Electronic device and method for modulation compression of data transmitted via user plane messages in fronthaul interface

Abstract

According to one embodiment, a method performed by a Distributed Unit (DU) includes generating modulation values corresponding to information bits based on a modulation compression technique. The method includes generating user plane (U-plane) data corresponding to the modulation value based on a shift operation corresponding to the modulation compression technique. The method includes transmitting a U-plane message including the generated U-plane data to a radio unit (RU) over a fronthaul interface. The modulation compression technique is arranged to perform the shift operation based on a specified first equation for binary phase shift keying (BPSK), and to perform the shift operation based on a specified second equation for a modulation technique other than BPSK.

Description

Technical Field

[0001] The present disclosure relates to a fronthaul interface that is defined for communication between a distributed unit (DU) and a radio unit (RU) of a base station in a wireless communication system. More specifically, the present disclosure relates to an electronic device and method for modulating and compressing data transmitted through user plane messages in a fronthaul interface. Background Art

[0002] As the transmission capacity in a wireless communication system increases, a functional split of separating the functions of a base station is being applied. According to the functional split, a base station can be divided into a DU and an RU.

[0003] The above information is provided as related art to help understand the purpose of the present disclosure. No assertion or determination is made as to whether any of the above information can be applied as prior art related to the present disclosure. Summary of the Invention

[0004] Technical Solution

[0005] According to an embodiment, a method performed by a distributed unit (DU) may include generating a modulation value corresponding to information bits based on a modulation compression scheme. The method may include generating user plane (U-plane) data corresponding to the modulation value based on a shift operation corresponding to the modulation compression scheme. The method may include transmitting a U-plane message including the generated U-plane data to a radio unit (RU) through a fronthaul interface. In the case of binary phase shift keying (BPSK), the modulation compression scheme may be set to perform the shift operation based on a specified first equation. In the case of non-BPSK, the modulation compression scheme may be set to perform the shift operation based on a specified second equation.

[0006] According to an embodiment, an electronic device may include: at least one transceiver, the at least one transceiver including a fronthaul transceiver; and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to generate a modulation value corresponding to information bits based on a modulation compression scheme. The at least one processor may be configured to generate user plane (U-plane) data corresponding to the modulation value based on a shift operation corresponding to the modulation compression scheme. The at least one processor may be configured to transmit a U-plane message including the generated U-plane data to a radio unit (RU) through a fronthaul interface. In the case of binary phase shift keying (BPSK), the modulation compression scheme may be set to perform the shift operation based on a specified first equation. In the case of non-BPSK, the modulation compression scheme may be set to perform the shift operation based on a specified second equation.

[0007] According to an embodiment, a method performed by a radio unit (RU) may include receiving, via a fronthaul interface, a U-plane message including user plane (U-plane) data from a distributed unit (DU). The method may include obtaining a modulation value corresponding to the U-plane data based on a shift operation corresponding to a modulation compression scheme. In the case of binary phase shift keying (BPSK), the modulation compression scheme may be set to perform the shift operation based on a specified first equation. In the case of non-BPSK, the modulation compression scheme may be set to perform the shift operation based on a specified second equation.

[0008] According to an embodiment, an electronic device may include: at least one transceiver including a fronthaul transceiver; and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to receive, via a fronthaul interface, a U-plane message including user plane (U-plane) data from a distributed unit (DU). The at least one processor may be configured to obtain a modulation value corresponding to the U-plane data based on a shift operation corresponding to a modulation compression scheme. In the case of binary phase shift keying (BPSK), the modulation compression scheme may be set to perform the shift operation based on a specified first equation. In the case of non-BPSK, the modulation compression scheme may be set to perform the shift operation based on a specified second equation. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] 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:

[0010] Figure 1 A wireless communication system is shown;

[0011] Figure 2a A fronthaul interface is shown;

[0012] Figure 2b A fronthaul interface of an open (O) radio access network (RAN) is shown;

[0013] Figure 3a A functional configuration of a distributed unit (DU) is shown;

[0014] Figure 3b A functional configuration of a radio unit (RU) is shown;

[0015] Figure 4 An example of a functional split between a DU and an RU is shown;

[0016] Figures 5a to 5dShows the constellation points of each modulation and coding scheme (MCS);

[0017] Figures 6a to 6d Shows the shifted constellation points of each MCS;

[0018] Figure 7a Shows an example of the modulation and compression process;

[0019] Figure 7b Shows an example of the decompression process;

[0020] Figure 8a Shows an example of the modulation and compression process through the shifting process;

[0021] Figure 8b Shows an example of the decompression process through the unshifting process;

[0022] Figure 9 Shows an example of the operations of the DU and RU;

[0023] Figure 10 Shows a flowchart of the operations of the DU; and

[0024] Figure 11 Shows a flowchart of the operations of the RU. Detailed Description

[0025] The terms used in this disclosure are only for better describing specific embodiments and may not be intended to limit the scope of other embodiments. Unless the context clearly indicates otherwise, singular expressions may include plural expressions. The terms used herein (including technical and scientific terms) may have the same meaning as those commonly understood by those skilled in the art to which this disclosure pertains. Unless explicitly defined in this disclosure, the terms defined in the comprehensive dictionary among the terms used in this disclosure may be interpreted as having the same or similar meaning as those in the context of the related art, and they should not be interpreted in an ideal or overly formal sense. In some cases, even the terms defined in this disclosure may not be interpreted as excluding the embodiments of this disclosure.

[0026] In the various embodiments of the present disclosure described below, hardware methods will be described as examples. However, since one or more embodiments of the present disclosure may include techniques that utilize both hardware-based methods and software-based methods, they are not intended to exclude software-based methods.

[0027] As used in the following description, terms referring to signals (e.g., signal, information, message, signaling), terms referring to resources (e.g., symbol, time slot, subframe, radio frame, subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), opportunity), terms referring to operation states (e.g., step, operation, process), terms referring to data (e.g., packet, user flow, information, bit, symbol, codeword), terms referring to channels, terms referring to network entities, terms referring to components of a device or apparatus, etc. are illustrated in the present disclosure only for the convenience of description. Therefore, the present disclosure is not limited to the terms described below, and other terms with the same or equivalent technical meanings may be used.

[0028] In addition, throughout the present disclosure, expressions such as "higher than" or "lower than" may be used to determine whether a specific condition is satisfied or fulfilled, but this is merely a description of an example of the expression and is not intended to exclude the meanings of "more than or equal to" or "less than or equal to". Accordingly, a condition described as "more than or equal to" may be replaced with an expression such as "higher than", a condition described as "less than or equal to" may be replaced with an expression such as "lower than", and a condition described as "more than or equal to and lower than" may be replaced with "higher than and less than or equal to". In addition, hereinafter, "A" to "B" means at least one of the elements from A (including A) to B (including B). Hereinafter, "C" and / or "D" means including at least one of "C" or "D", that is, {"C", "D", or "C and D"}.

[0029] The term "coupled" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not these elements are in physical contact with each other. The terms "transmit", "receive", and "communicate" and their derivatives encompass direct and indirect communication. The terms "comprising" and "including" and their derivatives mean including but not limited to. The term "or" is an inclusive term, meaning "and / or". The phrase "associated with" and its derivatives mean including, being included within, interconnected with, containing, being contained within, connected to or connecting with, coupled to or coupling with, capable of communicating with, cooperating with, interleaving, juxtaposing, being adjacent to, being incorporated into or incorporating with, having, having the characteristics of, having a relationship with or relating to, etc. The term "controller" refers to any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware or in a combination of hardware and software and / or firmware. The functions associated with any particular controller may be centralized or distributed, whether local or remote. The phrase "at least one of" when used with a list of items means that different combinations of one or more of the listed items may be used and that only one item in the list may be required. In one embodiment, "at least one of A, B, and C" includes any one of the following combinations: only A, only B, only C, both A and B, both A and C, both B and C, and all of A, B, and C. Similarly, the term "group" means one or more. Thus, a group of items may be a single item or a collection of two or more items.

[0030] This disclosure uses terms used in some communication standards (e.g., 3rd Generation Partnership Project (3GPP), eXtended Radio Access Network (xRAN), Open Radio Access Network (O-RAN), etc.) to describe one or more embodiments, but they are only examples for explanation. One or more embodiments of this disclosure can be easily modified and applied to other communication systems even in other communication systems.

[0031] Figure 1 A wireless communication system is shown.

[0032] Reference Figure 1 ,, the base station 110 and the terminal 120 are shown as part of nodes using a wireless channel in a wireless communication system. Although Figure 1 only one base station is shown, the wireless communication system may also include another base station that is the same as or similar to the base station 110.

[0033] Base station 110 is a network infrastructure that provides radio access to terminal 120. Base station 110 may have a coverage area defined based on the range within which signals can be transmitted. In addition to the term "base station", base station 110 may also be referred to as "access point (AP)", "eNodeB (eNB)", "5th generation node", "next generation nodeB (gNB)", "radio point", "transmission / reception point (TRP)", or any other term having the same or equivalent technical meaning.

[0034] Terminal 120 (which is a device used by a user) performs communication with base station 110 via a wireless channel. The link from base station 110 to terminal 120 is referred to as the downlink (DL), and the link from terminal 120 to base station 110 is referred to as the uplink (UL). Additionally, although Figure 1 not shown in the figure, terminal 120 and other terminals may communicate with each other via a wireless channel. In this context, the link between terminal 120 and other terminals (device-to-device link, D2D) is referred to as a "sidelink", and the sidelink may be used in combination with the PC5 interface. In some other embodiments, terminal 120 may operate without any user participation. According to an embodiment, terminal 120, as a device performing machine type communication (MTC), may not be carried by a user. Additionally, according to an embodiment, terminal 120 may be a narrowband (NB) Internet of Things (IoT) device.

[0035] Terminal 120 may be referred to as "user equipment (UE)", "customer premise equipment (CPE)", "mobile station", "subscriber station", "remote terminal", "wireless terminal", "electronic device", "user device", or any other term having the same or equivalent technical meaning.

[0036] Base station 110 may perform beamforming with terminal 120. The base station 110 and the terminal 120 may transmit and receive radio signals in a relatively low frequency band (e.g., FR 1 (Frequency Range 1) of NR). In addition, the base station 110 and the terminal 120 may transmit and receive radio signals in a relatively high frequency band (e.g., FR 2 (or FR 2-1, FR 2-2, FR 2-3) of NR, FR 3 of NR, or millimeter wave (mmWave) frequency band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz)). To enhance the channel gain, the base station 110 and the terminal 120 may perform beamforming. In this context, beamforming may include transmit beamforming and receive beamforming. The base station 110 and the terminal 120 may assign directivity to the transmitted signal or the received signal. For this purpose, the base station 110 and the terminal 120 may select a serving beam through a beam search or beam management process. After selecting the serving beam, subsequent communication may be performed through a resource having a quasi-co-location (QCL) relationship with the resource that has transmitted the serving beam.

[0037] If the large-scale characteristics of the channel carrying the symbol on the first antenna port can be inferred from the channel carrying the symbol on the second antenna port, the first antenna port and the second antenna port may be evaluated as being 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, or spatial receiver parameters.

[0038] Although Figure 1 It is described that both the base station 110 and the terminal 120 perform beamforming, but the embodiments of the present disclosure are not necessarily limited thereto. In some embodiments, the terminal may or may not perform beamforming. Similarly, the base station may or may not perform beamforming. That is, only one of the base station and the terminal may perform beamforming, or neither the base station nor the terminal may perform beamforming.

[0039] In the present disclosure, a beam (which means a spatial stream of a signal in a wireless channel) can be formed by one or more antennas (or antenna elements), and the process of forming the beam can be referred to as "beamforming". Beamforming can include at least one of analog beamforming and digital beamforming (e.g., precoding). The reference signal transmitted based on beamforming can include, for example, a demodulation reference signal (DM-RS), a channel state information reference signal (CSI-RS), a synchronization signal / physical broadcast channel (SS / PBCH), or a sounding reference signal (SRS). In addition, for the configuration of each reference signal, information elements (IEs) such as CSI-RS resources, SRS resources, etc. can be used, and such a configuration can include information associated with the beam. The beam-associated information can refer to whether the corresponding 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 a different spatial domain filter, or with which reference signal it is quasi-co-located (QCL), or if QCL, what type (e.g., QCL type A, B, C, or D).

[0040] In a communication system with a relatively large cell radius of a base station, each base station has been installed such that the corresponding base station includes the functions of a digital processing unit (or a distributed unit (DU)) and a radio frequency (RF) processing unit (or a radio unit (RU)). However, due to the use of high frequency bands in the 4th generation (4G) system and / or its subsequent communication systems (e.g., 5G) and the reduction of the cell coverage range of the base station, the number of base stations for covering a specific area has increased. Therefore, the increase in the number of base stations has led to an increased burden on the initial installation cost for the communication provider to install more base stations. To minimize the installation cost of the base station, a structure has been proposed in which the DU and RU of the base station are separated such that one or more RUs are connected to one DU through a wired network, and one or more RUs are arranged to be geographically distributed to cover a specific area. Hereinafter, an example of the deployment structure and expansion of a base station according to one or more embodiments of the present disclosure will be described with reference to Figures 2a to 2b Describe the deployment structure and expansion of a base station according to one or more embodiments of the present disclosure.

[0041] Figure 2a The fronthaul interface is shown. The fronthaul refers to the link for the entity between the wireless local area network (LAN) and the base station, rather than the backhaul for the link between the base station and the core network. Although Figure 2aAn example of the fronthaul structure between the DU 210 and one RU 220 is shown, but the present disclosure is not limited thereto. In other words, embodiments of the present disclosure can also be applied to the fronthaul structure between one DU and multiple RUs. For example, embodiments of the present disclosure can be applied to the fronthaul structure between one DU and two RUs. In addition, embodiments of the present disclosure can also be applied to the fronthaul structure between one DU and three RUs.

[0042] Reference Figure 2a , the base station 110 may include a DU 210 and an RU 220. The fronthaul 215 between the DU 210 and the RU 220 may operate through the Fx interface. For the operation of the fronthaul 215, an interface such as the enhanced common public radio interface (eCPRI) or radio over Ethernet (ROE) may be used.

[0043] With the further development of communication technologies, mobile data traffic has increased significantly, and thus, the bandwidth requirements for the fronthaul between the digital unit and the radio unit have also increased significantly. In a deployment such as a centralized / cloud radio access network (C-RAN), the DU may be implemented to perform the functions of packet data convergence protocol (PDCP), radio link control (RLC), media access control (MAC), and physical (PHY), and the RU may be implemented to perform the functions of the PHY layer in addition to the radio frequency (RF) function.

[0044] The DU 210 may be used as the upper-layer function of the wireless network. For example, the DU 210 may perform the functions of the MAC layer and / or a part of the PHY layer. Here, a part of the PHY layer that is executed at a higher level of the functions of the PHY layer may include, for example, channel coding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), or layer mapping (or layer demapping). According to an embodiment, when the DU210 complies with the O-RAN standard, it may be referred to as an O-DU (O-RAN DU). In embodiments of the present disclosure, according to the timing requirements, the DU 210 may be represented by a first network entity of a base station (e.g., gNB).

[0045] The RU 220 may be used as the lower-layer function of the wireless network. For example, the RU 220 may perform a part of the PHY layer and / or RF functions. Here, the part of the PHY layer that is executed at a relatively lower level than the DU 210 in the functions of the PHY layer may include, for example, inverse fast Fourier transform (iFFT) transform (or FFT transform), CP insertion (CP removal), and digital beamforming. Reference will be made to Figure 4Examples of this specific functional split are described in more detail. RU 220 may be referred to as an "Access Unit (AU)", "Access Point (AP)", "Transmit / Receive Point (TRP)", "Remote Radio Head (RRH)", "Radio Unit (RU)", or any other term with its equivalent technical meaning. According to an embodiment, when RU 220 complies with the O-RAN standard, it may be referred to as an O-RU (O-RAN RU). In an embodiment of the present disclosure, according to the timing requirement, RU 220 may be represented by a second network entity of a base station (e.g., gNB).

[0046] Although Figure 2a it is shown that the base station 110 includes a DU 210 and an RU 220, embodiments of the present disclosure are not limited thereto. According to an embodiment, a base station may be implemented by a distributed deployment according to a Centralized Unit (CU) and a Distributed Unit (DU), where the Centralized Unit (CU) is configured to perform functions of the upper layer of the access network (e.g., Packet Data Convergence Protocol (PDCP), Radio Resource Control (RRC), etc.), and the Distributed Unit (DU) is configured to perform functions of the lower layer. In this context, the Distributed Unit (DU) may include a Digital Unit (DU) and Figure 1 a Radio Unit (RU). Between the core network (e.g., 5G Core (5GC) or Next Generation Core (NGC) network) and the Radio Access Network (RAN), the base station may be implemented by a deployment set in the order of CU, DU, and RU. The interface between the CU and the Distributed Unit (DU) may be referred to as the F1 interface.

[0047] The Centralized Unit (CU) may be connected to one or more DUs to act as an upper layer function compared to the DUs. For example, the CU may act as the functions of the Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP) layers, and the DUs and RUs may act as lower layer functions. The DU may perform some functions of the Radio Link Control (RLC), Media Access Control (MAC), and Physical (PHY) layers (High PHY), and the RU may be responsible for the remaining functions of the PHY layer (Low PHY). In addition, for example, according to the implementation of the distributed deployment of the base station, the Digital Unit (DU) may be included in the Distributed Unit (DU). Hereinafter, unless otherwise defined, the operations of the Digital Unit (DU) and the RU will be described, but it should be noted that one or more embodiments of the present disclosure may be applied to both the deployment of a base station including a CU or the deployment where the DU is directly connected to the core network (i.e., being implemented as integrated into a base station (e.g., an NG-RAN node), where the CU and the DU form one entity).

[0048] Figure 2bShows the fronthaul interface of O-RAN (Open Radio Access Network), where according to the distributed deployment, eNB or gNB is shown as base station 110.

[0049] Reference Figure 2b , base station 110 may include an O-DU 251 and O-RUs (253-1,..., 253-n). Hereinafter, the operation and function of O-RU 253-1 can be understood by the explanation of each other O-RU (for example, O-RU 253-n).

[0050] According to what will be described later Figure 4 , O-DU 251 is a logical node including functions of the base station (for example, eNB, gNB) except for the functions specifically assigned to O-RU 253-1. O-DU 251 can control the operation of O-RUs (253-1,..., 253-n). O-DU 251 can be referred to as a Lower Layer Split (LLS) Central Unit (CU). According to what will be described later Figure 4 , O-RU253-1 is a logical node including a subset of the functions of the base station (for example, eNB, gNB). The real-time aspects of the control plane (C-plane) communication and user plane (U-plane) communication with O-RU 253-1 can be controlled by O-DU 251.

[0051] O-DU 251 can communicate with O-RU 253-1 via the LLS interface. The LLS interface corresponds to the fronthaul interface. The LLS interface means a logical interface between O-DU 251 and O-RU 253-1 using lower layer function split (i.e., function split within the PHY). The LLS-C between O-DU 251 and O-RU 253-1 provides the C-plane via the LLS interface. The LLS-U between O-DU 251 and O-RU253-1 provides the U-plane via the LLS interface.

[0052] In Figure 2b , the entities of base station 110 are called "O-DU" and "O-RU" to describe O-RAN. However, this naming should not be construed as limiting the embodiments of the present disclosure thereto. In the embodiment described in reference Figures 3a to 1 2, the operation of DU 210 can be performed by O-DU 251. In one embodiment, the description of DU 210 can also be applied to O-DU 251. Similarly, in the embodiment described in reference Figures 3a to 1 2, the operation of RU 220 can of course be performed by O-RU 253-1. The description of RU 220 can also be applied to O-DU 253-1.

[0053] Figure 3aShows the functional configuration of a Distributed Unit (DU). Figure 3a The configuration shown can be understood as Figure 2a the configuration of DU210 (or Figure 2b the O-DU 251) which is part of a base station. As used herein, terms such as "~module", "~unit", or "~part" may refer to a unit for handling at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

[0054] Referring to Figure 3a , DU 210 includes a transceiver 310, a memory 320, and a processor 330.

[0055] The transceiver 310 may perform functions for transmitting and / or receiving signals in a wired communication environment. The transceiver 310 may include a wired interface for controlling a direct connection between one device and another via a transmission medium (e.g., copper wire, optical fiber, etc.). For example, the transceiver 310 may transmit an electrical signal to another device via a copper wire, or perform a conversion between an electrical signal and an optical signal. DU 210 may communicate with a Radio Unit (RU) via the transceiver 310. DU 210 may be connected to a core network or a distributed CU via the transceiver 310.

[0056] The transceiver 310 may perform functions for transmitting and receiving signals in a wireless communication environment. For example, the transceiver 310 may perform a conversion function between a baseband signal and a bit string according to the physical layer standard of a communication system. For example, during data transmission, the transceiver 310 generates complex symbols by encoding and modulating the transmitted bit string. In addition, during data reception, the transceiver 310 recovers the received bit string by demodulating and decoding the baseband signal. In addition, the transceiver 310 may include multiple transmit / receive paths. Additionally, according to an embodiment, the transceiver 310 may be connected to a core network or connected to other nodes (e.g., Integrated Access Backhaul (IAB)).

[0057] The transceiver 310 may be configured to transmit and receive signals. For example, the transceiver 310 may transmit Management Plane (M-plane) messages. For example, the transceiver 310 may transmit Synchronization Plane (S-plane) messages. For example, the transceiver 310 may transmit Control Plane (C-plane) messages. For example, the transceiver 310 may transmit User Plane (U-plane) messages. For example, the transceiver 310 may receive U-plane messages. Although Figure 3a only the transceiver 310 is shown, according to another embodiment, DU 210 may include two or more transceivers.

[0058] The transceiver 310 may be configured to transmit and receive signals as described above. Accordingly, all or at least a part of the transceiver 310 may also be referred to as a communication unit, a transmitting unit, a receiving unit, or a transmitting / receiving unit. In addition, throughout the following description, transmission and / or reception performed via a wireless channel is used to mean including performing the above processes through the transceiver 310.

[0059] Although Figure 3a not shown in the figure, the transceiver 310 may further include a backhaul transceiver for connecting to a core network or another base station. The backhaul transceiver provides an interface for performing communication with other nodes in the network. In other words, the backhaul transceiver converts a bit string transmitted from the base station to another node (e.g., another access node, another base station, a higher layer node, a core network, etc.) into a physical signal, and converts a physical signal received from another node into a bit string.

[0060] The memory 320 stores data for the overall operation of the DU 210, such as basic programs, application programs, and setting information. The memory 320 may be referred to as a storage unit. The memory 320 may be configured with a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the memory 320 provides the stored data according to a request from the processor 330.

[0061] The processor 330 controls the overall operation of the DU 210. The processor 380 may be referred to as a controller. For example, the processor 330 transmits and receives signals via the transceiver 310 (or via the backhaul communication unit). In addition, the processor 330 records data into the memory 320 and reads data from the memory. In addition, the processor 330 may perform functions of a protocol stack required by communication standards. Although Figure 3a only the processor 330 is shown in the figure, according to an example of another implementation, the DU 210 may include two or more processors.

[0062] Figure 3a The configuration of the DU 210 shown is only an example, and the configuration of the DU implementing the embodiments of the present disclosure is not limited to Figure 3a the configuration shown. In some embodiments, a part of the configuration may be added, deleted, or changed.

[0063] Figure 3b The functional configuration of a radio unit (RU) is shown. Figure 3b The configuration shown may be understood as Figure 2b the RU220 of Figure 2bConfiguration of the O-RU 253-1, which is part of a base station. As used herein, terms such as "~ module", "~ unit", or "~ part" may refer to a unit for processing at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

[0064] Reference Figure 3b , the RU 220 may include an RF transceiver 360, a fronthaul transceiver 365, a memory 370, and a processor 380.

[0065] The RF transceiver 360 performs the function of transmitting and receiving signals via a wireless channel. For example, the RF transceiver 360 up-converts a baseband signal to an RF band signal for transmitting the RF band signal via an antenna, and down-converts the RF band signal received via the antenna to a baseband signal. For example, the RF transceiver 360 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0066] The RF transceiver 360 may include multiple transmit / receive paths. Additionally, the RF transceiver 360 may include an antenna unit. The RF transceiver 360 may include at least one antenna array configured with multiple antenna elements. In terms of hardware, the RF transceiver 360 may be configured with digital circuits and analog circuits (e.g., radio frequency integrated circuit (RFIC)). Here, the digital circuits and analog circuits may be implemented in a single package. Furthermore, the RF transceiver 360 may include multiple RF chains. The RF transceiver 360 may perform beamforming. The RF transceiver 360 may apply beamforming weights to signals in order to give directionality to the signals for transmission and reception according to the settings of the processor 380. According to an embodiment, the RF transceiver 360 may include a radio frequency (RF) block (or RF unit).

[0067] According to an embodiment, the RF transceiver 360 may transmit and receive signals via a radio access network. For example, the RF transceiver 360 may transmit a downlink signal. The downlink signal may include a synchronization signal (SS), a reference signal (RS) (e.g., cell-specific reference signal (CRS), DM (demodulation)-RS), system information (e.g., master information block (MIB), system message block (SIB), remaining system information (RMSI), other system information (OSI)), a configuration message, control information, or downlink data. Additionally, for example, the RF transceiver 360 may receive an uplink signal. The uplink signal may include a random access related signal (e.g., random access preamble: RAP) (or Msg1 (message 1), Msg3 (message 3)), a reference signal (e.g., sounding reference signal (SRS), DM-RS), a power headroom report (PHR), etc. Although Figure 3bOnly the RF transceiver 360 is shown, but according to an example of another implementation, the RU 220 may include two or more RF transceivers.

[0068] According to an embodiment, the RF transceiver 460 may transmit RIM-RS. The RF transceiver 460 may transmit a first type of RIM-RS (e.g., RIM-RS type 1 of 3GPP) for notifying the detection of far-field interference. The RF transceiver 460 may transmit a second type of RIM-RS (e.g., RIM-RS type 2 of 3GPP) for notifying the presence or absence of far-field interference.

[0069] The fronthaul transceiver 365 may transmit and receive signals. According to an embodiment, the fronthaul transceiver 365 may transmit and receive signals on a fronthaul interface. For example, the fronthaul transceiver 365 may receive management plane (M-plane) messages. For example, the fronthaul transceiver 365 may receive synchronization plane (S-plane) messages. For example, the fronthaul transceiver 365 may receive control plane (C-plane) messages. For example, the fronthaul transceiver 365 may transmit user plane (U-plane) messages. For example, the fronthaul transceiver 365 may receive user plane messages. Although Figure 3b only the fronthaul transceiver 365 is shown, but according to an example of another implementation, the RU 220 may include two or more fronthaul transceivers.

[0070] The RF transceiver 360 and the fronthaul transceiver 365 transmit and receive signals as described above. Therefore, all or at least a part of the RF transceiver 360 and the fronthaul transceiver 365 may be referred to as a "communication unit", "transmitting unit", "receiving unit" or "transceiver unit". In addition, throughout the following description, the transmission and / or reception performed via a wireless channel may be used to mean including performing the above processes through a transceiver.

[0071] The memory 370 stores data for the overall operation of the RU 220, such as basic programs, application programs, and setting information. The memory 370 may be referred to as a storage unit. The memory 370 may be configured with volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. In addition, the memory 370 provides the stored data according to a request from the processor 380. According to an embodiment, the memory 370 may include a memory for storing conditions, instructions, or setting values related to an SRS transmission scheme.

[0072] The processor 380 controls the overall operation of the RU 220. The processor 380 may be referred to as a controller. For example, the processor 380 transmits and receives signals via the RF transceiver 360 or the fronthaul transceiver 365. In addition, the processor 380 writes data to and reads data from the memory 370. In addition, the processor 380 may execute functions of a protocol stack required by communication standards. Although Figure 3b only the processor 380 is shown, according to another example implementation, the RU 220 may include two or more processors. The processor 380 may include a storage space for storing instructions / codes that at least temporarily reside in the processor 380, the instructions / codes being an instruction set or code stored in the memory 370, or the processor may be part of a circuit system that configures the processor 380. In addition, the processor 380 may include various communication modules for performing communication. The processor 380 may control the RU 220 to perform operations according to the following embodiments of the present disclosure.

[0073] Figure 3b The configuration of the RU 220 shown is only an example, and examples of RUs implementing the embodiments of the present disclosure are not limited to Figure 3b the configuration shown. In some configurations, some of the configurations may be added, deleted, or changed.

[0074] Figure 4 An example of the functional split between the DU and the RU is shown. With the latest development of wireless communication technologies (e.g., the introduction of 5G communication systems or NR (New Radio) communication systems), the frequency bands used have even increased further. In addition, as the cell radius of the base station becomes very small, the number of RUs that need to be installed further increases. Additionally, in 5G communication systems, the data transmission volume has increased significantly by 10 times or more, and thus, the data transmission capacity of the wired network for fronthaul transmission has increased significantly. Therefore, due to the above factors, the initial installation cost of the wired network in 5G communication systems may increase very significantly. Therefore, in order to reduce the transmission capacity of the wired network and lower the installation cost of the wired network, "functional split" can be used to reduce the fronthaul transmission capacity by transferring some functions of the DU's modem to the RU.

[0075] To relieve the burden on the DU, the role of the RU, which is only responsible for the existing RF functions, can be extended to some functions of the physical layer. The higher the functional layer that the RU executes, the more the throughput of the RU may increase to increase the transmission bandwidth at the fronthaul, and at the same time, due to the response processing, the constraint on the latency requirement is lower. At the same time, the higher the functional layer that the RU executes, the smaller the virtualization gain it obtains, and the more the size, weight, and cost of the RU increase. Therefore, it is necessary to consider the trade-off between the above advantages and disadvantages to achieve the optimal functional split.

[0076] Reference Figure 4 shows the functional split in the physical layer below the MAC layer. In the case of transmitting signals from a base station to a terminal via a wireless network in the downlink (DL), the base station may perform channel coding / scrambling, modulation, layer mapping, antenna mapping, RE mapping, digital beamforming (e.g., precoding), iFFT transform / CP insertion, and RF conversion in sequence. In the case of receiving signals from a terminal via a wireless network in the uplink (UL), the base station may perform RF conversion, FFT transform / CP removal, digital beamforming (e.g., pre-combination), RE demapping, channel estimation, layer demapping, demodulation, and decoding / descrambling in sequence. According to the above trade-off, the functional split between the uplink function and the downlink function may be defined in various types according to the needs among vendors, discussions on standards, etc.

[0077] In the first functional split 405, the RU performs the RF function and the DU performs the PHY function. In the first functional split, the PHY function in the RU is not substantially implemented, and for example, it may be referred to as Option 8. In the second functional split 410, the RU performs iFFT transform / CP addition in the DL of the PHY function and FFT transform / CP removal in the UL, and the DU performs the remaining PHY functions. For example, the second functional split 410 may be referred to as Option 7-1. In the third functional split 420a, the RU performs iFFT transform / CP addition in the DL of the PHY function and FFT transform / CP removal and digital beamforming in the UL, and the DU performs the remaining PHY functions. For example, the third functional split 420a may be referred to as Option 7-2x Category A. In the fourth functional split 420b, the RU performs up to digital beamforming in both the DL and the UL, and the DU performs the upper-layer PHY functions after digital beamforming. For example, the fourth functional split 420b may be referred to as Option 7-2x Category B. In the fifth functional split 425, the RU performs up to RE mapping (or RE demapping) in both the DL and the UL, and the DU performs the upper-layer PHY functions after RE mapping (or RF demapping). For example, the fifth functional split 425 may be referred to as Option 7-2. In the sixth functional split 430, the RU performs up to modulation (or demodulation) in both the DL and the UL, and the DU performs the upper-layer PHY functions after modulation (or demodulation). For example, the sixth functional split 430 may be referred to as Option 7-3. In the seventh functional split 440, the RU performs up to coding / scrambling (or decoding / descrambling) in both the DL and the UL, and the DU performs the upper-layer PHY functions after modulation (or demodulation). For example, the seventh functional split 440 may be referred to as Option 6.

[0078] According to an embodiment, in a case where a large amount of signal processing is expected as in an FR 1 MMU, it may be necessary to perform functional splitting at a relatively upper layer (e.g., the fourth functional splitting 420b) to reduce the fronthaul capacity. In addition, functional splitting performed at too high a layer (e.g., the sixth functional splitting 430) may result in a more complex control interface due to multiple PHY processing blocks included in the RU and impose a significant burden on the implementation of the RU, and thus, depending on the deployment and implementation scenarios of the DU and the RU, appropriate functional splitting may be required.

[0079] According to an embodiment, in a case where it is impossible to process precoding of data received from the DU (i.e., when the precoding capability of the RU is limited), the third functional splitting 420a or a lower functional splitting thereof (e.g., the second functional splitting 410) may be applied. On the contrary, in a case where it is possible to process precoding of data received from the DU, the fourth functional splitting 420b or a higher functional splitting thereof (e.g., the sixth functional splitting 430) may be applied.

[0080] Hereinafter, unless otherwise defined, in the present disclosure, embodiments are described based on the third functional splitting 420a (which may be referred to as category A or CAT-A) or the fourth functional splitting 420b (which may be referred to as category B or CAT-B) to perform a beamforming process in the RU. The O-RAN specification distinguishes the type of O-RU based on whether the precoding function is located on the O-DU interface or on the O-RU interface. The O-RU that does not perform precoding (i.e., has low complexity) may be referred to as a CAT-A O-RU. The O-RU that performs precoding may be referred to as a CAT-B O-RU.

[0081] Hereinafter, the upper-layer PHY refers to the physical layer processing performed in the DU of the fronthaul interface. For example, the upper-layer PHY may include forward error correction (FEC) encoding / decoding, scrambling, and modulation / demodulation. Hereinafter, the lower-layer PHY refers to the physical layer processing performed in the RU of the fronthaul interface. For example, the lower-layer PHY may include FFT / iFFT, digital beamforming, or physical random access channel (PRACH) extraction and filtering. However, it should be noted that the above criteria do not exclude embodiments implemented through other functional splittings. The functional configurations, signaling, or operations to be described below may be described based on the third functional splitting 420a or the fourth functional splitting 420b, but they may also be applied to other functional splittings.

[0082] As an example, embodiments of the present disclosure describe when in the DU (e.g., Figure 2a DU 210 in Figure 2aWhen transmitting messages between RU 220) in, the specifications of eCPRI and O-RAN as fronthaul interfaces. The Ethernet payload of the message can include an eCPRI header, an O-RAN header, and additional fields. Hereinafter, standard terms of eCPRI or O-RAN will be used to describe one or more embodiments of the present disclosure, but it should be noted that in one or more embodiments of the present disclosure, any other expression having the same or equivalent meaning as the corresponding term can be used instead.

[0083] For the transport protocol of the fronthaul, Ethernet and eCPRI that can be easily shared with the network can be used. The eCPRI header and the 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:

[0084] ecpriVersion (4 bits): This parameter indicates the eCPRI protocol version.

[0085] ecpriReserved (3 bits): This parameter is reserved for further use by eCPRI.

[0086] ecpriConcatenation (1 bit): This parameter indicates when eCPRI concatenation is in use.

[0087] ecpriMessage (1 byte): This parameter indicates the service type carried by the message type. For example, this parameter indicates an IQ (in-phase / quadrature phase) data message, a real-time control data message, or a transmission network delay measurement message.

[0088] ecpriPayload (2 bytes): This parameter indicates the byte size of the payload part of the eCPRI message.

[0089] ecpriRtcid / ecpriPcid (2 bytes): This parameter is the eAxC (extended antenna carrier) identifier (eAxC ID) that identifies the specific data stream associated with each C-plane (ecpriRtcid) or U-plane (ecpriPcid) message.

[0090] ecpriSeqid (2 bytes): This parameter provides unique message identification and sequence at two levels. The first octet of this parameter is the sequence ID used to identify the message sequence within the eAxC message stream, and the sequence ID is used to verify that all messages have been received and for rearranging out-of-order messages. The second octet of this parameter is the subsequence ID. When radio transmission-level segmentation (eCPRI or IEEE-1914.3) occurs, this subsequence ID is used to verify the sequence and achieve its rearrangement.

[0091] eAxC Identifier (ID): This ID includes a band and sector identifier ("BandSector_ID"), a component carrier identifier ("CC_ID"), a spatial stream identifier ("RU_Port_ID"), and a distributed unit identifier ("DU_Port_ID"). The bit allocation of the eAxC ID can be classified as follows.

[0092] DU_port ID: This ID is used to distinguish processing units in the O-DU (e.g., other baseband cards). It is expected that the O-DU will allocate bits for the DU_port ID, and the O-RU will append the same value to the UL U-plane message carrying the same sectionId data.

[0093] BandSector_ID: This ID is the aggregated cell identifier (the band and sector classification supported by the O-RU).

[0094] CC_ID: This ID is used to distinguish the carrier components supported by the O-RU.

[0095] RU_port ID: This ID specifies logical flows such as data layers or spatial streams, as well as logical flows such as signal channels that require special antenna assignments, such as separate parameter sets (e.g., PRACH) or SRS.

[0096] The application protocols for fronthaul can include a control plane (C-plane), a user plane (U-plane), a synchronization plane (S-plane), and a management plane (M-plane).

[0097] The control plane can be configured to provide scheduling information and beamforming information via control messages. The control plane means real-time control between the DU and the RU. The user plane can include IQ sample data transmitted between the DU and the RU. The user plane can include the user's 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 can be multiplied by the user's data. The synchronization plane typically means the traffic between the DU and the RU for a synchronization controller (e.g., IEEE grandmaster). The synchronization plane may be related to timing and synchronization. The management plane means non-real-time control between the DU and the RU. The management plane may be related to initial setup, non-real-time reset or reset, or non-real-time reporting.

[0098] Messages in the control plane (i.e., C-plane messages) can be encapsulated based on a two-layer header approach. The first layer can consist of an eCPRI common header or an IEEE 1914.3 common header, including a field for indicating the message type. The second layer is the application layer that includes fields required for control and synchronization. The sections in the application layer define the characteristics of the U-plane data transmitted or received in a beam with one mode ID. The following are the types of sections supported in the C-plane.

[0099] The section type can indicate the purpose of the control message transmitted in the control plane. For example, the purpose of each section type can be defined as follows.

[0100] 1) sectionType = 0: This is used to indicate unused resource blocks or symbols in the DL or UL.

[0101] 2) sectionType = 1: This is used for most DL / UL radio channels, where the term "most" indicates channels that do not require time or frequency offsets, such as those required for hybrid neuron channels.

[0102] 3) sectionType = 2: This is reserved for future use.

[0103] 4) sectionType = 3: This is used for PRACH and hybrid parameter set channels, as well as channels that require time or frequency offsets or different from the nominal SCS value.

[0104] 5) sectionType = 4: This is reserved for future use.

[0105] 6) sectionType = 5: This is UE scheduling information, delivering UE scheduling information so that the RU can perform real-time BF weight calculation (O-RAN optional BF scheme).

[0106] 7) sectionType = 6: This is used for UE-specific channel information transmission, thus periodically delivering UE channel information so that the RU can perform real-time BF weight calculation (O-RAN optional BF scheme).

[0107] 8) sectionType = 7: This is used to support LAA

[0108] According to the O-RAN standard, the fronthaul interface standard between the DU and the RU is defined according to various functional split structures. For example, according to the O-RAN standard, a standard interface in a split structure (e.g., 7-2x functional split structure) that applies Ethernet is provided.

[0109] According to an embodiment, one of multiple compression schemes can be used within each segment to increase the data transmission efficiency between the DU and the RU. Among the multiple compression schemes, the MC scheme is a lossless scheme with little data loss due to compression and has a very high compression efficiency. When the MC scheme is applied, the constellation shift flag (csf) corresponding to the U-plane information and the digital gain scaling information (e.g., modCompScaler, modScaleOffset) can be delivered to the C-plane together through an extended type 4 / 5.

[0110] For example, according to the MC scheme, a scaling process, a mapping process, and / or a shifting process of the signal can be performed during the modulation process and the compression process. The scaling values and / or shifting values used in each process can be set in various ways. Based on the scaling values and / or shifting values, a compression process and / or a decompression process can be performed.

[0111] In the following specification, technical features can be proposed for simplifying the scaling and mapping processes included in the compression and decompression processes of the MC scheme by using quantized integer values instead of floating-point values as the values of the constellation points used in the MC scheme (e.g., the compression process). According to the proposed technical features, the compression and decompression processes of the MC scheme can be easily implemented and interpreted. According to an embodiment, a new O-RAN standard can be proposed for implementing conflict prevention and backward compatibility according to the new MC scheme.

[0112] For example, when transmitting data, modulation compression (MC) can be applied (or used). When MC is applied, rules according to scaling, mapping, shifting, and conditions can be applied according to one or more steps. In the following specification, technical features can be proposed for simplifying the MC scheme of one or more steps.

[0113] In the RAN, several types of compression methods can be used in each segment to improve the data transmission efficiency between the DU and the RU. Compression techniques can include, for example, uncompressed techniques, block floating-point compression (BFPC) techniques, modulation compression (MC) techniques, etc. The IQ data frame of the O-RAN standard can include a user data compression header (e.g., udCompHdr). The user data compression header can be defined and transmitted with a specified bit width (e.g., 4-bit "udIqWidth") and a compression method (e.g., 4-bit "udCompMeth"). For example, the compression method can be defined as shown in Table 1 below.

[0114] [Table 1]

[0115]

[0116] In the above compression technology, the MC scheme is a lossless method with no data loss and high compression efficiency. The MC scheme is characterized in that the modulated data symbols can be expressed by a very limited number of bits of the in-phase (I) component and the bits of the quadrature (Q) component. For example, since QPSK (quadrature phase shift keying) modulation symbols have only two potential states for I and two potential states for Q, the QPSK modulation symbols can be represented by a single bit of the I component and a single bit of the Q component without loss of information. Another example is that symbols modulated with 64 QAM can be represented by at most 3 bits of the I component and 3 bits of the Q component.

[0117] Figures 5a to 5d The constellation points of each modulation and coding scheme (MCS) are shown.

[0118] Figures 6a to 6d The shifted constellation points of each MCS are shown.

[0119] Reference Figures 5a to 5d , the U-plane message can include the I component and the Q component of the data. For the I component of the data in the U-plane message, 16 bits can be used. For the Q component of the data in the U-plane message, 16 bits can be used. That is to say, 32 bits can be used for data transmission in the U-plane message.

[0120] For example, when binary phase shift keying (BPSK) modulation according to Figure 5a is used for modulation compression, the I component can be represented by 2 bits. The Q component can be represented by 2 bits. As an example, the I component and the Q component can be represented by 2 bits to represent -1 / 2, 0, and 1 / 2 respectively. For modulation compression, when BPSK modulation is used, the number of bits transmitted can be reduced from 32 bits to 4 bits.

[0121] For example, when QPSK modulation according to Figure 5b is used for modulation compression, the I component can be represented by 1 bit. The Q component can be expressed by 1 bit. For modulation compression, when QPSK modulation is used, the number of bits transmitted can be reduced from 32 bits to 2 bits.

[0122] For example, when 16-QAM modulation according to Figure 5c is used for modulation compression, the I component can be represented by 2 bits. The Q component can be represented by 2 bits. For modulation compression, when 16-QAM modulation is used, the number of bits transmitted can be reduced from 32 bits to 4 bits.

[0123] For example, when 64-QAM modulation according to Figure 5d is used for modulation compression, the I component can be represented by 3 bits. The Q component can be represented by 3 bits. For modulation compression, when 16-QAM modulation is used, the number of bits transmitted can be reduced from 32 bits to 6 bits.

[0124] ReferenceFigures 6a to 6d , in the MC scheme, constellation points can be obtained (or identified) by modulating the bit-level information of each modulation and coding scheme (MCS). The constellation points can be converted into shifted constellation points (SCPs) and transmitted (or delivered) to the U plane.

[0125] For example, to represent values of the I and Q components that can allow multiple constellation sizes, which can be represented as a single word width, to overlap, the constellation can be shifted so that two’s-complement can represent each constellation point. For example, the BPSK constellation points may not be shifted. The I component can be -1 / 2 or 1 / 2. The Q component can be zero. Additionally, for example, the QPSK constellation points can be shifted by -1 / 2. The I component can be -1 or 0. The Q component can be -1 or 0. Additionally, for example, the 16 QAM constellation points can be shifted by -1 / 4. The I component can be -1, -1 / 2, 0, or 1 / 2. The Q component can be -1, 1 / 2, 0, or 1 / 2. Additionally, for example, the 64 QAM constellation points can be shifted by -1 / 8. The I component can be -1, -3 / 4, -1 / 2, -1 / 4, 0, 1 / 4, 1 / 2, or 3 / 4. The Q component can be -1, -3 / 4, -1 / 2, -1 / 4, 0, 1 / 4, 1 / 2, or 3 / 4.

[0126] For example, the MC scheme converts the bit-level information into shifted constellation points (SCPs). The DU (e.g., DU 210) can transmit a U plane message including the information converted according to the SCP to the RU (e.g., RU 220). The DU 210 can transmit a constellation shift flag (csf) to the RU 220 to indicate whether to shift. For example, when the value of the csf is 1, the shift value of each constellation point at a specific bit width can be defined as shown in Table 2. For example, the shift value used when converting the constellation points into SCPs can be defined according to the MCS or the iq width (e.g., udIqWidth) value specified by the physical resource block (PRB), as shown in Table 2.

[0127] [Table 2]

[0128]

[0129] For example, when the constellation points are shifted, the constellation shift flag (csf) can be set to 1. When the constellation points are not shifted, the constellation shift flag can be set to 0.

[0130] According to an embodiment, when multiple MCSs are applied to one PRB (e.g., in the case of hybrid MCS), iqWidth can be specified as the maximum value. Only for the highest MCS among the MCSs used, the constellation shift flag can be specified (or set) to 1. The constellation shift flags for the remaining MCSs (e.g., lower MCSs) other than the highest MCS can be specified (or set) to 0. This embodiment can be basically executed in the case of hybrid MCS. The shift method can be set according to the situation related to MCS, as shown in the following examples.

[0131] For example, in the case of non - hybrid MCS, for BPSK modulation, the constellation shift flag can be specified (or set) to 0. In the case of non - hybrid MCS, for other QAMs other than BPSK, the constellation shift flag can be specified (or set) to 1.

[0132] For example, in the case of hybrid MCS, the constellation shift flag can be specified (or set) to 1 in the highest MCS and specified (or set) to 0 in the remaining MCSs (or other MCSs).

[0133] For example, in the case of hybrid MCS, QPSK modulation and BPSK modulation can be applied together. According to BPSK modulation, iqWidth can be specified (or set) to 2. In QPSK modulation, the constellation shift flag can be specified (or set) to 1. In BPSK modulation, the constellation shift flag can be specified (or set) to 0.

[0134] The data compressed according to the MC scheme does not indicate the actual power value. DU 210 can transmit a modulation compression scaler value (modCompScaler) to RU 220 so that RU 220 can set the power level for the modulated and compressed data. For example, the constellation shift flag (csf) corresponding to the U - plane information and digital gain scaling information (e.g., modCompScaler parameter and modScaleOffset parameter) can be delivered to the C - plane together through an extended type 4 / 5. For example, the digital gain scaling information is a value corresponding to the power level of the RE data and may not include phase information.

[0135] For example, the modCompScaler parameter indicates the scaling factor to be applied to the constellation points that are unshifted during decompression. In the O - RAN specification, the "modCompScaler" parameter can be provided to RU 220 through segment extension information (e.g., segment extension type 4). The "modCompScaler" parameter can indicate the exponent component and the mantissa component through the following equation.

[0136] [Equation 1]

[0137]

[0138] "mantissa" represents the mantissa component of the indicated value. "exponent" represents the exponent component of the indicated value. modCompScaler[k] represents the (k + 1)-th bit of the "modCompScaler" parameter. For example, modCompScaler[0] represents the first bit of the "modCompScaler" parameter. modCompScaler

[14] represents the 15th bit of the "modCompScaler" parameter.

[0139] The 4 most significant bits among the 15 bits of the "modCompScaler" parameter indicate the exponent component, and the 11 least significant bits among the 15 bits of the "modCompScaler" parameter indicate the mantissa component. Therefore, the value indicated by the "modCompScaler" parameter is the same as the following equation.

[0140] [Equation 2]

[0141]

[0142] "mantissa" represents the mantissa component of the indicated value. "exponent" represents the exponent component of the indicated value.

[0143] The segment extension 4 for delivering the "modCompScaler" parameter in the O-RAN specification is shown in the following table.

[0144] [Table 3]

[0145]

[0146] The DU 210 can transmit a modulation compression power scaling RE mask (mcScaleReMask) to the RU 220. The "mcScaleReMask" parameter can indicate the positions of the REs and the scaling and modulation types unified within the PRB. Similar to the "modCompScaler" parameter, the DU 210 can deliver a scaling value (mcScaleOffset) for modulation compression to the RU 220.

[0147] The "mcScaleOffset" parameter indicates the scaling factor to be applied to the constellation points for unshifting during decompression. In the O-RAN specification, the "mcScaleOffset" parameter can be provided to the RU 220 through segment extension information (e.g., segment extension type 4). The "mcScaleOffset" parameter can indicate the exponent component and the mantissa component through the following equation.

[0148] [Equation 3]

[0149]

[0150] "mantissa" indicates the mantissa component of the indicated value. "exponent" indicates the exponent component of the indicated value. mcScaleOffset[k] indicates the (k + 1)-th bit of the "mcScaleOffset" parameter. For example, mcScaleOffset[0] indicates the first bit of the "mcScaleOffset" parameter. mcScaleOffset

[14] indicates the 15th bit of the "mcScaleOffset" parameter.

[0151] The 4 most significant bits among the 15 bits of the "mcScaleOffset" parameter indicate the exponent component, and the 11 least significant bits among the 15 bits of the "mcScaleOffset" parameter indicate the mantissa component. Therefore, the value indicated by the "mcScaleOffset" parameter is the same as the following equation.

[0152] [Equation 4]

[0153]

[0154] "mantissa" indicates the mantissa component of the indicated value. "exponent" indicates the exponent component of the indicated value.

[0155] The segment extension 5 for delivering the "mcScaleOffset" parameter in the O-RAN specification is shown in the following table. Table 4 shows one scaling value, and Table 5 shows two scaling values.

[0156] [Table 4]

[0157]

[0158] [Table 5]

[0159]

[0160] The segment extension information of the above Tables 3 to 5 can be included in the C-plane message. The RU 220 can recover the original signal intended by the DU 210 based on the compressed data received through the U-plane message and the parameters received through the C-plane message. According to an embodiment, the RU 220 can obtain the original signal from the compressed bits based on the "csf" parameter. According to an embodiment, the RU 220 can obtain the original signal from the compressed bits based on the "modCompScaler" parameter. According to an embodiment, the RU 220 can obtain the original signal from the compressed bits based on the "mcscaleoffset" parameter and the "mcScaleReMask" parameter.

[0161] Figure 7a Shows an example of the modulation and compression process.

[0162] Figure 7b Shows an example of the decompression process.

[0163] Reference Figure 7a and Figure 7b , the DU 210 (or the processor of the DU 210) can convert (or compress) bit information (or bit-level information) into U-plane data based on the modulation process and the compression process. The RU 220 (or the processor of the RU 220) can decompress the U-plane data based on the U-plane data transmitted via the U-plane and the constellation shift flag (e.g., the "csf" parameter) and / or the scaler value (e.g., the "modCompScaler" parameter) of the U-plane data transmitted via the C-plane. The RU 220 can obtain the bit information by restoring the signal compressed in the DU 210.

[0164] Reference Figure 7a , operations 711 to 723 can be examples of the modulation and compression process. Operations 711 to 723 can be performed by the DU210.

[0165] In operation 711, a bit processing process can be performed. Based on the bit processing process, a bit processing value can be obtained. For example, the bit processing value can be obtained based on the modulation method (e.g., BPSK, QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM). The DU 210 (or the processor of the DU 210) can convert the bit information into the bit processing value by performing the bit processing process. Examples of the bit processing value according to the modulation scheme can be set as shown in Table 6.

[0166] [Table 6]

[0167]

[0168] In operation 712, a scaling process can be performed. A specified QAM value (e.g., the original QAM value) can be obtained based on the scaling process. The specified QAM value can be obtained based on the scaling process. The bit processing value can be converted into the specified QAM value based on the scaling process. The DU 210 can convert the bit processing value into the specified QAM value based on the scaling process.

[0169] For example, the scaling process can be performed based on a scaling factor. The DU 210 can perform the scaling process based on the scaling factor. The DU 210 can obtain the specified QAM value based on the scaling process. The specified QAM value can be set (or defined) based on the 3GPP standard. Examples of the specified QAM value according to the modulation scheme can be set (or defined) as shown in Table 7.

[0170] [Table 7]

[0171]

[0172] The bit processing process according to operation 711 and the scaling process according to operation 712 can be referred to as a modulation process. According to the modulation process, a specified QAM value can be obtained.

[0173] In operation 721, a mapping process to grid values can be performed. For example, DU 210 can map the specified QAM value to grid values. DU 210 can obtain a mapped floating-point value based on mapping the specified QAM value to grid values. Examples of the mapped floating-point values according to the modulation scheme can be set (or defined), as shown in Table 8.

[0174] [Table 8]

[0175]

[0176] In operation 722, a shifting process to shifted constellation points (SCP) can be performed. Based on subtracting the shift value from the mapped floating-point value, the shifting process to SCP can be performed. DU 210 can obtain the shifted value within SCP based on subtracting the shift value from the mapped floating-point value. Examples of the shift value and the shifted value in SCP according to the modulation method can be set (or defined), as shown in Table 9.

[0177] [Table 9]

[0178]

[0179] In operation 723, a mapping process to hexadecimal (HEX) values can be performed. The HEX value can refer to the value that is converted to a hexadecimal number to transmit data through the U plane. DU 210 can map the shifted value in SCP to a hexadecimal (HEX) value. For example, based on changing the integer value corresponding to the shifted value in SCP to its two's complement, the shifted value in SCP can be mapped to a HEX (hexadecimal) value. For example, in 64 QAM, when the shifted value is -1 / 4, the shifted value in SCP can be mapped to a HEX value based on changing the component of -1 to 2.

[0180] For example, examples of the HEX values corresponding to the shift values in SCP according to the modulation method can be set (or defined), as shown in Table 10.

[0181] [Table 10]

[0182]

[0183] The mapping process to floating-point values according to operation 721, the shifting process according to operation 722, and the mapping process to HEX values according to operation 723 can be referred to as the compression process. Based on the compression process, U-plane data can be obtained.

[0184] DU 210 can convert bit information (or bit-level information) into U-plane data based on the above operations 711 to 723. DU210 can transmit the U-plane data to RU 220.

[0185] Reference Figure 7b , operations 731 to 733 can be examples of the decompression process. Operations 731 to 733 can be performed by RU 220.

[0186] In operation 731, a mapping process to floating-point values can be performed. For example, RU 220 can map the U-plane data configured based on HEX values to floating-point values. Operation 731 can be Figure 7a the reverse process of operation 723.

[0187] In operation 732, an unshifting process can be performed. For example, RU 220 can unshift the value mapped to the floating-point value. In mapping the floating-point value, the unshifting process can be performed based on adding a shift value. RU 220 can perform the unshifting process by adding the shift value to the mapped floating-point value. Operation 732 can be Figure 7a the reverse process of operation 722.

[0188] In operation 733, a scaling process can be performed. For example, the scaling process can be performed based on the "modCompScaler" parameter. For example, a scaling process through the "modCompScaler" parameter can be performed. RU 220 can perform the scaling process through the "modCompScaler" parameter. Operation 733 can be Figure 7a the reverse process of at least one of operation 721 and / or operation 712.

[0189] Operations 731 to 733 can be referred to as the decompression process. Based on the decompression process, QAM signals can be obtained. RU220 can convert the U-plane data into QAM signals based on performing operations 731 to 733.

[0190] Reference Figure 7a and Figure 7b , a scaling process, a mapping process, and a shifting process of the signal can be performed during the modulation and compression processes. The scaling values and shifting values used in at least one of the scaling process, the mapping process, and the shifting process can be set in various ways. The compression process and the decompression process can be performed based on multiple values used in the scaling process, the mapping process, and the shifting process.

[0191] According to Figure 7a and Figure 7b the processes (or operations) shown, after converting the value of the constellation point into a floating-point value, a scaling process and a mapping process may be performed. As the value of the constellation point is converted into a floating-point value, the complexity may increase. Therefore, the features of a technique for reducing complexity by converting the value of the constellation point into a quantized integer value instead of a floating-point value may be described below.

[0192] Figure 8a Examples of a modulation process and a compression process through a shifting process are shown. The modulation process and the compression process may be performed by a DU (e.g., DU 210).

[0193] Figure 8b Examples of a decompression process through an unshifting process are shown. The decompression process may be performed by an RU (e.g., RU 220).

[0194] Referring to Figure 8a and Figure 8b , a DU 210 (e.g., a processor of the DU 210) may convert the value of the constellation point used in an MC scheme into a quantized integer value instead of a floating-point value. By converting the value of the constellation point used in the MC scheme into a quantized integer value instead of a floating-point value, at least one of a compression process, a decompression process, a scaling process, and / or a mapping process may be simplified. In addition, at least one of a compression process, a decompression process, a scaling process, and / or a mapping process may be easily implemented and interpreted. For example, examples of quantized constellation points according to a modulation method may be set (or defined) as shown in Table 11.

[0195] [Table 11]

[0196]

[0197] Referring to Table 11, the constellation points according to BPSK modulation may be set (or defined) as {-1, 0, 1}. The constellation points according to QPSK modulation may be set (or defined) as {-1, 1}. The constellation points according to 16 QAM may be set (or defined) as {-3, -1, 1, 3}. The constellation points according to 64 QAM may be set (or defined) as {-7, -5, -3, -1, 1, 3, 5, 7}. Table 11 is exemplary, and quantized constellation points according to various modulation schemes may be set (or defined).

[0198] According to an embodiment, the quantized constellation points may be shifted. Examples of the quantized and shifted constellation points may be set (or defined) as shown in Table 12.

[0199] [Table 12]

[0200]

[0201] Referring to Table 12, the quantized and shifted constellation points according to BPSK modulation can be set (or defined) as {-1, 0, 1}. The quantized and shifted constellation points according to QPSK modulation can be set (or defined) as {-1, 0}. The quantized and shifted constellation points according to 16 QAM can be set (or defined) as {-3, -1, 0, 1}. The quantized and shifted constellation points according to 64 QAM can be set (or defined) as {-4, -3, -2, -1, 0, 1, 2, 3}. Table 12 is exemplary, and the quantized and shifted constellation points according to various modulation schemes can be set or defined.

[0202] The modulation process and the compression process can be performed based on the quantized constellation points shown in Table 11 and Table 12. The decompression process can be performed based on the quantized constellation points shown in Table 11 and Table 12. Figure 8a An example of the modulation process and the compression process in DU 210 is shown. Figure 8b An example of the decompression process in RU 220 is shown.

[0203] Reference Figure 8a , operations 811 and 821 can be examples of the modulation and compression processes. Operations 811 to 821 can be performed by DU210.

[0204] In operation 811, a bit processing process can be performed. Based on the bit processing process, a bit processing value can be obtained. For example, the bit processing value can be obtained based on a modulation method (e.g., BPSK, QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM). DU 210 (or the processor of DU 210) can convert bit information into a bit processing value by performing the bit processing process. DU210 can obtain a QAM value based on the bit processing process. Different from Figure 7a operations 711 to 713, DU 210 can obtain a QAM value based on only performing the bit processing process without performing a scaling process.

[0205] For example, examples of bit processing values according to the modulation scheme can be set as shown in Table 13.

[0206] [Table 13]

[0207]

[0208] The bit processing process according to operation 811 above can be referred to as a modulation process. According to the modulation process, a QAM value can be obtained.

[0209] In operation 821, a shift process to the quantized SCP can be performed. For example, the DU 210 can perform a shift process to the quantized SCP based on a specified shift algorithm. The specified shift algorithm can be set differently according to the modulation scheme.

[0210] For example, when the QAM value is X and BPSK modulation is applied, X can be obtained according to the shift process to the quantized SCP. For example, when the QAM value is X and QPSK modulation is applied, can be obtained according to the shift process to the quantized SCP. For example, when the QAM value is X and 16 QAM modulation is applied, can be obtained according to the shift process to the quantized SCP. For example, when the QAM value is X and 64 QAM modulation is applied, can be obtained according to the shift process to the quantized SCP.

[0211] Examples of the shifted values in the quantized SCP according to the above examples can be set (or defined), as shown in Table 14.

[0212] [Table 14]

[0213]

[0214] Referring to Table 14, when the constellation shift flag is set to 1 and BPSK modulation is applied, the QAM value can be shifted to the same value. When the constellation shift flag is set to 1 and the remaining modulation schemes other than BPSK modulation (e.g., QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM) are applied, the QAM value can be shifted based on Equation 5.

[0215] [Equation 5]

[0216]

[0217] Referring to Equation 5, Y refers to the shifted value. X refers to the QAM value.

[0218] The shifted values in the quantized SCP can be converted to hexadecimal (HEX) values. Examples of converting the shifted values in the quantized SCP to HEX values can be set, as shown in Table 15.

[0219] [Table 15]

[0220]

[0221] The shift process to the quantized SCP according to operation 821 may be referred to as a compression process. According to the compression process, U-plane data can be obtained.

[0222] DU 210 can convert bit information (or bit-level information) into U-plane data based on the above operations 811 and 821. DU210 can transmit the U-plane data to RU 220.

[0223] In Figure 8b , operations 831 and 832 may be examples of a decompression process. Operation 831 can be performed by RU 220.

[0224] In operation 831, an unshift process can be performed. For example, when the constellation shift flag is set to 1 and BPSK modulation is applied, the U-plane data can be unshifted to the same value. For example, when the constellation shift flag is set to 1 and the remaining modulation schemes other than BPSK modulation (e.g., QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM) are applied, the U-plane data can be unshifted based on Equation 6.

[0225] [Equation 6]

[0226]

[0227] In operation 832, a scaling process can be performed. For example, RU 220 can perform a scaling process to transmit a signal to a terminal associated with RU 220 (e.g., a terminal located in the cell of RU 220).

[0228] Operations 831 and 832 may be referred to as a decompression process. According to the decompression process, a QAM signal can be obtained. RU 220 can convert the U-plane data into a QAM signal based on performing operations 831 and 832.

[0229] According to an embodiment, the operations for decompressing RU 220 can be represented as the pseudocode shown in Table 16.

[0230] [Table 16]

[0231]

[0232] According to the Figure 5a and Figure 6d MC scheme, the rule that "csf" is only applied to the highest MCS in the case of hybrid MCS is applied. When using the quantized SCP, the Figures 5a to 6dThe rule that "csf" is only applied to the highest MCS in the hybrid MCS scenario described in

[0233] For example, DU 210 and RU 220 can be backward compatible by supporting this rule and process signals according to the hybrid MCS scenario via a simple and unified algorithm by not using this rule. Different from the case where the shift value and the unshift value are determined according to the MCS or "udIqWidth" value when performing the shift process and the unshift process, the shift process and / or the scaling process can be performed according to Equation 5 above, and the unshift process and / or the scaling process can be performed according to Equation 6 above.

[0234] According to an embodiment, new field values as shown in Table 17 can be defined in the "udcompMeth" parameter that can be used in the M plane, C plane, and / or U plane to support according to Figure 8a and Figure 8b the MC scheme.

[0235] [Table 17]

[0236]

[0237] Referring to Table 17, when using the MC scheme (or compression scheme) based on the quantized SCP, the value of "udCompMeth" can be set to 0111b. When selective RE transmission is used together with the MC scheme (or compression scheme), based on the quantized SCP, the value of "udCompMeth" can be set to 1000b.

[0238] According to an embodiment, the M plane parameters can be configured to support the MC scheme according to Figure 8a and Figure 8b The negotiation protocol between the DU and the RU can be set to support the MC scheme according to Figure 8a and Figure 8b the MC scheme.

[0239] For example, at least one parameter (e.g., M plane parameter) can be configured to identify whether the DU and the RU support the MC scheme according to Figure 8a and Figure 8b the MC scheme. A delivery and negotiation protocol for exchanging at least one parameter (e.g., M plane parameter) between the DU and the RU can be established.

[0240] Figure 9 An example of the operations of the DU and the RU according to the application of modulation compression is shown.

[0241] Terms such as "…… unit" and "…… device" used hereinafter refer to a unit that processes at least one function or operation, which can be implemented by hardware, software, or a combination of hardware and software.

[0242] Reference Figure 9 , DU 210 may include an M-plane message processing unit 911, a C-plane message generation unit 915, and a U-plane message generation unit 917. According to an embodiment, the M-plane message processing unit 911 may generate an M-plane message including information about whether an MC scheme according to Figure 8a and Figure 8b is supported.

[0243] For example, the M-plane message processing unit 911 may generate an M-plane message including information indicating that the MC scheme according to Figure 8a and Figure 8b is applied to the U-plane message to be transmitted. For example, DU 210 may determine to apply the MC scheme according to Figure 8a and Figure 8b to the data to be transmitted through the U-plane message. DU 210 may generate an M-plane message including information indicating that the MC scheme according to Figure 8a and Figure 8b is applied by using the M-plane message processing unit 911. The M-plane message processing unit 911 may receive an M-plane message from the RU 220. DU 210 may execute a negotiation protocol by exchanging management information with the RU 220 by using the M-plane message processing unit 921. For example, the C-plane message generation unit 915 may generate a C-plane message including segment extension 4 as shown in Table 3. Additionally, for example, the C-plane message generation unit 915 may generate a C-plane message including segment extension 5 as shown in Table 4 or Table 5. For example, the U-plane message generation unit 917 may generate a U-plane message including an I component and a Q component according to the MC scheme described in Figure 8a and Figure 8b .

[0244] The RU 220 may include an M-plane message processing unit 921, a C-plane analysis unit 923, a buffer 925, a U-plane analysis unit 927, and a modulation and decompression unit 929.

[0245] For example, the M-plane message processing unit 921 may receive an M-plane message from the DU 210. The M-plane message processing unit 921 may obtain information indicating that the MC scheme according to Figure 8a and Figure 8bThe MC scheme is applied to the information of the U-plane message to be received via the M-plane message. The M-plane message processing unit 921 can generate an M-plane message. The M-plane message processing unit 921 can transmit the generated M-plane message to the DU 210. The RU 220 can execute a negotiation protocol by exchanging management information with the DU 210 using the M-plane message processing unit 921.

[0246] For example, the C-plane analysis unit 923 can receive a C-plane message from the DU 210. The C-plane analysis unit 923 can obtain parameters related to modulation compression from the segment extension information (e.g., segment extension 4, segment extension 5) included in the C-plane message. The C-plane analysis unit 923 can obtain segment information from the C-plane message. The C-plane analysis unit 923 can store the parameters related to modulation compression and the segment information in the buffer 925. The U-plane analysis unit 927 can receive a U-plane message from the DU 210. The U-plane analysis unit 927 can include the I component and the Q component included in the U-plane message. The modulation decompression unit 929 can obtain the parameters related to modulation compression and the segment information from the buffer 925. The modulation decompression unit 929 can obtain the I component and the Q component from the U-plane analysis unit 927. The modulation decompression unit 929 can obtain the bit string of the I component and the bit string of the Q component based on the parameters related to modulation compression. For example, during decompression, the modulation decompression unit 929 can cancel the constellation shift according to the "csf" value. The modulation decompression unit 929 can cancel the constellation shift according to the modulation method. For example, when BPSK is applied, the modulation decompression unit 929 can keep the same constellation. For example, when applying a remaining modulation method other than BPSK, the modulation decompression unit 929 can cancel the constellation shift according to Equation 6. The modulation decompression unit 929 can cancel the constellation shift according to the modulation scheme and apply the scaling factor of the constellation type shown in the segment. For example, there are multiple modulation schemes in one segment. The modulation type can be inferred from the reMask bit. In the reMask bit, each 1 bit represents a shift command ("csf") for the RE of the PRB and a scaling factor (e.g., "modCompScaler" when using segment extension 4, "mcScaleOffset" when using segment extension 5).

[0247] Although not shown, according to an embodiment, the RU 220 can transmit to the DU 210 information about the capabilities according to Figure 8a and Figure 8b the MC scheme.

[0248] According to an embodiment, the DU 210 can use according to Figure 8a and Figure 8bThe MC scheme modulates and compresses the data and transmits the modulated and compressed data to the RU 220. The RU 220 can use the MC scheme to recover the modulated and compressed data. According to the MC scheme, the decompression process can be simplified by simple parameters (or algorithms). In addition, in the case of hybrid MCS, the complexity of the system including the DU 210 and the RU 220 can be reduced by avoiding applying the rule of only applying "csf" to the highest MCS.

[0249] Figure 10 A flowchart showing the operation of the DU is presented.

[0250] Refer to Figure 10 , in operation 1010, the DU 210 (or the processor of the DU 210) can generate modulation values corresponding to the information bits. For example, the DU 210 can generate modulation values corresponding to the information bits based on a modulation compression scheme. For example, the modulation compression scheme can include one of BPSK, QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM.

[0251] For example, the DU 210 can generate modulation values corresponding to the information bits based on a bit processing procedure related to the modulation compression scheme. For example, the DU 210 can generate modulation values corresponding to the information bits without scaling. The modulation values can be generated based on the information bits without scaling. For example, operation 1010 can correspond to operation 811 in FIG. 8.

[0252] In operation 1020, the DU 210 can generate U-plane data corresponding to the modulation values. For example, the DU 210 can generate U-plane data corresponding to the modulation values based on a shift operation corresponding to the modulation compression scheme.

[0253] For example, in the case of BPSK, the modulation compression scheme can be set to perform a shift operation based on a specified first equation. For example, the specified first equation can be set to . In the specified first equation, X is the modulation value and Y is the shifted value.

[0254] For example, in the case of not BPSK (e.g., in the case of QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM), the modulation compression scheme can be set to perform a shift operation based on a specified second equation. For example, the specified second equation can be set to . In the specified second equation, X is the modulation value and Y is the shifted value.

[0255] For example, the U-plane data may include hexadecimal (HEX) values obtained based on shifted values. The DU 210 may use one of a specified first equation and a specified second equation to obtain the shifted values. The DU 210 may obtain the HEX values included in the U-plane data based on the shifted values. For example, the modulation values, the shifted values, and the HEX values may all be set as integers.

[0256] In operation 1030, the DU 210 may transmit a U-plane message including the generated U-plane data to the RU 220. For example, the DU 210 may transmit a U-plane message including the generated U-plane data to the RU 220 via a fronthaul interface. For example, the DU may transmit a U-plane message configured according to the above embodiments to the RU.

[0257] For example, the DU 210 may transmit information indicating the execution of a shift operation to the RU 220 via a C-plane message. The C-plane message may include segment extension information. The segment extension information may include a constellation shift flag (csf) set to 1.

[0258] Figure 11 A flowchart showing the operations of the RU is presented.

[0259] Refer to Figure 11 , in operation 1110, the RU 220 (or the processor of the RU 220) may receive a U-plane message including U-plane data from the DU 210. For example, the RU 220 may receive a U-plane message including U-plane data from the DU 210 via a fronthaul interface.

[0260] For example, the RU 220 may receive information indicating the execution of a shift operation from the DU 210 via a C-plane message. For example, the C-plane message may include segment extension information. The segment extension information may include a constellation shift flag (csf) set to 1. After receiving the C-plane message, the RU 220 may receive the U-plane message.

[0261] In operation 1120, the RU 220 may obtain a modulation value corresponding to the U-plane data. For example, the RU 220 may obtain a modulation value corresponding to the U-plane data based on a shift operation corresponding to a modulation compression scheme. For example, the modulation value may be generated without scaling based on the information bits in the DU 210.

[0262] For example, the U-plane data may include hexadecimal (HEX) values. The HEX values may be values set based on hexadecimal numbers. The RU 220 may obtain a shifted value based on converting the HEX value to a decimal number.

[0263] The RU 220 can obtain a modulation value via a shifted value by using one of the specified first equation and the specified second equation. The RU 220 can obtain the shifted value and obtain the modulation value based on the HEX value included in the U-plane data. For example, the modulation value, the shifted value, and the HEX value can all be set to integers.

[0264] For example, in the case of BPSK, the modulation compression scheme can be set to perform a shift operation based on the specified first equation. For example, the specified first equation can be set to . In the specified first equation, X is the shifted value and Y is the modulation value.

[0265] In the case other than BPSK (e.g., in the cases of QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM), based on the specified second equation, the modulation compression scheme can be set to perform a shift operation. For example, the specified second equation can be set to . In the specified second equation, X is the shifted value and Y is the modulation value.

[0266] The effects that can be obtained from the present disclosure are not limited to the above effects, and those of ordinary skill in the art to which the present disclosure pertains will clearly understand any other effects not mentioned herein from the following description.

[0267] According to an embodiment, a method for a distributed unit (DU) may include generating a modulation value corresponding to information bits based on a modulation compression scheme. The method may include generating user plane (U-plane) data corresponding to the modulation value based on a shift operation corresponding to the modulation compression scheme. The method may include transmitting a U-plane message including the generated U-plane data to a radio unit (RU) through a fronthaul interface. The modulation compression scheme may be set to perform the shift operation based on the specified first equation in the case of binary phase shift keying (BPSK), and set to perform the shift operation based on the specified second equation in the case other than BPSK.

[0268] According to an embodiment, the specified first equation may be set to . The specified second equation may be set to . In the specified first equation and the specified second equation, X may be the modulation value, and Y may be the shifted value.

[0269] According to an embodiment, the U-plane data may include a hexadecimal (HEX) value obtained based on the shifted value. The modulation value, the shifted value, and the HEX value may be set to integers.

[0270] According to an embodiment, the HEX value may be obtained based on calculating the modulation value instead of mapping the modulation value.

[0271] According to an embodiment, the modulation value may be generated based on information bits without scaling.

[0272] According to an embodiment, the method may include transmitting, to the RU, information indicating execution of the shift operation through a control plane (C plane) message. The C plane message may include segment extension information. The segment extension information may include a constellation shift flag (csf) set to one (1).

[0273] According to an embodiment, in order to obtain U plane data, a shift value defined as a fractional value may not be used.

[0274] According to an embodiment, an electronic device performed by a distributed unit (DU) may include: at least one transceiver including a fronthaul transceiver; and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to generate a modulation value corresponding to information bits based on a modulation compression scheme. The at least one processor may be configured to generate user plane (U plane) data corresponding to the modulation value based on a shift operation corresponding to the modulation compression scheme. The at least one processor may be configured to transmit a U plane message including the generated U plane data to a radio unit (RU) through a fronthaul interface. The modulation compression scheme may be set to perform the shift operation based on a specified first equation in the case of binary phase shift keying (BPSK), and set to perform the shift operation based on a specified second equation in the case of not BPSK.

[0275] According to an embodiment, the specified first equation may be set to .. The specified second equation may be set to .. In the specified first equation and the specified second equation, X may be the modulation value, and Y may be the shifted value.

[0276] According to an embodiment, the U plane data may include a hexadecimal (HEX) value obtained based on the shifted value. The modulation value, the shifted value, and the HEX value may be set to integers.

[0277] According to an embodiment, the HEX value may be obtained based on calculating the modulation value instead of mapping the modulation value.

[0278] According to an embodiment, the modulation value may be generated based on information bits without scaling.

[0279] According to an embodiment, the at least one processor may be configured to transmit information indicating execution of the shift operation to the RU via a control plane (C plane) message. The C plane message may include segment extension information. The segment extension information may include a constellation shift flag (csf) set to one (1).

[0280] According to an embodiment, in order to obtain U plane data, a shift value defined as a fractional value may not be used.

[0281] According to an embodiment, a method for a radio unit (RU) may include receiving a user plane (U plane) message including U plane data from a distributed unit (DU) via a fronthaul interface. The method may include obtaining a modulation value corresponding to the U plane data based on a shift operation corresponding to a modulation compression scheme. The modulation compression scheme may be set to perform the shift operation based on a specified first equation in the case of binary phase shift keying (BPSK), and set to perform the shift operation based on a specified second equation in the case of not BPSK.

[0282] According to an embodiment, the specified first equation may be set to The specified second equation may be set to In the specified first equation and the specified second equation, X may be a shifted value, and Y may be a modulation value.

[0283] According to an embodiment, the U plane data may include a hexadecimal (HEX) value obtained based on the shifted value. The modulation value, the shifted value, and the HEX value may be set to integers.

[0284] According to an embodiment, the HEX value may be obtained based on calculating the modulation value rather than mapping the modulation value.

[0285] According to an embodiment, the modulation value may be generated based on information bits without scaling.

[0286] According to an embodiment, the method may include receiving, via a control plane (C plane) message, information indicating execution of the shift operation for transmission. The C plane message may include segment extension information. The segment extension information may include a constellation shift flag (csf) set to one (1).

[0287] According to an embodiment, in order to obtain U plane data, a shift value defined as a fractional value may not be used.

[0288] According to an embodiment, an electronic device performed by a radio unit (RU) may include: at least one transceiver including a fronthaul transceiver; and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to receive a user plane (U-plane) message including U-plane data from a distributed unit (DU) through a fronthaul interface. The at least one processor may be configured to obtain a modulation value corresponding to the U-plane data based on a shift operation corresponding to a modulation compression scheme. The modulation compression scheme may be set to perform the shift operation based on a specified first equation in the case of binary phase shift keying (BPSK), and set to perform the shift operation based on a specified second equation in the case of not BPSK.

[0289] According to an embodiment, the specified first equation may be set to . The specified second equation may be set to . In the specified first equation and the specified second equation, X may be a shifted value, and Y may be a modulation value.

[0290] According to an embodiment, the U-plane data may include a hexadecimal (HEX) value obtained based on the shifted value. The modulation value, the shifted value, and the HEX value may be set as integers.

[0291] According to an embodiment, the HEX value may be obtained by calculating the modulation value instead of mapping the modulation value.

[0292] According to an embodiment, the modulation value may be generated based on information bits without scaling.

[0293] According to an embodiment, the at least one processor may be configured to receive information indicating execution of the shift operation through a control plane (C-plane) message. The C-plane message may include segment extension information. The segment extension information may include a constellation shift flag (csf) set to one (1).

[0294] According to an embodiment, in order to obtain U-plane data, a shift value defined as a fractional value may not be used.

[0295] The method according to the embodiments described in the claims or the present specification may be implemented in the form of hardware, software, or a combination of hardware and software.

[0296] When implemented as software, a computer-readable storage medium storing one or more programs (software modules) can be provided. The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to execute the methods according to the embodiments described in the claims or the specification of the present disclosure. The one or more programs can be included in a computer program product and provided. The computer program product can be traded between a seller and a purchaser as a product. The computer program product can be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or distributed online (e.g., downloaded or uploaded) via an app store (e.g., PlayStore™), or directly distributed between two user devices (e.g., smartphones). If distributed online, at least a part of the computer program product can be temporarily generated or at least temporarily stored in a machine-readable storage medium (such as the memory of a manufacturer's server, an app store's server, or a relay server).

[0297] Such programs (software modules, software) can be stored in random access memory, non-volatile memory, including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage devices, compact disc-ROM (CD-ROM), digital versatile disc (DVD), or other forms of optical storage devices, magnetic tape cartridges. Alternatively, they can be stored in a memory configured with some or all of their combinations. Additionally, each configured memory can include multiple ones.

[0298] Additionally, the program can be stored in an attachable storage device, which can be accessed via a communication network (such as the Internet, intranet, local area network (LAN), wide area network (WAN), or storage area network (SAN), or a combination thereof). Such a storage device can be connected to the device implementing the embodiments of the present disclosure through an external port. Additionally, an independent storage device on the communication network can access the device implementing the embodiments of the present disclosure.

[0299] In the above specific embodiments of the present disclosure, according to the presented specific embodiments, the components included in the present disclosure are expressed as singular or plural. However, the singular or plural expressions are appropriately selected according to the presented situations, and the present disclosure is not limited to singular or plural components. And even if the components are expressed in the plural, the components can be configured as singular, or even if expressed in the singular, they can be configured in the plural.

[0300] According to various embodiments, each of the above components (e.g., a module or a program) may include a single entity or multiple entities, and some of the multiple entities may be separately provided in different components. According to various embodiments, one or more of the above components may be omitted, or one or more other components may be added. Alternatively or additionally, multiple components (e.g., modules or programs) may be integrated into a single component. In this case, according to various embodiments, the integrated component may still perform one or more functions of each of the multiple components in the same or similar manner as a corresponding one of the multiple components performed one or more functions before integration. According to various embodiments, operations performed by a module, a program, or another component may be performed sequentially, in parallel, repeatedly, or in a heuristic manner, or one or more of the operations may be performed in a different order or omitted, or one or more other operations may be added.

[0301] In the detailed description of the present disclosure, specific embodiments have been described, but it will be apparent that various modifications can be made without departing from the scope of the present disclosure.

Claims

1. A method performed by a distributed unit (DU), the method comprising: Generating a modulation value corresponding to information bits based on a modulation compression scheme; Generating user plane (U-plane) data corresponding to the modulation value based on a shift operation corresponding to the modulation compression scheme; and Transmitting a U-plane message including the generated U-plane data to a radio unit (RU) via a fronthaul interface, wherein in the case of binary phase shift keying (BPSK), the modulation compression scheme is set to perform the shift operation based on a specified first equation, and wherein in the case of non-BPSK, the modulation compression scheme is set to perform the shift operation based on a specified second equation.

2. The method according to claim 1, wherein the specified first equation is set to , wherein the specified second equation is set to , wherein X is the modulation value, and wherein Y is the shifted value.

3. The method according to claim 2, wherein the U-plane data includes a hexadecimal (HEX) value obtained based on the shifted value, and wherein the modulation value, the shifted value, and the HEX value are set as integers.

4. The method according to claim 1, wherein the modulation value is generated based on the information bits without scaling.

5. The method according to claim 1, further comprising: Transmitting information indicating the execution of the shift operation to the RU via a control plane (C-plane) message, wherein the C-plane message includes segment extension information, and wherein the segment extension information includes a constellation shift flag (csf) set to one (1).

6. An electronic device performed by a distributed unit (DU), comprising: At least one transceiver, the at least one transceiver including a fronthaul transceiver; and At least one processor, the at least one processor being coupled to the at least one transceiver, wherein the at least one processor is configured to: Generating a modulation value corresponding to information bits based on a modulation compression scheme; Generating user plane (U-plane) data corresponding to the modulation value based on a shift operation corresponding to the modulation compression scheme; and Transmitting a U-plane message including the generated U-plane data to a radio unit (RU) via a fronthaul interface, wherein in the case of binary phase shift keying (BPSK), the modulation compression scheme is set to perform the shift operation based on a specified first equation, and wherein in the case of non-BPSK, the modulation compression scheme is set to perform the shift operation based on a specified second equation.

7. The electronic device according to claim 6, wherein the designated first equation is set to , wherein the specified second equation is set to , wherein X is the modulation value, and wherein Y is the shifted value.

8. The electronic device according to claim 7, wherein the U-plane data includes a hexadecimal (HEX) value obtained based on the shifted value, and wherein the modulation value, the shifted value, and the HEX value are set as integers.

9. The electronic device according to claim 6, wherein the modulation value is generated based on the information bits without scaling.

10. The electronic device according to claim 6, wherein the at least one processor is further configured to transmit information indicating the execution of the shift operation to the RU via a control plane (C-plane) message, wherein the C-plane message includes segment extension information, and Wherein the segment extension information includes a constellation shift flag (csf) set to one (1).

11. A method performed by a radio unit (RU), comprising: Receiving a user plane (U-plane) message including U-plane data from a distributed unit (DU) via a fronthaul interface; And Obtaining a modulation value corresponding to the U-plane data based on a shift operation corresponding to a modulation compression scheme, Wherein in the case of binary phase shift keying (BPSK), the modulation compression scheme is set to perform the shift operation based on a specified first equation, and Wherein in the case of non-BPSK, the modulation compression scheme is set to perform the shift operation based on a specified second equation.

12. The method according to claim 11, wherein the specified first equation is set to , wherein the specified second equation is set to , Where X is the shifted value, and Where Y is the modulation value.

13. The method according to claim 12, wherein the U-plane data includes a hexadecimal (HEX) value obtained based on the shifted value, and Where each of the modulation value, the shifted value, and the HEX value is set to an integer.

14. The method according to claim 11, wherein the modulation value is generated based on information bits without scaling.

15. An electronic device, comprising: At least one transceiver, the at least one transceiver including a fronthaul transceiver; And At least one processor, the at least one processor being coupled to the at least one transceiver, wherein the at least one processor is configured to: Receive a user plane (U-plane) message including U-plane data from a distributed unit (DU) via a fronthaul interface; and Obtain a modulation value corresponding to the U-plane data based on a shift operation corresponding to a modulation compression scheme, Wherein in the case of binary phase shift keying (BPSK), the modulation compression scheme is set to perform the shift operation based on a specified first equation, and Wherein in the case of non-BPSK, the modulation compression scheme is set to perform the shift operation based on a specified second equation.

Images