Apparatus and method for fronthaul transmission in wireless communication system

Abstract

A pre-5th-Generation (5G) or 5G communication system for supporting higher data rates beyond a 4th-Generation (4G) communication system, such as Long Term Evolution (LTE), is provided. An apparatus of a radio unit (RU) of a base station in a wireless communication system includes at least one transceiver and at least one processor coupled to the at least one transceiver, where the at least one processor is configured to receive a first control message comprising a segment extension field from a digital unit (DU) via a fronthaul interface, identify additional information based on the segment extension field, and acquiring a beamforming weight based on the additional information, wherein the first control message is configured to schedule the terminal in the control plane.

Description

[0001] This application is a divisional application of an invention patent application with an application date of October 30, 2020, application number 202080076517.2, and invention name “Device and method for fronthaul transmission in a wireless communication system”. Technical Field

[0002] The present disclosure relates to a wireless communication system, and more particularly to an apparatus and method for fronthaul transmission in a wireless communication system. Background Art

[0003] Since the deployment of the fourth generation (4G) communication system, efforts have been made to develop improved fifth generation (5G) or pre-5G communication systems to meet the demand for wireless data traffic. Therefore, 5G or pre-5G communication systems are also called "beyond 4G networks" or "post-Long Term Evolution (LTE) systems."

[0004] The 5G communication system is considered to be implemented at a higher frequency (millimeter (mm) wave) band, for example, the 60 gigahertz (GHz) band, to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies are discussed in the 5G communication system.

[0005] In addition, in 5G communication systems, development of system network improvements based on advanced small cells, cloud radio access networks, ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), receiving-end interference cancellation, etc. is underway.

[0006] In 5G systems, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM), frequency quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) are developed as advanced coding modulation (ACM) technologies, and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) are developed as advanced access technologies.

[0007] When the transmission capacity in the wireless communication system increases, functional division of the base station is applied. According to the functional division, the base station can be divided into a digital unit (DU) and a radio unit (RU), and the fronthaul for communication between the DU and the RU is defined, and transmission needs to be performed via the fronthaul.

[0008] The above information is presented as background information only to assist with understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above may be applicable as prior art with respect to the present disclosure. Summary of the invention

[0009] An aspect of the present disclosure is to solve at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below. Therefore, as an aspect of the present disclosure, a device and method for sending a control message on a fronthaul interface are provided.

[0010] Another aspect of the present disclosure is to provide an apparatus and method for sending a management message on a fronthaul interface in a wireless communication system.

[0011] Another aspect of the present disclosure is to provide an apparatus and method for transmitting scheduling information and other information over a fronthaul interface in a wireless communication system.

[0012] Another aspect of the present disclosure is to provide an apparatus and method for transmitting scheduling information and in particular regularization parameters over a fronthaul interface in a wireless communication system.

[0013] Another aspect of the present disclosure is to provide an apparatus and method for reducing a memory burden of a digital unit (DU) and a radio unit (RU) due to storage of a normalization parameter when operating the RU in a wireless communication system.

[0014] Another aspect of the present disclosure is to provide a functional structure of an RU for processing a normalization parameter in a wireless communication system.

[0015] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

[0016] According to one aspect of the present disclosure, a method for operating a digital unit (DU) of a base station in a wireless communication system is provided. The method includes configuring a segment extension field including additional information, and sending a first control message including the segment extension field to a radio unit (RU) via a fronthaul interface, wherein the first control message is configured to schedule a terminal in a control plane.

[0017] According to another aspect of the present disclosure, a method for operating a radio unit (RU) of a base station in a wireless communication system is provided. The method includes receiving a first control message including a segment extension field from a digital unit (DU) via a fronthaul interface, identifying additional information based on the segment extension field, and acquiring a beamforming weight based on the additional information, wherein the first control message is configured to schedule a terminal in a control plane.

[0018] According to another aspect of the present disclosure, a device of a digital unit (DU) of a base station in a wireless communication system is provided. The device includes at least one transceiver and at least one processor coupled to the at least one transceiver, wherein the at least one processor is configured to configure a segment extension field including additional information, and send a first control message including the segment extension field to a radio unit (RU) via a fronthaul interface, wherein the first control message is configured to schedule a terminal in a control plane.

[0019] According to another aspect of the present disclosure, a device of a radio unit (RU) of a base station in a wireless communication system is provided. The device includes at least one transceiver and at least one processor coupled to the at least one transceiver, wherein the at least one processor is configured to receive a first control message including a segment extension field from a digital unit (DU) via a fronthaul interface, identify additional information based on the segment extension field, and acquire a beamforming weight based on the additional information, wherein the first control message is configured to schedule a terminal in a control plane.

[0020] Apparatuses and methods according to various embodiments enable efficient operation of an interface of a digital unit (DU) and a radio unit (RU) via control messages and management messages.

[0021] Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1A A wireless communication system according to an embodiment of the present disclosure is shown;

[0024] Figure 1B An example of a fronthaul structure divided according to functions of a base station according to an embodiment of the present disclosure is shown;

[0025] Figure 2 shows a configuration of a digital unit (DU) according to an embodiment of the present disclosure;

[0026] Figure 3 shows a configuration of a radio unit (RU) according to an embodiment of the present disclosure;

[0027] Figure 4 An example of functional division according to an embodiment of the present disclosure is shown;

[0028] Figure 5A An example of a control message according to segment type 6 according to an embodiment of the present disclosure is shown;

[0029] Figure 5B An example of a functional configuration of an RU for beamforming information processing according to an embodiment of the present disclosure is shown;

[0030] Figure 5C shows the relationship between the regularization factor and the schedule according to an embodiment of the present disclosure;

[0031] Figure 6 An example of an extension field according to an embodiment of the present disclosure is shown;

[0032] Figure 7 shows an example of a management message of segment type 6 according to an embodiment of the present disclosure;

[0033] Fig. 8A The operation flow of the DU for the extension field according to an embodiment of the present disclosure is shown;

[0034] Figure 8B The operation flow of the RU for the extension field according to an embodiment of the present disclosure is shown;

[0035] Fig. 9A The operation flow of the DU for the management message of segment type 6 according to an embodiment of the present disclosure is shown;

[0036] Fig. 9B The operation flow of the RU for the management message of segment type 6 according to an embodiment of the present disclosure is shown;

[0037] Fig.10 An example of a functional configuration of an RU for beamforming information processing according to an embodiment of the present disclosure is shown;

[0038] Fig.11 shows the relationship between the regularization factor and the schedule according to an embodiment of the present disclosure; and

[0039] Fig.12 An example of a relationship between a DU and a RU via a segment extension field according to an embodiment of the present disclosure is shown.

[0040] Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. DETAILED DESCRIPTION

[0041] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in this understanding, but these are considered to be exemplary only. Therefore, it will be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and configurations may be omitted for clarity and brevity.

[0042] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Therefore, it should be clear to those skilled in the art that the description of various embodiments of the present disclosure provided below is for illustrative purposes only and is not intended to limit the present disclosure as defined by the appended claims and their equivalents.

[0043] It should be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0044] Hereinafter, various embodiments of the present disclosure will be described based on a hardware method. However, various embodiments of the present disclosure include techniques using both hardware and software, and thus various embodiments of the present disclosure may not exclude the viewpoint of software.

[0045] In the following description, terms related to signals (e.g., messages, information, preambles, signals, signaling, sequences, and streams), terms related to resources (e.g., symbols, time slots, subframes, radio frames, subcarriers, resource elements (REs), resource blocks (RBs), bandwidth parts (BWPs), and opportunities), terms related to operating states (e.g., operations and procedures), terms related to data (e.g., user streams, IQ data, information, bits, symbols, and codewords), terms related to channels, terms related to control information (e.g., downlink control information (DCI), medium access control (MAC) control elements (CEs), and radio resource control (RRC) signaling), terms related to network entities, terms related to device elements, etc., are explained for the convenience of description. Therefore, the present disclosure is not limited to the terms described below, and other terms with equivalent technical meanings may be used.

[0046] In the present disclosure, in order to determine whether a specific condition is satisfied or reached, the expression of more / greater / greater than or less / less than may be used, but this is only a description for expressing an example, and does not exclude the description of equal to or more / greater / greater than or the description of equal to or less / less than. The condition described as "equal to or more / greater / greater than" may be replaced with "more / greater / greater than", the condition described as "equal to or less / less than" may be replaced with "less / less than", and the condition described as "equal to or more / greater / greater than, and less / less than" may be replaced with "more / greater / greater than, and equal to or less / less than".

[0047] In the present disclosure, various embodiments are described using terms used in some communication standards (e.g., the Third Generation Partnership Project (3GPP), Scalable Radio Access Network (xRAN), and Open Radio Access Network (O-RAN), but these are merely examples for description. Various embodiments of the present disclosure can also be easily modified and applied to other communication systems.

[0048] Figure 1A A wireless communication system according to an embodiment of the present disclosure is shown.

[0049] refer to Figure 1A , which shows a base station 110, a terminal 120, and a terminal 130 as parts of nodes using a wireless channel in a wireless communication system. Figure 1A Only one base station is shown, but another base station that is the same as or similar to the base station 110 may be further included.

[0050] The base station 110 is a network infrastructure that provides wireless access to the terminals 120 and 130. The base station 110 has coverage defined as a predetermined geographical area based on the distance at which a signal can be transmitted. In addition to "base station", the base station 110 may also be referred to as an "access point (AP)", "eNodeB (eNB)", "5G node (fifth generation node)", "next generation nodeB (gNB)", "radio point", "transmit / receive point (TRP)" or other terms with equivalent technical meanings.

[0051] Each of the terminal 120 and the terminal 130 is a device used by the user, and performs communication with the base station 110 via a radio channel. The link from the base station 110 to the terminal 120 or the terminal 130 is called a downlink (DL), and the link from the terminal 120 or the terminal 130 to the base station 110 is called an uplink (UL). The terminal 120 and the terminal 130 can communicate with each other via a radio channel. In this case, the device-to-device (D2D) link between the terminal 120 and the terminal 130 is called a side link, and the side link can be used interchangeably with the PC5 interface. In some cases, at least one of the terminal 120 and the terminal 130 can operate without user participation. That is, at least one of the terminal 120 and the terminal 130 is a device that performs machine type communication (MTC) and may not be carried by the user. In addition to the "terminal", each of the terminal 120 and the terminal 130 may be referred to as a "user equipment (UE)", "customer premises equipment (CPE)", "mobile station", "subscriber station", "remote terminal", "wireless terminal", "electronic device", "user equipment" or other terms with equivalent technical meanings.

[0052] Base station 110, terminal 120, and terminal 130 may perform beamforming. Base station 110, terminal 120, and terminal 130 may transmit and receive radio signals in relatively low frequency bands (e.g., frequency range 1 (FR1) of new radio (NR)) and high frequency bands (e.g., FR2 of NR and millimeter wave (mmWave) bands (e.g., 28 GHz, 30 GHz, 38 GHz, and 60 GHz)). In some embodiments, the base station may communicate with the terminal within a frequency range corresponding to FR1. In some embodiments, the base station may communicate with the terminal within a frequency range corresponding to FR2. At this time, in order to improve channel gain, base station 110, terminal 120, and terminal 130 may perform beamforming. Beamforming may include transmit beamforming and receive beamforming. That is, base station 110, terminal 120, and terminal 130 may assign directivity to a transmit signal or a receive signal. To this end, the base station 110 and the terminals 120 and 130 may select the service beams 112, 113, 121, and 131 via a beam search procedure or a beam management procedure. After selecting the service beams 112, 113, 121, and 131, communication may then be performed via resources that are in a quasi-co-location (QCL) relationship with resources that transmit the service beams 112, 113, 121, and 131.

[0053] If large-scale characteristics of a channel over which symbols on a first antenna port have been transmitted can be inferred from a channel over which symbols on a second antenna port have been transmitted, then it can be estimated that the first antenna port and the second antenna port are in a QCL relationship. For example, the large-scale characteristics may include at least one of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial receiver parameters.

[0054] Reference Figure 1A , it is shown that both the base station and the terminal perform beamforming, but various embodiments are not necessarily limited to this. In some embodiments, the terminal may perform beamforming or may not perform beamforming. The base station may perform beamforming or may not perform beamforming. That is, only one of the base station and the terminal may perform beamforming, or both the base station and the terminal may not perform beamforming.

[0055] In the present disclosure, a beam refers to a spatial stream of a signal in a radio channel, and is formed by one or more antennas (or antenna elements), and the formation procedure may be referred to as beamforming. Beamforming may include analog beamforming and digital beamforming (e.g., precoding). Reference signals sent based on beamforming may be, for example, demodulation reference signals (DM-RS), channel state information reference signals (CSI-RS), synchronization signals / physical broadcast channels (SS / PBCH), and sounding reference signals (SRS). As a configuration for each reference signal, an Internet browser (IE) such as a CSI-RS resource or an SRS resource may be used, and the configuration may include information associated with the beam. The information associated with the beam may indicate whether the configuration (e.g., a CSI-RS resource) uses the same spatial domain filter as another configuration (e.g., another CSI-RS resource in the same CSI-RS resource set), or uses a different spatial domain filter, or may indicate a reference signal with which the configuration is quasi-co-located (QCL), and the type of QCL if the configuration is quasi-co-located (e.g., QCL type A, B, C, D).

[0056] Reference Figure 1A , it is shown that both the base station and the terminal perform beamforming, but various embodiments are not necessarily limited to this. In some embodiments, the terminal may perform beamforming or may not perform beamforming. The base station may perform beamforming or may not perform beamforming. That is, only one of the base station and the terminal may perform beamforming, or both the base station and the terminal may not perform beamforming.

[0057] In a communication system of the prior art in which the cell radius of a base station is relatively large, each base station is installed such that each base station includes the function of a digital processing unit (or DU) and the function of a radio frequency (RF) processing unit (or RU). However, when a high frequency band is used in a fourth generation (4G) and / or later communication system, as the cell radius of a base station decreases, the number of base stations used to cover a specific area increases, and the installation cost burden of an operator for installing the increased number of base stations increases. In order to minimize the installation cost of a base station, a structure has been proposed in which the DU and RU of a base station are separated so that one or more RUs are connected to one DU via a wired network, and one or more RUs distributed geographically are deployed to cover a specific area. In the following, the structure of the base station will be described via a wired network. Figure 1B Describe the deployment structure and extension examples of base stations according to various embodiments.

[0058] Figure 1B An example of a fronthaul structure divided according to the functions of a base station according to an embodiment of the present disclosure is shown. Unlike the backhaul between a base station and a core network, the fronthaul is located between entities between a WLAN and a base station.

[0059] refer to Figure 1B , the base station 110 may include a DU 160 and a RU 180. A fronthaul 170 between the DU 160 and the RU 180 may be operated via an Fx interface. For the operation of the fronthaul 170, for example, an interface such as an enhanced Common Public Radio Interface (eCPRI) and a Radio over Ethernet (ROE) may be used.

[0060] As communication technology develops, the amount of mobile data traffic increases, and accordingly, the amount of bandwidth required for fronthaul between digital units and radio units also increases significantly. In an arrangement such as a centralized / cloud radio access network (C-RAN), the DU may be implemented to perform the functions of the packet data convergence protocol (PDCP), radio link control (RLC), medium access control (MAC), and physical (PHY) layers, and the RU may be implemented to perform more functions of the PHY layer in addition to the radio frequency (RF) function.

[0061] DU 160 may be responsible for the upper layer functions of the radio network. For example, DU 160 may perform the functions of a portion of the MAC layer and the PHY layer. Here, a portion of the PHY layer is a function performed at a higher stage among the functions of the PHY layer, and may include, for example, channel coding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), and layer mapping (or layer demapping). According to an embodiment, if DU 160 complies with the O-RAN standard, it may be referred to as O-RAN DU (O-DU). As required, in an embodiment of the present disclosure, DU 160 may be replaced with and represented by a first network entity of a base station (e.g., gNB).

[0062] The RU 180 may be responsible for lower layer functions of the wireless network. For example, the RU 180 may perform a portion of the PHY layer and RF functions. Here, a portion of the PHY layer is a function performed at a relatively lower stage in the functions of the PHY layer compared to the DU 160, and may include, for example, inverse fast Fourier transform (IFFT) transform (or FFT transform), cyclic prefix (CP) insertion (CP removal), and digital beamforming. Figure 4 An example of this specific functional division is described in detail in . RU 180 may be referred to as an "access unit (AU)", "access point (AP)", "transmit / receive point (TRP)", "remote radio head (RRH)", "radio unit (RU)", or another term with equivalent technical meaning. According to an embodiment, if RU 180 complies with the O-RAN standard, it may be referred to as an O-RAN RU (O-RU). As needed, in an embodiment of the present disclosure, DU 180 may be replaced with and represented by a second network entity of a base station (e.g., gNB).

[0063] Figure 1B The base station is shown to include a DU and a RU, but various embodiments are not limited thereto. In some embodiments, the base station may be implemented to have a distributed deployment according to a centralized unit (CU) configured to perform functions of upper layers (e.g., packet data convergence protocol (PDCP) and RRC) of the access network and a distributed unit (DU) configured to perform lower layer functions. The distributed unit (DU) may include Figure 1B The digital unit (DU) and the radio unit (RU) of the 5G network. Between the core (e.g., 5G core (5GC) or next generation core (NGC)) network and the radio network (RAN), the base station can be implemented in a structure in which the CU, DU, and RU are deployed in that order. The interface between the CU and the distributed unit (DU) can be referred to as the F1 interface.

[0064] A centralized unit (CU) may be connected to one or more DUs so as to be responsible for the functions of layers higher than the DU. For example, the CU may be responsible for the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, and the DU and RU may be responsible for the functions of the lower layers. The DU may perform some functions of the physical (PHY) layer, the media access control (MAC), and the radio link control (RLC), and the RU may be responsible for the remaining functions of the PHY layer (low PHY). For example, according to the distributed deployment implementation of the base station, the digital unit (DU) may be included in the distributed unit (DU). In the following, unless otherwise defined, a description of the operation of the digital unit (DU) and the RU is provided. However, various embodiments may be applied to base station deployments including CUs and / or deployments in which the DU is directly connected to the core network without the CU (ie, the CU and the DU are integrated and implemented into one entity).

[0065] Figure 2 The configuration of a DU in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 2 The configuration shown can be understood as Figure 1B The DU 160 is configured as a part of the base station. The terms "-unit", "-device" and the like used below refer to a unit that processes at least one function or operation, which function or operation can be implemented by hardware or software or a combination of hardware and software.

[0066] refer to Figure 2 , the DU 160 includes a communication unit 210 , a storage unit 220 , and a controller 230 .

[0067] The communication unit 210 may perform a function for sending or receiving a signal in a wired communication environment. The communication unit 210 may include a wired interface for controlling direct connection between devices via a transmission medium (e.g., copper wire and optical fiber). For example, the communication unit 210 may transmit an electrical signal to another device via a copper wire, or may perform conversion between an electrical signal and an optical signal. The communication unit 210 may be connected to a radio unit (RU). The communication unit 210 may be connected to a core network, or may be connected to a CU in a distributed deployment.

[0068] The communication unit 210 may perform a function for sending or receiving a signal in a wired communication environment. For example, the communication unit 210 may perform conversion between a baseband signal and a bit stream according to the physical layer specification of the system. For example, when sending data, the communication unit 210 generates complex symbols by encoding and modulating the transmission bit stream. When receiving data, the communication unit 210 reconstructs the received bit stream by demodulating and decoding the baseband signal. In addition, the communication unit 210 may include multiple transmission / reception paths. According to an embodiment, the communication unit 210 may be connected to a core network, or may be connected to other nodes (e.g., access backhaul integration (IAB)).

[0069] The communication unit 210 may transmit or receive a signal. To this end, the communication unit 210 may include at least one transmitter. For example, the communication unit 210 may transmit a synchronization signal, a reference signal, system information, a message, a control message, a stream, control information, data, etc. The communication unit 210 may perform beamforming.

[0070] The communication unit 210 transmits and receives signals as described above. Therefore, all or part of the communication unit 210 may be referred to as a "transmitter," "receiver," or "transceiver." In the following description, transmission and reception performed via a wireless channel are used in the sense of including the processing performed by the communication unit 210 as described above.

[0071] Although not in Figure 2 , but the communication unit 210 may further include a backhaul communication unit for connecting to the core network or another base station. The backhaul communicator unit provides an interface for performing communication with other nodes in the network. That is, the backhaul communication unit converts a bit stream sent from the base station to another node (e.g., another access node, another base station, an upper node, a core network, etc.) into a physical signal, and converts a physical signal received from another node into a bit stream.

[0072] The storage unit 220 stores data such as basic programs, application programs, and configuration information for the operation of the DU 160. The storage unit 220 may include a memory. The storage unit 220 may include a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage unit 220 provides the stored data in response to a request of the controller 230.

[0073] The controller 230 may control the overall operation of the DU 160. For example, the controller 230 sends and receives signals via the communication unit 210 (or the backhaul communication unit). In addition, the controller 230 records and reads data in the storage unit 220 in the storage unit 220. The controller 230 may perform the functions of the protocol stack required by the communication standard. To this end, the controller 230 may include at least one processor. In some embodiments, the controller 230 may include: a control message generator that generates a control plane message with an extension field, the extension field including a regularization factor; and a management message generator that generates a management message for a regularization factor field of a deactivation message (e.g., a control plane message of segment type 6 of O-RAN), the message including an existing regularization factor. The control message generator and the management message generator are instruction sets / codes stored in the storage unit 220, and may be instructions / codes that reside at least temporarily in the controller 240, or a storage space that stores instructions / codes, or may be part of a circuit constituting the controller 240. According to various embodiments, the controller 230 may control the DU 160 to perform operations based on various embodiments described below.

[0074] Figure 2 The configuration of the DU 160 shown is only an example, and examples of the DU 160 for performing various embodiments of the present disclosure are not limited to Figure 2 That is, some elements may be added, deleted or changed according to various embodiments.

[0075] Figure 3 The configuration of an RU in a wireless communication system according to an embodiment of the present disclosure is shown. Figure 3 The configuration shown can be understood as Figure 1B The configuration of RU 180 is as a part of a base station. The terms "-unit", "-device" and the like used below refer to a unit that processes at least one function or operation, which function or operation can be implemented by hardware or software or a combination of hardware and software.

[0076] refer to Figure 3 , the RU 180 includes a communication unit 310 , a storage unit 320 , and a controller 330 .

[0077] The communication unit 310 performs a function for transmitting or receiving a signal via a radio channel. For example, the communication unit 310 up-converts a baseband signal into an RF band signal, transmits the up-converted RF band signal via an antenna, and then down-converts the RF band signal received via the antenna into a baseband signal. For example, the communication unit 310 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

[0078] In addition, the communication unit 310 may include multiple transmit / receive paths. In addition, the communication unit 310 may include an antenna unit. The communication unit 310 may include at least one antenna array, which includes multiple antenna units. In terms of hardware, the communication unit 310 may include digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFIC)). The digital circuits and analog circuits may be implemented in a single package. The communication unit 310 may include multiple RF chains. The communication unit 310 may perform beamforming. In order to give directionality to the signal to be sent or received according to the configuration of the controller 330, the communication unit 310 may apply beamforming weights to the signal. According to an embodiment, the communication unit 310 may include a radio frequency (RF) block (or RF unit).

[0079] The communication unit 310 may send or receive a signal. To this end, the communication unit 310 may include at least one transceiver. The communication unit 310 may send a downlink signal. The downlink signal may include a synchronization signal (SS), a reference signal (RS) (e.g., a cell-specific reference signal (CRS) and a demodulation (DM)-RS), system information (e.g., a master information block (MIB), a system information block (SIB), remaining system information (RMSI), and other system information (OSI)), a configuration message, control information, downlink data, etc. The communication unit 310 may receive an uplink signal. The uplink signal may include a random access-related signal (e.g., a random access preamble (RAP) (or message 1 (Msg1)) and message 3 (Msg3)) or a reference signal (e.g., a sounding reference signal (SRS) and DM-RS), a power headroom report (PHR), etc.

[0080] The communication unit 310 transmits and receives signals as described above. Therefore, all or part of the communication unit 310 may be referred to as a "transmitter," "receiver," or "transceiver." In the following description, transmission and reception performed via a wireless channel are used in the sense of including the processing performed by the wireless communication unit 310 as described above.

[0081] The storage unit 320 stores data such as basic programs, application programs, and configuration information for the operation of the RU 180. The storage unit 320 may include a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage unit 320 provides the stored data in response to a request of the controller 330. According to an embodiment, the storage unit 320 may include a channel memory for updating channel information, rather than a memory for storing separate regularization parameter related information in real time.

[0082] The controller 330 controls the overall operation of the RU 180. For example, the controller 330 sends and receives signals via the communication unit 310. The controller 330 records and reads data in the storage unit 320 in the storage unit 320. The controller 330 may perform the functions of the protocol stack required by the communication standard. To this end, the controller 330 may include at least one processor. In some embodiments, the controller 330 may include: a control message interpreter that interprets a message of a control plane (C-plane) having an extension field, the extension field including a regularization factor; and a management message interpreter that interprets a message of a management plane (M-plane) to deactivate a regularization factor field of a message (e.g., a control plane message of segment type 6 of O-RAN), the message including an existing regularization factor. The control message interpreter and the management message interpreter, which are instruction sets or codes stored in the storage unit 320, may be instructions / codes that reside at least temporarily in the controller 330, or a storage space that stores instructions / codes, or may be a part of a circuit constituting the controller 330. The controller 330 may include various modules for performing communication. According to various embodiments, the controller 330 may control the terminal to perform operations based on various embodiments described below.

[0083] Figure 4 An example of functional division in a wireless communication system according to an embodiment of the present disclosure is shown. With the advancement of wireless communication technology, such as the fifth generation communication system (or the introduced new radio (NR) communication system), the frequency band used is getting larger and larger, and as the cell radius of the base station becomes very small, the number of RUs that need to be installed further increases. In a 5G communication system, the amount of data sent is increased by up to 10 times or more, and the transmission capacity of the wired network sent via the fronthaul is significantly increased. Due to these factors, the installation cost of the wired network in a 5G communication system may increase significantly. Therefore, in order to reduce the transmission capacity of the wired network and reduce the installation cost of the wired network, technologies for reducing the transmission capacity of the fronthaul by transferring some functions of the modem of the DU to the RU have been proposed, and these technologies may be referred to as "functional division."

[0084] In order to reduce the burden on the DU, a method of extending the role of the RU, which is only responsible for RF functions, to some functions of the physical layer is considered. In this case, when the RU performs higher-layer functions, the throughput of the RU increases, so that the transmission bandwidth in the fronthaul can be increased, while the delay time requirement constraints caused by response processing are reduced. When the RU performs higher-layer functions, the virtualization gain decreases, while the size / weight / cost of the RU increases. Considering the trade-offs between the above advantages and disadvantages, it is required to implement the optimal functional division.

[0085] refer to Figure 4, showing the functional division in the physical layer below the MAC layer. In the case of a downlink (DL) that sends a signal to a terminal via a radio network, the base station can sequentially perform channel coding / scrambling, modulation, layer mapping, antenna mapping, RE mapping, digital beamforming (e.g., precoding), IFFT transform / CP insertion, and RF conversion. In the case of an uplink (UL) that receives a signal from a terminal via a radio network, the base station can sequentially perform RF conversion, FFT transform / CP removal, digital beamforming (pre-combining), RE demapping, channel estimation, layer demapping, demodulation, and decoding / descrambling. The separation of uplink functions and downlink functions can be defined in various types according to the above-mentioned trade-offs, through necessity between manufacturers, discussions on specifications, and the like.

[0086] The first functional division 405 can be a separation of RF functions and PHY functions. The first functional division is that the PHY functions in the RU are basically not implemented, and can be referred to as, for example, option 8. The second functional division 410 enables the RU to perform PHY functions, namely, perform IFFT transform / CP insertion in DL and perform FFT transform / CP removal in UL, and enables the DU to perform the remaining PHY functions. For example, the second functional division 410 can be referred to as option 7-1. The third functional division 420a enables the RU to perform PHY functions, namely, perform IFFT transform / CP insertion in DL and perform FFT transform / CP removal and digital beamforming in UL, and enables the DU to perform the remaining PHY functions. For example, the third functional division 420A can be referred to as option 7-2x category A. The fourth functional division 420b enables the RU to perform up to digital beamforming in DL and UL, and enables the DU to perform higher PHY functions after digital beamforming. For example, the fourth functional division 420b can be referred to as option 7-2x category B. The fifth functional division 425 enables the RU to perform up to RE mapping (or RE demapping) in DL and UL, and enables the DU to perform higher PHY functions after RE mapping (or RE demapping). For example, the fifth functional division 425 can be referred to as option 7-2. The sixth functional division 430 enables the RU to perform up to modulation (or demodulation) in DL and UL, and enables the DU to perform higher PHY functions after modulation (or demodulation). For example, the sixth functional division 430 can be referred to as option 7-3. The seventh functional division 440 enables the RU to perform up to encoding / scrambling (or decoding / descrambling) in DL and UL, and enables the DU to perform higher PHY functions after encoding / scrambling (or decoding / descrambling). For example, the seventh functional division 440 can be referred to as option 6.

[0087] According to an embodiment, when large-capacity signal processing such as FR1 MMU is expected, functional division at a relatively high level (e.g., the fourth functional division 420b) may be required to reduce the fronthaul capacity. In the functional division at too high a layer (e.g., the sixth functional division 430), the control interface becomes complicated, and the implementation burden of the RU may be caused due to the multiple PHY processing blocks included in the RU, so appropriate functional division may be required according to the deployment and implementation scheme of the DU and RU.

[0088] According to an embodiment, if it is impossible to process precoding of data received from the DU (i.e., if there is a limitation on the precoding capability of the RU), the third functional division 420a or a lower functional division (e.g., the second functional division 410) may be applied. On the contrary, if it is possible to process precoding of data received from the DU, the fourth functional division 420b or a higher functional division (e.g., the sixth functional division 430) may be applied. Hereinafter, unless otherwise limited, various embodiments are described based on the third functional division 420a or the fourth functional division 420b in which the RU performs beamforming processing, but configurations of embodiments via other functional divisions are not excluded. The following description FIG. 5A to FIG. 11 Control plane messages, management plane messages, or configuration / operation flows of other devices in the device may be applied not only to the third functional partition 420a or the fourth functional partition 420b, but also to other functional partitions.

[0089] In various embodiments, when a message is received in a DU (e.g., Figure 1B DU 160) and RU (e.g. Figure 1B When the message is sent between RU180 in the eCPRI and O-RAN standards, the eCPRI and O-RAN standards are exemplarily used as the fronthaul interface. The eCPRI header, O-RAN header, and additional fields may be included in the Ethernet payload of the message. In the following, various embodiments will be described using standard terms of eCPRI or O-RAN, but other expressions with equivalent meanings to each term may be replaced and used in various embodiments.

[0090] For fronthaul transport protocols, Ethernet and eCPRI can be used, which can be easily shared with the network. The eCPRI header and O-RAN header can be included in the Ethernet payload. The eCPRI header can be located at the front end of the Ethernet payload. The content of the eCPRI header is as follows.

[0091] ecpriVersion (4 bits): 0001b (fixed value)

[0092] ecpriReserved (3 bits): 0000b (fixed value)

[0093] ecpriConcatenation (1 bit): 0b (fixed value)

[0094] ecpriMessage (1 byte): message type

[0095] ecpriPayload (2 bytes): Payload size in bytes

[0096] ecpriRtcid / ecpriPcid (2 bytes): x, y, and z can be configured via the management plane (M-plane). The corresponding field can indicate the transmission path of the control message according to various embodiments during multi-layer transmission (extended antenna carrier (eAxC) in eCPRI).

[0097] CU_Port_ID (x bits): The channel card is classified. The classification may include up to modem (2 bits for channel card, 2 bits for modem).

[0098] BandSector_ID (y bits): Classification is performed according to cell / sector.

[0099] CC_ID (z bits): Classification is performed according to component carriers.

[0100] RU_Port_ID (w bits): Classification is performed according to layer, T, antenna, etc.

[0101] ecpriSeqid (2 bytes): A sequence identification (ID) is managed for each ecpriRtcid / ecpriPcid, and a sequence ID and a subsequence ID are managed separately. If a subsequence ID is used, radio transmission level segmentation is possible (different from application level segmentation).

[0102] The fronthaul application protocol may include a control plane (C-plane), a user plane (U-plane), a synchronization plane (S-plane), and a management plane (M-plane).

[0103] The control plane may be configured to provide scheduling information and beamforming information via control messages. The user plane may include user downlink data (IQ data or SSB / RS), uplink data (IQ data or SRS / RS), or PRACH data. The weight vector of the above beamforming information may be multiplied by the user data. The synchronization plane may be related to timing and synchronization. The management plane may be related to initial setup, non-real-time reset or reset, and non-real-time reporting.

[0104] In order to define the type of message sent in the control plane, segment types are defined. The segment type can indicate the purpose of the control message sent in the control plane. For example, the usage of each segment type is as follows.

[0105] sectionType=0: DL idle / guard period - Tx blanking for power saving purposes

[0106] SectionType=1: Mapping BF index or weight (O-RAN mandatory BF scheme) to REs of DL / UL channels

[0107] SectionType=2: Reserved

[0108] SectionType=3: Mapping beamforming index or weight to REs of hybrid digital channels and PRACH

[0109] SectionType=4: Reserved

[0110] SectionType=5: Transmit UE scheduling information to enable RU to calculate real-time BF weight (O-RAN optional BF solution)

[0111] SectionType=6: Periodically transmit UE channel information to enable RU to calculate real-time BF weight (O-RAN optional BF solution)

[0112] SectionType=7: for LAA support

[0113] When the RU communicates with the UE via beamforming, the RU needs information about the current channel and scheduling information. That is, the RU is required to obtain a control message of segment type 5 and a control message of segment type 6. The RU can identify whether the UE is scheduled for each time slot from the control message of segment type 5, and can identify information about the current channel state from the control message of segment type 6. The control message of segment type 6 can be transmitted periodically. Channel information can be transmitted periodically to enable the RU to calculate the beamforming weights for each time slot. Figure 5A An example of a control message according to segment type 6 is described.

[0114] Figure 5A An example of a control message according to segment type 6 according to an embodiment of the present disclosure is shown. The control message according to segment type 6 is configured for the purpose of carrying channel information.

[0115] Reference Figure 5A , the control message of segment type 6 may include a transport header 501, a common header 503, a first segment information 505, and a second segment information 507. The transport header 501 may include a header according to eCPRI or IEEE.

[0116] The common header 503 is a common radio application header and may include the following parameters.

[0117] dataDirection (gNB Tx / Rx) field: 1 bit

[0118] payloadVersion field: 3 bits

[0119] Value = "1" should be set (Protocol version 1 of payload and time reference format)

[0120] filterIndex (filter index) field: 4 bits,

[0121] FrameId (frame identifier) ​​field: 8 bits

[0122] SubframeId (subframe identifier) ​​field: 4 bits

[0123] SlotID (time slot identifier) ​​field: 6 bits

[0124] startSymbolid (start symbol identifier) ​​field: 6 bits

[0125] numberOfsections (number of sections) field: 8 bits

[0126] Section Type field: 8 bits, value = 6

[0127] numberOfUEs (number of UE-specific channel information data sets) field: 8 bits

[0128] Reserved (reserved for future use) field: 8 bits

[0129] The first piece of information 505 and the second piece of information 507 may be configured for each UE. For example, the first piece of information 505 may be configured for the first UE, and the second piece of information may be configured for the second UE. Hereinafter, although a description is provided based on the first piece of information 505, the same or similar format may also be applied to the second piece of information 507. The first piece of information 505 may include the following parameters.

[0130] ef (extension flag) field: 1 bit

[0131] ueId (UE identifier) ​​field: 15 bits

[0132] regularizationFactor (regularization factor for MMSE reception) field: 16 bits

[0133] Reserved (reserved for future use) field: 4 bits

[0134] rb (resource block identifier) ​​field: 1 bit

[0135] symInc (Symbol Number Increment Command) field: 1 bit

[0136] startPrbc (start PRB of data segment description) field: 10 bits

[0137] numPrbc (number of consecutive PRBs described in each data segment) field: 8 bits

[0138] ciIsample (channel information value, in-phase sample) field: 16 bits

[0139] ciQsample (channel information value, orthogonal sample) field: 16 bits

[0140] Here, "regularizationFactor" is a parameter defined in the control message of segment type 6 and is transmitted periodically. "RegularizationFactor" may provide a signaling value for supporting RU, Option 7-2x Category B DL / UL (e.g., Figure 4 4th functional division) or when RU (e.g., Option 7-2x Category A (e.g., Figure 4 The third functional partition 420a)) supports a minimum mean square error (MMSE) operation of the UL when beamforming weights are used. "regularizationFactor" is 2 bytes (ie, 16 bits) and indicates a value.

[0141] According to various embodiments, the regularization parameter indicated by "regularizationFactor" may be used to derive the beamforming weights. For example, the relationship between the regularization parameter and the beamforming weights may be derived based on the following equation.

[0142]

[0143] Here, G represents a beamforming weight matrix, Ψ represents a power normalization parameter for limiting full power, and ζ represents a regularization parameter. H represents a channel matrix. In addition to Equation 1, a variety of methods can be used to calculate the beamforming weight. That is, various embodiments are not limited to calculating the beamforming weight from the regularization parameter by using the method of Equation 1.

[0144] For example, the beamforming weights may be derived based on the channel covariance parameters, and the relationship between the channel covariance parameters and the regularization parameter may be derived based on the following equation.

[0145] R matrix =HH H +R nn …Equation 2

[0146] Here, R matrix represents the covariance matrix of interference / noise, H represents the channel matrix, and R nn represents the regularization parameter. For example, when the R nn When 0, this may indicate zero forcing (ZF) beamforming (BF).

[0147] Hereinafter, the present disclosure describes devices and methods for efficiently processing the DU / RU, signaling, and messages of the above-mentioned regularization parameter ("regularizationFactor"). In the present disclosure, the regularization parameter may be referred to and described as a regularization factor, regularization information, a regularization element, etc. An embodiment is described using an example in which the regularization parameter is a 2-byte value of "regularizationFactor" of segment type 6. However, with respect to the scheme for data size / calculation, it is easy for a person skilled in the art to convert the scheme into a table, and executing the scheme in the table may also be understood as an embodiment of the present disclosure.

[0148] Figure 5B An example of a functional configuration of an RU for beamforming information processing according to an embodiment of the present disclosure is shown. The RU may include a channel memory 521 and a regularization factor memory 523.

[0149] Reference Figure 5B , the channel memory 521 can obtain channel information from the control message of segment type 6. The RU can store the channel information in the channel memory 521. The channel information can be updated periodically. For example, the channel information can be "ciIsample(Ci)" or "ciQsample(Cq)" of segment type 6, or can include a value obtained therefrom. Ci represents the I value of the complex channel information, and Cq represents the Q value of the complex channel information. The regularization factor memory 523 can obtain information about the regularization parameter from the control message of segment type 6. When the channel information is transmitted (updated) in the C-plane segment type 6, the regularization parameter is also transmitted (updated). The RU can store information about the regularization parameter in the regularization factor memory 523. In this case, the information about the regularization parameter can be updated periodically. For example, the information about the regularization parameter can be the "regularization factor" of the segment type 6, or can include a value obtained therefrom. The regularization factor memory 523 can be referred to as R nn Memory (e.g., R nn is the regularization parameter value of Equation 2).

[0150] The control message of segment type 5 may include scheduling information of the UE. Scheduling may be performed in a designated unit (e.g., a time slot unit). The scheduling information may be repeatedly provided to the regularization factor memory 523 for each time slot. Information about the regularization parameter is transmitted together with the channel information, so the RU may include a regularization factor memory 523 at the same level as the channel memory 521 storing the channel information. The RU may obtain the corresponding channel value and regularization parameter value from each memory according to the scheduling information (e.g., the control message of segment type 5) transmitted for each time slot in order to calculate the beamforming weight. Specifically, in order to calculate the beamforming weight, the RU may obtain the channel information from the channel memory 521, and may obtain the regularization parameter from the regularization factor memory 523. The RU may calculate and obtain the beamforming weight (or multi-user (MU) weight) of the MMSE (or ZFBF) of the current channel based on the regularization parameter and the channel information.

[0151] Although the beamforming weights need to be calculated only when the UE is scheduled, the regularization factor memory 523 periodically acquires and stores channel information and regularization parameters in addition to the scheduling information acquired each time the UE is scheduled. When the UE is actually scheduled, the most recently transmitted regularization parameter value should be used, and therefore, the regularization factor memory 523 is required to store all transmitted regularization parameter values, even if these values ​​are not actually used. Therefore, even if the UE is not actually scheduled, the repeatedly stored information about the regularization parameters causes a burden on the regularization factor memory 523. In addition, if the period of channel information update is relatively long compared to the scheduling information updated in each time slot (e.g., 0.5ms), the regularization parameters of segment type 6 cannot correctly reflect the increased probability of the channel actually experienced by the UE. Via Figure 5C Specific examples are described.

[0152] Figure 5C The relationship between the regularization factor and the schedule according to an embodiment of the present disclosure is shown.

[0153] Reference Figure 5C , the upward arrow indicates that the "regularization factor" of the control message of segment type 6 for UE#3 is transmitted. The transmission period 540 of the control message can be 40ms. Multiple UEs can be scheduled. UE#3 can be scheduled at each of the front end 551 and the back end 553 within the period 540 of 40ms.

[0154] If UE#3 is scheduled in the front end 551, the RU can derive beamforming weights that are more consistent with the actual channel because a relatively small amount of time has passed after the channel information of segment type 6 is updated. However, if UE#3 is scheduled at the back end 553, it is difficult for the RU to derive beamforming weights that are more consistent with the actual channel because a relatively long time has passed after the channel information of segment type 6 is updated. This is because the channel changes over time, and thus a difference occurs between the actual channel and the channel that appears in the channel information transmitted via the DU. When the transmission period of the control message of segment type 6 is long, such a problem results in a larger error, and the error results in the generation of incorrect beamforming weights, resulting in a decrease in transmission performance.

[0155] In the following, various embodiments describe a method for transmitting regularization parameters together with the transmission of scheduling information, rather than periodically transmitting regularization parameters, to solve the problem of FIG. 5A to FIG. 5C Various embodiments describe methods for handling the periodically transmitted "regularizationFactor" of segment type 6 defined in the existing O-RAN standard to meet backward compatibility. Various embodiments describe methods for implementing new functions of RU to avoid memory burden when storing periodically transmitted information.

[0156] In the present disclosure, not only the transmission of scheduling / channel information of a 5G communication system (e.g., NR) but also the implementation of a 4G communication system (e.g., LTE) can be understood as an embodiment of the present disclosure. That is, the communication system in which the DU and RU operations described later are provided is neither limited to the 5G communication system nor to the 4G communication system.

[0157] Figure 6 is an example of an extension field according to an embodiment of the present disclosure. When sending a control message according to an existing segment type, the DU can send additional information together with the control message via the extension field. That is, the DU can send a control message on the control plane segment by attaching a new extension field, namely, the "Segment Extension" field.

[0158] Reference Figure 6 , the segment extension field 600 according to various embodiments may include information about a regularization parameter. The regularization parameter may be a value of "regularizationFactor" corresponding to segment type 6.

[0159] -extType may indicate the type of additional parameters. According to an embodiment, if extType indicates 11, extType may indicate that the additional parameters include the value of the regularization factor for MMSE (or ZFBF). The value "11" is exemplary, and of course, another number may be assigned for a specified type of parameter.

[0160] -ef may indicate whether there is an additional segment extension field. An ef value of "1" indicates that there is an additional segment extension field, and an ef value of "0" indicates that there is no additional segment extension field.

[0161] -extLen may indicate the length of the segment extension field in units of 4 bytes. According to an embodiment, extLen may indicate 1.

[0162] According to various embodiments, the segment extension field including the regularization parameter may be attached to a control message including scheduling information (e.g., a control plane message of segment type 5 of O-RAN) so as to be transmitted together with the control message. Due to the difference between the scheduling time and the transmission time of the regularization parameter, the problem of not being able to reflect the actual channel state when calculating the beamforming weight can be solved by transmitting the regularization parameter together with the scheduling information by the DU.

[0163] although Figure 6 Not shown, a segment extension field including channel information may be defined. For example, a segment extension field including channel information (e.g., ciIsample and ciQsample) within a control message of segment type 6 may be defined. The channel information in the segment extension field may be configured for each frequency resource (e.g., PRB, PRB group, bandwidth part (BWP), etc.) for each antenna. By considering the capabilities of the terminal that the RU intends to serve and / or the rank information of the terminal, the DU can obtain the number of antennas required among all antennas. When a relatively small amount of channel information is required depending on the type of communication scheme (e.g., LTE), or by considering the scheduling area for a specific terminal, the DU can identify the frequency domain that actually serves the terminal from the resources of the entire frequency domain.

[0164] In some embodiments, the channel information may include channel information for each of all antennas and channel information for each of all PRBs. In some other embodiments, the channel information may include channel information for each of some of all antennas and channel information for each of some of all PRBs. In some other embodiments, the channel information may include channel information for each of some of all antennas and channel information for each of all PRBs. In some other embodiments, the channel information may include channel information for each of all antennas and channel information for each of some PRBs. According to an embodiment, by transmitting the channel information of the actual scheduling area of ​​the terminal, the channel information with a relatively small capacity can be configured as a segment extension field.

[0165] Instead of transmitting periodically as in segment type 6, channel information can be attached to segment type 5 via which scheduling information is transmitted so as to be transmitted to the RU in the form of a segment extension field. As with the regularization parameter, by providing channel information during the actual scheduling of the terminal, the problem of deterioration of communication performance due to the difference between the channel information transmission time and the actual scheduling time can be solved. In addition, if accurate channel information is required irregularly when necessary, the RU can obtain the optimal beamforming weight via the segment extension field.

[0166] According to an embodiment, the segment extension field including channel information may be configured as shown in the following table: The segment extension field including channel information may be attached to a control message including scheduling information of a terminal (UE) (eg, a control message of segment type 5 of a C-plane) so as to be transmitted.

[0167] Table 1

[0168]

[0169]

[0170] According to an embodiment, the segment extension field including channel information may be configured as shown in the following table. The segment extension field including channel information may include information about "regularizationFactor", i.e., regularization parameter. The segment extension field including both channel information and regularization parameter information may be attached to a control message including scheduling information of a terminal (UE) (e.g., a control message of segment type 5 of a C-plane) so as to be transmitted.

[0171] Table 2

[0172]

[0173]

[0174] In Tables 1 and 2, ciIsample and ciQsample for one antenna / one PRB are shown for channel information, but various embodiments are not limited thereto. A segment extension field may be defined for more antennas or more PRBs. For example, the lengths of ciIsample and ciQsample may be variable and may be configured by the M plane.

[0175] Even if the regularization parameter is transmitted together with the scheduling information via the segment extension field, the regularization parameter transmitted via the control message of the segment type 6 of the existing standard (e.g., O-RAN2.00) is periodically transmitted to the RU. The memory of the RU periodically receives the regularization parameter, so the control message of the segment type 6 is still a burden. In the following, various embodiments propose a method for reducing the impact of the "regularizationFactor" of the control message of the segment type 6 while satisfying backward compatibility with the existing standard.

[0176] Figure 7 An example of a management message of segment type 6 according to an embodiment of the present disclosure is shown. Management messages refer to messages transmitted in the management plane (M plane) of O-RAN. The DU can perform packet communication with the RU in the management area within the main card. Management messages can be sent from the DU to the RU, or from the RU to the DU. In the management plane, "boot" installation, software management, configuration management, performance management, fault management, and file management can be performed.

[0177] refer to Figure 7 , the DU may generate a management message. The management message according to various embodiments may be a message for configuring the RU so that the "regularization factor" of the control message of segment type 6 is invalid. In some embodiments, the management message may include a parameter indicating the selection of the transmission medium (hereinafter, the selection parameter). The selection parameter may indicate whether the regularization parameter is transmitted via a message of segment type 6 of the control plane, or whether the regularization parameter is transmitted via the segment extension field as before. For example, a selection parameter value of "0" may indicate that the regularization parameter is transmitted via a message of segment type 6. A selection parameter value of "1" may indicate that the regularization parameter is transmitted via the segment extension field. If the selection parameter value indicates that the regularization parameter is transmitted via the segment extension field, the regularizationFactor value in the control message of segment type 6 is invalid. An RU that receives a management message including a selection parameter value may not consider the regularizationFactor value of segment type 6. For example, the RU may ignore or discard the regularizationFactor value of segment type 6 that is periodically sent. For example, the RU may not consider the regularizationFactor value within a specified period of time.

[0178] DU can send a management message to RU. RU can identify a method for obtaining regularization parameters from the management message. For example, RU can obtain regularization parameters from the segment extension field. For example, RU can obtain regularization parameters from segment type 6.

[0179] Although not in Figure 7, but the field in the existing segment type 6 can be used for backward compatibility. In some embodiments, if the "regularizationFactor" indicates a specific value (e.g., 1111 1111 11111111), the field value of the "regularizationFactor" may be an invalid value. The RU may ignore or discard the corresponding "regularizationFactor" without storing it. In some other embodiments, if at least one of the reserved bits in the field in the existing segment type 6 indicates a specific value (e.g., 1), the field value of the "regularizationFactor" may be an invalid value. The RU may ignore or discard the corresponding "regularizationFactor" without storing it. In still some other embodiments, via a combination of at least two fields in the existing segment type 6, it can be indicated that the field value of the "regularizationFactor" is an invalid value.

[0180] According to various embodiments, in a case where it is difficult to send a message for periodically transmitting channel information (e.g., a control message of segment type 6) (e.g., or if the memory allocation amount of the RU becomes large, or the capacity of the RU is insufficient), or in a case where the transmission capacity of the fronthaul is large enough, the DU may transmit additional information as well as scheduling information via the segment extension field. The additional information may include information that replaces the information in the control message of segment type 6. For example, the additional information may include channel information. For example, the additional information may include information about regularization parameters. By sending the additional information via the segment extension field, the DU may perform replacement of segment type 6 via a control message of segment type 5.

[0181] Fig. 8A FIG. 4 shows the operation flow of the DU for the extension field according to an embodiment of the present disclosure. Figure 2 DU160.

[0182] refer to Fig. 8A In operation 801, the DU may configure a segment extension field including a regularization parameter. The regularization parameter may be a parameter for deriving a beamforming weight. The beamforming weight may be a matrix configured so that the effective channel matrix experienced by the transmitted signal can smoothly reach the receiving end. According to an embodiment, the beamforming weight may be derived based on MMSE or zero-forcing beamforming (ZFBF). For example, the beamforming weight may be derived by the above equation 1. The regularization parameter may be a value indicated by a "regularization factor" field in a control message of segment type 6 of the O-RAN standard.

[0183] In operation 803, the DU may send a control message for scheduling including a segment extension field to the RU. The DU may configure the control message for scheduling. That is, the DU may generate a message including the scheduling information of the UE in the control message of the C-plane. For example, the DU may generate a control message of segment type 5. The DU may attach an extended segment field to the control message. Here, the extended segment field may be the segment extension field configured in operation 801. The DU may send a control message to the RU via the fronthaul interface. That is, via the control message for scheduling, the scheduling information of the terminal and the regularization parameters of the channel may be transmitted to the RU together.

[0184] Figure 8B FIG. 4 shows an operation flow of an RU for an extension field according to an embodiment of the present disclosure. Figure 2 RU 180.

[0185] refer to Figure 8B In operation 851, the RU may receive a control message for scheduling. The control message may include scheduling information for the UE. For example, the control message may correspond to a message of segment type 5 of the C-plane of the O-RAN. The RU may receive the control message from the DU via a fronthaul interface.

[0186] In operation 853, the RU may identify the regularization parameter from the segment extension field in the control message. The RU may identify the segment extension field in the control message. The RU may determine what information is included in the segment extension field based on the type information (e.g., extType) of the segment extension field. The RU may determine that the segment extension field includes the regularization parameter from the specified type value. The RU may identify the regularization parameter. For example, the regularization parameter may be indicated by a 2-byte value.

[0187] In operation 855, the RU may acquire beamforming weights. The beamforming weights may be beamforming weights of a multi-user (MU). The RU may derive the beamforming weights based on the regularization parameter obtained in operation 853. For example, the RU may derive the beamforming weights based on Equation 1. For example, the RU may derive the beamforming weights based on Equation 2 from R nn The values ​​are used to derive the beamforming weights.

[0188] Although in Fig. 8A and Figure 8B The channel information in the control message for scheduling may be not shown, but may be additionally included. Here, the channel information may be I / Q data of complex channel information in resources (e.g., x PRBs, where x is an integer less than or equal to 273) allocated to the terminal / antenna of the terminal.

[0189] Fig. 8A and 8BA method for reducing errors caused by a time difference in acquiring channel information and improving transmission performance by sending a regularization parameter included in an existing segment type 6 via adding an extension field to a control message including channel information is described. However, if the regularization parameter of segment type 6 is sent via an extended segment field without processing the regularization parameter separately, there is a problem that the working capacity in the memory of the RU becomes too large. Specifically, segment type 6 is sent periodically while scheduling is performed in units much shorter than the above-mentioned period, and therefore, in order to calculate beamforming weights by reflecting real-time channel information, a problem arises of storing information related to the channel of each scheduling unit (e.g., channel information and regularization parameters) during a period. Therefore, a method for deactivating (or invalidating) the regularization parameter of the control message of the existing segment type 6 that is periodically transmitted is described.

[0190] Fig. 9A FIG. 4 shows the operation flow of the DU for the management message of segment type 6 according to an embodiment of the present disclosure. Figure 2 DU 160.

[0191] refer to Fig. 9A In operation 901, the DU may send a management message for a regularization parameter. The DU may send a management message to the RU via a fronthaul interface. The management message may be a message transmitted from the DU to the RU on the M plane. The management message is a non-real-time message and may be sent in the main card of the DU. The management message for the regularization parameter may be a message indicating a method for obtaining the regularization parameter by the RU. In some embodiments, the management message may indicate whether the regularization parameter is transmitted via a segment extension field or via a control message of the channel information. For example, the management message may include 1 bit. 1 bit may indicate a transmission scheme for the regularization parameter. For example, "1", i.e., a value of 1 bit, may indicate that the regularization parameter is transmitted via a segment extension field. "0", i.e., a value of 1 bit, may indicate that the regularization parameter is transmitted via a control message of segment type 6 (C plane).

[0192] In some embodiments, the management message may include information about the validity of the regularization parameter of the control message of the channel information. For example, the management message may indicate with 1 bit whether the "regularizationFactor" in the control message of segment type 6 is valid. The value "1" may indicate that the regularization parameter in segment type 6 is invalid. The value "1" may implicitly indicate that the regularization parameter is transmitted via the segment extension field. The value "0" may indicate that the regularization parameter in segment type 6 is valid.

[0193] In some embodiments, the management message may include information related to the validity of the regularization parameters of the extended segment field. For example, the management message may indicate with 1 bit whether the "regularizationFactor" in the segment extension field is valid. The value "1" may indicate that the regularization parameter in the segment extension field is invalid. The value "1" may implicitly indicate that the regularization parameter is transmitted via segment type 6. The value "0" may indicate that the regularization parameter in the segment extension field is valid. For example, the management message may include information about the validity period of the regularization parameters of the extended segment field. The regularization parameters of the control message of segment type 6 may be configured as default, and the regularization parameters of the extended segment field may be provided to the RU as needed. In this case, within the validity period according to the management message, only the regularization parameters of the extended segment field may be received, and the regularization parameters of the control message of segment type 6 may be ignored or discarded.

[0194] In operation 903, the DU may send a control message including channel information of a regularization parameter. The DU may send the control message to the RU via a fronthaul interface. The control message may be configured to include channel information and may be periodically transmitted from the DU to the RU. For example, the control message may be a message of segment type 6 of the O-RAN, and the regularization parameter may be "regularizationFactor".

[0195] The DU can configure the RU via a management message whether the regularization parameter for the channel is valid, so that even if the DU sends a management message as in the existing standard, the RU can effectively process the regularization parameter. That is, backward compatibility can be met.

[0196] Fig. 9B FIG. 4 shows an operation flow of the RU for the management message of segment type 6 according to an embodiment of the present disclosure. Figure 2 RU 180.

[0197] refer to Fig. 9B , in operation 951, the RU may receive a management message for a regularization parameter. The RU may receive a management message from the DU via a fronthaul interface. The management message is a message transmitted in the M plane and may be transmitted in the main card of the DU. The management message for the regularization parameter may include information about a scheme for transmitting the regularization parameter. In some embodiments, the management message may indicate whether the regularization parameter is transmitted via a segment extension field or via a control message of the channel information. In some embodiments, the management message may include information about the validity of the regularization parameter of segment type 6. In some embodiments, the management message may include information about the validity of the regularization parameter transmitted via the segment extension field.

[0198] At operation 953, the RU may identify a transmission scheme of the regularization parameter. The RU may identify the transmission scheme of the regularization parameter based on a management message received from the DU. For example, the RU may acquire the regularization parameter only via a control message of the channel information (e.g., a control message of segment type 6). For example, the RU may acquire the regularization parameter only via a segment extension field. For example, the RU may acquire the regularization parameter via at least one of the segment extension field or the control message of the channel information.

[0199] At operation 955, the RU may receive a control message of channel information including a regularization parameter. The RU may receive the control message from the DU via a fronthaul interface. The RU may determine whether to allow the regularization parameter to be acquired via the control message of the channel information. If the regularization parameter is allowed to be acquired via the control message of the channel information, the RU may acquire the regularization parameter from the control message (e.g., a control message of segment type 6). The RU may determine the beamforming weight based on the acquired regularization parameter.

[0200] If the acquisition of the regularization parameter via the control message of the channel information is not allowed, the RU may ignore or discard the regularization parameter of the control message of the channel information (e.g., the control message of segment type 6). According to an embodiment, if the scheduling information is received, the RU may acquire the regularization parameter from the extension field in the control message including the scheduling information. The RU may determine the beamforming weight based on the acquired regularization parameter.

[0201] Despite Fig. 9A and 9B Not shown, but control messages other than management messages may be used to indicate a scheme for transmitting regularization parameters. Management messages may be transmitted to the RU in the main card of the DU, and control messages may be transmitted to the RU from the channel card of the DU. Control messages may be sent in real time relative to management messages. According to an embodiment, the invalidity of the "regularizationFactor" in the control message of segment type 6 may be indicated via a partial value of the "regularizationFactor" or a partial field of the control message.

[0202] Fig.10 An example of a functional configuration of an RU for beamforming information processing according to an embodiment of the present disclosure is shown. The RU may include a channel memory 1021.

[0203] Reference Fig.10, the channel memory 1021 may obtain channel information from the control message of segment type 6. The RU may store the channel information in the channel memory 1021. The channel information may be updated periodically. For example, the channel information may be "ciIsample(Ci)" or "ciQsample(Cq)" of segment type 6, or may include a value obtained therefrom. Ci represents the I value of the complex channel information, and Cq represents the Q value of the complex channel information. The RU may ignore or discard information about the regularization parameters in the control message of segment type 6. The RU may recognize that the regularization parameters in the control message of segment type 6 are invalid. According to an embodiment, the RU may recognize that the regularization parameters in the control message of the control plane of segment type 6 are invalid based on a management message from the management plane of the DU. According to an embodiment, the RU may recognize that the regularization parameters in the control message of segment type 6 are invalid based on the control message of the DU.

[0204] The RU may transfer the scheduling information of the segment type 5 to the channel memory 1021. The channel memory 1021 may store the scheduling information in units of time slots (scheduling units), and may use the channel information result according to the scheduling information when calculating the beamforming weight. The channel memory 1021 may output the channel information in units of time slots, and may use the output result when calculating the beamforming weight.

[0205] The RU can obtain the regularization parameters from the segment extension field transmitted with segment type 5. Figure 5B Different from the description in, the RU according to various embodiments may not include a regularization factor memory. That is, the RU may be configured not to store the regularizationFactor value of the control message of segment type 6 that is periodically transmitted. Due to the memory burden, the RU may be configured to obtain only the regularization parameter of the segment extension field. Therefore, the RU obtains the regularization parameter via the segment extension field in the control message including the scheduling information (i.e., the control message of segment type 5), so that the obtained regularization parameter can be directly used to calculate the beamforming weight. This is because the terminal is scheduled in the corresponding time slot, so it is expected to directly determine the beamforming weight.

[0206] By transmitting the regularization parameter value (i.e., R nn value), the regularization parameters can be directly transferred to the beamforming weight calculator without the need for a separate memory for storing the regularization parameters (e.g., Figure 5BThe regularization factor memory 523 in the segment type 6 is used). Since the regularization parameter transmitted via the extension field corresponds to the channel actually used, its accuracy is improved compared with the regularization parameter transmitted via the existing segment type 6. The update time of the regularization parameter and the use time of the regularization parameter are almost the same, so the degradation of the transmission performance due to the channel error can be reduced. In addition, a separate memory for storing the regularization parameter of the segment type 6 is not required, so the implementation of the RU can be simplified.

[0207] although Fig.10 Not shown, but the DU or RU may further include a multiplexer (MUX). The MUX may configure the regularization parameters of the extension field in the control message of segment type 5 and the regularization parameters in the control message of segment type 6 as inputs. The MUX may select an output based on the message of the M plane. If the message of the M plane allows the regularization parameters to be transmitted through the segment extension field, the MUX may output the regularization parameters of the control message of segment type 5. The RU may calculate the beamforming weights based on the output regularization parameters. If the message of the M plane does not allow the regularization parameters to be transmitted through the segment extension field, the MUX may output the regularization parameters of the control message of segment type 6. The RU may calculate the beamforming weights based on the corresponding regularization parameters. The central processing unit (CPU) of the DU that generates the message in the control plane may also provide an output to the RU via the MUX.

[0208] Fig.11 The relationship between the regularization factor and the schedule according to an embodiment of the present disclosure is shown.

[0209] Reference Fig.11 , the upward arrow indicates the "regularization factor" for transmitting the control message of segment type 5 for UE#3. Figure 5C Unlike the example shown in FIG. 1 , the effective “regularization factor” can be transmitted according to the scheduling time of UE#3 instead of periodically. The regularization factor is updated immediately before UE#3 is scheduled, so the RU can derive beamforming weights that are more consistent with the actual channel. Therefore, Figure 5C As shown, no matter whether the RU is located at the front end 551 or the back end 553 during the scheduling period, the RU can obtain the optimal beamforming weight.

[0210] although Fig.11 Although not shown in the figure, according to an embodiment, channel information can be transmitted together with the regularization parameters via segment type 5. By transmitting not only the regularization parameters but also the actual channel state information (for each antenna, each PRB) together with the regularization parameters, the RU can obtain beamforming weights that are more consistent with the actual channel.

[0211] Fig.12An example of a relationship between a DU and a RU via a segment extension field according to an embodiment of the present disclosure is shown. The segment extension field according to various embodiments may be configured to replace a control message of segment type 6. In some embodiments, the segment extension field may include information about a regularization parameter. In some embodiments, the segment extension field may include channel information.

[0212] Reference Fig.12 , the DU can be connected to multiple RUs. The RU complies with the O-RAN standard and can therefore be referred to as an O-RU. The DU can be connected to X number of O-RUs. The DU can be connected to O-RU#0, O-RU#1, O-RU#2, ..., O-RU#x-1. According to an embodiment, some of the O-RUs may periodically acquire channel information via segment type 6. On the other hand, according to various embodiments, some other O-RUs may acquire channel information via a segment extension field. According to an embodiment, the transmission scheme (e.g., a scheme for transmitting regularization parameters) for each O-RU may be determined based on management plane parameters (M-plane parameters), that is, whether the transmission is performed via segment type 6 or via a segment extension field. Via the M-plane parameters, it can be selected whether to transmit channel-related information (e.g., regularization parameters) via segment type 6, or to transmit channel-related information via a segment extension field including optional additional information. The DU can configure this to each RU via the M-plane parameters.

[0213] According to an embodiment, a method for operating a digital unit (DU) of a base station in a wireless communication system includes: configuring a segment extension field including additional information; and sending a first control message including the segment extension field to a radio unit (RU) via a fronthaul interface, wherein the first control message is configured to schedule a terminal in a control plane.

[0214] In some embodiments, the first control message corresponds to a control message of a segment type 5 of an open radio access network (O-RAN), and the first control message includes scheduling information about the terminal.

[0215] In some embodiments, the method further comprises: sending a management message related to the segment extension field, wherein the management message is configured in a management plane.

[0216] In some embodiments, the additional information includes a regularization parameter.

[0217] In some embodiments, the method further includes: configuring a segment extension field to include a regularization parameter; and sending a first control message including the segment extension field including the regularization parameter, wherein the first control message including the segment extension field including the regularization parameter is configured to schedule the terminal in a control plane.

[0218] In some embodiments, the method further includes: sending a management message related to the regularization parameter; and sending a second control message including the regularization parameter to the RU, wherein the second control message is configured to periodically send channel information in a control plane, and the management message is configured in a management plane.

[0219] In some embodiments, the second control message corresponds to a segment type 6 message of an open radio access network (O-RAN), and the second control message includes channel information.

[0220] In some embodiments, the regularization parameter is used to calculate beamforming weights for a minimum mean square error (MMSE) operation, and the regularization parameter corresponds to a regularizationFactor field of a segment type 6 message of an open radio access network (O-RAN).

[0221] According to an embodiment, a method for operating a radio unit (RU) of a base station in a wireless communication system includes: receiving a first control message including a segment extension field from a digital unit (DU) via a fronthaul interface; identifying additional information based on the segment extension field; and acquiring a beamforming weight based on the additional information, wherein the first control message is configured to schedule a terminal in a control plane.

[0222] In some embodiments, the method further comprises: receiving a management message related to the segment extension field, wherein the management message is configured in a management plane.

[0223] In some embodiments, the additional information includes a regularization parameter.

[0224] In some embodiments, the first control message corresponds to a control message of a segment type 5 of an open radio access network (O-RAN), and the first control message includes scheduling information about the terminal.

[0225] In some embodiments, the method also includes: receiving a management message related to a regularization parameter configured in a management plane from the DU; based on the management message, identifying at least one of a scheme via a first control message or a scheme via a second control message configured to periodically send channel information in the control plane as a scheme for transmitting the regularization parameter; receiving a second control message including another regularization parameter from the DU; identifying one of the regularization parameter or the other regularization parameter according to at least one scheme; and acquiring a beamforming weight based on the identified regularization parameter or the other regularization parameter.

[0226] In some embodiments, the second control message corresponds to a segment type 6 message of an open radio access network (O-RAN), and the second control message includes channel information.

[0227] In some embodiments, the regularization parameter is used to calculate beamforming weights for a minimum mean square error (MMSE) operation, and the regularization parameter corresponds to a regularizationFactor field of a segment type 6 message of an open radio access network (O-RAN).

[0228] According to an embodiment, a device of a digital unit (DU) of a base station in a wireless communication system, the device comprising:

[0229] at least one transceiver; and

[0230] at least one processor coupled to the at least one transceiver, wherein the at least one processor is configured to:

[0231] configuring the segment extension fields including regularization parameters; and

[0232] A first control message including a segment extension field is sent to a radio unit (RU) via a fronthaul interface, wherein the first control message is configured to schedule the terminal in a control plane.

[0233] In some embodiments, the additional information includes a regularization parameter.

[0234] In some embodiments, at least one processor is further configured to: configure a segment extension field to include a regularization parameter; and send a first control message including the segment extension field including the regularization parameter, wherein the first control message including the segment extension field including the regularization parameter is configured to schedule the terminal in a control plane.

[0235] In some embodiments, the first control message corresponds to a control message of a segment type 5 of an open radio access network (O-RAN), and the first control message includes scheduling information about the terminal.

[0236] In some embodiments, at least one processor is further configured to: send a management message related to the regularization parameter; and send a second control message including the regularization parameter to the RU, wherein the second control message is configured to periodically send channel information in the control plane, and the management message is configured in the management plane.

[0237] In some embodiments, the second control message corresponds to a segment type 6 message of an open radio access network (O-RAN), and the second control message includes channel information.

[0238] In some embodiments, at least one processor is configured to send a management message related to the segment extension field, and the management message is configured in a management plane.

[0239] In some embodiments, the regularization parameter is used to calculate beamforming weights for a minimum mean square error (MMSE) operation, and the regularization parameter corresponds to a regularizationFactor field of a segment type 6 message of an open radio access network (O-RAN).

[0240] According to an embodiment, a device of a radio unit (RU) of a base station in a wireless communication system, the device comprising at least one transceiver; and at least one processor coupled to the at least one transceiver, wherein the at least one processor is configured to: receive a first control message including a segment extension field from a digital unit (DU) via a fronthaul interface; identify a regularization parameter based on the segment extension field; and obtain a beamforming weight based on the regularization parameter, wherein the first control message is configured to schedule a terminal in a control plane.

[0241] In some embodiments, the additional information includes a regularization parameter.

[0242] In some embodiments, the first control message corresponds to a control message of a segment type 5 of an open radio access network (O-RAN), and the first control message includes scheduling information about the terminal.

[0243] In some embodiments, the at least one processor is further configured to receive a management message related to the segment extension field, and the management message is configured in a management plane.

[0244] In some embodiments, at least one processor is configured to: receive a management message related to a regularization parameter configured in a management plane from a DU; based on the management message, identify at least one of a scheme via a first control message or a scheme via a second control message configured to periodically send channel information in a control plane as a scheme for transmitting the regularization parameter; receive a second control message including another regularization parameter from the DU; identify one of the regularization parameter or the other regularization parameter according to at least one scheme; and obtain a beamforming weight based on the identified regularization parameter or the other regularization parameter.

[0245] In some embodiments, the second control message corresponds to a segment type 6 message of an open radio access network (O-RAN), and the second control message includes channel information.

[0246] In some embodiments, the regularization parameter is used to calculate beamforming weights for a minimum mean square error (MMSE) operation, and the regularization parameter corresponds to a regularizationFactor field of a segment type 6 message of an open radio access network (O-RAN).

[0247] In some embodiments, the beamforming weights are calculated based on a channel matrix, a regularization parameter, and a power normalization parameter for limiting full power.

[0248] In some embodiments, to calculate the beamforming weights, at least one processor is further configured to: generate a channel covariance matrix for interference / noise based on the channel matrix and the regularization parameter, and determine the beamforming weight matrix based on the channel covariance matrix.

[0249] The methods disclosed in the claims and / or the methods according to the various embodiments described in the specification of the present disclosure may be implemented by hardware, software, or a combination of hardware and software.

[0250] When the method is implemented by software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured for execution by one or more processors in an electronic device. At least one program may include instructions for causing an electronic device to perform a method according to various embodiments of the present disclosure as defined in the appended claims and / or disclosed herein.

[0251] The program (software module or software) may be stored in a non-volatile memory, including a random access memory (RAM) or flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magneto-optical disk storage device, a compact disc (CD)-ROM, a digital versatile disc (DVD), other optical storage devices or magnetic tape. Alternatively, any combination of some or all of them may form a memory in which the program is stored. In addition, a plurality of such memories may be included in an electronic device.

[0252] In addition, the program can be stored in an attachable storage device that can access the electronic device through a communication network (such as the Internet, an intranet, a local area network (LAN), a wide area network (WLAN), and a storage area network (SAN) or a combination thereof). Such a storage device can access the electronic device via an external port. In addition, a separate storage device on a communication network can access a portable electronic device.

[0253] In the above detailed embodiments of the present disclosure, the elements included in the present disclosure are expressed in the singular or plural, depending on the detailed embodiments presented. However, for ease of description, the singular form or plural form is selected to be appropriately suitable for the presented situation, and the present disclosure is not limited to the elements expressed in the singular or plural. Therefore, an element expressed in the plural may also include a single element, or an element expressed in the singular may also include multiple elements.

[0254] While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a distributed unit (DU) of a base station in a wireless communication system, the method comprising: sending a management plane message to a radio unit (RU) configuring a regularization factor in segment type 5 of scheduling information for a user equipment (UE); and The regularization factor is used to generate a minimum mean square error (MMSE) calculation of multi-user (MU) beamforming weights for the UE in a time slot.

2. The method according to claim 1, wherein: The management plane messages are sent based on the capabilities of the RU.

3. The method according to claim 1, further comprising: generating a control plane message of segment type 5 for UE scheduling information, the control plane message comprising segment extension information; as well as Send control plane messages to RU, The segment extension information indicates the regularization factor.

4. The method according to claim 1, in, The segment type 5 is defined in the Open Radio Access Network (O-RAN), wherein, based on the capabilities of the RU, the regularization factor is sent to the RU via segment type 5 instead of segment type 6 for channel information, and The regularization factor is associated with the noise variance used for MMSE calculation.

5. The method according to claim 1, in, The segment extension information includes information about the type of the segment extension information and information about the length of the segment extension information. Wherein, the type of segment extension information is associated with the regularization factor, and The length of the regularization factor is 16 bits.

6. A method performed by a radio unit (RU) of a base station in a wireless communication system, the method comprising: receiving a management plane message from a distributed unit (DU) configuring a regularization factor in segment type 5 for user equipment (UE) scheduling information, The regularization factor is used to generate a minimum mean square error (MMSE) calculation of multi-user (MU) beamforming weights for the UE in a time slot.

7. The method according to claim 6, in, The management plane messages are received based on the capabilities of the RU.

8. The method according to claim 6, further comprising: receiving a control plane message of segment type 5 for UE scheduling information from the DU, the control plane message including segment extension information; identifying segment extension information indicating the regularization factor; as well as A beamforming weight is obtained based on the regularization factor.

9. The method according to claim 6, in, The segment type 5 is defined in the Open Radio Access Network (O-RAN), wherein, based on the capabilities of the RU, the regularization factor is received from the DU via segment type 5 instead of segment type 6 for channel information, and The regularization factor is associated with the noise variance used for MMSE calculation.

10. The method according to claim 6, in, The segment extension information includes information about the type of the segment extension information and information about the length of the segment extension information. Wherein, the type of segment extension information is associated with the regularization factor, and The length of the regularization factor is 16 bits.

11. A distributed unit (DU) of a base station in a wireless communication system, the DU comprising: Transceiver; as well as A controller is coupled to the transceiver and is configured to: sending a management plane message to a radio unit (RU) configuring a regularization factor in segment type 5 of scheduling information for a user equipment (UE); and The regularization factor is used to generate a minimum mean square error (MMSE) calculation of multi-user (MU) beamforming weights for the UE in a time slot.

12. The DU according to claim 11, wherein: The management plane messages are sent based on the capabilities of the RU.

13. The DU according to claim 11, wherein: The controller is also configured to: generating a control plane message of segment type 5 for UE scheduling information, the control plane message comprising segment extension information, and Send control plane messages to RU, The segment extension information indicates the regularization factor.

14. The DU according to claim 11, in, The segment type 5 is defined in the Open Radio Access Network (O-RAN), wherein, based on the capabilities of the RU, the regularization factor is sent to the RU via segment type 5 instead of segment type 6 for channel information, and The regularization factor is associated with the noise variance used for MMSE calculation.

15. The DU according to claim 11, in, The segment extension information includes information about the type of the segment extension information and information about the length of the segment extension information. Wherein, the type of segment extension information is associated with the regularization factor, and The length of the regularization factor is 16 bits.

16. A radio unit (RU) of a base station in a wireless communication system, the RU comprising: Transceiver; as well as A controller is coupled to the transceiver and is configured to: receiving a management plane message from a distributed unit (DU) configuring a regularization factor in segment type 5 for user equipment (UE) scheduling information, The regularization factor is used to generate a minimum mean square error (MMSE) calculation of multi-user (MU) beamforming weights for the UE in a time slot.

17. The RU according to claim 16, in, The management plane messages are received based on the capabilities of the RU.

18. The RU according to claim 16, wherein: The controller is also configured to: receiving a control plane message of segment type 5 for UE scheduling information from the DU, the control plane message including segment extension information, identifying segment extension information indicating the regularization factor, and A beamforming weight is obtained based on the regularization factor.

19. The RU according to claim 16, in, The segment type 5 is defined in the Open Radio Access Network (O-RAN), wherein, based on the capabilities of the RU, the regularization factor is received from the DU via segment type 5 instead of segment type 6 for channel information, and The regularization factor is associated with the noise variance used for MMSE calculation.

20. The RU according to claim 16, in, The segment extension information includes information about the type of the segment extension information and information about the length of the segment extension information. Wherein, the type of segment extension information is associated with the regularization factor, and The length of the regularization factor is 16 bits.

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