Base station and base station control method

Abstract

This base station capable of communicating with a plurality of user devices (user equipment: UE) by a wireless communication system includes a radio link control (RLC) layer, a medium access control (MAC) layer, and a physical (PHY) layer. The PHY layer is provided with a common processing unit that performs common processing for a plurality of user devices to be connected, and a plurality of user processing units that respectively perform specific processing for the plurality of user devices to be connected. Among the plurality of user processing units, those connected to the user devices are supplied with power and those not connected to the user devices are not supplied with power.

Description

Base station and base station control method

[0001] This application claims priority to Japanese Patent Application No. 2024-055653, filed on March 29, 2024, the contents of which are incorporated herein by reference.

[0002] Recently, a fifth-generation mobile communication system that can be used by various entities according to regional or individual needs has been attracting attention. Such a mobile communication system is also called 5G (5th Generation).

[0003] Non-Patent Document 1 shows an example in which the functions of the PHY (Physical) layer are divided into an RU (Radio Unit) and a DU (Distributed Unit) in fifth-generation mobile communications. Non-Patent Document 2 also shows a specific example of dividing the functions of the PHY layer. The signal processing unit that executes the functions of the PHY layer provided in the DU is also called the H-PHY (High-Physical) layer.

[0004] O-RAN Working Group 8 Base Station O-DU and O-CU Software Architecture and APIsO-RAN Working Group 4 (Open Fronthaul Interfaces WG)Control, User and Synchronization Plane Specification

[0005] In the past, in the H-PHY layer, for processing of user equipment (UE), an accelerator having computational resources capable of processing all of the maximum number of user equipments connected to a base station was assigned, and all of the user equipments were processed at once. Therefore, when the number of user equipments connected to a base station is less than the maximum number of connections, excessive computational resources were assigned, resulting in unnecessary power consumption.

[0006] The present invention has been made in consideration of the above-mentioned points, and has an object to provide a technique that can suitably reduce power consumption according to the number of connected user devices.

[0007] One aspect of the present invention is a base station capable of communicating with a plurality of user equipment (UE) via a wireless communication system, the base station comprising an RLC layer (Radio Link Control layer), a MAC layer (Medium Access Control layer), and a PHY layer (Physical layer), the PHY layer comprising a common processing unit that performs common processing for a plurality of connected user equipment, and a plurality of user processing units that perform specific processing for each of the connected user equipment, and among the plurality of user processing units, power is supplied to the user processing unit that is connected to the user equipment, and power is not supplied to the user processing unit that is not connected to the user equipment.

[0008] In one aspect of the present invention, each of the user processing units is connected to a plurality of the user devices, and the maximum number of the user devices that can be simultaneously connected to each of the user processing units is predetermined.

[0009] In one aspect of the present invention, the maximum number of user devices that can be simultaneously connected to the user processing unit varies depending on the area in which the user devices are installed.

[0010] In one aspect of the present invention, the common processing unit receives a signal used to establish a connection with the user equipment using a physical random access channel (PRACH) in uplink communication with the user equipment.

[0011] In one aspect of the present invention, the user processing unit receives user data of the connected user equipment using a PUSCH (Physical Uplink Shared Channel) in uplink communication with the user equipment.

[0012] In one aspect of the present invention, the common processing unit performs precoding processing on the signals transmitted from the respective user processing units before transmitting the signals to the user equipment.

[0013] In one aspect of the present invention, the common processing unit transmits a signal used for connection with the user equipment in downlink communication with the user equipment, and the signal used for connection with the user equipment includes a synchronization signal (SS) that indicates a signal detection timing and is transmitted from the base station to the user equipment, and a broadcast signal that is transmitted using a PBCH (Physical Broadcast Channel).

[0014] In one aspect of the present invention, the user processing unit transmits user data of the connected user equipment using a PDSCH (Physical Downlink Shared Channel) in downlink communication with the user equipment.

[0015] In one aspect of the present invention, the common processing unit and each of the user processing units are provided separately and independently as a node lower than a DU (Distributed Unit) having at least a MAC layer, and a node higher than an RU (Radio Unit) in the PHY layer that controls an antenna and communicates with the user device.

[0016] Another aspect of the present invention is a method for controlling a base station capable of communicating with a plurality of user equipment (UE) via a wireless communication system, the base station comprising an RLC layer (Radio Link Control layer), a MAC layer (Medium Access Control layer), and a PHY layer (Physical layer), the PHY layer comprising a common processing unit that performs common processing for a plurality of connected user equipment, and a plurality of user processing units that perform specific processing for each of the connected user equipment, the method comprising: supplying power to the user processing unit that is connected to the user equipment, and not supplying power to the user processing unit that is not connected to the user equipment.

[0017] According to the present invention, it is possible to reduce power consumption appropriately according to the number of connected user devices.

[0018] 1 is a diagram illustrating an example of the configuration of a wireless communication system according to a first embodiment. FIG. 1 is a diagram illustrating an example of functional division of a base station according to a first embodiment. FIG. 2 is a diagram illustrating a first example of functional division of an O-DU according to the first embodiment during uplink communication. FIG. 3 is a diagram illustrating a second example of functional division of an O-DU according to the first embodiment during uplink communication. FIG. 4 is a diagram illustrating a fourth example of functional division of an O-DU according to the first embodiment during uplink communication. FIG. 5 is a diagram illustrating a first example of functional division of an O-DU according to the first embodiment during downlink communication. FIG. 6 is a diagram illustrating a second example of functional division of an O-DU according to the first embodiment during downlink communication. FIG. 7 is a diagram illustrating a third example of functional division of an O-DU according to the first embodiment during downlink communication. FIG. 8 is a flowchart illustrating an example of processing of a base station according to the first embodiment. FIG. 9 is a diagram illustrating an example of functional division of a base station according to a second embodiment. FIG. 10 is a block diagram illustrating an example of the internal configuration of a base station of the present embodiment.

[0019] [Embodiment 1] A preferred embodiment of a base station and a base station control method according to the present embodiment will be described in detail below with reference to the accompanying drawings. In the drawings, identical or similar parts are designated by identical or similar reference numerals. Note that the present embodiment is not limited to these embodiments and includes various modifications or improvements. In other words, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical, and the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components of the present embodiment may be made without departing from the spirit of the present invention.

[0020] [Configuration of Wireless Communication System 10] First, the wireless communication system 10 will be described with reference to FIG.

[0021] Fig. 1 is a diagram illustrating an example of a configuration of a wireless communication system 10 according to a first embodiment. The wireless communication system 10 includes a base station 100 and multiple user equipments 200. In Fig. 1, user equipments 200-1 to 200-3 illustrate the multiple user equipments 200. Hereinafter, when the user equipments 200-1 to 200-3 are not distinguished from each other, they may be simply referred to as user equipments 200.

[0022] The base station 100 can communicate with each user equipment 200 via an antenna provided in the base station 100. The base station 100 is, for example, a next generation Node B (gNB). The base station 100 performs wireless communication with each user equipment 200 and provides various services to each user equipment 200.

[0023] The base station 100 may also be a device included in a local 5G system. The local 5G system may be a non-public cellular network. The non-public cellular network may be an example of an NPN (Non Public Network). The local 5G system may be a 5G system built within a building or on land by the owner of the building or land. In this case, the wireless communication system 10 according to the embodiment is an example of a non-public cellular network.

[0024] The user device 200 is an information processing device. The user device 200 may be, for example, a smartphone, a feature phone, an IoT (Internet of Things) device, a personal computer, a vehicle or a device provided in a vehicle, an aircraft or a device provided in an aircraft, etc. The user device 200 may also be referred to as UE (User Equipment).

[0025] [Configuration of Base Station 100] As shown in Fig. 1, base station 100 includes an O-CU (Open-Centralized Unit) 110, multiple O-DUs (Open-Distributed Units) 120, and multiple O-RUs (Open-Radio Units) 130. The multiple O-DUs 120 may be referred to as O-DU120-1 and O-DU120-2, respectively. The multiple O-RUs 130 may be referred to as O-RU130-1, O-RU130-2, O-RU130-3, and O-RU130-4, respectively.

[0026] The O-CU 110 may be referred to as an aggregation unit. The O-CU 110 controls the connected O-DUs 120. Specifically, the O-CU 110 is connected to each of the O-DUs 120-1 and 120-2, and controls each of the O-DUs 120-1 and 120-2. The O-CU 110 may be connected to an external network to transmit and receive data.

[0027] The O-DU 120 may be referred to as a distributed unit. The O-DU 120-1 is connected to the O-CU 110, the O-RU 130-1, and the O-RU 130-2, and controls the O-RU 130-1 and the O-RU 130-2. The O-DU 120-2 is connected to the O-CU 110, the O-RU 130-3, and the O-RU 130-4, and controls the O-RU 130-3 and the O-RU 130-4.

[0028] The O-RU 130 may be referred to as a radio unit. The O-RU 130 is controlled by the O-DU 120 and performs radio communication using a predetermined method such as TDD (Time Division Duplex) or FDD (Frequency Division Duplex). The O-RU 130 controls the antennas provided in the base station to perform downlink (DL) communication from the base station 100 to the user equipment 200 and uplink (UL) communication from the user equipment 200 to the base station 100.

[0029] In the base station 100 according to the embodiment, the O-RAN (Open Radio Access Network) fronthaul specification may be adopted between the O-DU 120 and the O-RU 130. The O-RAN is a specification established by the O-RAN Alliance, which includes multiple telecommunications carriers. However, other communication protocols may also be used between the O-DU 120 and the O-RU 130, and the O-RAN fronthaul specification (hereinafter sometimes referred to as "O-RAN") is not limited to this example.

[0030] [Outline of Functional Division] FIG. 2 is a diagram illustrating an example of functional division of the base station 100 according to the first embodiment.

[0031] The O-CU 110 can perform the functions of a Service Data Adaptation Protocol (SDAP) layer 111, a Radio Resource Control (RRC) layer 112, and a Packet Data Convergence Protocol (PDCP) layer 113.

[0032] Furthermore, the O-DU 120 can perform the functions of an RLC (Radio Link Control) layer 121, a MAC (Media Access Control) layer 122, and part of a PHY (Physical) layer. Of the PHY layer functions, the H-PHY (High-Physical) layer functions provided in the O-DU 120 are performed by a CH-PHY (Common High-Physical) layer 123 and multiple UH-PHY (User-centric High-Physical) layers 124. UH-PHY layers 124-1 and 124-2 are examples of the multiple UH-PHY layers 124. Hereinafter, when there is no need to distinguish between the UH-PHY layer 124-1 and the UH-PHY layer 124-2, they may be simply referred to as the UH-PHY layer 124. Note that while the same figure shows an example in which two UH-PHY layers 124 are provided, the number of UH-PHY layers 124 is arbitrary. The number of UH-PHY layers 124 may differ for each base station 100. By dividing the functions of the UH-PHY layer within the O-DU 120, the base station 100 can reduce processing delays caused by dividing the functions.

[0033] The CH-PHY layer 123 performs common processing for multiple user equipment 200 connected to the base station 100. The CH-PHY layer 123 is also called a common processing unit. Power is supplied to the CH-PHY layer 123 regardless of whether or not there is a user equipment 200 connected.

[0034] The UH-PHY layer 124 performs processing specific to each of the multiple user equipment devices 200 connected to the base station 100. The UH-PHY layer 124 is also referred to as a user processing unit. Power is supplied to the UH-PHY layer 124 connected to the user equipment device 200, and power is not supplied to the user equipment device 200 not connected to the user equipment device 200. In other words, power is not supplied to the UH-PHY layer 124 not connected to the user equipment device 200 and not performing processing. As a result, the base station 100 does not supply power to the UH-PHY layer 124 not connected to the user equipment device 200 and not performing processing. By not supplying power to the UH-PHY layer 124 not connected to the user equipment device 200, the base station 100 can allocate appropriate computational resources according to the number of user equipment devices 200. Therefore, the base station 100 according to the embodiment can effectively reduce unnecessary power consumption due to the allocation of excessive computational resources.

[0035] The UH-PHY layer 124 may be started up for each user equipment 200. In other words, the maximum number of user equipment 200 that can be simultaneously connected to the UH-PHY layer 124 may be one. This allows the base station 100 to accurately allocate computational resources according to the number of connected user equipment 200. By allocating appropriate computational resources for processing by the user equipment 200, the base station 100 can reduce unnecessary power consumption.

[0036] Furthermore, the UH-PHY layer 124 may be started up for each predetermined number of user equipment devices 200. In other words, the maximum number of user equipment devices 200 that can be simultaneously connected to the UH-PHY layer 124 may be multiple and may be predetermined. The base station 100 according to the embodiment can limit the number of UH-PHY layers 124 while allocating computational resources according to the number of connected user equipment devices 200 by setting the maximum number of user equipment devices 200 that can be processed by each UH-PHY layer 124. By limiting the number of UH-PHY layers 124, the base station 100 can reduce the number of times it controls whether or not power is supplied to the UH-PHY layers 124, making the control relatively simple.

[0037] Furthermore, the maximum number of user equipment 200 simultaneously connected to the UH-PHY layer 124 may vary depending on the region in which the base station 100 is installed. In densely populated areas, such as urban areas, the number of mobile people is relatively large, and the number of user equipment 200 connected to the base station 100 is likely to fluctuate. Therefore, in densely populated areas, by increasing the maximum number of user equipment 200 simultaneously connected to the UH-PHY layer 124, it is possible to allocate computational resources according to the number of user equipment 200 while reducing the frequency of control over whether or not power is supplied to the UH-PHY layer 124. On the other hand, in sparsely populated areas, such as rural areas, the number of mobile people is relatively small, and the number of user equipment 200 connected to the base station 100 is unlikely to fluctuate. Therefore, in sparsely populated areas, by reducing the maximum number of user equipment 200 simultaneously connected to the UH-PHY layer 124, it is possible to accurately allocate computational resources according to the number of user equipment 200. Therefore, the base station 100 according to the embodiment can reduce unnecessary power consumption.

[0038] The O-RU 130 can execute some of the PHY layer functions. Hereinafter, the signal processing unit that executes the PHY layer functions provided in the O-RU 130 may be referred to as the Low-PHY layer.

[0039] [Functional Division of O-DU 120 During Uplink Communication] A first example of functional division between the CH-PHY layer 123 and the UH-PHY layer 124 during uplink communication will be specifically described with reference to FIG.

[0040] 3 is a diagram illustrating a first example of functional division during uplink communication for the O-DU 120 according to embodiment 1. FIG. 3 illustrates a specific example of functional division among a CH-PHY layer 123, a UH-PHY layer 124, and a Low-PHY layer.

[0041] The CH-PHY layer 123 performs processing related to a PRACH (Physical Random Access Channel), a PUCCH (Physical Uplink Control Channel), and an SRS (Sounding Reference Signal).

[0042] The PRACH is a channel for uplink communication from the user equipment 200 to the base station 100. The CH-PHY layer 123 receives a random access preamble using the PRACH as a signal used to establish a connection with the user equipment 200. The PRACH is used for processing to detect the user equipment 200. Therefore, processing using the PRACH is performed before a connection with the user equipment 200 is established. By having the CH-PHY layer 123 perform processing that is performed before a connection with the user equipment 200 is established, the UH-PHY layer 124 does not need to perform processing when not connected to the user equipment 200. Therefore, the base station 100 can cut off the supply of power to the UH-PHY layer 124 that is not connected to the user equipment 200. Therefore, the base station 100 according to the embodiment can effectively suppress unnecessary power consumption due to the allocation of excessive computational resources.

[0043] The PUCCH is a channel for uplink communication from the user equipment 200 to the base station 100. The CH-PHY layer 123 uses the PUCCH to receive Acknowledgement (Ack) / Negative Acknowledgement (Nack), which are response signals to downlink transmissions. The CH-PHY layer 123 also uses the PUCCH to receive Channel Quality Indicator (CQI) reports. The CQI is quality information indicating the quality of received data or the quality of the communication path. The CH-PHY layer 123 also uses the PUCCH to receive Scheduling Requests (SRs). The amount of calculation required for processing using the PUCCH does not change significantly in proportion to the number of user equipments 200. Therefore, by performing all the processing using the PUCCH in the CH-PHY layer 123, the amount of calculation required by the base station 100 as a whole can be reduced.

[0044] The SRS is a signal for uplink communication from the user equipment 200 to the base station 100. The CH-PHY layer 123 receives the SRS, which is a reference signal used for channel estimation. In "Cell-Free massive MIMO (Multiple Input Multiple Output)," the channel estimation results of the user equipment 200 to which the signal is transmitted are used in addition to the channel estimation results of the other user equipment 200, thereby making it possible to prevent a signal transmitted to the target user equipment 200 from interfering with the other user equipment 200. In "Cell-Free massive MIMO," when the UH-PHY layer 124 performs channel estimation processing, each UH-PHY layer 124 performs channel estimation for its own user equipment 200, which may result in overlapping processing between the UH-PHY layers 124. By having the CH-PHY layer 123 perform all the processing using the SRS, the amount of calculation required by the base station 100 as a whole can be reduced.

[0045] The UH-PHY layer 124 performs processing related to a PUSCH (Physical Uplink Shared Channel).

[0046] The PUSCH is a channel for uplink communication from the user equipment 200 to the base station 100. An uplink shared channel (UL-SCH) is mapped to the PUSCH. The UH-PHY layer 124 receives user data and information for controlling higher layers using the PUSCH. The computational resources required for processing the PUSCH vary significantly depending on the number of connected user equipment 200. By supplying power to the UH-PHY layer 124 that processes the PUSCH and not supplying power to the UH-PHY layer 124 that does not process the PUSCH, the base station 100 can allocate appropriate computational resources according to the number of user equipment 200. Therefore, the base station 100 according to the embodiment can effectively reduce unnecessary power consumption due to the allocation of excessive computational resources.

[0047] [Variations of Functional Division of O-DU 120 During Uplink Communication] The base station 100 according to the embodiment does not necessarily need to divide the functions of the O-DU 120 as shown in Fig. 3. Even if the functions of the O-DU 120 are divided as shown in Figs. 4 to 6 below, the base station 100 according to the embodiment can preferably suppress unnecessary power consumption due to allocation of excessive computational resources.

[0048] 4 is a diagram illustrating a second example of functional division during uplink communication for the O-DU 120 according to the first embodiment. Fig. 4 differs from the example of functional division illustrated in Fig. 3 in that the UH-PHY layer 124 performs processing using the PUCCH. That is, the functions of the O-DU 120 may be divided so that the CH-PHY layer 123 performs processing using the PRACH and processing using the SRS, and the UH-PHY layer 124 performs processing using the PUCCH and processing using the PUSCH.

[0049] 5 is a diagram illustrating a third example of functional division during uplink communication for the O-DU 120 according to the first embodiment. Fig. 5 differs from the example of functional division illustrated in Fig. 3 in that the UH-PHY layer 124 performs processing using the SRS. That is, the functions of the O-DU 120 may be divided so that the CH-PHY layer 123 performs processing using the PRACH and processing using the PUCCH, and the UH-PHY layer 124 performs processing using the PUSCH and processing using the SRS.

[0050] 6 is a diagram illustrating a fourth example of functional division during uplink communication for the O-DU 120 according to the first embodiment. Fig. 6 differs from the example of functional division illustrated in Fig. 3 in that the UH-PHY layer 124 performs processing using the PUCCH and the SRS. That is, the functions of the O-DU 120 may be divided so that the CH-PHY layer 123 performs processing using the PRACH, and the UH-PHY layer 124 performs processing using the PUCCH, processing using the PUSCH, and processing using the SRS.

[0051] [Modification of Functional Division of O-DU 120 During Downlink] Next, a first example of functional division between the CH-PHY layer 123 and the UH-PHY layer 124 during downlink communication will be specifically described with reference to FIG.

[0052] FIG. 7 is a diagram showing a first example of functional division during downlink communication for the O-DU 120 according to the first embodiment.

[0053] The CH-PHY layer 123 performs precoding (precoding) and the following processing for the PSS (Primary Synchronization Signal), SSS (Primary Synchronization Signal), PBCH (Primary Synchronization Signal), PDCCH (Physical Downlink Control channel), and PDSCH (Physical Downlink Shared CHannel). In the following description, the PSS and SSS may be collectively referred to as a synchronization signal (Synchronization Signal: SS).

[0054] The synchronization signal is a downlink communication signal from the base station 100 to the user equipment 200. The CH-PHY layer 123 transmits the synchronization signal indicating the detection timing of the signal. The synchronization signal is assigned a synchronization code that corresponds one-to-one to a PCI (Physical Cell ID) assigned to each cell. Based on the received synchronization signal, the user equipment 200 controls the scheduling (resource allocation) of system information, downlink data signals (e.g., signals transmitted using the PDSCH), and downlink control signals (e.g., signals including acknowledgement information transmitted via the PDCCH, etc.). The user equipment 200 also controls the scheduling of the synchronization signal, downlink reference signals, etc.

[0055] The PBCH is a channel for downlink communication from the base station 100 to the user equipment 200. The CH-PHY layer 123 uses the PBCH to transmit broadcast signals that the user equipment 200 needs to acquire after performing a cell search, such as system bandwidth, system frame number, and number of transmit antennas. Hereinafter, a signal block including a synchronization signal and a broadcast signal may be referred to as an SSB (Synchronization Signal Block). The user equipment 200 receives the SSB and performs timing synchronization and frequency synchronization. Furthermore, the user equipment 200 identifies PRACH resources based on the received system information.

[0056] SSB is used for connection requests from the user equipment 200 to the base station 100. Therefore, processing using SSB is performed before a connection with the user equipment 200 is established. By having the CH-PHY layer 123 perform the processing that is performed before a connection with the user equipment 200 is established, the UH-PHY layer 124 does not need to perform processing when not connected to the user equipment 200. Therefore, the base station 100 can cut off the supply of power to the UH-PHY layer 124 that is not connected to the user equipment 200. Therefore, the base station 100 according to the embodiment can suitably suppress unnecessary power consumption due to allocation of excessive computational resources.

[0057] The PDCCH is a channel for downlink communication from the base station 100 to the user equipment 200. The CH-PHY layer 123 uses the PDCCH to transmit resource allocation information for a downlink shared channel (DL-SCH), resource allocation information for a paging channel (PCH), hybrid automatic repeat reQuest (HARQ) information for the DL-SCH, an uplink scheduling grant, and Ack / Nack, which are response signals to uplink transmissions. The amount of calculation required for processing using the PDCCH does not change significantly in proportion to the number of user equipments 200. Therefore, by performing the processing using the PDCCH collectively in the CH-PHY layer 123, the amount of calculation required by the base station 100 as a whole can be reduced.

[0058] In "Cell-Free Massive MIMO," when spatially multiplexing transmission is performed for each user device 200, user data for each user device 200 is combined by precoding. Therefore, the CH-PHY layer 123 performs functions following precoding related to the PDSCH. When each UH-PHY layer 124 performs processing to combine user data for each user device 200 by precoding, there is a possibility that processing will overlap between the UH-PHY layers 124 because the user data for each user device 200 is used. By having the CH-PHY layer 123 collectively perform processing to combine user data for each user device 200 by precoding, the overall computational load of the base station 100 can be reduced.

[0059] The UH-PHY layer 124 performs processing related to the PDSCH.

[0060] The PDSCH is a channel for downlink communication from the base station 100 to the user equipment 200. A downlink shared channel (DL-SCH) and a PCH (Paging Channel), which are transport channels, are mapped to the PDSCH. The UH-PHY layer 124 transmits user data using the PDSCH. A user operating the user equipment 200 receives various services based on the user data.

[0061] [Variation of Functional Division of O-DU 120 During Downlink Communication] The base station 100 according to the embodiment does not necessarily need to divide the functions of the O-DU 120 as shown in Fig. 7. Even if the functions of the O-DU 120 are divided as shown in Fig. 8 below, the base station 100 according to the embodiment can preferably suppress unnecessary power consumption due to allocation of excessive computational resources.

[0062] 8 is a diagram showing a second example of functional division during downlink communication for the O-DU 120 according to embodiment 1. FIG. 8 differs from the example of functional division shown in FIG. 7 in that the UH-PHY layer 124 performs processing using the PDCCH. That is, the functions of the O-DU 120 may be divided so that the CH-PHY layer 123 performs processing using SSB (PSS, SSS, PBCH) and processing below precoding of the PDSCH and the PDSCH, and the UH-PHY layer 124 performs processing using the PDSCH and processing above precoding among processing using the PDCCH.

[0063] 9 is a diagram illustrating a third example of functional division during downlink communication for the O-DU 120 according to the first embodiment. FIG. 9 illustrates an example of functional division when spatial multiplexing is not performed for each user equipment 200. FIG. 9 differs from the example of functional division illustrated in FIG. 7 in that the UH-PHY layer 124 performs precoding and subsequent processing related to the PRACH. That is, the CH-PHY layer 123 may perform processing using the SSB and processing using the PDCCH, and the UH-PHY layer 124 may perform processing using the PDSCH including precoding.

[0064] 10 is a flowchart showing an example of processing by the base station 100 according to the first embodiment. The base station 100 establishes a connection with the user equipment 200 (step S101). The base station 100 assigns the connected user equipment 200 to one of the user equipment 200 (step S102). The base station 100 does not supply power to the UH-PHY layer 124 to which a user equipment 200 has not been assigned (step S103). By not supplying power to the UH-PHY layer 124 to which a user equipment 200 has not been assigned, the base station 100 can allocate appropriate computational resources according to the number of user equipment 200, thereby reducing unnecessary power consumption.

[0065] [Embodiment 2] Next, the configuration of a base station 100A according to embodiment 2 will be described with reference to Fig. 11. Items already described in embodiment 1 may be omitted.

[0066] The base station 100 according to the first embodiment includes a CH-PHY layer 123 and a UH-PHY layer 124 in the O-DU 120. In contrast, the base station 100A according to the second embodiment includes the CH-PHY layer 123 and the UH-PHY layer 124 as nodes separate from the O-DU 120.

[0067] FIG. 11 is a diagram showing an example of functional division of a base station 100A according to the second embodiment. The base station 100A includes an O-CU 110, an O-DU 120, a first O-HU (Open-High Physical Unit) 310, and multiple second O-HUs 320. In FIG. 11, the second O-HUs 320-1 and 320-2 exemplify multiple second O-HUs 320. Hereinafter, when the second O-HUs 320-1 and 320-2 are not to be distinguished from each other, they may be simply referred to as the second O-HUs 320.

[0068] The first O-HU 310 and the second O-HU 320 are provided in the base station 100A as nodes lower than the O-DU 120, and are connected to the common O-DU 120. The first O-HU 310 and the second O-HU 320 are also provided in the base station 100A as nodes higher than the O-RU 130, and are connected to the common O-RU 130.

[0069] The first O-HU 310 performs the functions of the CH-PHY layer 123. The second O-HU 320 performs the functions of the UH-PHY layer 124. By providing the CH-PHY layer 123 and the UH-PHY layer 124 as different nodes, the base station 100 can configure the first O-HU 310, which performs the functions of the CH-PHY layer 123, and the second O-HU 320, which performs the functions of the UH-PHY layer 124, with devices from different manufacturers. In other words, multi-vendor support is possible. By providing multi-vendor support, the base station 100A can relatively inexpensively realize a wireless communication system 10 with performance that meets the needs of the installer of the base station 100A and the user operating the user equipment 200.

[0070] Furthermore, the UH-PHY layers 124 may be provided in the second O-HUs 320 manufactured by different manufacturers. By providing the UH-PHY layers 124 from multiple vendors, the base station 100 can configure each second O-HU 320 with a device having different characteristics depending on the service provided to the user operating the user equipment 200. Specifically, the second O-HU 320 may be a device having characteristics depending on the service provided to the user, such as a high-capacity service or a low-latency service. Furthermore, the user equipment 200 may be connected to a second O-HU 320 having characteristics depending on the service to which the user subscribes.

[0071] FIG. 12 is a block diagram showing an example of the internal configuration of a base station according to this embodiment. At least some of the functions of the base station 100 and the base station 100A can be implemented using a computer. As shown in the figure, the computer includes a central processing unit 901, a RAM 902, an input / output port 903, input / output devices 904 and 905, and a bus 906. The computer itself can be implemented using existing technology. The central processing unit 901 executes instructions contained in a program read from the RAM 902 or the like. In accordance with each instruction, the central processing unit 901 writes data to the RAM 902, reads data from the RAM 902, and performs arithmetic and logical operations. The RAM 902 stores data and programs. Each element included in the RAM 902 has an address and can be accessed using the address. RAM is an abbreviation for "random access memory." The input / output port 903 is a port through which the central processing unit 901 exchanges data with external input / output devices. The input / output devices 904 and 905 are input / output devices. The input / output devices 904 and 905 exchange data with the central processing unit 901 via the input / output port 903. The bus 906 is a common communication path used within the computer. For example, the central processing unit 901 reads and writes data from the RAM 902 via the bus 906. Also, for example, the central processing unit 901 accesses the input / output port via the bus 906. Furthermore, all or part of the functional units provided in the base station 100 and the base station 100A may be realized using hardware such as an ASIC, a PLD, or an FPGA. Furthermore, all or part of the functional units may be realized by a combination of software and hardware.

[0072] In addition, all or part of the functions of each unit provided in base station 100 and base station 100A in the above-mentioned embodiment may be realized by recording a program for realizing these functions on a computer-readable recording medium, and reading and executing the program recorded on this recording medium into a computer system. Note that the "computer system" here includes hardware such as an OS and peripheral devices.

[0073] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design modifications can be made without departing from the spirit of the present invention. Furthermore, the configurations described in the above-described embodiments and examples can be combined.

[0074] Furthermore, the above-described embodiment makes it possible to, for example, "optimally reduce power consumption according to the number of connected user devices," thereby contributing to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), which is to "build resilient infrastructure, promote sustainable industrialization, and foster innovation."

[0075] According to the present invention, it is possible to reduce power consumption appropriately according to the number of connected user devices.

[0076] DESCRIPTION OF SYMBOLS 10... Wireless communication system, 100... Base station, 110... O-CU, 111... SDAP layer, 112... RRC layer, 113... PDCP layer, 120... O-DU, 121... RLC layer, 122... MA C layer, 123...CH-PHY layer, 124...UH-PHY layer, 130...O-RU, 131...Low-PHY layer, 200...user equipment, 310...first O-HU, 320...second O-HU

Claims

1. A base station capable of communicating with a plurality of user equipment (UE) via a wireless communication system, comprising an RLC layer (Radio Link Control layer), a MAC layer (Medium Access Control layer), and a PHY layer (Physical layer), wherein the PHY layer comprises: a common processing unit that performs common processing for a plurality of connected user equipment; and a plurality of user processing units that perform specific processing for each of the connected user equipment, wherein power is supplied to the user processing unit that is connected to the user equipment, and power is not supplied to the user processing unit that is not connected to the user equipment.

2. The base station according to claim 1, wherein each of the user processing units is connected to a plurality of the user devices, and the maximum number of the user devices that can be simultaneously connected to each of the user processing units is predetermined.

3. The base station according to claim 2, wherein the maximum number of user devices that can be simultaneously connected to the user processing unit varies depending on the area in which the base station is installed.

4. The base station according to any one of claims 1 to 3, wherein the common processing unit receives a signal used to establish a connection with the user equipment using a PRACH (Physical Random Access Channel) in uplink communication with the user equipment.

5. The base station according to claim 1, wherein the user processing unit receives user data of the connected user equipment using a PUSCH (Physical Uplink Shared Channel) in uplink communication with the user equipment.

6. The base station according to any one of claims 1 to 3, wherein the common processing unit performs precoding processing on signals transmitted from each of the user processing units before transmitting the signals to the user equipment.

7. The base station according to any one of claims 1 to 3, wherein the common processing unit transmits signals used for connection with the user equipment in downlink communication with the user equipment, and the signals used for connection with the user equipment include: a synchronization signal (SS) transmitted from the base station to the user equipment indicating a signal detection timing; and a broadcast signal transmitted using a PBCH (Physical Broadcast Channel).

8. The base station according to claim 1, wherein the user processing unit transmits user data of the connected user equipment using a PDSCH (Physical Downlink Shared Channel) in downlink communication with the user equipment.

9. The base station according to any one of claims 1 to 3, wherein the common processing unit and each of the user processing units are provided separately and independently as a node lower than a Distributed Unit (DU) having at least a MAC layer, and a node higher than a Radio Unit (RU) in the PHY layer that controls an antenna and communicates with the user equipment.

10. A method for controlling a base station capable of communicating with multiple user equipment (UE) via a wireless communication system, the base station comprising an RLC layer (Radio Link Control layer), a MAC layer (Medium Access Control layer), and a PHY layer (Physical layer), the PHY layer comprising: a common processing unit that performs common processing for multiple connected user equipment; and multiple user processing units that perform specific processing for each of the connected user equipment, the method comprising: supplying power to the user processing unit connected to the user equipment among the multiple user processing units, and not supplying power to the user processing unit not connected to the user equipment.

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