Base station and communication method

Abstract

This base station has a distributed unit and a wireless unit. The distributed unit has: a control part that configures, as user identification information, an antenna port identifier in a sounding reference signal (SRS) and terminal layer information pertaining to a communication layer in a terminal, and generates a first message that includes the user identification information and triggers beamforming based on the SRS; and a transmission part that transmits the first message to the wireless unit.

Description

Base Station and Communication Method

[0001] The present invention relates to a base station and a communication method in a wireless communication system.

[0002] In a wireless communication system based on the 3GPP (registered trademark) standard, such as NR (New Radio) (also referred to as "5G") and a successor system of NR (e.g., "6G"), technologies that meet requirements such as a large-capacity system, high data transmission speed, low latency, simultaneous connection of a large number of terminals, low cost, and power saving are being studied (e.g., Non-Patent Document 1).

[0003] Also, in O-RAN (Open-Radio Access Network), improving the bandwidth requirements in the front haul (Open Fronthaul) interface between the distributed unit (O-DU (Distributed Unit)) and the radio unit (O-RU (Radio Unit)) in a base station is being studied (e.g., Non-Patent Document 2).

[0004] In the fronthaul splitting option in the prior art, the SRS (Sounding Reference Signal) channel estimation and SRS processing functions are arranged in the distributed unit (O-DU). Here, in O-RAN, arranging the SRS channel estimation and SRS processing functions in the radio unit (O-RU) and performing beam forming (BF) based on SRS in the radio unit are being studied to improve the bandwidth of the fronthaul interface.

[0005] 3GPP TS 38.300 V18.3.0 (2024-09) O-RAN.WG4.TS.CUS.0-R004-v16.01 (October 2024)

[0006] In the existing O-RAN specifications, ST5 (Section Type 5), designed for UE scheduling, is widely used as the control plane message format between O-RU and O-DU (fronthaul). Furthermore, O-RAN is considering using ST5 to trigger SRS-based beamforming. However, the procedure for performing this trigger has not been clearly defined.

[0007] The present invention has been made in view of the above points, and aims to trigger beamforming based on SRS (Sounding Reference Signal) using messages of existing specifications in the fronthaul interface of a base station.

[0008] According to the disclosed technology, a base station is provided having a distributed unit and a radio unit, wherein the distributed unit includes a control unit that sets an antenna port identifier in SRS (Sounding Reference Signal) and terminal layer information relating to the communication layer at the terminal as user identification information and generates a first message that triggers beamforming based on SRS, including the user identification information, and a transmission unit that transmits the first message to the radio unit.

[0009] According to the disclosed technology, beamforming based on Sounding Reference Signal (SRS) can be triggered using messages from existing specifications in the base station's fronthaul interface.

[0010] This figure shows an example configuration (1) of a wireless communication system in an embodiment of the present invention. This figure shows an example configuration (2) of a wireless communication system in an embodiment of the present invention. This figure shows an example configuration (3) of a wireless communication system in an embodiment of the present invention. This figure illustrates beamforming based on SRS in an embodiment of the present invention. This is a figure (1) illustrating the message format (ST5) in an existing specification. This is a figure (2) illustrating the message format (ST5) in an existing specification. This figure shows an example of a sequence diagram in an embodiment of the present invention. This figure shows an example of user identifier (ueId) bits in an embodiment of the present invention. This figure shows an example of the functional configuration of the base station 10 in an embodiment of the present invention. This figure shows an example of the functional configuration of the terminal 20 in an embodiment of the present invention. This figure shows an example of the hardware configuration of the base station 10 or terminal 20 in an embodiment of the present invention. This figure shows an example of the configuration of a vehicle 2001 in an embodiment of the present invention.

[0011] Embodiments of the present invention will be described below with reference to the drawings. Note that the embodiments described below are examples, and the embodiments to which the present invention is applied are not limited to those described below.

[0012] Existing technologies may be used as appropriate in the operation of the wireless communication system according to the embodiment of the present invention.

[0013] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies may be used as appropriate. However, such existing technologies may include, for example, existing LTE or existing NR, but are not limited to existing LTE or NR.

[0014] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies may be used as appropriate. However, such existing technologies may include, for example, existing LTE or existing NR, but are not limited to existing LTE or NR.

[0015] Furthermore, in the embodiments of the present invention described below, terms such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel), which are used in existing LTE systems, will be used. This is for convenience of description, and similar signals, functions, etc., may be called by other names. Also, the above terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even if a signal is used in NR, it is not necessarily explicitly stated as "NR-".

[0016] Furthermore, in the embodiments of the present invention, the duplex system may be a TDD (Time Division Duplex) system, an FDD (Frequency Division Duplex) system, or any other system (for example, a Flexible Duplex).

[0017] Furthermore, in embodiments of the present invention, "configuring" wireless parameters means that predetermined values ​​are pre-configured, or that wireless parameters notified from the base station 10 or terminal 20 are configured. Also, in the following description, " / " means "and / or" unless otherwise specified, or unless it is clear from the context that it has a different meaning.

[0018] Figure 1 shows an example configuration (1) of a wireless communication system according to an embodiment of the present invention. The wireless communication system according to an embodiment of the present invention includes a base station 10 and a terminal 20, as shown in Figure 1. Figure 1 shows one base station 10 and one terminal 20, but this is an example, and there may be multiple base stations 10 and terminals 20.

[0019] Base station 10 is a communication device that provides one or more cells and communicates wirelessly with terminal 20. The physical resources of the wireless signal are defined in the time domain and the frequency domain. The time domain may be defined by the number of OFDM (Orthogonal Frequency Division Multiplexing) symbols, and the frequency domain may be defined by the number of subcarriers or resource blocks. Base station 10 transmits synchronization signals and system information to terminal 20. Synchronization signals are, for example, NR-PSS and NR-SSS. System information is transmitted, for example, in NR-PBCH and is also called broadcast information. Synchronization signals and system information may also be called SSB (SS / PBCH block). As shown in Figure 1, base station 10 transmits control signals or data to terminal 20 via DL (Downlink) and receives control signals or data from terminal 20 via UL (Uplink). Both base station 10 and terminal 20 are capable of transmitting and receiving signals using beamforming. Furthermore, both the base station 10 and the terminal 20 can apply MIMO (Multiple Input Multiple Output) communication to DL or UL. Also, both the base station 10 and the terminal 20 may communicate via Carrier Aggregation (CA) through secondary cells (SCell) and primary cells (PCell). Additionally, the terminal 20 may communicate via Dual Connectivity (DC) through the primary cell of base station 10 and the primary secondary cell group cell (PSCell) of another base station 10.

[0020] Terminal 20 is a communication device equipped with wireless communication capabilities, such as a smartphone, mobile phone, tablet, wearable device, or M2M (Machine-to-Machine) communication module. As shown in Figure 1, Terminal 20 receives control signals or data from the base station 10 via DL and transmits control signals or data to the base station 10 via UL, thereby utilizing various communication services provided by the wireless communication system. Terminal 20 also receives various reference signals transmitted from the base station 10 and performs propagation path quality measurement based on the reception results of said reference signals.

[0021] Furthermore, various requirements are being considered for the next generation of 6G. For example, these requirements may include ultra-broadband communication, mission-critical communication, ultra-massive connection, universal coverage, intelligent connection, and ubiquitous sensing.

[0022] Furthermore, these requirements may include ultra-high-speed communication, large-capacity communication, ultra-wide coverage, ultra-low power consumption, cost reduction, ultra-low latency, ultra-high reliability communication, ultra-high connectivity, and sensing.

[0023] To meet these requirements, the new concept aims for extensibility (e.g., making it more effective for future use), ease of operation, customizability (e.g., making it easier to operate), and sustainability (e.g., cost reduction, a more robust configuration, and resilience). Furthermore, guaranteed communication, ensuring a minimum level of performance at all times, is being considered.

[0024] Figure 2 shows an example configuration (2) of a wireless communication system according to an embodiment of the present invention. Figure 2 shows an example configuration of a wireless communication system when DC (Dual connectivity) is performed. As shown in Figure 2, a base station 10A that will be an MN (Master Node) and a base station 10B that will be an SN (Secondary Node) are provided. Base stations 10A and 10B are each connected to the core network. Terminal 20 can communicate with both base station 10A and base station 10B.

[0025] A cell group provided by base station 10A, which is an MN (Mobile Network), is called an MCG (Master Cell Group), and a cell group provided by base station 10B, which is an SN (Mobile Network), is called an SCG (Secondary Cell Group). In a data center, an MCG consists of one PCell and one or more SCells, and an SCG consists of one PSCell (Primary SCG Cell) and one or more SCells.

[0026] Figure 3 shows an example configuration (3) of a wireless communication system according to an embodiment of the present invention. As shown in Figure 3, the radio unit O-RU10A communicates with the distributed unit O-DU10B and the SMO (Service Management and Operation) 30A via an Open Fronthaul (or simply a fronthaul). The SMO 30A communicates with the central control unit O-CU10C via the O1 interface and with the virtualization environment O-Cloud 30B, which provides RAN functions, etc., via the O2 interface. The O-DU10B and O-CU10C communicate via the F1 interface. In the following description, O-DU10B and O-RU10A may be simply referred to as O-DU and O-RU.

[0027] In O-RAN (Open-Radio Access Network), improvements are being considered to improve the bandwidth requirements in the open fronthaul between distributed units (O-DUs) and radio units (O-RUs) at base stations.

[0028] In conventional front hole splitting options, the SRS (Sounding Reference Signal) channel estimation and SRS processing functions are located in the distributed unit (O-DU). For example, in conventional technology, based on scheduling messages from the O-DU, an SRS IQ stream is sent from the O-RU to the O-DU, and SRS channel estimation and SRS processing are performed on the O-DU side. Furthermore, when using CIBF (Channel Information-Based Beamforming) in a Category B O-RU, estimated channel information is sent from the O-DU to the O-RU. Also, when using WDBF (Weight-Based Beamforming), the O-DU calculates beamforming weights using the estimated channels and sends them to the O-RU.

[0029] Figure 4 is a diagram illustrating beamforming based on SRS in an embodiment of the present invention. As shown in Figure 4, in O-RAN, it is being considered to place the SRS channel estimation and SRS processing functions in the radio unit (O-RU) and perform SRS-based beamforming in the radio unit. This makes it possible to significantly reduce the front hole bandwidth, as it is possible to omit the transmission of beamforming weights from the O-DU to the O-RU in the case of WDBF, and to omit the transmission of channel information from the O-DU to the O-RU in the case of CIBF.

[0030] Figure 5 is a diagram (1) illustrating the message format (ST5) in the existing specifications. In O-RAN, ST5 (Section Type 5) is used as the format for control plane messages between O-RU and O-DU (fronthaul). Figure 5 defines the information contained in the Common Header Fields and Section Fields in the ST5 format.

[0031] Figure 6 is a diagram (2) illustrating the message format (ST5) in the existing specification. Figure 6 defines the bit arrangement for the information contained in the Common Header Fields and the Section Fields in the ST5 format.

[0032] Furthermore, O-RAN is considering using ST5 to trigger beamforming based on SRS. While ST5 messages are useful for sending user-specific frequency allocation and symbol counts from O-DU to O-RU, directly triggering beamforming requires additional extensions such as SRS settings and port information, which increases message overhead and complicates implementation.

[0033] Furthermore, the user identifier (ueId) included in the ST5 message must contain information about the SRS antenna port and the UE-layer (the terminal layer used to distinguish between multiple MIMO layers and communication layers). Also, in ST5, when the same ueId is reused, it is not possible to distinguish whether the user assigned to the ueId has changed or not. Moreover, in the existing system, since ueIds are assigned on a slot-by-slot basis, it is not possible to continuously perform beamforming settings using the same ueID across multiple slots.

[0034] The following describes how to trigger beamforming based on the Sounding Reference Signal (SRS) using messages from existing specifications in the base station's fronthaul interface.

[0035] (Beamforming trigger using ST5) While maintaining consistency with the existing ST5 format used for user data scheduling, the system efficiently triggers the start of beamforming by combining SRS settings and antenna port information.

[0036] (Setting SRS port ID and UE-layer using ueId bit) A portion of the bits assigned to the user identifier (ueId) is used to set information regarding the SRS antenna port identifier (SRS port ID) and the UE-layer (the communication layer at the terminal used to distinguish between multiple MIMO layers and communication layers). This makes it possible to set information regarding the SRS port and UE-layer while utilizing the format of existing specifications.

[0037] (Identification of ueId reset) By using a portion of the bits assigned to the user identifier (ueId), it is possible to determine whether the terminal (UE) corresponding to the ueId has been reset or not.

[0038] (Example 1) Triggering beamforming using ST5 A method for triggering SRS-based beamforming using an existing specification message (ST5) will be explained with reference to a sequence diagram. Figure 7 is a diagram showing an example of a sequence diagram in an embodiment of the present invention. Details of each step will be explained below.

[0039] S101: O-DU10B sends an SRS configuration message to O-RU10A, which includes configuration information related to SRS (such as frequency band, symbol arrangement, and reference port configuration).

[0040] S102: O-DU10B and O-RU10A decide and share information (policies, rules, etc.) regarding bit assignments for the user identifier (ueId) included in the message that triggers beamforming based on SRS. For example, O-DU10B may send assignment information to O-RU10A that assigns the 4 bits on the LSB side of the ueId to the SRS port ID and the 10 bits on the MSB side to the UE-layer. Alternatively, O-RU10A may send a response message to O-DU10B indicating that it agrees to the received assignment information. This allows O-RU10A to obtain information about the SRS port ID and UE-layer included in the ueId. Alternatively, the bit assignment for the user identifier (ueId) may be determined by specifications, etc. Furthermore, O-DU10B and 0-RU10A may assume that a message (ST5) will trigger SRS-based beamforming if it is recognized / agreement that the user identifier (ueId) in the existing specification message (ST5) includes (is set to) information about the SRS port ID and UE-layer. In other words, if there is no such recognition / agreement, O-DU10B and 0-RU10A assume that the message will be used only as an existing specification message (ST5) for UE scheduling.

[0041] S103: O-DU10B generates a message indicating the start of beamforming (trigger) at the timing when O-RU10A should start beamforming based on SRS (for example, the communication timing for slot n). This message may use an existing specification message (ST5) that includes a user identifier (ueId), and the bits of ueId are set with information about the SRS port ID and UE-layer based on the rules determined in S102. For example, if SRS port ID=12 and UE-layer=3 are set, ueId=0x30C. By utilizing the existing specification (ST5) format without significantly changing it, UE scheduling (frequency and timing) information is also notified by ST5, making it possible to manage the beamforming start timing all at once.

[0042] S104: O-DU10B transmits a message indicating a trigger / notification / indication of the start of beamforming based on the SRS, which was generated in S103, to O-RU10A.

[0043] S105: O-RU10A analyzes the user identifier (ueId) included in the message received in S104 to obtain information regarding the SRS port ID and the UE-layer. Further, O-RU10A applies beamforming weights using the obtained information, executes beamforming based on the SRS, and starts communication with the terminal. Thereby, it is possible to trigger beamforming by a message of an existing specification (ST5), and the implementation can be simplified.

[0044] (Example 2) A method for reusing (re-assigning to a different terminal) the user identifier (ueId) included in a message that triggers user identifier (ueId) reuse beamforming will be described.

[0045] (ueId bit design) FIG. 8 is a diagram showing an example of bits of a user identifier (ueId) in an embodiment of the present invention. As shown in FIG. 8, for example, in a 15-bit ueId, 1 bit of the most significant bit (MSB), bit 14, is assigned to recycleIndicator, 10 bits from bit 13 to bit 4 are assigned to the UE-layer and user identification information (information for identifying a terminal), and 4 bits from bit 3 to bit 0 are assigned to the SRS port ID. Here, recycleIndicator is information for indicating that the user identifier (ueId) has been reused, that is, the terminal (for example, UE0) assigned to the ueId has been assigned to another terminal (for example, UE1). For example, when reused, the bit is set to 1. Thus, in the existing specification, the ueId is only used as user identification information, but in this embodiment, information indicating the SRS port ID, the UE-layer, and the reuse of the user identifier is also included in the ueId for management.

[0046] (Reuse of ueID) When the ueId assigned to a certain user / terminal (for example, UE0) becomes unnecessary (for example, at the end of a session, etc.), the O-DU assigns the ueId with the same value to another user / terminal (for example, UE1). Here, the O-DU sets the recycleIndicator in the ueId to 1 and sends a message containing the ueId to the O-RU. If the recycleIndicator in the ueId contained in the message received from the O-RU is set to 1, the O-RU recognizes that the user / terminal assigned to the ueId has been changed. If the recycleIndicator is set to 0, the O-RU recognizes that the user / terminal has not been changed. Thus, the recycleIndicator is information (terminal change information) indicating that the user / terminal assigned to the user identifier has been changed. In the above example, for the recycleIndicator, 1 is set when the user / terminal assigned to the user identifier has been changed, and 0 is set when it has not been changed. However, 0 may be set when the user / terminal assigned to the user identifier has been changed, and 1 may be set when it has not been changed.

[0047] Thus, the O-DU can clearly notify the O-RU of the timing when the user / terminal assigned to the user identifier has been changed, avoid duplication of the user identifier, and save the amount of information necessary to identify the user.

[0048] (Continuous reuse of ueId in multiple slots) The O-DU and the O-RU may assume that in multiple slots where the user / terminal assigned to the ueId has not been changed, they continuously use the settings related to beamforming and the SRS resources. Thereby, it becomes unnecessary to transmit control messages for each slot, and it is possible to reduce the transmission cost of control messages.

[0049] (Effects) The above-described method and embodiment allows for the execution of beamforming triggers based on the Sounding Reference Signal (SRS) using messages of the existing specifications in the base station's fronthaul interface. Furthermore, by managing beamforming triggers and scheduling together using the same message (ST5), the amount of C-plane messages transmitted can be significantly reduced. In addition, by using the newly designed bit assignment of the user identifier (ueId), it is possible to simultaneously identify the SRS port and the UE-layer. Moreover, by adding information (recycleIndicator) to the ueId indicating that the user / terminal assigned to the user identifier has changed, it becomes possible to explicitly distinguish the user / terminal assigned to the ueID, thereby stabilizing the continuation and reassignment of beamforming settings.

[0050] (Device Configuration) Next, an example of the functional configuration of the base station 10 and terminal 20 that perform the processes and operations described above will be explained. The base station 10 and terminal 20 include the functions to carry out the above-described embodiment. However, the base station 10 and terminal 20 may each be equipped with only some of the functions in the embodiment.

[0051] <Base Station 10> Figure 9 is a diagram showing an example of the functional configuration of a base station 10 in an embodiment of the present invention. As shown in Figure 9, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Figure 9 is merely an example. Any functional classification and functional unit names are acceptable as long as they can perform the operations according to the embodiment of the present invention.

[0052] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The transmitting unit 110 also transmits inter-network node messages to other network nodes. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 and obtaining information from the received signals, for example, higher layer information. The transmitting unit 110 also has the function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, etc. to the terminal 20. The receiving unit 120 also receives inter-network node messages from other network nodes.

[0053] The setting unit 130 stores pre-configured setting information and various setting information to be transmitted to the terminal 20.

[0054] The control unit 140 performs control related to the processing described in the embodiment. The control unit 140 also performs scheduling. The signal transmission function unit of the control unit 140 may be included in the transmission unit 110, and the signal reception function unit of the control unit 140 may be included in the reception unit 120.

[0055] Furthermore, the base station 10 may include a distributed unit (O-DU) and a wireless unit (O-RU), and the distributed unit (O-DU) and the wireless unit (O-RU) may each have a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. Also, the distributed unit (O-DU) and the wireless unit (O-RU) may communicate with each other using the transmitting unit 110 and the receiving unit 120.

[0056] <Terminal 20> Figure 10 is a diagram showing an example of the functional configuration of terminal 20 in an embodiment of the present invention. As shown in Figure 10, terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Figure 10 is merely an example. Any functional classification and functional unit names are acceptable as long as they can perform the operations according to the embodiment of the present invention.

[0057] The transmitting unit 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and acquires signals from higher layers from the received physical layer signals. The receiving unit 220 also has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, etc. transmitted from the base station 10. For example, the transmitting unit 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to other terminals 20 as D2D communication, and the receiving unit 220 receives PSCCH, PSSCH, PSDCH or PSBCH, etc. from other terminals 20.

[0058] The setting unit 230 stores various setting information received from the base station 10 by the receiving unit 220. The setting unit 230 also stores pre-configured setting information.

[0059] The control unit 240 performs control related to the processing described in the embodiment. The signal transmission function in the control unit 240 may be included in the transmission unit 210, and the signal reception function in the control unit 240 may be included in the reception unit 220.

[0060] (Hardware Configuration) The block diagrams (Figures 9 and 10) used in the description of the above embodiments show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the one device or the multiple devices with software.

[0061] Functions include, but are not limited to, judgment, decision, determination, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited.

[0062] For example, the base station 10, terminal 20, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 11 is a diagram showing an example of the hardware configuration of the base station 10 and terminal 20 according to one embodiment of the present disclosure. The above-mentioned base station 10 and terminal 20 may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0063] In the following explanation, the term "device" can be read as "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and terminal 20 may include one or more of the devices shown in the figure, or it may be configured without some of the devices.

[0064] Each function in the base station 10 and terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and storage device 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of data reading and writing in the storage device 1002 and auxiliary storage device 1003.

[0065] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. For example, the control unit 140, control unit 240, etc., described above may be implemented by the processor 1001.

[0066] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 140 of the base station 10 shown in Figure 9 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in Figure 10 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-described processes have been explained as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may also be transmitted from the network via a telecommunications line.

[0067] The storage device 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may also be called a register, cache, main memory, etc. The storage device 1002 can store executable programs (program code), software modules, etc., for implementing a communication method according to one embodiment of the present disclosure.

[0068] The auxiliary storage device 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital multipurpose disk, a Blu-ray® disk), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. The above-mentioned storage medium may also be a database, server, or other suitable medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0069] The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include, for example, a high-frequency switch, duplexer, filter, frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the transmitting and receiving antenna, amplifier section, transmitting and receiving section, transmission path interface, etc., may be implemented by the communication device 1004. The transmitting and receiving section may be implemented in a physically or logically separated manner, with a transmitting section and a receiving section.

[0070] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0071] Furthermore, each device, such as the processor 1001 and the storage device 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0072] Furthermore, the base station 10 and terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0073] Figure 12 shows an example of the configuration of vehicle 2001. As shown in Figure 12, vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect / embodiment described in this disclosure may be applied to a communication device mounted on vehicle 2001, for example, to the communication module 2013.

[0074] The drive unit 2002 consists of, for example, an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel, which is operated by the user.

[0075] The electronic control unit 2010 consists of a microprocessor 2031, memory (ROM, RAM) 2032, and communication ports (IO ports) 2033. Signals from various sensors 2021 to 2029 installed in the vehicle 2001 are input to the electronic control unit 2010. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0076] Signals from various sensors 2021 to 2029 include current signals from current sensor 2021 for sensing motor current, front and rear wheel rotation speed signals acquired by rotation speed sensor 2022, front and rear wheel air pressure signals acquired by air pressure sensor 2023, vehicle speed signals acquired by vehicle speed sensor 2024, acceleration signals acquired by acceleration sensor 2025, accelerator pedal depression signals acquired by accelerator pedal sensor 2029, brake pedal depression signals acquired by brake pedal sensor 2026, shift lever operation signals acquired by shift lever sensor 2027, and detection signals acquired by object detection sensor 2028 for detecting obstacles, vehicles, pedestrians, etc.

[0077] The Information Service Unit 2012 consists of various devices for providing (outputting) various types of information such as driving information, traffic information, and entertainment information, including a car navigation system, audio system, speakers, television, and radio, and one or more ECUs that control these devices. The Information Service Unit 2012 uses information acquired from external devices via a communication module 2013, etc., to provide various multimedia information and multimedia services to the occupants of the vehicle 2001. The Information Service Unit 2012 may include input devices that accept input from the outside (e.g., keyboard, mouse, microphone, switch, button, sensor, touch panel, etc.) and output devices that perform output to the outside (e.g., display, speaker, LED lamp, touch panel, etc.).

[0078] The driver assistance system unit 2030 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System)), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driver assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driver assistance functions or autonomous driving functions.

[0079] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via its communication port. For example, the communication module 2013 sends and receives data via the communication port 2033 between the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, the microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021-29 provided in the vehicle 2001.

[0080] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with external devices. For example, it can send and receive various types of information with external devices via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station or a mobile station.

[0081] The communication module 2013 may transmit at least one of the following to an external device via wireless communication: signals from the various sensors 2021-2028 input to the electronic control unit 2010, information obtained based on said signals, and information based on input from an external source (user) obtained via the information service unit 2012. The electronic control unit 2010, the various sensors 2021-2028, the information service unit 2012, etc., may also be called input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include the information based on the above input.

[0082] The communication module 2013 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it on the information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may also be called an output unit, which outputs information (for example, outputs information to devices such as displays and speakers based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from the external device in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021-2029, etc., provided in the vehicle 2001.

[0083] <Notes> (Note 1) A base station having a distributed unit and a radio unit, wherein the distributed unit has a control unit that sets an antenna port identifier in SRS (Sounding Reference Signal) and terminal layer information relating to the communication layer at the terminal as user identification information, and generates a first message that triggers beamforming based on SRS, including the user identification information, and a transmission unit that transmits the first message to the radio unit. (Note 2) The base station according to Note 1, wherein the transmission unit transmits a second message to the radio unit before transmitting the first message, which includes information regarding the bit allocation of the antenna port identifier and the terminal layer information in the user identification information. (Note 3) The base station according to Note 1, wherein the control unit includes terminal change information in the user identification information indicating whether or not the terminal assigned to the user identification information has been changed to a different terminal. (Appendix 4) The base station according to Appendix 1, wherein the control unit assumes that the first message will trigger beamforming based on SRS when the user identification information in the first message is set to the antenna port identifier and the terminal layer information. (Appendix 5) A communication method performed by a base station having a distributed unit and a radio unit, comprising the steps of: setting the antenna port identifier in SRS (Sounding Reference Signal) and terminal layer information relating to the communication layer at the terminal as user identification information, and generating a first message that triggers beamforming based on SRS, which includes the user identification information; and transmitting the first message to the radio unit.

[0084] According to any of the provisions of Appendix 1 to Appendix 5, beamforming based on the Sounding Reference Signal (SRS) can be triggered using messages of the existing specifications in the base station's fronthaul interface.

[0085] (Supplement to Embodiments) Embodiments of the present invention have been described above, but the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, substitutions, etc. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be combined as needed, and matters described in one item may be applied to matters described in another item (as long as they do not contradict each other). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operation of multiple functional units may be physically performed by one part, or the operation of one functional unit may be physically performed by multiple parts. The processing procedures described in the embodiments may be rearranged as long as they do not contradict each other. For the convenience of explaining the processing, the base station 10 and terminal 20 have been described using functional block diagrams, but such devices may be realized in hardware, software, or a combination thereof. The software operated by the processor of the base station 10 according to an embodiment of the present invention and the software operated by the processor of the terminal 20 according to an embodiment of the present invention may be stored in any suitable storage medium such as random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or other appropriate storage medium.

[0086] Furthermore, notification of information is not limited to the embodiments described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or combinations thereof. Also, RRC signaling may be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0087] Each aspect / embodiment described in this disclosure refers to LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (where x is, for example, an integer or decimal)), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20 may apply to at least one system utilizing UWB (Ultra-WideBand), Bluetooth®, or other appropriate systems, and to next-generation systems extended, modified, created, or defined based thereon. Alternatively, multiple systems may be applied in combination (e.g., a combination of at least one of LTE and LTE-A with 5G).

[0088] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0089] In this specification, specific operations performed by the base station 10 may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station 10, it is clear that various operations performed for communication with the terminal 20 can be performed by the base station 10 and at least one of the other network nodes (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station 10, the other network node may be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0090] The information or signals described in this disclosure may be output from a higher layer (or lower layer) to a lower layer (or higher layer). They may also be input and output via multiple network nodes.

[0091] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be transmitted to other devices.

[0092] The determination in this disclosure may be made by a value represented by one bit (0 or 1), by a Boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0093] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0094] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0095] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0096] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0097] The terms “system” and “network” as used in this disclosure are interchangeable.

[0098] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0099] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0100] In this disclosure, terms such as "Base Station (BS)", "wireless base station", "base station equipment", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0101] A base station can accommodate one or more (e.g., three) cells. If a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a Remote Radio Head (RRH)). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0102] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform control or operation based on the information.

[0103] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0104] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or several other appropriate terms.

[0105] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may also be a device mounted on a mobile body, the mobile body itself, etc. The mobile body refers to a movable object, and its speed of movement is arbitrary. This also includes the case when the mobile body is stationary. The mobile body includes, but is not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and items mounted on them. The mobile body may also be a mobile body that moves autonomously based on operation commands. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Furthermore, at least one of the base station and the mobile station may include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0106] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminals 20 may have the functions that the base station 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc., may be interpreted as side channel.

[0107] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station may be configured to have the same functions as the user terminal described above.

[0108] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, or inquiring (e.g., searching in a table, database, or other data structure), or ascertaining. “Determining” may also include receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, or accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0109] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0110] The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard.

[0111] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0112] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the first and second elements do not imply that only two elements may be employed, or that the first element must precede the second element in any way.

[0113] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0114] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0115] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0116] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0117] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0118] Although the present disclosure has been described in detail above, it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way.

[0119] This patent application claims priority based on Japanese Patent Application No. 2025-024542, filed on 18 February 2025, and the entire contents of Japanese Patent Application No. 2025-024542 are incorporated herein by reference.

[0120] 10 Base station 110 Transmitting unit 120 Receiving unit 130 Setting unit 140 Control unit 20 Terminal 210 Transmitting unit 220 Receiving unit 230 Setting unit 240 Control unit 30 Network node 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device 2001 Vehicle 2002 Drive unit 2003 Steering unit 2004 Accelerator pedal 2005 Brake pedal 2006 Shift lever 2007 Front wheel 2008 Rear wheel 2009 Axle 2010 Electronic control unit 2012 Information service unit 2013 Communication module 2021 Current sensor 2022 Rotation speed sensor 2023 Air pressure sensor 2024 Vehicle speed sensor 2025 Acceleration sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object detection sensor 2029 Accelerator pedal sensor 2030 Driver assistance system unit 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication port (I / O port)

Claims

1. A base station having a distributed unit and a radio unit, wherein the distributed unit includes a control unit that sets an antenna port identifier in SRS (Sounding Reference Signal) and terminal layer information relating to the communication layer at the terminal as user identification information and generates a first message that triggers beamforming based on SRS, including the user identification information, and a transmission unit that transmits the first message to the radio unit.

2. The base station according to claim 1, wherein the transmitting unit transmits a second message to the radio unit before transmitting the first message, the second message containing information regarding the bit allocation of the antenna port identifier and the terminal layer information in the user identification information.

3. The base station according to claim 1, wherein the control unit includes terminal change information in the user identification information indicating whether or not the terminal assigned to the user identification information has been changed to a different terminal.

4. The base station according to claim 1, wherein the control unit assumes that the first message triggers beamforming based on SRS when the user identification information in the first message is set to include the antenna port identifier and the terminal layer information.

5. A communication method performed by a base station having a distributed unit and a radio unit, comprising the steps of: setting an antenna port identifier in SRS (Sounding Reference Signal) and terminal layer information relating to the communication layer at the terminal as user identification information; generating a first message that triggers beamforming based on SRS, including the user identification information; and transmitting the first message to the radio unit.

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