apparent from the following description.

[0068] Those skilled in the art will understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the functionality of the various illustrative components, blocks, modules, circuits, and steps has been described above in general terms. Whether such functionality is implemented as hardware or as software depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art can implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the invention.

[0069] The prior description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the 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. Therefore, the invention is not intended to be limited to the embodiments shown herein, but is given the widest scope consistent with the principles and novel features disclosed herein.

[0070] The benefits and advantages that can be provided by the invention have been described above with reference to specific embodiments. These benefits and advantages, as well as any elements or limitations that may bring them to or make them more significant, should not be construed as key, desired, 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 interpreted as non-exclusively including elements or limitations following those terms. Therefore, a system, method, or other embodiment that comprises a set of elements is not limited to those elements and may include other elements not expressly listed or inherent to the claimed embodiment.

[0071] While the invention has been described with reference to specific embodiments, it should be understood that the embodiments are illustrative and the scope of the invention is not limited to these embodiments. Many variations, modifications, additions, and improvements to the embodiments described above are possible. It is contemplated that such variations, modifications, additions, and improvements fall within the scope of the invention as detailed in the appended claims.

Claims

1. A method for sidelink beam management in a wireless network, comprising the following steps: Channel State Information Reference Signal (CSI-RS) is periodically transmitted via one or more beams; based on the received reference signal, a beam fault detection (BFD) or candidate beam determination (CBD) process is performed for the one or more beams; wherein the transmission period is adjusted based on one or more criteria.

2. The method of claim 1, wherein the one or more criteria are related to congestion level, priority level and / or mobility level.

3. The method according to claim 2, further comprising the following steps: Determine the congestion level in the channel, preferably in all directions or at the 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 the channel busy rate (CBR) and / or channel occupancy rate (CR).

5. The method according to any one of claims 1 to 4, wherein the mapping between the one or more criteria and the cycle is stored in a table.

6. The method of claim 5, wherein the mapping is based on: system information provided by the base station of the wireless network; and / or pre-coded information in the specification; and / or negotiation or settings during the connection establishment process.

7. The method of claim 5 or 6, wherein the table stores a plurality of mappings, and wherein each mapping further includes a corresponding reference flag.

8. The method of claim 7, wherein one of the corresponding reference flags is transmitted to indicate the mapping to be used.

9. The method according to any one of claims 5 to 8, wherein each mapping is associated with one or more beams.

10. The method according to any one of claims 5 to 9, wherein the mapping is adjusted over time.

11. A computer program comprising instructions that, when executed by a computer processor, cause the computer processor to perform the steps of the method as claimed in any one of claims 1 to 10.

12. A computer-readable medium having a computer program according to claim 11 stored thereon.

13. A user equipment (UE) comprising a processor and a computer-readable medium according to claim 12, wherein the user equipment (UE) is arranged to perform the steps of the method according to any one of claims 1 to 10.

14. A vehicle comprising the user equipment according to claim 13.

15. A wireless communication system having network devices arranged for connecting to each other using a wireless network, and comprising at least one base station and at least two UEs according to claim 13.

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