Base station and control method
The base station with a distributed unit and radio units optimizes the open fronthaul interface for distributed MIMO, addressing unclear operations in O-RAN, by implementing cooperative beamforming, diversity gain maximization, and dynamic antenna placement to enhance communication reliability and quality.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NTT DOCOMO INC
- Filing Date
- 2024-11-13
- Publication Date
- 2026-05-21
AI Technical Summary
The operation of the open fronthaul interface in O-RAN for distributed MIMO is not clearly defined, which affects the performance and implementation complexity in 6G communication systems.
A base station comprising a distributed unit and multiple radio units, where the radio units receive configuration information for cooperative beamforming, synchronization, and dynamic antenna placement, enabling coordinated beamforming, diversity gain maximization, and decentralized cooperation mechanisms to optimize communication quality and efficiency.
The solution clarifies the operation of the open fronthaul interface, enhancing communication reliability, quality, and coverage by implementing advanced features like coordinated beamforming, diversity gain maximization, and dynamic antenna placement, improving user experience and network resource utilization.
Smart Images

Figure JP2024040309_21052026_PF_FP_ABST
Abstract
Description
Base Station and Control Method ,
[0006] ,
[0005] ,
[0001] The present invention relates to a base station and a control method in a communication system.
[0002] In a radio communication system NR (New Radio) (also referred to as "5G") and a successor system of NR (e.g., "6G") based on the 3GPP (registered trademark) standard, as requirements, technologies that satisfy a large-capacity system, high data transmission speed, low latency, simultaneous connection of a large number of terminals, low cost, power saving, etc. are being studied (e.g., Non-Patent Document 1).
[0003] Also, the network architecture in 5GC (5G Core Network) or 5GS (5G System), which is the core network in 5G, and 6GC (6G Core Network) or 6GS (6G System), which is a successor to 5G, is being studied.
[0004] Also, in O-RAN, as technologies for realizing 6G, an AI-Native RAN architecture, multi-RAT (Radio Access Technology) spectrum sharing (Mult-RAT Spectrum Sharing (MRSS)), enhanced massive MIMO (Multiple Input Multiple Output) considering 1000 or more antenna elements, and distributed MIMO, etc. are being studied. The technology is closely related to an Open Fronthaul Interface that connects a distributed unit (O-DU (Distribution Unit)) responsible for the functions of the physical upper layer (PHY-high) and a radio unit (O-RU (Radio Unit)) responsible for the functions of the physical lower layer (PHY-low). For example, the performance and implementation complexity in the technology are affected by the low-layer division options that determine the functions of PHY-high and PHY-low.
[0005] 3GPP TS 38.300 V18.3.0 (2024-09)
[0006] Distributed MIMO, one of the technologies being considered for 6G in O-RAN, is feared to be strongly affected by the functionality and requirements of the open fronthaul interface. However, the operation of this open fronthaul interface in O-RAN is not yet clearly defined.
[0007] This invention has been made in view of the above points, and aims to clarify the operation of an open fronthaul interface for distributed MIMO.
[0008] According to the disclosed technology, a base station is provided, comprising a distributed unit and a plurality of radio units, wherein the plurality of radio units include: a receiving unit that receives configuration information relating to cooperative beamforming control from the distributed unit; a control unit that activates a synchronization window for synchronizing the timing of data transmission among the plurality of radio units based on the configuration information; and a transmitting unit that performs data transmission to a terminal using the synchronization window.
[0009] The disclosed technology clarifies the operation of the open fronthaul interface for distributed MIMO.
[0010] This figure shows an example configuration of a wireless communication system in an embodiment of the present invention (1). This figure shows an example configuration of a wireless communication system in an embodiment of the present invention (2). This figure shows an example of a logical architecture in O-RAN. This figure shows an example of a sequence diagram relating to Method 1 in an embodiment of the present invention. This figure shows an example of a sequence diagram relating to Method 2 in an embodiment of the present invention. This figure shows an example of a sequence diagram relating to Method 3 in an embodiment of the present invention. This figure shows an example of a sequence diagram relating to Method 4 in an embodiment of the present invention. This figure shows an example of the functional configuration of a base station 10 and a network node 30 in an embodiment of the present invention. This figure shows an example of the functional configuration of a terminal 20 in an embodiment of the present invention. This figure shows an example of the hardware configuration of a base station 10 and a 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] 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.
[0013] 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-".
[0014] 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).
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] Furthermore, these requirements may include ultra-high-speed communication, large-capacity communication, ultra-wide coverage, ultra-low power consumption, low cost, ultra-low latency, ultra-high reliability communication, ultra-high connectivity, and sensing.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] Figure 3 shows an example of the logical architecture in O-RAN. As shown in Figure 3, at base station 10, the distributed unit (O-DU) and the radio unit (O-RU) are connected via an open fronthaul interface. In addition, the open fronthaul control / user / synchronous plane (Open FH CUS-Plane) transmits and receives control signals, user data, and synchronization signals, while the open fronthaul management plane (Open FH M-Plane) transmits and receives management signals.
[0025] Furthermore, in 6G communication systems, expanded massive MIMO technology using more than 1,000 antenna elements is expected. However, such a large-scale antenna configuration presents the following challenges.
[0026] The following describes a method for clarifying the operation of an open fronthaul interface with respect to distributed MIMO. This method adds / extends distributed MIMO functionality to the fronthaul interface in O-RAN to support the advanced features expected in 6G. In the following method, requests / instructions / notifications / reports sent and received by O-DU and O-RU may be messages containing requests / instructions / notifications / reports. Furthermore, multiple methods shown below may be used in combination.
[0027] (Method 1) Cooperative beamforming Method 1 describes the procedure for adding cooperative beamforming functionality to the O-RAN fronthaul interface. Figure 4 is a diagram showing an example of a sequence diagram relating to Method 1 in an embodiment of the present invention. In this sequence, the O-DU coordinates beamforming settings and data among multiple O-RUs to achieve seamless coverage. It also synchronizes the transmission of user data from multiple points between different O-RUs. The processing of each step will be described below.
[0028] S101: O-DU10A transmits CooperationBeamformingControlParams to multiple O-RU10B (10B1, 10B2, ...). These parameters are configuration information for sharing beamforming settings among multiple O-RUs to perform beamforming in a coordinated manner. These parameters may also include information indicating the activation of the synchronization window.
[0029] S102: Multiple O-RU10B (10B1, 10B2, ...) activate a synchronization window to synchronize the data transmission timing among the multiple O-RUs based on the parameters received in S101.
[0030] S103: Multiple O-RU10B units (10B1, 10B2, ...) use the synchronization window set in S102 to synchronize and transmit the same user data to the terminal. The terminal can improve communication quality by combining the received signals.
[0031] In the above process, O-DU10A and O-RU10B may transmit and receive the following parameters and set them on their own devices: • CooperationBeamformingControlParams include Synchronization window (e.g., Enabled) and Beamforming strategy (e.g., Coordinated Multi-Point (CoMP)). • TransmissionTimingParams include Time alignment error (e.g., less than 1 μs).
[0032] Method 1 enables coordinated beamforming among multiple O-RUs, achieving seamless coverage and high communication quality. Furthermore, by sharing signal processing, the load on each device can be reduced. This also improves coverage and achieves seamless coverage, enhancing the user experience.
[0033] (Method 2) Diversity Gain Maximization Control Method 2 describes the procedure for maximizing diversity gain in the O-RAN fronthaul interface. Figure 5 is a diagram showing an example of a sequence diagram relating to Method 2 in an embodiment of the present invention. In this sequence, the O-DU uses multiple O-RUs to receive and transmit signals through different paths to improve the reliability and quality of communication. For example, user data is transmitted through different paths, and the path with the optimal reception quality is selected. The processing of each step is described below.
[0034] S201: O-DU10A sends diversity control parameters (MaxDiversityGainControlParams) to multiple O-RU10B units (10B1, 10B2, ...) to maximize the diversity gain.
[0035] S202: Multiple O-RU10B units (10B1, 10B2, ...) set the parameters received in S201 and send user data to the terminal using different paths for each O-RU.
[0036] S203: Based on the measurement report transmitted from the terminal, O-DU10A evaluates the reception quality of each path through which O-RU10B transmitted user data to the terminal, and performs the selection of the optimal path / path combination.
[0037] In the above process, O-DU10A and O-RU10B may transmit and receive the following parameters and set them on their own devices: • MaxDiversityGainControlParams (diversity gain maximization control parameters) include Signal paths (number of signal paths, e.g., 2 or more) and Selection criteria (path selection criteria, e.g., Signal-to-Noise Ratio (SNR)). • DiversityTechniqueParams (diversity technology parameters) include Diversity type (diversity type, e.g., Space diversity).
[0038] Method 2 allows for the use of multiple O-RUs to receive and transmit signals through different paths, thereby improving communication reliability and quality. For example, using different paths can prevent communication interruptions. Furthermore, selecting the optimal reception quality can improve data transmission efficiency.
[0039] (Method 3) Method 3 for dynamic placement of distributed antennas describes the procedure for adding a dynamic placement function for distributed antennas to the O-RAN fronthaul interface. Figure 6 is a diagram showing an example of a sequence diagram relating to Method 3 in an embodiment of the present invention. In this sequence, the O-DU optimizes the placement of antennas in real time based on the environment and user traffic patterns and instructs the O-RU to change the placement. A use case is to readjust the placement of antennas to a specific area when there is a traffic concentration at an event venue. The processing of each step will be described below.
[0040] S301: O-DU10A sets the dynamic placement parameters (DynamicAntennaPlacementParams) for the distributed antennas and transmits them to multiple O-RU10B units (10B1, 10B2, ...).
[0041] S302: O-DU10A collects environmental information such as traffic load and information regarding the implementation of events (concerts, etc.) from O-CU / multiple O-RU10B (10B1, 10B2, ...) etc.
[0042] S303: The O-DU10A dynamically optimizes the antenna placement in real time based on the collected information.
[0043] S304: O-DU10A transmits instructions to multiple O-RU10B units (10B1, 10B2, ...) to change the antenna configuration, including information about the optimized antenna configuration in S303.
[0044] In the above process, O-DU10A and O-RU10B may perform the transmission and reception of the following parameters and the setting to the self-device. - As DynamicAntennaPlacementParams (dynamic placement parameters of distributed antennas), it includes Placement criteria (placement criteria, e.g., Traffic load, Event occurrence) and Update interval (update interval, e.g., 5 minutes). - As DistributedAntennaCommProtocol (communication protocol between distributed antennas), it includes Protocol (protocol information, mmWave, Sub-6 GHz).
[0045] By Method 3, it is possible to optimize the antenna placement in real time based on the environment and the user's traffic pattern, and improve the communication efficiency. For example, by repositioning the antennas in the traffic concentration area, it is possible to enhance the communication capacity. Also, by alleviating the network congestion and providing high-speed and stable communication, it is possible to improve the user experience.
[0046] (Method 4) In the decentralized cooperation mechanism Method 3, the procedure for efficiently performing the cooperation between distributed antennas and optimizing the performance of the entire system will be described. FIG. 6 is a diagram showing an example of a sequence diagram related to Method 3 in the embodiment of the present invention.
[0047] S401: O-DU10A sets the first setting information including the decentralized coordination mechanism (DecentralizedCoordinationMechanism) and the second setting information including the dynamic power control parameters (DynamicPowerControlParams).
[0048] Here, the decentralized coordination mechanism (DecentralizedCoordinationMechanism) may include, for example, a decentralized protocol (Coordination method, e.g., Blockchain-based, P2P, etc.) and a consensus algorithm (Consensus algorithm, e.g., Proof of Stake).
[0049] Also, the dynamic power control parameters (DynamicPowerControlParams) may include, for example, a power threshold (Power threshold, e.g., 5W) and an adjustment time interval (Adjustment interval, e.g., 1 minute).
[0050] S402: O-DU10A transmits the first setting information and the second setting information set in S401 to a plurality of O-RU10B (10B1, 10B2,...).
[0051] S403: Based on the first setting information received in S402, O-RU10B (10B1, 10B2,...) sets a distributed protocol and executes information sharing between O-RUs using the set protocol.
[0052] S404: Based on the second setting information received in S402, O-RU10B (10B1, 10B2,...) sets dynamic power control parameters and executes dynamic power control. Here, O-RU10B (10B1, 10B2,...) may execute the dynamic power control using the information shared between O-RUs by the process of S403.
[0053] In the above process, at least one of the first setting information and the second setting information of O-RU10B (10B1, 10B2,...) may be received not from O-DU10A but from SMO (Service Management Orchestration), or may be set in the device in advance.
[0054] By using a distributed cooperation mechanism that enables efficient cooperation according to Method 4, rapid and reliable information sharing is possible. Also, by dynamic power control, it is possible to reduce power consumption and improve energy efficiency.
[0055] (Effects) The above method clarifies the operation of the open fronthaul interface for distributed MIMO. It also enables the effective implementation of advanced features in distributed MIMO, such as coordinated beamforming, maximization of diversity gain, dynamic placement of distributed antennas, and the introduction of distributed coordination mechanisms. This significantly improves communication reliability, quality, and coverage, leading to an improved user experience and optimal utilization of network resources. Furthermore, these features are achieved by extending the fronthaul interface, maintaining compatibility with existing network infrastructure.
[0056] (Device Configuration) Next, an example of the functional configuration of the base station 10, network node 30, and terminal 20 that perform the processing and operations described above will be explained. The base station 10, network node 30, and terminal 20 include the functions to perform the embodiments described above. However, the base station 10, network node 30, and terminal 20 may each be equipped with only some of the functions in the embodiments.
[0057] <Base Station 10 and Network Node 30> Figure 8 shows an example of the functional configuration of a base station 10 and a network node 30. As shown in Figure 8, 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 8 is merely an example. The functional classifications and names of the functional units can be anything as long as they can perform the operations according to the embodiment of the present invention. The network node 30 may have the same functional configuration as the base station 10. Furthermore, a network node 30 having multiple different functions on the system architecture may be composed of multiple network nodes 30 separated by function.
[0058] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 or other network node 30 and transmitting the signal by wire or wireless. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 or other network node 30 and obtaining information from the received signal, for example, information from a higher layer. A communication unit including the transmitting unit 110 and the receiving unit 120 may be configured.
[0059] The setting unit 130 stores pre-configured setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads them from the storage device as needed.
[0060] The control unit 140 performs the processing described in the embodiment. The signal transmission function in the control unit 140 may be included in the transmission unit 110, and the signal reception function in the control unit 140 may be included in the reception unit 120.
[0061] Furthermore, the base station 10 may include a distributed unit (O-DU), a radio unit (O-RU), a central unit (O-CU), and a near-real-time control device (Near-Real Time RIC), and the O-DU, O-RU, O-CU, and Near-Real Time RIC may each have a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. Also, the O-DU, O-RU, O-CU, and Real Time RIC may communicate with each other using the transmitting unit 110 and the receiving unit 120.
[0062] <Terminal 20> Figure 9 is a diagram showing an example of the functional configuration of terminal 20. As shown in Figure 9, 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 9 is merely an example. The functional classifications and names of the functional units can be anything as long as they can perform the operations according to the embodiment of the present invention. In addition, the communication device that becomes the resource holder may have a functional configuration similar to that of terminal 20.
[0063] 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 obtains 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 control signals or reference signals transmitted from the network node 30. A communication unit including the transmitting unit 210 and the receiving unit 220 may be configured.
[0064] The setting unit 230 stores various setting information received from the network node 30 by the receiving unit 220 in its storage device and reads it from the storage device as needed. The setting unit 230 also stores pre-configured setting information.
[0065] The control unit 240 performs 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.
[0066] (Hardware Configuration) The block diagrams (Figures 8 and 9) 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 above one device or the above multiple devices with software.
[0067] 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.
[0068] For example, the network node 30, 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 10 is a diagram showing an example of the hardware configuration of a base station 10 and terminal 20 according to one embodiment of the present disclosure. The network node 30 may have the same hardware configuration as the base station 10. 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.
[0069] 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.
[0070] 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.
[0071] 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.
[0072] 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 8 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 9 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.
[0073] 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.
[0074] 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.
[0075] 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.
[0076] 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).
[0077] 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.
[0078] 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.
[0079] Figure 11 shows an example of the configuration of vehicle 2001. As shown in Figure 11, vehicle 2001 includes an operating 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.
[0080] The operating 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.
[0081] 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).
[0082] 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.
[0083] 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.).
[0084] 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.
[0085] 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 moving parts 2002, steering parts 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.
[0086] 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.
[0087] 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.
[0088] 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 operating 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.
[0089] <Notes> (Note 1) A base station comprising a distributed unit and a plurality of radio units, wherein the plurality of radio units include: a receiving unit that receives setting information relating to cooperative beamforming control from the distributed unit; a control unit that activates a synchronization window for synchronizing the data transmission timing among the plurality of radio units based on the setting information; and a transmitting unit that performs data transmission to a terminal using the synchronization window. (Note 2) A base station comprising a distributed unit and a plurality of radio units, wherein the distributed unit includes: a transmitting unit that transmits control parameters to maximize diversity gain to the plurality of radio units; and a control unit that evaluates the reception quality of the path through which the plurality of radio units have transmitted user data to the terminal based on a measurement report transmitted from the terminal, and performs the selection of the optimal path. (Note 3) A base station comprising a distributed unit and a plurality of radio units, wherein the distributed unit comprises a transmitting unit that transmits configuration information relating to the dynamic arrangement of distributed antennas to the plurality of radio units, and a control unit that performs dynamic optimization of antenna arrangement based on information relating to traffic load, wherein the transmitting unit transmits an antenna arrangement update instruction to the plurality of radio units, which includes information relating to the optimized antenna arrangement. (Note 4) A base station comprising a distributed unit and a plurality of radio units, wherein the plurality of radio units comprises a receiving unit that receives first configuration information relating to a distributed coordination mechanism and second configuration information relating to dynamic power control from the distributed unit, and a control unit that performs information sharing among the plurality of radio units using a distributed protocol configured based on the first configuration information, wherein the control unit performs dynamic power control based on the second configuration information and the information shared.(Appendix 5) A control method performed by a base station including a distributed unit and a plurality of radio units, wherein the plurality of radio units include: a receiving unit that receives setting information relating to cooperative beamforming control from the distributed unit; a control unit that activates a synchronization window for synchronizing the data transmission timing among the plurality of radio units based on the setting information; and a transmitting unit that performs data transmission to a terminal using the synchronization window.
[0090] Any of the appendices 1 to 5 can clarify the operation of the open fronthaul interface for distributed MIMO.
[0091] (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.
[0092] 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.
[0093] 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).
[0094] 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.
[0095] 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).
[0096] 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.
[0097] 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.
[0098] 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).
[0099] 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.
[0100] 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.
[0101] 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.
[0102] 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.
[0103] The terms “system” and “network” as used in this disclosure are interchangeable.
[0104] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values from a given value, or corresponding other information. For example, wireless resources may be indicated by an index.
[0105] 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.
[0106] 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.
[0107] 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.
[0108] 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.
[0109] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.
[0110] 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.
[0111] 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.
[0112] 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.
[0113] 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.
[0114] 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."
[0115] 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.
[0116] The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard.
[0117] 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."
[0118] 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.
[0119] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.
[0120] 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.
[0121] 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.
[0122] 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."
[0123] 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).
[0124] 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.
[0125] 10 Base station 110 Transmitter 120 Receiver 130 Setting unit 140 Control unit 20 Terminal 210 Transmitter 220 Receiver 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
Claims
1. A base station comprising a distributed unit and a plurality of radio units, wherein the plurality of radio units include: a receiving unit that receives setting information relating to cooperative beamforming control from the distributed unit; a control unit that activates a synchronization window for synchronizing the data transmission timing among the plurality of radio units based on the setting information; and a transmitting unit that performs data transmission to a terminal using the synchronization window.
2. A base station comprising a distributed unit and a plurality of radio units, wherein the distributed unit includes a transmitting unit that transmits control parameters to the plurality of radio units to maximize diversity gain, and a control unit that evaluates the reception quality of the paths through which the plurality of radio units transmit user data to the terminal based on measurement reports transmitted from the terminal, and performs the selection of the optimal path.
3. A base station comprising a distributed unit and a plurality of radio units, wherein the distributed unit includes a transmitting unit that transmits configuration information relating to the dynamic arrangement of distributed antennas to the plurality of radio units, and a control unit that performs dynamic optimization of the antenna arrangement based on information relating to the traffic load, and the transmitting unit transmits an antenna arrangement update instruction to the plurality of radio units, the instruction including information relating to the optimized antenna arrangement.
4. A base station comprising a distributed unit and a plurality of radio units, wherein the plurality of radio units include: a receiving unit that receives first configuration information relating to a distributed coordination mechanism and second configuration information relating to dynamic power control from the distributed unit; and a control unit that performs information sharing among the plurality of radio units using a distributed protocol configured based on the first configuration information, wherein the control unit performs dynamic power control based on the second configuration information and the information shared.
5. A control method performed by a base station including a distributed unit and a plurality of radio units, wherein the plurality of radio units include: a receiving unit that receives setting information relating to cooperative beamforming control from the distributed unit; a control unit that activates a synchronization window for synchronizing the data transmission timing among the plurality of radio units based on the setting information; and a transmitting unit that performs data transmission to a terminal using the synchronization window.