Method and apparatus for port combining signaling based on singular value decomposition (SVD) in a wireless communication system

Abstract

This disclosure relates to 5G or 6G communication systems capable of achieving higher data transmission rates compared to 4G communication systems such as LTE. Additionally, this disclosure relates to a method performed by a remote unit (RU) in a wireless communication system, comprising the steps of: receiving a port combining configuration from a digital unit (DU); determining, based on the port combining configuration, whether to perform singular value decomposition (SVD) port combining; if SVD port combining is performed, sending an indication to the DU indicating that SVD port combining has been applied; and sending a signal to the DU indicating that SVD port combining has been applied, wherein the indication is used to decode the signal.

Description

Technical Field

[0001] This disclosure relates to the operation of terminals and base stations in wireless communication systems. More specifically, this disclosure relates to methods and apparatus for terminals and base stations performing port-merging signaling for DU (Open RAN Digital Unit) in wireless communication systems using SVD. Background Technology

[0002] A review of the generational development of wireless communication reveals that most advancements have focused on technologies serving humans, such as voice-based services, multimedia services, and data services. An exponential increase in connected devices is expected after the commercialization of 5G communication systems. Examples of things connected to the network include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction machinery, factory equipment, and more. Mobile devices are expected to evolve into various forms, such as augmented reality glasses, virtual reality headsets, and holographic devices. To provide a wide range of services by connecting hundreds of billions of devices and things in the 6G era, efforts are underway to develop improved 6G communication systems. Therefore, 6G communication systems are referred to as "beyond 5G" systems.

[0003] The 6G communication system, expected to be realized around 2030, will have a maximum transmission rate in the terabyte (1000 gigabyte) range and a wireless latency of 100 μsec. That is, the 6G communication system will be 50 times faster than the 5G communication system, and the wireless latency will be one-tenth of that of the 5G communication system.

[0004] To achieve such high data transmission rates and ultra-low latency, 6G communication systems have been considered for implementation in the terahertz band (e.g., the 95 GHz to 3 THz band). Given that path loss and atmospheric absorption in the terahertz band are more severe than those in the millimeter-wave (mmWave) band introduced in 5G, technologies capable of ensuring signal transmission distance (i.e., coverage) will become even more critical. Key technologies to be developed for ensuring coverage include: multi-antenna transmission technologies incorporating radio frequency (RF) elements, antennas, novel waveforms with better coverage than OFDM, beamforming and massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, and massive MIMO. Additionally, new technologies for improving terahertz band signal coverage have been discussed, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS).

[0005] Furthermore, to improve frequency efficiency and system networks, the following technologies have been developed for 6G communication systems: full-duplex technology to enable uplink (UE transmission) and downlink (Node B transmission) to use the same frequency resources simultaneously; network technologies for integrated utilization of satellites, High Altitude Platform Stations (HAPS), etc.; network architecture innovation technologies to support mobile Node Bs and achieve network operation optimization and automation; dynamic spectrum sharing technology to avoid conflicts based on spectrum usage prediction; AI-based communication technologies to achieve system optimization by using artificial intelligence (AI) from the technical design stage and to incorporate end-to-end AI support; and next-generation distributed computing technologies to achieve services with complexity exceeding the UE's computing power limitations by using ultra-high-performance communication and computing resources (Mobile Edge Computing (MEC), cloud, etc.). In addition, continuous efforts are being made to further enhance connectivity between devices, further optimize networks, promote the software implementation of network entities, and improve the openness of wireless communication by designing new protocols for 6G communication systems, developing mechanisms for achieving hardware-based secure environments and secure data usage, and developing privacy maintenance methods.

[0006] The research and development of 6G communication systems is expected to enable next-generation hyper-connected experiences in a new dimension through the hyper-connectivity of 6G communication systems, connecting objects and people and things. Specifically, services such as truly immersive XR, high-fidelity mobile holograms, and digital copies are expected to be provided through 6G communication systems. Furthermore, leveraging enhanced security and reliability, services such as remote surgery, industrial automation, and emergency response will be offered through 6G communication systems, thus extending their application to various sectors including industry, healthcare, automotive, and home appliances. Summary of the Invention

[0007] [Technical Issues]

[0008] This disclosure aims to provide apparatus and methods for efficiently providing services in wireless communication systems. The disclosure provides a method and apparatus in which an RU in an O-RAN indicates to a DU the port combining method used, thereby improving communication performance and fronthaul (hereinafter referred to as FH) resource utilization efficiency in the wireless communication system.

[0009] The technical subject matter pursued in this disclosure is not limited to the above-mentioned technical subject matter, and other technical subject matter not mentioned herein will be clearly understood by those skilled in the art from the following description.

[0010] Solution to the problem

[0011] A method performed by a remote unit (RU) in a wireless communication system according to an embodiment of the present disclosure may include: receiving a port merging configuration from a digital unit (DU); identifying whether singular value decomposition (SVD) port merging is to be performed based on the port merging configuration; if SVD port merging is performed, sending an indication to the DU indicating that SVD port merging has been performed; and sending a signal to the DU indicating that SVD port merging has been applied, wherein the indication is used to decode the signal.

[0012] A method performed by a digital unit (DU) in a wireless communication system according to an embodiment of the present disclosure may include: sending a port merging configuration to a remote unit (RU); receiving an instruction from the RU indicating SVD port merging if singular value decomposition (SVD) port merging identified based on the port merging configuration is performed; receiving a signal from the RU in which SVD port merging has been applied; and decoding the signal based on the instruction.

[0013] A remote unit (RU) in a wireless communication system according to an embodiment of the present disclosure may include a transceiver and a controller connected to the transceiver, wherein the controller is configured to: receive a port combining configuration from a digital unit (DU); identify whether singular value decomposition (SVD) port combining is performed based on the port combining configuration; if SVD port combining is performed, send an indication to the DU indicating that SVD port combining has been applied; and send a signal to the DU indicating that SVD port combining has been applied, wherein the indication is used to decode the signal.

[0014] A digital unit (DU) in a wireless communication system according to an embodiment of the present disclosure may include a transceiver and a controller connected to the transceiver, wherein the controller is configured to: send a port merging configuration to a remote unit (RU); receive an instruction from the RU indicating SVD port merging if singular value decomposition (SVD) port merging identified based on the port merging configuration is performed; receive a signal from the DU indicating that SVD port merging has been applied; and decode the signal based on the instruction.

[0015] [Beneficial effects of the invention]

[0016] This disclosure provides a method and apparatus in which port merging used in data transmission and reception between RU and DU in an O-RAN network environment is indicated by the RU to the DU, thereby enabling more appropriate and efficient execution of wireless communication system services in a 6G environment.

[0017] The beneficial effects that can be obtained from this disclosure are not limited to the above-mentioned beneficial effects, and other beneficial effects not mentioned herein will be clearly understood by those skilled in the art to which this disclosure pertains from the following description. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the architecture of O-RAN.

[0019] Figure 2 This is a diagram illustrating a wireless communication system using MIMO technology.

[0020] Figure 3 This is a diagram illustrating the method of using the MRC port merging approach.

[0021] Figure 4 This is a diagram illustrating the process of performing SVD-based port merging between RU and DU.

[0022] Figure 5 This is a diagram illustrating the matrix inversion process in DU.

[0023] Figure 6 This is a diagram illustrating the low-complexity matrix inversion process in DU.

[0024] Figure 7 This is a diagram illustrating the process of performing port merging between RU and DU according to an embodiment of the present disclosure.

[0025] Figure 8 This is a diagram illustrating the port merging signaling process of a RU according to an embodiment of the present disclosure.

[0026] Figure 9 This is a diagram illustrating the port merging signaling process of a DU according to an embodiment of the present disclosure.

[0027] Figure 10 The illustration shows RU and DU devices in a wireless communication system according to an embodiment of the present disclosure. Detailed Implementation

[0028] In the following description, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0029] In describing the embodiments, descriptions of technical content known in the relevant art and not directly related to this disclosure will be omitted. Unnecessary descriptions are omitted to prevent obscuring the main points of this disclosure and to more clearly convey them.

[0030] For the same reason, some elements may be exaggerated, omitted, or shown schematically in the accompanying drawings. Furthermore, the dimensions of each element do not perfectly reflect its actual size. In the various drawings, identical or corresponding elements are given the same or similar reference numerals.

[0031] The advantages and features of this disclosure, and the ways in which they are implemented, will become clear from reference to the embodiments described in detail below in conjunction with the accompanying drawings. However, this disclosure is not limited to the embodiments set forth below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose this disclosure and to inform those skilled in the art of its scope, which is defined solely by the scope of the appended claims. Throughout the specification, the same or similar reference numerals denote the same or similar elements. Furthermore, in describing this disclosure, detailed descriptions of known functions or configurations incorporated herein are omitted where it is determined that the description might unnecessarily obscure the subject matter of the disclosure. The terminology described below is defined in consideration of the functions in this disclosure and may vary depending on the user, the user's intent, or custom. Therefore, the definitions of the terms should be made based on the entire contents of the specification.

[0032] In the following description, a base station is an entity that allocates resources to a terminal and can be at least one of a gNode B, eNode B, Node B, base station (BS), radio access unit, base station controller, and a node on a network. A terminal may include a user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. In this disclosure, "downlink (DL)" refers to a radio link through which a base station transmits signals to a terminal, and "uplink (UL)" refers to a radio link through which a terminal transmits signals to a base station. Furthermore, while LTE or LTE-A systems may be described by way of example in the following description, embodiments of this disclosure can also be applied to other communication systems with similar technical backgrounds or channel types. Examples of such communication systems may include fifth-generation mobile communication technologies (5G, New Radio, and NR) developed after LTE-A, and in the following description, "5G" may be a concept encompassing existing LTE, LTE-A, and other similar services. Additionally, based on the judgment of those skilled in the art, this disclosure can also be applied to other communication systems with some modifications without significantly departing from the scope of this disclosure.

[0033] In this document, it will be understood that each box in a flowchart illustration, and combinations of boxes in a flowchart illustration, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart boxes or blocks. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium that can instruct the computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-usable or computer-readable storage medium produce an article of writing including instruction means that implement the functions specified in the flowchart boxes. Instructions that execute on a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable data processing apparatus provide steps for implementing the functions specified in the flowchart boxes.

[0034] Furthermore, each box in the flowchart may represent a module, segment, or portion of code, including one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the boxes may occur out of order. For example, two boxes shown consecutively may actually execute substantially simultaneously, or the boxes may sometimes execute in reverse order, depending on the functions involved.

[0035] As used in embodiments of this disclosure, the term "unit" refers to a software element or hardware element, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC), and a "unit" performs a specific function. However, "unit" is not always limited to software or hardware. A "unit" may be configured to be stored in addressable storage media or to execute one or more processors. Thus, a "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and parameters. Elements and functions provided by a "unit" may be combined into a smaller number of elements or "units," or divided into a larger number of elements or "units." Furthermore, elements and "units" may be implemented to reproduce one or more central processing units (CPUs) within a device or secure multimedia card. Additionally, a "unit" in the embodiments may include one or more processors. In the following description, the term "a / b" may be understood as at least one of a and b.

[0036] Furthermore, in the following description of various embodiments, systems based on LTE, LTE-A, NR, or 6G are described by way of example. However, the various embodiments of this disclosure can also be applied to other communication systems with similar technical backgrounds or channel types. Moreover, based on the judgment of those skilled in the art, the various embodiments of this disclosure can also be applied to other communication systems with some modifications without significantly departing from the scope of the embodiments of this disclosure.

[0037] In the following description, for ease of description, some terms and names defined in the 3GPP standards (standards for 5G, NR, LTE, or similar systems) may be used. Additionally, terms and names used in existing communication systems or newly defined in next-generation communication systems (e.g., 6G and beyond 5G systems) may also be used, and this disclosure applies to next-generation communication systems. The use of these terms is not intended to limit this disclosure in terms of terminology and names, and this disclosure can be applied in the same manner to systems conforming to other standards and can be modified into other forms without departing from the technical concept of this disclosure. Various embodiments of this disclosure can also be readily applied to other communication systems with modifications.

[0038] In recent years, wireless communication technology has made considerable progress, offering faster data speeds, expanded application range, and more stable connections. However, as the demand for wireless communication services continues to increase, many problems remain to be solved, such as network congestion, signal interference, and dynamic changes in network conditions.

[0039] This disclosure relates to Open RAN (O-RAN) systems, and more particularly, to signaling methods and apparatus, wherein during transmission and reception processes between a radio signal processing device (remote unit, hereinafter referred to as RU) in the O-RAN and a digital data processing device (digital unit, hereinafter referred to as DU) in the O-RAN, the RU uses SVD-based port combining to improve communication performance and FH resource utilization efficiency.

[0040] In the following, RU and DU in this disclosure are assumed to be RU and DU in an O-RAN network. Depending on the circumstances, RU may be understood as O-RU and DU may be understood as O-DU. However, the networks covered by this disclosure are not limited to O-RAN, and this disclosure may apply even if RU and DU are included in other networks.

[0041] Figure 1 This is a diagram illustrating the architecture of O-RAN.

[0042] according to Figure 1O-RAN network is a standard that logically separates the functions of eNB and gNB in ​​traditional 4G and 5G systems. In the O-RAN standard, NRT-RIC 110, RIC 120, CU-CP 130, CU-UP 140, DU 150 and RU 160 in O-RAN gNB are defined.

[0043] The NRT-RIC 110 is a logical node that performs non-real-time control, RAN element and resource optimization, model training and updates, and other operations. The newly defined RIC 120 is a logical node that performs near real-time control and RAN element and resource optimization based on data collected via the E2 interface from DU 150, CU-CP 130, and CU-UP 140, which are centrally deployed on servers in the same physical location. The CUs, including CU-CP 130 and CU-UP 140, are logical nodes that provide Radio Resource Control (RRC), Serving Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) functions. CU-CP 130 provides the control plane portion of RRC and PDCP functions, and CU-UP 140 provides the user plane portion of SDAP and PDCP functions. CU-CP 130 connects via the NGAP interface to the Access and Mobility Management Function (AMF) included in the 5G network (5G core). DU 150 is a logical node providing RLC, MAC, and high-PHY functions, while RU 160, connected to DU 150, is a logical node providing low-PHY functions and RF processing. Although Figure 1 Each logical node is shown as a single instance, but each logical node can connect to multiple logical nodes. For example, multiple RU 160s can connect to one DU 150, and multiple DU 150s can connect to one CU-UP 140.

[0044] This disclosure is not limited to the node names described above, and the configurations described herein can be applied to logical nodes or entities that perform the functions described above. Furthermore, logical nodes can be deployed in the same or different physical locations, and the functionality of logical nodes can be provided by the same physical device (e.g., a processor or controller) or different physical devices. For example, the functionality of at least one of the logical nodes described above can be provided in a single physical device through virtualization. In the following, DU can be used interchangeably with O-DU, and RU can be used interchangeably with O-RU.

[0045] Figure 2 This is a diagram illustrating a wireless communication system using MIMO technology.

[0046] In wireless communication systems, the number of antennas used may increase with the adoption of Multiple-Input Multiple-Output (MIMO) technology. (See reference...) Figure 2 UE 1, UE 2, ... and UE K can use MIMO to transmit and receive signals. The information that the UE wants to send to the RU can be, for example, s 210.

[0047] The information can be multiplied by the P value corresponding to the precoder. The resulting signal, such as Ps 220, can be a signal transmitted from each antenna port of the UE. Here, the generated signal Ps can have a dimension of N_TX × N_L. N_TX can indicate the number of antenna ports, and N_L can indicate the number of layers.

[0048] The RU of the base station can receive signals using its receive antenna ports. The received signal can be represented as y = HPs + n 230. Here, H can be the channel through which the signal passes, and the dimension of H can be N_RX × N_TX. N_RX can refer to the number of receive antenna ports of the RU.

[0049] The base station's RU can use the fronthaul (FH) as a link (or interface) connecting the RU and DU to transmit signal (y') 240 to the DU. Specifically, y' can be the result of y multiplied by the F^H value. Here, the dimension of F^H can be N_C × N_RX. N_C can be the number of antenna ports transmitted from the RU to the DU. N_C can be less than or equal to N_RX.

[0050] Thus, with the use of MIMO, the number of antennas used increases, and the amount of data sent from the RU to the DU may increase.

[0051] As the amount of data sent from the RU to the DU via the FH increases, the capacity required by the FH may increase, and this disclosure provides a method for addressing this problem.

[0052] Specifically, to address the issue of excessive FH capacity requirements, port combining can be used to efficiently utilize FH resources. Port combining refers to a scheme that uses a small number of data streams transmitted between RU and DU. For example, when it is determined that there is no significant loss in the data to be transmitted, instead of transmitting all the data streams corresponding to the number of RU receive antennas, only a portion of the data streams are transmitted. By reducing the number of data streams sent from RU to DU through port combining, the amount of data sent to FH can be reduced.

[0053] As an example of an application port merging method, the Maximum Ratio Merging (MRC) method can be used.

[0054] Figure 3 This is a diagram illustrating the method of using the MRC port merging approach.

[0055] Specifically, in the MRC port combining method, the combining can be performed by multiplying the received signals received through different antenna ports by weight values ​​that reflect the signal-to-noise ratio (SNR) weights, and then adding the received signals multiplied by the weight values ​​to maximize the SNR of the combined signal.

[0056] Additionally, DFT-based port combining can be considered another method of port combining. To perform DFT-based port combining, a projection matrix can be used. Specifically, the RU can determine the projection matrix based on the codebook and send DMRS symbols and the signal obtained by applying the projection matrix to the signal received from the UE to the DU. The DU can calculate, generate, and apply the combining matrix using the DMRS symbols. Since DFT-based port combining determines the projection matrix based on the codebook, the port combining weights can be determined from a predefined set.

[0057] In environments using only a single layer, port combining typically employs the MRC port combining method. However, current communication systems support multi-layer uplink operation. With the increasing prevalence of environments such as X-MIMO, UEs supporting multi-layer uplinks are becoming more common. However, when applying SVD-based port combining in multi-layer uplink environments, the following problems exist: despite significant performance gains, computational complexity is high. Therefore, this disclosure proposes an efficient method for performing SVD-based port combining.

[0058] Figure 4 This is a diagram illustrating the process of port merging between RU and DU.

[0059] according to Figure 4 In operation 410, RU can receive signal (y).

[0060] Additionally, RU can obtain H through channel estimation (CE). Here, H is the channel matrix, which reflects the changes that occur when a signal passes through the channel in a wireless communication environment.

[0061] The RU can perform SVD-based port combining on the received signal. Specifically, the RU can obtain weights for SVD-based port combining and perform SVD-based port combining based on these weights. The weights for SVD-based port combining can be obtained according to the following Equation 1.

[0062] [Equation 1]

[0063] When performing SVD on the channel matrix H, H can be decomposed into: Here, the U matrix obtained by SVD, or the values ​​determined based on the U matrix, can be used as weight values ​​(F) in SVD-based port combining. The U matrix can be defined as the values ​​or matrix obtained by performing SVD on the channel. The signal y' obtained by port combining (e.g., RX port combining) can be obtained according to the following Equation 2 by multiplying the received signal y by F corresponding to the port combining filter value.

[0064] [Equation 2]

[0065] In operation 420, RU can send y' corresponding to the merged signal to DU.

[0066] The received DU of y' can be used by the detector to estimate the original signal y. The estimated signal has been obtained. The DU can send signals to the network.

[0067] When using SVD-based port merging, the F value can be determined to satisfy the following Equation 3.

[0068] [Equation 3]

[0069] Equation 3 above indicates that the F value can be determined to maximize the SNIR, but does not indicate the F value itself. By determining the F value to maximize the SNIR as described above, channel capacity can be maximized. However, as mentioned above, there is a problem of high computational complexity when using SVD-based port combining. Therefore, this disclosure proposes a method for efficiently performing SVD-based port combining.

[0070] Figure 5 This is a diagram illustrating the matrix inversion process in DU.

[0071] The RU can receive signal (y) and can perform port combining on the received signal to send y' to the DU. Its detailed description is consistent with... Figure 4 The same as in the previous text, therefore it will be omitted in the following text.

[0072] like Figure 4 As shown, DU can receive y' and obtain an estimated signal through a specific process. And it sends the signal to the network entity. Figure 5 The diagram shows that the estimated signal is obtained from the received DU of y' through a detection operation including matrix inversion. The process of matrix inversion can include performing forward and backward substitutions through Cholesky decomposition. However, as... Figure 5 The process of inverting a matrix in Chinese involves computationally very complex problems.

[0073] Figure 6 This is a diagram illustrating the low-complexity matrix inversion process in DU.

[0074] When using the SVD-based port merging method, the following problem exists: the computational complexity is high when using general matrix inversion. However, in the case of using SVD-based port merging, it can be achieved through methods such as... Figure 6 The process shown performs a low-complexity matrix inversion.

[0075] Specifically, DU can be determined by matrix inversion. Value. That is, during the execution of zero-forcing (ZF) or interference suppression combining (IRC) operations, DU can perform low-complexity channel matrix inversion.

[0076] It can be obtained from the following equation 4.

[0077] [Equation 4]

[0078] Specifically, the RU can perform SVD on the estimated channel H. The transpose of the left singular vector matrix U obtained by performing SVD can be applied as port combining weights. The RU can send the value y' obtained by multiplying the received signal y by the port combining filter to the DU. The DU that receives y' can perform channel estimation on the received value. The value corresponding to the estimation result... It can be Here, because Therefore, the corresponding value can be represented as Since V is a unitary matrix, its inverse matrix is ​​the same as the Hermitian matrix. The relationship holds. The diagonal singular value matrix Σ can be represented as follows: shown With its Hermitian matrix The multiplication operation is used for identification. In this case, since the inverse operation of the diagonal matrix requires a division operation corresponding to the number of diagonal elements, the required computation is very low. That is, instead of using the Cholesky decomposition and forward / backward substitution operations traditionally used to obtain the inverse matrix, only the multiplication operation obtained through CE can be performed. The Hermitian operations and the inverse operation of the diagonal matrix Σ are performed. As a result, low-complexity channel matrix inversion can be performed in the case of SVD-based port combining.

[0079] The meaning of each variable is as follows.

[0080] - Channel matrix multiplied by port combining weights

[0081] - U: Left singular vector matrix

[0082] - Σ: Diagonal singular value matrix

[0083] - V: Right singular vector matrix

[0084] In order to use low-complexity matrix inversion, the DU needs to know the port merging method used in the RU. If the DU cannot know which port merging method the RU uses, it cannot determine whether a low-complexity matrix inversion process can be used in the DU. If the DU cannot know the port merging method used in the RU, the DU performs a matrix inversion process with high computational complexity instead of low-complexity matrix inversion.

[0085] According to the current O-RAN standard, there is no instruction from the RU regarding the port merging method. Therefore, this disclosure presents a method for instructing the DU on the port merging method used in the RU.

[0086] Furthermore, the RU can send the singular values ​​computed during SVD execution in the RU to the DU. When the singular values ​​are sent to the DU, the operation of obtaining the diagonal singular value matrix in the DU can be omitted, thus reducing the computational complexity in the DU. Therefore, this disclosure proposes a method for sending singular values ​​from the RU to the DU.

[0087] Figure 7 This is a diagram illustrating the port merging signaling process between the RU and DU according to an embodiment of the present disclosure.

[0088] according to Figure 7 In operation 710, the DU can send a capability request message related to port merging to the RU.

[0089] In operation 720, in response to the capability request message, the RU may send a capability information message to the DU. The capability information message may include capability information related to RU port merging.

[0090] Capability request messages can be sent from the RU not only during the initial connection process between the RU and DU, but also during operations after the initial connection. Similarly, capability information messages can be sent from the DU to the RU not only during the initial connection process between the RU and DU, but also during operations after the initial connection.

[0091] In operation 730, the DU can send port merging-related configurations to the RU. Additionally, the RU can send port merging-related configurations to the DU. The configurations may include port merging parameters configured based on capability information. These port merging-related parameters can be used to instruct on port merging.

[0092] The RU that has received the parameters can apply them immediately after receipt. Alternatively, the RU can apply the parameters at a time specified by the DU. In this case, the DU can send information about the application time and whether the parameters are applied to the RU via port merging enable. Alternatively, the RU can determine the application time and whether to apply the parameters independently.

[0093] In operation 740, the DU may send a port merging enable signal to the RU. This port merging enable signal can activate or deactivate the port merging configuration in the RU depending on whether port merging can be applied. Additionally, the port merging enable signal may indicate whether parameters included in the configuration have been applied.

[0094] For example, considering the SVD capability of the RU, the DU can enable the signal in single-user scheduling and disable the signal in multi-user scheduling. In single-user scheduling, the DU can send an enable signal to ensure that SVD port merging is performed only in specific resources based on the RU's SVD performance capability.

[0095] This operation is optional, and if this operation is not performed, the port merging enable signal can be included in the configuration to be sent and received during the process of merging the send and receive ports.

[0096] In operation 750, the RU can send a port merging indication signal to the DU. The RU can perform port merging by applying a configuration configured by the DU, and then notify the DU of whether port merging has been performed via the port merging indication signal. Alternatively, the RU can send an indication signal to indicate an acknowledgment (ACK) or negative acknowledgment (NACK) for a resource specified by the DU. Alternatively, the RU can send an indication signal indicating whether SVD port merging has been applied in response to the DU's port merging enable signal. Alternatively, even without a request from the DU, the RU can apply SVD port merging autonomously and then send an indication signal indicating whether SVD port merging has been applied.

[0097] The indication can be configured by bits indicating whether a port merging configuration has been applied. The indication can be appended to and sent after a predefined message from the RU to the DU, or a separate message can be defined for the indication. Alternatively, the indication can indicate whether SVD has been applied using the port merging configuration described below. Furthermore, in this disclosure, the method of sending an indication from the RU to the DU is described as an example, but the method of sending an indication from the DU to the RU can also be used if a signal indicating that SVD has been applied is sent from the DU to the RU. Additionally, the operation of sending the indication can be performed optionally.

[0098] In operation 760, the RU can send signals to the DU. These signals can be those with SVD port combining applied. The signals can correspond to messages that include I / Q data.

[0099] In Operation 770, if the RU uses an SVD-based port merging method, the RU can send singular values ​​to the DU. When singular values ​​are sent to the DU, the computational cost required to compute the singular values ​​in the DU can be reduced, thereby reducing computational complexity.

[0100] When no singular value is received, DU can perform the above-mentioned procedure. Figure 6 The matrix inversion process is described. Specifically, DU can perform H on the channel H obtained by the channel estimator. The hermitian(H) operation is used to determine the squared values ​​of the singular values. Specifically, the singular values ​​can correspond to the diagonal elements of Σ corresponding to the diagonal singular value matrix.

[0101] Conversely, a DU that has received a singular value from the RU can use the singular value, and therefore can avoid performing the operation via H. The hermitian(H) operation is used to obtain the square of the diagonal singular value matrix Σ. That is, when DU receives singular values, the computational cost can be reduced.

[0102] This operation is optional, and if this operation is not performed, the DU may send a singular value request value to the RU during the process of merging the transmit and receive ports.

[0103] The following embodiments present a method for performing port merging by enabling transmit and receive port merging between RU and DU.

[0104] Example 1: Port merging capability via management plane (M-plane)

[0105] According to embodiments of this disclosure, the RU can send port merging capability to the DU. Specifically, the port merging capability message can be sent via the M-plane as shown in Table 1 below. Specifically, the message can be sent via o-ran-module-cap (e.g., o-ran-module-cap.yang.module) in the M-plane.

[0106] [Table 1]

[0107] Specifically, the capability information sent via o-ran-module-cap may include port merging configuration. The port merging configuration may include supported port merging methods (e.g., method-of-port-combining). Alternatively, the port merging configuration may include information about whether the RU is capable of performing port merging. The port merging method may include SVD-based port merging (e.g., svd-port-combining). When using an SVD-based port merging method, at least one of the following may be included as a specific description of the port merging method: the maximum number of supported layers (e.g., max-svd-layers), the number of SVD computation engines (e.g., number-of-svd-engines), and information indicating whether singular values ​​are sent. The corresponding information may be transmitted as parameters.

[0108] Alternatively, according to embodiments of this disclosure, the RU may send a capability message to the DU including capability information related to RU port merging. Specifically, the capability message may be sent in the same manner as shown in Table 2 below. The capability message may be transmitted as a subfield value of a field related to beamforming in the O-RAN M-plane.

[0109] [Table 2]

[0110] Specifically, the capability information sent via o-ran-module-cap may include port merging configuration. The port merging configuration may include supported port merging methods (e.g., method-of-port-combining). Alternatively, the port merging configuration may include information about whether the RU is capable of performing port merging. The port merging method may include SVD-based port merging (e.g., svd-port-combining). When using an SVD-based port merging method, at least one of the following may be included as a specific description of the port merging method: the maximum number of supported layers (e.g., max-svd-layers), the number of SVD computation engines (e.g., number-of-svd-engines), and information indicating whether singular values ​​are sent. The corresponding information may be transmitted as parameters.

[0111] Capability messages, including capability information related to RU port merging, can be sent via the M-plane as shown in Table 1 or Table 2 above. However, the capability information transmission scheme is not limited to the above schemes and other schemes can be used.

[0112] Capability information can be included in a capability report message and sent in response to a capability request message sent by the DU to the RU in operation 710. The DU can receive port merging capability information from the RU during the initial connection process. Additionally, the DU can send request messages even in operations following the initial connection. The RU can then receive capability information in response to these messages.

[0113] The following embodiments propose a port merging configuration for sending and receiving data between the RU and DU, and for sending data to the RU to perform port merging. Additionally, this disclosure proposes the following information as a port merging configuration for sending data from the DU to the RU or from the RU to the DU. The following information can be sent from the RU to the DU to indicate whether SVD port merging has been applied.

[0114] [Example 2: Port Merging Configuration via Control Plane – Segmentation Extension Using Type 1 Segmentation]

[0115] According to embodiments of this disclosure, the RU can send port merging-related configurations to the DU. Specifically, the port merging-related configurations (hereinafter referred to as port merging configurations) can include at least one of the information included in the port merging capability information of Embodiment 1. The port merging configurations can be sent via a C-plane.

[0116] Port merging configuration can be based on parameters defined for SVD-based port merging in the segment extension of type 1 segmentation. Specifically, a new extension type (e.g., exType) can be added to the segment extension, and the extension type can indicate SVD-based port merging (e.g., SVD port merging). The extension type indicating SVD-based port merging can indicate parameters associated with SVD-based port merging.

[0117] The following table [Table 3] shows the existing Type 1 segment: DL / UL control messages.

[0118] [Table 3]

[0119] The following Table 4 illustrates a case where a new extension type is added to the segmented extensions in Table 3 above, according to an embodiment of this disclosure, and indicates SVD (based) port merging.

[0120] [Table 4]

[0121] When defining a new extension type that indicates SVD-based port merging, the port merging configuration can include the following segmentation extension parameters.

[0122] In addition to the parameters mentioned in the M-plane embodiments (e.g., supported port merging methods, information about whether the RU can perform port merging, the maximum number of supported layers, the number of SVD operation engines, and information indicating whether singular values ​​are sent), the segmented extension parameters may also include at least one of the following: the number of antenna ports of the RU (antenna ports may mean logical antenna ports), the number of reduced ports determined considering fronthaul capacity, the ratio between the number of antennas applied to port merging and the number of reduced ports, the port merging method used, whether port merging is applied, the value of the port merging weight (e.g., in-phase and quadrature phase values), whether compression is applied to the port merging weight, the value of the compressed port merging weight (e.g., in-phase and quadrature phase values), the compressed bit width of the port merging weight, the resources for applying port merging, a repetition indication to improve the field read and processing speed of the RU, port merging weight extension, port merging weight extension type, whether a switch is performed, and at least one of the following: singular values.

[0123] The number of antenna ports of the RU can be defined as, for example... numLogicalAntPort And it can have values ​​of 64, 128, 512, 1024, etc. The number of reduced ports, determined considering fronthaul capacity, can be defined as, for example... numReducedPort And it can have values ​​of 4, 8, 16, etc. The ratio between the number of antennas applied to port combining and the number of ports reduced can be defined as, for example... PortCombiningRatio And it can have values ​​of 2:1, 4:1, 8:1, etc. numReducedPort The value can be derived from PortCombiningRatio Value substitution. The port merging method used can be defined as, for example... Port Combining Method And it can have values ​​such as MRC, SVD, DFT, and none. When the port merging method used is SVD, a low-complexity scheme can be used for inverse matrix operations. The port merging weights can be defined as follows: Port CombiningWeight If the port merge weights are in phase, then the port merge weights can be defined as follows: pcwI And if the port merging weights are orthogonal, then the port merging weights can be defined as follows: pcwQ The port merging weight can be defined under the assumption that the DU calculates the corresponding value and sends it to the RU. Whether to apply compression to the port merging weight can be defined, for example... PortCombiningWeightCompression If defined PortCombiningWeightCompression Then, the same operation as weight compression in beamforming can be performed. When performing weight compression, for example, a weight can be defined. pcwCompHdr or pcwCompParam The value or parameter of a singular value. A singular value can be defined as, for example... SingularValueSingular values ​​can be defined under the assumption that the RU sends singular values ​​rather than the DU computes them. Resources for application port merging can have... PortCombiningRB , PortCombiningRE , PortCombiningSymb Equivalent values. Each value can be defined to indicate which resource port merging is applied to. A repeat indicator can be defined as, for example... Repetition Furthermore, when the corresponding value is 0b, the previous configuration is used as is, so the parameters are not read again, thus reducing computation time. Whether to perform a toggle corresponds to the value used to indicate whether to toggle the combination method, and can be defined as... Switching .if Repetition The value is 1 and Switching If the value is also 1, then only the port merging method is switched, so other parameters do not need to be read, thus shortening the computation time. Repetition The value is 1 and Switching In all cases except when the value is also 1, it may be necessary to read all other fields.

[0124] To identify whether port merging weight extension is used, for example, you can define... Port CombiningWeight Extension .if Port CombiningWeight Extension A value of 1 indicates that extensions are available. To identify the type of port merging weight extension, you can define... typePortCombingWeightExtension Furthermore, it can have values ​​such as orthogonal and partially orthogonal. Parameters related to the port merge weight extension and type combination weight extension types can be integrated into the port merge method parameters. Among these parameters are the port merge weights for in-phase and orthogonal phase cases, whether to apply compression to the port merge weights, and the value used for performing weight compression (e.g., ...). pcwCompHdr and pcwCompParam At least one of the following), resources for application port merging (e.g., PortCombiningRB , PortCombiningRE and PortCombiningSymb At least one of the following can be sent from DU to RU.

[0125] Among the parameters, singular values ​​can be sent from RU to DU.

[0126] At least one of the other parameters, such as the number of antenna ports, the number of reduced ports determined considering fronthaul capacity, the ratio between the number of antennas applied to port combining and the number of reduced ports, the port combining method used, repetition indication, and whether a handover is performed, can be sent from the RU to the DU. Alternatively, it can also be sent from the DU to the RU.

[0127] Configuration related to port merging can be sent from the DU to the RU in operation 730. Additionally, configuration related to port merging can be sent from the RU to the DU in operation 730.

[0128] The following embodiments propose a port merging configuration for sending and receiving data between the RU and DU, and for sending data to the RU to perform port merging. Additionally, this disclosure proposes the following information as a port merging configuration for sending data from the DU to the RU or from the RU to the DU. The following information can be sent from the RU to the DU to indicate whether SVD port merging has been applied.

[0129] [Example 3: Port Merging Configuration via C-plane Transmitter – Using Type 4 Segmented dt4CmdType]

[0130] According to embodiments of this disclosure, the RU can send port merging-related configurations to the DU. Specifically, the port merging configuration may include at least one of the information included in the port merging capability information in Embodiment 1. The port merging configuration can be sent via a C-plane.

[0131] Port merging configuration can be based on parameters defined for SVD-based port merging in st4CmdType of type 4 segment. Here, st4CmdType can refer to a parameter that specifies a unique command type value to apply to the slot level of a single or multiple IDs. Specifically, a new type (e.g., ST4CmdType) can be added to st4CmdType, and this type can indicate SVD-based port merging.

[0132] The type of SVD-based port merging indicates parameters associated with SVD port merging. Parameters associated with SVD port merging may include at least one of the following: configuration parameters related to SVD-based port merging and port merging weights used for command transmission.

[0133] The following table [Table 5] shows the existing type 4 segment: command general header format.

[0134] [Table 5]

[0135] Table 6 below illustrates a scenario where, according to an embodiment of this disclosure, a new command type is added to st4CmdType and indicates SVD-based port merging when st4CmdType=1 according to Table 5 above.

[0136] Referring to Table 6 below, port merging configuration can be configured based on parameters defined for SVD-based port merging in st4CmdType of type 4 segment. Specifically, a new type (e.g., ST4CmdType) can be added to st4CmdType, and this type can indicate SVD-based merging. The type indicating SVD-based port merging can indicate parameters associated with SVD-based port merging.

[0137] For example, referring to the table below, when the new field is configured as 0000 0011b, SVD-based port merging can be indicated. If SVD-based port merging is indicated, the sending of port merging configuration and / or port merging weights can be specified.

[0138] [Table 6]

[0139] Table 7 below shows the port combining configuration when st4CmdType indicates SVD-based port combining. According to Table 7 below, the port combining configuration may include PortCombiningType, at least one singular value (firstSingularValue, secondSingularValue, ...), and at least one of the compression headers.

[0140] [Table 7]

[0141] Configuration related to port merging can be sent from the DU to the RU in operation 730. Additionally, configuration related to port merging can be sent from the RU to the DU in operation 730.

[0142] The following embodiments propose a port merging configuration for sending and receiving data between the RU and DU, and for sending data to the RU to perform port merging. Additionally, this disclosure proposes the following information as a port merging configuration for sending data from the DU to the RU or from the RU to the DU. The following information can be sent from the RU to the DU to indicate whether SVD port merging has been applied.

[0143] [Example 4: Port Merging Configuration via C-plane or User Plane (U-plane) – Using Type 1 Segmented udCompMeth]

[0144] According to embodiments of this disclosure, the RU can send port merging-related configurations to the DU. Specifically, the port merging configuration may include at least one of the information included in the port merging capability information of Embodiment 1. The port merging configuration can be sent via a C-plane or a U-plane.

[0145] The following table [Table 8] shows the existing Type 1 segment: DL / UL I / Q data messages.

[0146] [Table 8]

[0147] Table 9 below illustrates the case where a new udCompMeth is added to udCompHdr above Table 8 according to an embodiment of this disclosure and indicates SVD (based) port merging.

[0148] Referring to Table 9 below, port merging configuration can be defined in a type 1 segment of udCompHdr. Here, udCompHdr is provided to the U-plane and can refer to information instructing the RU and DU on methods for interpreting and decompressing received U-plane data. Specifically, new methods (e.g., udCompMeth) can be added to udCompHdr, and these methods can instruct SVD-based port merging (e.g., SVD port merging). The method instructing SVD-based port merging can indicate parameters associated with SVD-based port merging.

[0149] For example, referring to the table below, when the new field is configured as 0111b, it can indicate SVD-based port merging (e.g., SVD port merging).

[0150] [Table 9]

[0151] Configuration related to port merging can be sent from the DU to the RU in operation 730. Additionally, configuration related to port merging can be sent from the RU to the DU in operation 730.

[0152] The following embodiments propose a port merging configuration for sending and receiving data between the RU and DU, and for sending data to the RU to perform port merging. Additionally, this disclosure proposes the following information as a port merging configuration for sending data from the DU to the RU or from the RU to the DU. The following information can be sent from the RU to the DU to indicate whether SVD port merging has been applied.

[0153] [Example 5: Port Merging Configuration via C-plane or U-plane Transmit Ports – Using Type 6 Segmented ciCompHdr]

[0154] According to embodiments of this disclosure, the RU can send port merging-related configurations to the DU. Specifically, the port merging configuration may include at least one of the information included in the port merging capability information of Embodiment 1. The port merging configuration can be sent via a C-plane or a U-plane.

[0155] The following table [Table 10] shows the existing Type 6 segment: Channel Information Frame format.

[0156] [Table 10]

[0157] The following [Table 11] illustrates the case where a new ciCompMeth, according to an embodiment of this disclosure, is added to the ciCompHdr above [Table 10] and indicates SVD (based) port merging.

[0158] Referring to Table 11 below, port merging configurations can be defined in a type 1 segment of ciCompHdr. Here, ciCompHdr is provided to the U-plane and can refer to information instructing the RU and DU on methods for interpreting and decompressing received U-plane data. Specifically, new methods (e.g., ciCompMeth) can be added to ciCompHdr, and these methods can instruct SVD-based port merging (e.g., SVD port merging). The method instructing SVD-based port merging can indicate parameters associated with SVD-based port merging.

[0159] For example, referring to the table below, when the new field is configured as 0111b, it can indicate SVD-based port merging (e.g., SVD port merging).

[0160] [Table 11]

[0161] Figure 8 This is a diagram illustrating the port merging signaling process of a RU according to an embodiment of the present disclosure.

[0162] according to Figure 8 In operation 810, the RU can receive capability request messages related to port merging from the DU.

[0163] In operation 820, in response to the capability request message, the RU may send a capability information message to the DU. This capability information message may include capability information related to RU port merging.

[0164] The RU can receive capability request messages from the DU not only during the initial connection process between the RU and the DU, but also during processes outside the initial connection. Furthermore, the RU can send capability information messages to the DU not only during the initial connection process between the RU and the DU, but also during processes outside the initial connection.

[0165] In operation 830, the RU can send port merging-related configurations to the DU. Additionally, the RU can receive port merging-related configurations from the DU. The configurations may include port merging parameters configured based on capability information. These port merging-related parameters can be used to instruct port merging.

[0166] The RU that has received parameters can apply them immediately after receipt. Alternatively, the RU can apply the parameters at a time specified by the DU. In this case, the RU can receive information from the DU about the application time and whether the parameters are applied via port merging enable. Alternatively, the RU can determine the application time and whether to apply the parameters autonomously.

[0167] In operation 840, the RU may receive a port merging enable or port merging enable signal from the DU. The port merging enable or port merging enable signal can activate or deactivate the port merging configuration in the RU depending on whether port merging can be applied. Additionally, the port merging enable or port merging enable signal may indicate whether parameters included in the configuration have been applied.

[0168] For example, the DU can enable the SVD signal in single-user scheduling and disable the SVD signal in multi-user scheduling, taking into account the RU's SVD capabilities. In single-user scheduling, the RU can receive an enable signal configured to perform SVD port merging only in specific resources based on the RU's SVD performance capabilities.

[0169] This operation is optional, and if this operation is not performed, the port merge enable or port merge enable signal may be included in the configuration to be sent and received during the process of sending and receiving port merge configuration.

[0170] In operation 850, the RU can send a port merging indication signal to the DU. The RU can perform port merging by applying a configuration configured by the DU, and then notify the DU of whether port merging has been performed via the port merging indication signal. Alternatively, the RU can send an indication signal to indicate an acknowledgment (ACK) or negative acknowledgment (NACK) for a resource specified by the DU. Alternatively, the RU can send an indication signal to indicate whether SVD port merging has been applied in response to a port merging enable or port merging enable signal from the DU. Alternatively, even without a request from the DU, the RU can apply SVD port merging autonomously and then send an indication signal indicating whether the combination has been applied.

[0171] The indication can be configured by bits indicating whether a port merging configuration has been applied. The indication can be sent after being appended to a predefined message sent from the RU to the DU, or a separate message can be defined for the indication. Alternatively, the indication can indicate whether SVD has been applied using the port merging configuration described below. Furthermore, in this disclosure, the method of sending an indication from the RU to the DU is described as an example, but the method of sending an indication from the DU to the RU can also be used if a signal indicating that SVD has been applied is sent from the DU to the RU. Additionally, the operation of sending the indication can be performed optionally.

[0172] In operation 860, the RU can send signals to the DU. These signals can be those with SVD port combining applied. The signals can correspond to messages that include I / Q data.

[0173] In Operation 870, if the RU uses an SVD-based port merging method, the RU can send singular values ​​to the DU. When singular values ​​are sent to the DU, the computational cost required to compute the singular values ​​in the DU can be reduced, thereby reducing computational complexity.

[0174] This operation is optional, and if this operation is not performed, the DU may send a singular value request value to the RU during the process of merging the transmit and receive ports.

[0175] Figure 9 This is a diagram illustrating the port merging signaling process of a DU according to an embodiment of the present disclosure.

[0176] according to Figure 9 In operation 910, the DU can send a capability request message related to port merging to the RU.

[0177] In operation 920, in response to the capability request message, the DU may receive a capability information message from the RU. The capability information message may include capability information related to RU port merging.

[0178] The DU can send capability request messages to the RU not only during the initial connection process between the RU and the DU, but also during processes outside the initial connection. Furthermore, the DU can receive capability information messages from the RU not only during the initial connection process between the RU and the DU, but also during processes outside the initial connection.

[0179] In operation 930, the DU can send port merging-related configurations to the RU. Additionally, the RU can send port merging-related configurations to the DU. The configurations may include port merging parameters configured based on capability information. These port merging-related parameters can be used to instruct port merging.

[0180] The RU that has received the parameters can apply them immediately after receipt. Alternatively, the RU can apply the parameters at a time specified by the DU. In this case, the DU can send information about the application time and whether the parameters are applied to the RU via port merging enable. Alternatively, the RU can determine the application time and whether to apply the parameters independently.

[0181] In operation 940, the DU may send a port merging enable or port merging enable signal to the RU. The port merging enable or port merging enable signal can activate or deactivate the port merging configuration in the RU depending on whether port merging can be applied. Additionally, the port merging enable or port merging enable signal may indicate whether parameters included in the configuration have been applied.

[0182] For example, the DU can enable the SVD signal in single-user scheduling and disable it in multi-user scheduling, taking into account the RU's SVD capabilities. In single-user scheduling, the DU can send an enable signal so that SVD port merging is performed only in specific resources based on the RU's SVD performance capabilities.

[0183] This operation is optional, and if this operation is not performed, the port merge enable or port merge enable signal may be included in the configuration to be sent and received during the process of sending and receiving port merge configuration.

[0184] In operation 950, the DU may receive a port merging indication signal from the RU. The port merging indication signal may include whether port merging has been performed in the RU based on the application configured by the DU. Alternatively, the DU may receive an indication signal from the RU to indicate an acknowledgment (ACK) or negative acknowledgment (NACK) for a resource specified by the DU. Alternatively, the DU may receive an indication signal from the RU indicating whether SVD port merging has been applied in response to a port merging enable or port merging enable signal from the DU. Alternatively, the DU may receive an indication signal from the RU indicating whether SVD port merging has been applied based on the RU's autonomous determination of the application of SVD port merging.

[0185] The indication can be configured by bits indicating whether port merging configuration has been applied. The indication can be sent after being appended to a predefined message sent from the RU to the DU, or a separate message can be defined for the indication. Alternatively, the indication can indicate whether SVD has been applied using the port merging configuration described below. Furthermore, in this disclosure, the method of sending an indication from the RU to the DU is described as an example, but the method of sending an indication from the DU to the RU can also be used when a signal indicating that SVD has been applied is sent from the DU to the RU. Additionally, the operation of sending the indication can be optionally performed. In operation 960, the DU can receive a signal from the RU. The signal can be a signal indicating that SVD port merging has been applied. The signal can correspond to a message including I / Q data.

[0186] In Operation 970, if the RU uses an SVD-based port merging method, the DU can receive singular values ​​from the RU. When the DU receives singular values, the computational cost required to compute those singular values ​​in the DU can be reduced, thereby lowering computational complexity.

[0187] When no singular value is received, DU can perform the above-mentioned procedure. Figure 6 The matrix inversion process is described. Specifically, DU can perform H on the channel H obtained by the channel estimator. The hermitian(H) operation is used to determine the squared values ​​of the singular values. Specifically, the singular values ​​can correspond to the squared values ​​of Σ corresponding to the diagonal singular value matrix.

[0188] Conversely, a DU that has received a singular value from the RU can use the singular value, and therefore can avoid performing the operation via H. The hermitian(H) operation is used to obtain the square of the diagonal singular value matrix Σ. That is, when DU receives singular values, the computational cost can be reduced.

[0189] This operation is optional, and if this operation is not performed, the DU may send a singular value request value to the RU during the process of merging the transmit and receive ports.

[0190] Figure 10 This is a diagram illustrating devices for RU and DU in a wireless communication system according to an embodiment of the present disclosure. Figure 10 This is a block diagram illustrating a device capable of executing the RU and DU of this disclosure. (Refer to...) Figure 10 RU 1000 includes a transceiver 1010, a controller 1020, a connector 1030, and a memory 1040. However, the components of RU 1000 are not limited to the examples shown above. For example, RU 1000 may include more or fewer components than those shown. Additionally, the transceiver 1010, memory 1030, and controller 1020 may be implemented as a single chip.

[0191] Transceiver 1010 can transmit and receive signals with the UE. Signals may include control information and data. For this purpose, transceiver 1010 may include an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that amplifies and down-converts the received signal with low noise. However, this is merely one embodiment of transceiver 1010, and the components of transceiver 1010 are not limited to RF transmitters and RF receivers. Additionally, transceiver 1010 can receive signals via a wireless channel and output signals to controller 1020, and can also transmit signals output from controller 1020 via a wireless channel. Furthermore, transceiver 1010 may separately include an RF transceiver for an LTE system and an RF transceiver for an NR system, or a single transceiver may be used to perform both LTE and NR physical layer processing.

[0192] The memory 1040 can store programs and data required for the operation of the RU. Additionally, the memory 1040 can store control information or data included in signals sent and received by the RU. The memory 1040 can be configured using storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Furthermore, multiple memories 1040 may be included.

[0193] The controller 1020 can control a series of processes to enable the RU 800 to operate according to the embodiments of the present disclosure described above. For example, the controller 1020 can perform the following operations: receive a port merging configuration from a digital unit (DU), identify whether to perform outlier value decomposition (SVD) port merging based on the port merging configuration, and when SVD port merging is performed, send an indication to the DU indicating that SVD port merging has been applied, and send a signal to the DU indicating that SVD port merging has been applied.

[0194] Connector 1030 is a device for connecting RU 1000 and DU 1050, and is capable of performing the following operations: performing physical layer processing for message sending and receiving, sending messages to DU 1050, and receiving messages from DU 1050.

[0195] DU 1050 includes a controller 1070, a connector 1060, and a memory 1080. However, the components of DU 1050 are not limited to the examples shown above. For example, DU 1050 may include more or fewer components than those shown. Additionally, the connector 1060, memory 1080, and controller 1070 may be implemented as a single chip.

[0196] The controller 1060 can control a series of processes to enable the DU 1050 to operate according to the embodiments of the present disclosure described above. For example, the controller 1060 can perform the following operations: send a port merging configuration to a remote unit (RU), receive an indication of SVD port merging from the RU when an outlier value decomposition (SVD) port merging identified based on the port merging configuration is performed, and receive a signal from the DU indicating that SVD port merging has been applied.

[0197] The memory 1040 can store programs and data required for the operation of the DU. Additionally, the memory 1040 can store control information or data included in signals sent and received by the RU. The memory 1040 can be configured using storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Furthermore, multiple memories 1040 may be included.

[0198] Connector 1060 is a device for connecting RU 1000 and DU 1050 and is capable of performing the following operations: performing physical layer processing for message sending and receiving, sending messages to RU 1000, and receiving messages from RU 1000.

[0199] In the detailed embodiments described above, the elements included in this disclosure are expressed in either a singular or plural form according to the presented detailed embodiments. However, for ease of description, the singular or plural form is appropriately chosen depending on the presentation, and this disclosure is not limited to elements expressed in either a singular or plural form. Thus, an element expressed in a plural form may also include a single element, and an element expressed in a singular form may also include multiple elements.

[0200] The embodiments of this disclosure described and illustrated in the specification and drawings are merely specific examples presented to facilitate explanation of the technical content of the embodiments of this disclosure and to aid in understanding the embodiments of this disclosure, and are not intended to limit the scope of the embodiments of this disclosure. That is, it will be apparent to those skilled in the art that other variations based on the technical concept of this disclosure can be implemented. Furthermore, the various embodiments described above can be combined and applied as needed. For example, a portion of one embodiment of this disclosure can be combined with a portion of another embodiment to operate a base station and a terminal. As an example, the first, second, third, fourth, and fifth embodiments of this disclosure can be partially combined with each other to operate a base station and a terminal.

Claims

1. A method performed by a remote unit RU of a base station in a wireless communication system, the method comprising: Merge configuration from the digital unit (DU) port of the base station; Based on the port merging configuration, determine whether to perform Singular Value Decomposition (SVD) port merging; When performing the SVD port merging, an instruction instructing the SVD port merging is sent to the DU; as well as Send a signal to the DU that the SVD port merging has been applied. The instruction is used to decode the signal that has been combined with the SVD port.

2. The method according to claim 1, further comprising: Receive a capability request message related to port merging from the DU; as well as In response to the capability request message, a capability report message including capability information is sent to the DU. The capability information includes information about supported port merging methods or whether port merging can be performed at least one of these.

3. The method of claim 1, further comprising sending information to the DU including at least one of the application-calculated values ​​based on the SVD port merging.

4. The method according to claim 1, wherein, The port merging configuration includes port merging parameters, which include at least one of the port merging method used and the number of ports reduced.

5. A method performed by a digital unit (DU) of a base station in a wireless communication system, the method comprising: Send port merging configuration to the remote unit RU; When the singular value decomposition (SVD) port merge identified based on the port merge configuration is performed, an instruction indicating the SVD port merge is received from the RU; Receive the signal from the RU that the SVD port merging has been applied; as well as Based on the instruction, the signal is decoded.

6. The method according to claim 5, further comprising: Send a capability request message related to port merging to the RU; as well as The RU receives a capability report message in response to the capability request message, the capability report message including capability information. The capability information includes information about at least one of the supported port merging methods or whether the RU is capable of performing port merging.

7. The method of claim 5, further comprising receiving from the RU information including at least one of the application-calculated values ​​based on the SVD port merging.

8. The method according to claim 5, wherein, The port merging configuration includes port merging parameters, which include at least one of the port merging method used and the number of ports reduced.

9. A remote unit RU for a base station in a wireless communication system, the RU comprising: transceiver; as well as The controller connected to the transceiver, The controller is configured as follows: Merge configuration from the digital unit (DU) receiving port; Based on the port merging configuration, determine whether to perform Singular Value Decomposition (SVD) port merging; In the case of performing the SVD port merging, an instruction instructing the SVD port merging is sent to the DU; and Send a signal to the DU that the SVD port merging has been applied. The indication is used to decode the signal.

10. The RU according to claim 9, wherein, The controller is configured as follows: Receive a capability request message related to port merging from the DU; and In response to the capability request message, a capability report message including capability information is sent to the DU. The capability information includes information about at least one of the supported port merging methods or whether the RU is capable of performing port merging.

11. The RU according to claim 9, wherein, The controller is configured to send information to the DU including at least one of the application-calculated values ​​based on the SVD port merging.

12. The RU according to claim 9, wherein, The port merging configuration includes port merging parameters, which include at least one of the port merging method used and the number of ports reduced.

13. A digital unit (DU) of a base station in a wireless communication system, the DU comprising: transceiver; as well as The controller connected to the transceiver, The controller is configured as follows: Send port merging configuration to the remote unit RU; When the singular value decomposition (SVD) port merge identified based on the port merge configuration is performed, an instruction indicating the SVD port merge is received from the RU; Receive from the DU a signal that the SVD port merging has been applied; and Based on the instruction, the signal is decoded.

14. The DU according to claim 13, wherein, The controller is configured as follows: Send a capability request message related to port merging to the RU; as well as The RU receives a capability report message in response to the capability request message, the capability report message including capability information. The capability information includes information about at least one of the supported port merging methods or whether the RU is capable of performing port merging.

15. The DU according to claim 13, wherein, The controller is configured to receive from the RU information including at least one of the application-calculated values ​​based on the SVD port merging.

16. The DU according to claim 13, wherein, The port merging configuration includes port merging parameters, which include at least one of the port merging method used and the number of ports reduced.

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