Electronic device and method for providing remote interference-management reference signals in fronthaul interface

Abstract

According to an embodiment, a method performed by a radio unit (RU) may include an operation of receiving configuration information for a remote interference management (RIM)-reference signal (RS) from a distributed unit (DU). The method may include an operation of receiving, from the DU, a message including bit data for the RIM-RS. The method may include an operation of generating a complex valued symbol corresponding to bit data for the RIM-RS. The method may include an operation of generating the RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex valued symbol based on the configuration information. The method may include an operation of generating a baseband signal corresponding to the RIM-RS signal based on inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU.

Description

Technical Field

[0001] The present disclosure relates to a fronthaul interface. More particularly, the present disclosure relates to an electronic device and method for providing a Remote Interference-Management Reference Signal (RIM-RS) in a fronthaul interface. Background Art

[0002] Time Division Duplex (TDD) communication systems support downlink and uplink communications between base stations and terminals using different time resources. Because a signal sent by a cell far away from a certain cell takes a long time to transmit, the signal can be received during the uplink of another cell beyond the protection period. In order to measure and manage this remote interference, the base station can send a Remote Interference Management (RIM)-Reference Signal (RS).

[0003] The above information may be provided as related art to assist in understanding the present disclosure. No claim or determination is made as to whether the above information may be applicable 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 radio unit (RU) may include receiving configuration information for a remote interference management (RIM)-reference signal (RS) from a distributed unit (DU). The method may include receiving a message including bit data for the RIM-RS from the DU. The method may include generating a complex-valued symbol corresponding to the bit data for the RIM-RS. The method may include generating a RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex-valued symbol based on the configuration information. The method may include generating a baseband signal corresponding to the RIM-RS signal based on an inverse fast Fourier transform (IFFT) and a cyclic prefix (CP) insertion of the RU.

[0006] According to an embodiment, the electronic device of the radio unit (RU) may include a fronthaul transceiver, at least one radio frequency (RF) transceiver, and at least one processor coupled to the fronthaul transceiver and the at least one RF transceiver. At least one processor may be configured to receive configuration information for a remote interference management (RIM)-reference signal (RS) from a distributed unit (DU) through the fronthaul transceiver. At least one processor may be configured to receive a message including bit data for RIM-RS from the DU through the fronthaul transceiver. At least one processor may be configured to generate a complex value symbol corresponding to the bit data for RIM-RS. At least one processor may be configured to generate a RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex value symbol based on the configuration information. At least one processor may be configured to generate a baseband signal corresponding to the RIM-RS signal based on an inverse fast Fourier transform (IFFT) and a cyclic prefix (CP) insertion of the RU.

[0007] According to an embodiment, a method performed by a distributed unit (DU) may include sending configuration information for a remote interference management (RIM)-reference signal (RS) to a radio unit (RU). The method may include sending a message including bit data for the RIM-RS to the RU. The configuration information may be used for at least one of phase rotation or phase difference compensation of a complex-valued symbol to generate a baseband signal by inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU. The complex-valued symbol may correspond to a modulation result of the bit data for the RIM-RS.

[0008] According to an embodiment, the electronic device of the 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 send configuration information for a remote interference management (RIM)-reference signal (RS) to a radio unit (RU) through the fronthaul transceiver. The at least one processor may be configured to send a message including bit data for the RIM-RS to the RU through the fronthaul transceiver. The configuration information may be used for at least one of phase rotation or phase difference compensation of a complex-valued symbol to generate a baseband signal through an inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU. The complex-valued symbol may correspond to a modulation result of the bit data for the RIM-RS.

[0009] According to an embodiment, a non-transitory computer-readable storage medium is provided. The non-transitory computer-readable storage medium may store one or more programs. One or more programs may include instructions that, when executed by a processor of a radio unit (RU), cause the RU to receive configuration information for a remote interference management (RIM)-reference signal (RS) from a distributed unit (DU). One or more programs may include instructions that cause the RU to receive a message including bit data for the RIM-RS from the DU. The one or more programs may include instructions that cause the RU to generate a complex-valued symbol corresponding to the bit data for the RIM-RS. The one or more programs may include instructions that cause the RU to generate a RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex-valued symbol based on the configuration information. The one or more programs may include instructions that cause the RU to generate a baseband signal corresponding to the RIM-RS signal based on the inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU.

[0010] According to an embodiment, a non-transitory computer-readable storage medium is provided. The non-transitory computer-readable storage medium may store one or more programs. The one or more programs may include instructions that, when executed by a processor of a distributed unit (DU), cause the RU to send configuration information for a remote interference management (RIM)-reference signal (RS) to a radio unit (RU). The one or more programs may include instructions that cause the RU to send a message including bit data for the RIM-RS to the RU. The configuration information may be used for at least one of phase rotation or phase difference compensation of a complex-valued symbol to generate a baseband signal by an inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU. The complex-valued symbol may correspond to a modulation result of the bit data for the RIM-RS. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 An example of long-range interference according to an embodiment is shown.

[0012] Figure 2a , 2b 2c show examples of remote interference management according to an embodiment.

[0013] Figure 3a A fronthaul interface according to an embodiment is shown.

[0014] Figure 3b A fronthaul interface of an Open (O)-Radio Access Network (RAN) according to an embodiment is shown.

[0015] Figure 4a A functional configuration of a distributed unit (DU) according to an embodiment is shown.

[0016] Figure 4b A functional configuration of a radio unit (RU) according to an embodiment is shown.

[0017] Figure 5 An example of a Remote Interference Management (RIM)-Reference Signal (RS) structure according to an embodiment is shown.

[0018] Figure 6 A functional configuration of each network entity for compressed bit data transmission according to an embodiment is shown.

[0019] Figure 7 An example of cyclic shift according to an embodiment is shown.

[0020] Figure 8 A functional configuration of each network entity for downlink transmission is shown.

[0021] Figure 9a An example of a cyclic shifter according to an embodiment is shown.

[0022] Figure 9b An example of a phase difference compensator according to an embodiment is shown.

[0023] Fig.10 A functional configuration of each network entity for RIM-RS transmission according to an embodiment is shown.

[0024] Fig.11 An example of RIM-RS mapping according to an embodiment is shown.

[0025] Fig.12 An operation flow of an RU for RIM-RS transmission according to an embodiment is shown.

[0026] Fig.13 The operation flow of the RU for complex mapping of RIM-RS according to an embodiment is shown.

[0027] Fig.14 An operation flow of an RU for phase rotation of a RIM-RS according to an embodiment is shown.

[0028] Fig.15 The operation flow of the RU for phase difference compensation of the RIM-RS according to the embodiment is shown.

[0029] Fig.16 An operation flow of a DU for RIM-RS transmission according to an embodiment is shown. DETAILED DESCRIPTION

[0030] The terms used in this disclosure are only used to describe specific embodiments and may not be intended to limit the scope of another embodiment. Unless the context clearly states otherwise, singular expressions may include plural expressions. The terms used herein, including technical or scientific terms, may have the same meaning as the meanings generally understood by those of ordinary skill in the art described in this disclosure. Among the terms used in this disclosure, the terms defined in conventional dictionaries may be interpreted as meanings identical or similar to the contextual meanings of the relevant technology, and unless clearly defined in this disclosure, are not interpreted as ideal or overly formal meanings. In some cases, even the terms defined in this disclosure may not be interpreted as excluding embodiments of the present disclosure.

[0031] In various embodiments of the present disclosure described below, a hardware method will be described as an example. However, since various embodiments of the present disclosure include techniques using hardware and software, various embodiments of the present disclosure do not exclude software-based methods.

[0032] Terms referring to information (e.g., configuration information, additional information, control information), terms referring to operating states (e.g., steps, operations, procedures), terms referring to data (e.g., information, values, commands), terms referring to signals (e.g., packets, messages, signals, information, signaling), terms referring to resources (e.g., segments, symbols, time slots, subframes, radio frames, subcarriers, resource elements (REs), resource blocks (RBs), bandwidth parts (BWPs), opportunities), terms referring to operating states (e.g., steps, operations, procedures), terms referring to data (e.g., packets, messages, user flows, information, bits, symbols, codewords), terms referring to channels, terms referring to network entities (e.g., distributed unit (DU), radio unit (RU), central unit (CU), CU-control plane (CP), CU-user plane (UP), open radio access network (O-RAN) DU (O-DU), O-RAN RU (O-RU), O-RAN CU (O-CU), O-RAN CU-CP (O-CU-UP), O-RAN CU-CP (O-CU-CP)), and terms referring to components of the device, the terms used in the following description are exemplified for the convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms with equivalent technical meanings may also be used. In addition, the terms "...... unit", "...... device", "...... material" and "...... structure" used below may refer to at least one shape structure, and may also refer to a unit of processing function.

[0033] In addition, in the present disclosure, the term "greater than" or "less than" can be used to determine whether a specific condition is satisfied or satisfied, but this is only a description of an expression example and does not exclude the description of "greater than or equal to" or "less than or equal to". The condition described as "greater than or equal to" can be replaced by "greater than", the condition described as "less than or equal to" can be replaced by "less than", and the condition described as "greater than or equal to and less than" can be replaced by "greater than and less than or equal to". In addition, hereinafter, "A to B" refers to at least one element from A (including A) to B (including B). hereinafter, "C" and / or "D" means at least one of "C" or "D", i.e. {"C", "D", "C" and "D"}.

[0034] Although the present disclosure describes various embodiments using terms used in some communication standards (e.g., 3rd Generation Partnership Project (3GPP), Scalable Radio Access Network (xRAN), and Open Radio Access Network (O-RAN)), this is just an explanatory example. Various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0035] The present disclosure provides an electronic device and method for providing a remote interference management (RIM)-reference signal (RS) on a fronthaul interface. In addition, the present disclosure provides an electronic device and method for transmitting configuration information for RIM-RS to provide RIM-RS through a lossless compression technique on a fronthaul interface. In addition, the present disclosure also provides an electronic device and method for performing complex modulation mapping for RIM-RS in a radio unit (RU) by sending the configuration information for RIM-RS to RU on a fronthaul interface.

[0036] The electronic device and method according to the embodiments of the present disclosure may reduce the bandwidth of the fronthaul interface by providing RIM-RS using a lossless compression technology on the fronthaul interface.

[0037] An electronic device and method according to an embodiment of the present disclosure may transmit a Remote Interference Management (RIM)-Reference Signal (RIM-RS) through cyclic shift and phase difference compensation of the RIM-RS based on an existing hardware configuration.

[0038] Effects obtainable from the present disclosure are not limited to those described above, and any other effects not mentioned herein will be clearly understood from the following description by a person of ordinary skill in the art to which the present disclosure pertains.

[0039] Figure 1 An example of long-range interference according to an embodiment is shown.

[0040] Reference Figure 1 , Figure 1A base station 110 and a terminal 120 are shown as a part of nodes utilizing a wireless channel in a wireless communication system. Figure 1 Only one base station is shown, but the wireless communication system may also include another base station that is the same as or similar to the base station 110 .

[0041] The base station 110 is a network infrastructure that provides wireless access to the terminal 120. The coverage of the base station 110 is limited based on the distance over which the signal can be transmitted. In addition to the base station, the base station 110 may be referred to as an "access point (AP)", "eNode B (eNB)", "5th generation node", "next generation node B (gNB)", "radio point", "transmission / reception point (TRP)" or other terms with the same technical meaning.

[0042] The terminal 120 is a device used by a user, and performs communication with the base station 110 through a wireless channel. The link from the base station 110 to the terminal 120 is called a downlink (DL), and the link from the terminal 120 to the base station 110 is called an uplink (UL). Figure 1 Although not shown in the figure, the terminal 120 and another terminal can perform communication through a wireless channel. At this time, the link between the terminal 120 and another terminal (device-to-device link (D2D)) is called a side link, and the side link can be used interchangeably with the PC5 interface. In some other embodiments, the terminal 120 can be operated without user participation. According to an embodiment, the terminal 120, as a device for performing machine-type communication (MTC), may not be carried by the user. In addition, according to an embodiment, the terminal 120 may be a narrowband (NB) Internet of Things (IoT) device.

[0043] In addition to the term terminal, terminal 120 may also be referred to as user equipment (UE), customer premises equipment (CPE), mobile station, user station, remote terminal, wireless terminal, electronic device, user equipment or other terms with the same technical meaning.

[0044] In time division duplex (TDD) communication technology, the same frequency domain as the uplink channel and the downlink channel can be used. At this time, downlink communication and uplink communication use different time resources, because if the downlink communication and uplink communication overlap in the time domain, interference between channels will be generated. The time resource combination for TDD communication can be called TDD mode. The downlink period of TDD mode can be set. The downlink period can be set based on at least one of one or more time slots or one or more symbols. The downlink period can be set based on one or more time slots. The downlink period can be set based on one or more symbols. The downlink period can be set based on one or more time slots and one or more symbols. In addition, the uplink period of TDD mode can be set. The uplink period can be set based on at least one of one or more time slots or one or more symbols. The uplink period can be set based on one or more time slots. The uplink period can be set based on one or more symbols. The uplink period can be set based on one or more time slots. The uplink period can be set based on one or more symbols. The uplink period can be set based on one or more time slots and one or more symbols.

[0045] In a TDD communication system, the flexible period of the TDD mode can be operated for switching between a downlink period and an uplink period. The flexible period may also be referred to as a protection period. In general, the flexible period is set considering the propagation speed and typical path loss of the wireless signal, but under certain climatic conditions, the propagation range of the wireless signal may increase. For example, since the downlink signal 150 transmitted on the cell of the base station 130 far away from the base station 110 is to be transmitted for a long time, it can be received during the uplink of another cell, exceeding the protection period. This interference may be referred to as long-range interference, time of flight (TOF) interference, long-distance cell interference, propagation delay interference or self-interference. In a TDD communication system, the quality of uplink communication may be reduced by this long-range interference.

[0046] In the case where a downlink signal 150 of another base station 130 flows into the uplink transmission period of the base station 110, the uplink signal transmitted with a relatively low output may be susceptible to interference (i.e., remote interference) caused by the downlink signal 150. Therefore, a method for measuring remote interference and controlling remote interference is required. In the 5G NR system, a remote interference management reference signal (RIM-RS) has been introduced to detect the above-mentioned remote interference and control the interference. In the following, Figures 2a to 2c An example of remote interference detection and interference control based on RIM-RS is described in.

[0047] Figure 2a , 2b 2c show examples of remote interference management according to an embodiment. Figures 2a to 2c, a framework for remote interference handling is described. The difference between the frameworks lies in the decision of where to apply interference mitigation in the network, and the way the decision is communicated between nodes. In the following, three frameworks are shown, but other framework variants can be easily considered, and artificial intelligence and machine learning can be used in the frameworks.

[0048] Reference Figure 2a , the operation and management (OAM) device 210 can perform all decisions related to remote interference mitigation in a centralized remote interference management framework. If remote interference is detected, the base station 110, which is a victim node, can send a first type of RIM-RS (S201). The first type corresponds to the RIM-RS type 1 of 3GPP. The first type of RIM-RS can not only indicate that the cell is experiencing remote interference, but also include information about the ID of the node (or a group of nodes) sending the reference signal, and information about the number of orthogonal frequency division multiplexing (OFDM) symbols in the affected uplink period. This information can be implicitly encoded in the RIM-RS. Since the atmospheric waveguide is reciprocal, the base station 130 of the aggressor cell that provides remote interference that helps the victim can receive the RIM-RS.

[0049] Upon receiving the RIM-RS, the base station 130 as the attacker node may report the detected RIM-RS to the OAM device 210 (S202). In order to further determine how to solve the interference problem, the base station 130 may send the detected RIM-RS including the information encoded in the RIM-RS to the OAM device 210. The OAM device 210 may send a command indicating a change in the TDD mode to the base station 130 (S203). The OAM device 210 may decide on an appropriate mitigation scheme that requests the attacker cell to stop downlink transmission earlier to extend the protection period. Thereafter, if the waveguide phenomenon disappears, the base station 130 no longer detects the RIM-RS. The base station 130 may send a report on interference elimination to the OAM device 210. The OAM device 210 may command the base station 110 to stop RIM-RS transmission (S205). In addition, the OAM device 210 may request the base station 130 to restore the previous configuration of the TDD mode (S204). Operation S204 may be performed independently of operation S205.

[0050] Reference Figure 2b, if long-range interference is detected, the base station 110 as a victim node may transmit a first type of RIM-RS (S231). When the base station 130 as an attacker node receives the first type of RIM-RS, the base station 130 may recognize that the base station 110 is experiencing long-range interference. The base station 130 may transmit a second type of RIM-RS to the base station 110 (S233). The second type corresponds to the RIM-RS type 2 of 3GPP. The base station 130 may transmit a radio signal to the base station 110 to notify that the first type of RIM-RS has been received and to apply an appropriate mitigation plan. The base station 110 receiving the second type of RIM-RS may detect whether there is long-range interference. If the base station 110 does not detect the second type of RIM-RS, the base station 110 may recognize that the long-range interference disappears. The base station 110 may stop transmitting the first type of RIM-RS. Thereafter, the base station 130 as an attacker node may restore the mode configuration before interference detection based on recognizing that the first type of RIM-RS is no longer received.

[0051] Reference Figure 2c , if remote interference is detected, the base station 110 as a victim node may transmit a first type of RIM-RS (S231). When the base station 130 as an attacker node receives the first type of RIM-RS, the base station 130 may recognize that the base station 110 is experiencing remote interference. The base station 130 may send a backhaul signal to the base station 110 via the Xn interface (S233). The backhaul signal via the Xn interface may be used to notify the base station 110 of the presence or absence of the first type of RIM-RS from the base station 130. The backhaul signal indicating the absence of the first type of RIM-RS may be used to determine that the remote interference no longer exists and to stop transmitting the first type of RIM-RS. The base station 130 as an attacker node may restore the mode configuration before interference detection based on recognizing that the first type of RIM-RS is no longer received.

[0052] In the past, in a communication system with a relatively large base station cell radius, each base station was installed to include a digital processing unit (or distributed unit (DU)) and a radio frequency (RF) processing unit (or radio unit (RU)). However, as high-frequency bands are used in fourth-generation (4G) and / or subsequent communication systems (e.g., 5G), and the cell coverage of base stations becomes smaller, the number of base stations covering a specific area increases. The installation cost burden of operators for installing base stations also increases. In order to minimize the installation cost of base stations, a structure is proposed in which the DU and RU of a base station are separated, one or more RUs are connected to one DU via a wired network, and one or more RUs are geographically distributed to cover a specific area. The following is described by Figure 3a and 3bDeployment structures and extension examples of base stations according to various embodiments of the present disclosure are described.

[0053] Figure 3a 1 shows a fronthaul interface according to an embodiment. Fronthaul refers to the interface between entities between a radio access network and a base station, which is different from the backhaul between a base station and a core network. Figure 3a In the figure, an example of a fronthaul structure between a DU 310 and a RU 320 is shown, but this is only for the convenience of explanation, and the present disclosure is not limited to this. In other words, the embodiments of the present disclosure can also be applied to the fronthaul structure between a DU and multiple RUs. For example, the embodiments of the present disclosure can be applied to the fronthaul structure between a DU and two RUs. In addition, the embodiments of the present disclosure can also be applied to the fronthaul structure between a DU and three RUs.

[0054] Reference Figure 3a , the base station 110 may include a DU 310 and a RU 320. The fronthaul 315 between the DU 310 and the RU 320 may be operated through an Fx interface. For example, to operate the fronthaul 315, an interface such as an enhanced common public radio interface (eCPRI) or a radio over Ethernet (ROE) may be used.

[0055] With the development of communication technology, mobile data traffic has increased, and therefore the bandwidth demand required for fronthaul between digital units and radio units has increased significantly. In deployments such as centralized / cloud radio access networks (C-RAN), DU can be implemented to perform packet data convergence protocol (PDCP), radio link control (RLC), medium access control (MAC) and physical (PHY) functions, and RU can be implemented to perform PHY layer functions in addition to radio frequency (RF) functions.

[0056] DU 310 may be responsible for high-level functions of a wireless network. For example, DU 310 may perform functions of a MAC layer and functions of a portion of a PHY layer. Here, a portion of a PHY layer refers to functions of a PHY layer that are performed at a higher level in the functions of the PHY layer, and may include, for example, channel coding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), and layer mapping (or layer demapping). According to an embodiment, DU 310 may perform only bit arrangement for resource mapping during a modulation operation. Bit arrangement refers to an operation of distinguishing bits into symbol units according to a modulation order in order to map bits to REs. Subsequently, in a modulation operation, RU 320 may perform complex mapping of bits into complex-valued symbols. In addition, according to an embodiment, if DU 310 complies with the O-RAN standard, it may be referred to as O-DU (O-RAN DU). If necessary, DU 310 in an embodiment of the present disclosure may be replaced by a first network entity (e.g., gNB) of a base station.

[0057] RU 320 may be responsible for the low-level functions of the wireless network. For example, RU 320 may perform a portion of the PHY layer and RF functions. Here, a portion of the PHY layer refers to the functions of the PHY layer performed at a relatively lower level than DU 310, and may include, for example, iFFT conversion (or FFT conversion), CP insertion (CP removal), and digital beamforming. According to an embodiment, RU 320 may perform complex mapping between modulation operations. Complex mapping refers to the operation of converting the bit corresponding to the symbol into an in-phase / quadrature phase (IQ) signal. RU 320 may be referred to as an access unit (AU), an access point (AP), a transmit / receive point (TRP), a remote radio head (RRH), a radio unit (RU), or other terms with the same technical meaning. According to an embodiment, if RU 320 complies with the O-RAN standard, it may be referred to as an O-RAN RU (O-RU). If necessary, the RU 320 in the embodiment of the present disclosure may be replaced by a second network entity (e.g., gNB) of the base station.

[0058] although Figure 3a The base station 110 is described as including the DU 310 and the RU 320, but the embodiments of the present disclosure are not limited thereto. The base station according to the embodiment can be implemented in a distributed deployment manner according to a central unit (CU) configured to perform high-layer functions of the access network (e.g., packet data convergence protocol (PDCP), radio resource control (RRC)) and a distributed unit (DU) configured to perform low-layer functions. At this time, the distributed unit (DU) may include Figure 1 The base station may be implemented in a structure in which the CU, DU, and RU are arranged in sequence between the core (e.g., 5G core (5GC) or next generation core (NGC)) network and the radio network (RAN). The interface between the CU and the distributed unit (DU) may be referred to as the F1 interface.

[0059] The central unit (CU) may be connected to one or more DUs to perform functions at a higher layer than the DU. For example, the CU may be responsible for the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, and the DU and RU may be responsible for the functions of the lower layers. The DU may perform certain functions of the radio link control (RLC), media access control (MAC), and PHY layers (high PHY), and the RU may perform the remaining functions of the PHY layer (low PHY). In addition, as an example, depending on the implementation of a distributed deployment of a base station, a digital unit (DU) may be included in a distributed unit (DU). Hereinafter, unless otherwise defined, the present disclosure describes the operation of a digital unit (DU) and a RU, but various embodiments of the present disclosure may be applied to a base station arrangement including a CU or an arrangement in which the DU is directly connected to a core network (i.e., the CU and DU are integrated into a base station (e.g., an NG-RAN node) as a single entity).

[0060] Figure 3b A fronthaul interface of an open (O)-radio access network (RAN) according to an embodiment is shown. As a base station 110 according to a distributed deployment, an eNB or a gNB is exemplified.

[0061] Reference Figure 3b , the base station 110 may include an O-DU 351 and O-RUs 353-1, ..., and 353-n. Hereinafter, for ease of explanation, the operation and function of the O-RU 353-1 may be understood as the description of each other O-RU (e.g., O-RU 353-n).

[0062] In addition to the functions specifically assigned to O-RU 353-1, according to Figure 4 to be described later, O-DU 351 is a logical node that includes functions of a base station (e.g., eNB, gNB). O-DU 351 can control the operation of O-RU 353-1,..., and 353-n. O-DU 351 can be referred to as a low-layer segmentation (LLS) central unit (CU). According to Figure 4 to be described later, O-RU353-1 is a logical node that includes a subset of the functions of a base station (e.g., eNB, gNB). Real-time aspects of control plane (C-plane) communications and user plane (U-plane) communications with O-RU 353-1 can be controlled by O-DU 351.

[0063] The O-DU 351 may communicate with the O-RU 353-1 via an LLS interface. The LLS interface corresponds to a fronthaul interface. The LLS interface refers to a logical interface between the O-DU 351 and the O-RU 353-1 using a low-layer functional split (i.e., an intra-PHY-based functional split). The LLS-C between the O-DU 351 and the O-RU 353-1 provides a C-plane via an LLS interface. The LLS-U between the O-DU 351 and the O-RU 353-1 provides a U-plane via an LLS interface.

[0064] exist Figure 3b In the embodiment of the present disclosure, the entities of the base station 110 are described as O-DU and O-RU to describe the O-RAN. However, these names should not be construed as limiting the embodiments of the present disclosure. Figures 3a to 16 In the described embodiment, the operations of DU 310 may also be performed by O-DU 351. The description of DU 310 may also be applied to O-DU 351. Figures 4a to 16 In the described embodiment, the operations of RU 320 may also be performed by O-RU 353-1. The description of RU 320 may also be applied to O-RU 353-1.

[0065] Figure 4a A functional configuration of a distributed unit (DU) according to an embodiment is shown. Figure 4a The configuration of the example can be understood as a part of the base station Figure 3a DU 310 (or Figure 3b The terms "...unit" and "...device" used below refer to a unit that processes at least one function or operation, which can be implemented by hardware or software, or by a combination of hardware and software.

[0066] Reference Figure 4a , the DU 310 includes a transceiver 410 , a memory 420 , and a processor 430 .

[0067] The transceiver 410 may perform the function of sending and receiving signals in a wired communication environment. The transceiver 410 may include a wired interface for controlling direct connections between devices through a transmission medium (e.g., copper wire, optical fiber). For example, the transceiver 410 may transmit an electrical signal to another device through a copper wire, or perform conversion between an electrical signal and an optical signal. The DU 310 may communicate with a radio unit (RU) through the transceiver 410. The DU 310 may be connected to a core network or a distributedly deployed CU through the transceiver 410.

[0068] The transceiver 410 can perform functions for sending and receiving signals in a wireless communication environment. For example, the transceiver 410 can perform conversion functions between baseband signals and bit strings according to the physical layer specifications of the system. For example, when sending data, the transceiver 410 generates complex symbols by encoding and modulating the transmission bit string. In addition, when receiving data, the transceiver 410 recovers the received bit string by demodulating and decoding the baseband signal. In addition, the transceiver 410 may include multiple transmit / receive paths. In addition, according to an embodiment, the transceiver 410 may be connected to a core network or other nodes (e.g., integrated access backhaul (IAB)).

[0069] The transceiver 410 may send and receive signals. For example, the transceiver 410 may send a management plane (M-plane) message. For example, the transceiver 410 may send a synchronization plane (S-plane) message. For example, the transceiver 410 may send a control plane (C-plane) message. For example, the transceiver 410 may send a user plane (U-plane) message. For example, the transceiver 410 may receive a U-plane message. Figure 4a Only the transceiver 410 is shown in FIG. 3 , but according to another implementation, the DU 310 may include two or more transceivers.

[0070] The transceiver 410 transmits and receives signals as described above. Therefore, all or part of the transceiver 410 may be referred to as a "communication unit", "transmission unit", "reception unit" or "transmission / reception unit". In addition, in the following description, transmission and reception performed through a wireless channel are used to include the processing performed by the transceiver 410 as described above.

[0071] although Figure 4a Although not shown in the figure, the transceiver 410 may also include a backhaul transceiver for connecting to the 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 sent from the base station to another node (e.g., another access node, another base station, a high-level node, and a core network) into a physical signal, and converts a physical signal received from another node into a bit string.

[0072] The memory 420 stores basic programs, application programs, and data such as configuration information for the operation of the DU 310. The memory 420 may be referred to as a storage unit. The memory 420 may be configured with a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, the memory 420 provides storage data according to a request from the processor 430.

[0073] The processor 430 controls the overall operation of the DU 310. The processor 480 may be referred to as a control unit. For example, the processor 430 sends and receives signals through the transceiver 410 (or through the backhaul communication unit). In addition, the processor 430 writes and reads data in the memory 420. In addition, the processor 430 may perform the functions of the protocol stack required in the communication standard. Although Figure 4a Only processor 430 is shown in FIG. 3 , but according to another implementation, DU 310 may include two or more processors.

[0074] Figure 4a The configuration of the DU 310 shown in FIG. 1 is only an example, and examples of the DU for performing the embodiments of the present disclosure are not limited to Figure 4a In some embodiments, some configurations may be added, deleted or changed.

[0075] Figure 4b A functional configuration of a radio unit (RU) according to an embodiment is shown. Figure 4b The configuration shown in the figure can be understood as a part of a base station. Figure 3a RU 320 or Figure 3b The terms "...unit" and "...device" used below refer to a unit that processes at least one function or operation, which can be implemented by hardware or software, or by a combination of hardware and software.

[0076] Reference Figure 4b , RU 320 includes an RF transceiver 460 , a fronthaul transceiver 465 , a memory 470 , and a processor 480 .

[0077] The RF transceiver 460 performs the function of sending and receiving signals through a wireless channel. For example, the RF transceiver 460 up-converts a baseband signal into an RF band signal and then transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF transceiver 460 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC.

[0078] The RF transceiver 460 may include multiple transmit / receive paths. In addition, the RF transceiver 460 may include an antenna unit. The RF transceiver 460 may include at least one antenna array consisting of multiple antenna elements. In terms of hardware, the RF transceiver 460 may be composed of digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFIC)). Here, the digital circuits and the analog circuits may be implemented as a single package. In addition, the RF transceiver 460 may include multiple RF chains. The RF transceiver 460 may perform beamforming. In order to provide directionality for signals to be sent and received according to the settings of the processor 480, the RF transceiver 460 may apply beamforming weights to the signals. According to an embodiment, the RF transceiver 460 may include a radio frequency (RF) block (or RF unit).

[0079] The RF transceiver 460 can send and receive signals on the radio access network. For example, the RF transceiver 460 can send downlink signals. The downlink signal may include a synchronization signal (SS), a reference signal (RS) (e.g., a cell-specific reference signal (CRS), a demodulation (DM)-RS), system information (e.g., MIB, SIB, remaining system information (RMSI), other system information (OSI)), a configuration message, control information, or downlink data. In addition, for example, the RF transceiver 460 can receive an uplink signal. The uplink signal may include a random access-related signal (e.g., a random access preamble (RAP)) (or message 1 (Msg1), message 3 (Msg3)), a reference signal (e.g., a sounding reference signal (SRS), DM-RS), or a power headroom report (PHR). Although Figure 4b Only the RF transceiver 460 is shown in FIG. 3 , but the RU 320 may include two or more RF transceivers according to another embodiment.

[0080] According to an embodiment, the RF transceiver 460 may transmit a RIM-RS. The RF transceiver 460 may transmit a first type of RIM-RS (e.g., RIM-RS type 1 of 3GPP) to notify detection of remote interference. The RF transceiver 460 may transmit a second type of RIM-RS (e.g., RIM-RS type 2 of 3GPP) to notify the presence or absence of remote interference.

[0081] The fronthaul transceiver 465 may send and receive signals. According to an embodiment, the fronthaul transceiver 465 may send and receive signals on the fronthaul interface. For example, the fronthaul transceiver 465 may receive a management plane (M-plane) message. For example, the fronthaul transceiver 465 may receive a synchronization plane (S-plane) message. For example, the fronthaul transceiver 465 may receive a control plane (C-plane) message. For example, the fronthaul transceiver 465 may send a user plane (U-plane) message. For example, the fronthaul transceiver 465 may receive U-plane information. Although only the fronthaul transceiver 465 is Figure 4b , but RU 320 may include two or more fronthaul transceivers according to another embodiment.

[0082] As described above, the RF transceiver 460 and the fronthaul transceiver 465 transmit and receive signals. Therefore, all or part of the RF transceiver 460 and the fronthaul transceiver 465 may be referred to as a "communication unit", "transmission unit", "reception unit" or "transmission / reception unit". In addition, in the following description, transmission and reception performed through a wireless channel are used to include the processing as described above performed by the RF transceiver 460. In the following description, transmission and reception performed through a wireless channel are used to include the processing as described above performed by the RF transceiver 460.

[0083] The memory 470 stores basic programs, application programs, and data such as configuration information for the operation of the RU 320. The memory 470 may be referred to as a storage unit. The memory 470 may be configured with a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, the memory 470 provides storage data according to a request from the processor 480. According to an embodiment, the memory 470 may include a memory for conditions, commands, or setting values ​​related to the SRS transmission scheme.

[0084] The processor 480 controls the overall operation of the RU 320. The processor 480 may be referred to as a control unit. For example, the processor 480 sends and receives signals through the RF transceiver 460 or the fronthaul transceiver 465. In addition, the processor 480 writes and reads data in the memory 470. In addition, the processor 480 may perform the functions of the protocol stack required by the communication standard. Although Figure 4b Only the processor 480 is shown in the figure, but the RU 320 may include two or more processors according to another embodiment. The processor 480, which is an instruction set or code stored in the memory 470, may be an instruction / code or a storage space storing the instruction / code at least temporarily residing in the processor 480, or a part of the circuit constituting the processor 480. In addition, the processor 480 may include various modules for performing communication. The processor 480 may control the RU 320 to perform operations according to the embodiments described later.

[0085] Figure 4b The configuration of the RU 320 shown in FIG. 1 is only an example, and examples of the RU for performing the embodiments of the present disclosure are not limited to the following. Figure 4b Configurations shown. In some embodiments, some configurations may be added, deleted or changed.

[0086] As described above, in order to manage long-range interference, the base station may transmit a RIM-RS. The victim node may transmit a first type of RIM-RS (e.g., RIM-RS type 1 of 3GPP). The first type of RIM-RS may be used to indicate that long-range interference exists in the victim cell, that is, to notify that a waveguide phenomenon exists. In a specific framework (e.g., Figure 2b The attacker node may transmit a second type of RIM-RS (e.g., RIM-RS type 2 of 3GPP) in the framework of the present invention. The second type of RIM-RS may be used to notify the victim cell of the presence of the waveguide phenomenon. Unlike the first type of RIM-RS, the second type of RIM-RS may not send additional information (e.g., the number of symbols). Hereinafter, the following description of the RIM-RS structure may be applicable to both the first type of RIM-RS and the second type of RIM-RS.

[0087] Figure 5 An example of a Remote Interference Management (RIM)-Reference Signal (RS) structure according to an embodiment is shown. The RIM-RS is intended to notify remote interference, and the RIM-RS structure requires detection of the RIM-RS without OFDM symbol synchronization between the aggressor and the victim.

[0088] Reference Figure 5 , the structure of a conventional OFDM symbol may include a data symbol and a cyclic prefix (CP). In this article, a conventional OFDM symbol refers to a symbol used to transmit bits of other NR channels other than RIM-RS (e.g., physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH)). A data symbol refers to a complex-valued symbol corresponding to a data payload and on which complex mapping is performed. For example, a first OFDM symbol may include a CP 511 and a data symbol 512. CP 511 corresponds to one or more samples of data symbol 512. Symbol 512 refers to a complex-valued symbol on which complex mapping is performed. A second OFDM symbol may include a CP 521 and a data symbol 522. CP 521 corresponds to one or more samples of data symbol 522.

[0089] RIM-RS can be transmitted through two consecutive symbols. Two consecutive symbols may include a first RIM-RS symbol 531 and a second RIM-RS symbol 532. Here, a symbol refers to a complex value symbol corresponding to a bit, rather than a resource length including a CP. The useful part of each symbol may be the same. The useful part refers to a data payload. The data symbol of the first RIM-RS symbol 531 and the data symbol of the second RIM-RS symbol 532 may be the same. Different from the transmission structure of a conventional OFDM symbol, in RIM-RS, the CP is not located in front of each symbol, but the RIM-RS CP 533 may be located at the front end of the first symbol 531 located in front of the two symbols. The duplicate sample for the RIM-RS CP 533 is located at the end portion of the second symbol of the RIM-RS. Since the length of the CP is relatively long, it is possible to detect the RIM-RS without estimating the timing of a separate OFDM symbol.

[0090] In 5G wireless communication systems, in order to carry out large-capacity data transmission, the bandwidth of the wireless channel and the number of antennas will increase, and the interface bandwidth between the DU and the RU will also increase significantly. In addition, since one DU should transmit traffic to multiple RUs, the required interface bandwidth between the DU and the RU increases linearly with the number of RUs. In conventional functional split systems, in order to reduce the required interface bandwidth between the DU and the RU, the DU generates frequency domain signals and generates time domain signals through inverse fast Fourier transform and CP insertion in the RU. In OFDM systems, guard subcarriers are inserted to reduce channel interference. If only frequency domain (where guard subcarriers are excluded) signals are transmitted, the required bandwidth between the DU and the RU can be reduced. Combined with the functional split in which the DU processes signals in the frequency domain and the RU processes signals in the time domain, various compression schemes have been proposed to reduce the required bandwidth by compressing the traffic between the DU and the RU. These traffic compression techniques can be divided into lossy compression techniques and lossless compression techniques.

[0091] Lossy compression technology is a method of generating complex-valued symbols with channel gain applied after performing modulation in the DU, removing low-critical low-bit information, and transmitting the remaining bits to the RU. For example, assume that the lower 8 bits are removed from the 16 bits and the remaining top 8 bits are transmitted to the RU. The required bandwidth between the DU and the RU can be reduced by 50%. However, in the RU, only the higher 8 bits of information should be used to recover the symbol. Lossy compression technology has the disadvantage of causing information distortion between the DU and the RU.

[0092] The lossless compression technology is divided into a method of generating complex-valued symbols in the DU and transmitting data (hereinafter referred to as compressed bit data) to the RU by applying lossless compression based on information theory to the complex-valued symbols, and a method of transmitting bit data to the RU in the DU and the RU generating complex-valued symbols by reflecting modulation and channel gain. Lossless compression based on information theory has the disadvantage of being difficult to process a large amount of data in real time due to the large amount of calculations required for compression and recovery. In the lossless compression in which the RU performs modulation using compressed bit data received from the DU, the modulation function of the DU is passed to the RU. As far as the system is concerned, the bandwidth required between the DU and the RU can be effectively reduced without additionally increasing the computational complexity. In order for the RU to perform modulation (referring to the process of generating an IQ signal by complex mapping) and reflect the channel gain, additional control information (modulation method, channel type) is required. The DU can send control information and bit data together to the RU. The compressed data sent from the DU to the RU may include bit data and control information. For example, the DU can compress the bit data and control information into 10 bits. The DU can send 10 bits of compressed bit data to the RU. The RU can perform complex mapping of modulation based on the compressed bit data. In the following, complex mapping refers to the operation of converting a bit corresponding to one symbol into an IQ signal. Through the complex mapping of modulation, the RU can generate a 16-bit complex-valued symbol, that is, a complex-valued symbol with a 16-bit real part and a 16-bit imaginary part. Therefore, compared with the uncompressed case, the RU can reduce the required bandwidth between the DU and the RU to 31.25% (= 10 / 32). In the following, the function of the lossless compression technology between the DU and the RU will refer to Figure 6 to describe.

[0093] Figure 6 The functional configuration of each network entity for compressed bit data transmission according to an embodiment is shown. The network entity may include a DU 310 or a RU 320.

[0094] Reference Figure 6 , DU 310 may obtain bit data corresponding to information to be transmitted by RU 320. DU 310 may obtain bit data by receiving a bit from a higher node or generating a signal at DU 310. According to an embodiment, DU 310 may obtain control / traffic bit data 610a. Control / traffic bit data 610a may include at least one of control bit data and traffic bit data. Hereinafter, control bit data may include one or more bits associated with a control channel (e.g., a physical downlink control channel (PDCCH)). Traffic bit data may include one or more bits associated with a data channel (e.g., a physical downlink shared channel (PDSCH)). According to an embodiment, DU 310 may obtain reference signal bit data 610b. According to an embodiment, reference signal bit data may include one or more bits corresponding to a RIM-RS.

[0095] DU 310 may generate control information 612. DU 310 may generate control information 612 related to bit data. Control information 612 may generate control information 612 for control bit data 610a, traffic bit data 610a, or reference signal bit data 610b. Control information 612 may indicate a channel type of the bit data and a modulation method for the bit data.

[0096] The DU 310 may perform bit compression 615 based on at least one of the control / traffic bit data 610a, the reference signal bit data 610b, or the control information 612. In addition to the control / traffic bit data 610a or the reference signal bit data 610b, the DU 310 may generate compressed bit data 630 including the control information 612. The DU 310 may perform resource mapping 617 on the generated compressed bit data 630. The DU 310 may sort the bits of the compressed bit data. In the present disclosure, modulation may include bit alignment and complex mapping 651. Here, bit alignment refers to an operation of distinguishing bits by the size of a symbol unit corresponding to the modulation order (e.g., 2 bits for QPSK and 4 bits for 16QAM) to map bits to REs. Complex mapping 651 refers to an operation of converting the aligned bits corresponding to one symbol into an IQ signal. The converted IQ signal may be referred to as a complex-valued symbol. The DU 310 may perform bit alignment on the compressed bit data. The DU 310 maps bits corresponding to one symbol to a resource element (RE) which is a frequency-time resource and transmits the bits to the RU 320. For example, in case that the modulation scheme is QPSK, the DU 310 may map two bits to one RE.

[0097] DU 310 may send the generated compressed bit data 630 to RU 320. DU 310 may send the generated compressed bit data 630 to RU 320 through a fronthaul interface. DU 310 may send configuration information 635 to RU 320. Configuration information 635 may include information used for signal processing in RU 320. Configuration information 635 may include information about the gain of each channel. Configuration information 635 may include information about precoding (e.g., precoding matrix). In addition, configuration information 635 may include channel-specific gain, precoding matrix, and other additional information. Configuration information 635 may be transmitted only once for the first time or may be updated as needed. Therefore, the transmission frequency of configuration information 635 may be lower than the transmission frequency of compressed bit data 630. The transmission of configuration information 635 may be performed at a bandwidth lower than the bandwidth of compressed bit data 630. RU 320 may obtain modulation scheme 661 and channel type 663 based on control information 612 of compressed bit data 630.

[0098] RU 320 may perform complex mapping 651. RU 320 may generate an IQ signal corresponding to bit data 630. Based on modulation scheme 661 and channel type 663, RU 320 may generate complex-valued symbols corresponding to bit data 630. RU 320 may perform IFFT and CP insertion 657. RU 320 may apply the obtained channel gain and precoding matrix to the generated complex-valued symbols based on configuration information 635. RU 320 may generate RIM-RS symbols based on an inverse fast Fourier transform (IFFT) of the complex-valued symbols to be applied to modulation, and may generate an OFDM baseband signal by inserting a cyclic prefix (CP). The baseband signal may be a time domain signal.

[0099] The RIM-RS according to the embodiment corresponds to a reference signal. The RIM-RS can be generated based on 2-bit bit data. The RIM-RS can be generated based on quadrature phase shift keying (QPSK). Figure 6 In the lossless compression scheme of , DU 310 may send 2-bit reference signal bit data 610b related to RIM-RS to RU 320. RU 320 may perform QPSK modulation on the 2 bits based on control information 612. Here, bit alignment for RE mapping may be performed by DU 310. RU 320 may generate complex-valued symbols for RIM-RS based on the channel gain obtained through configuration information 635. The compressed bit data 630 sent from DU 310 to RU 320 may include bit data (e.g., reference signal bit data 610b) and control information 612. For example, the number of bits of the compressed bit data 630 may be 10. The index of the modulation scheme 661 and the index of the channel type 663 may be determined by a predefined setting between DU 310 and RU 320 (e.g., presetting the M-plane of O-RAN). For example, the index "00" of the modulation scheme 661 may refer to QPSK modulation. The index '101100' of the channel type 663 may indicate a RIM-RS.

[0100] Figure 7 An example of cyclic shift according to an embodiment is shown. Figure 5 As described above, in order to detect RIM-RS, it has been standardized to connect two identical data symbols and use a cyclic prefix (CP) that is longer than a conventional OFDM symbol. The CP inserter of the hardware of the RU developed before the standardization of RIM-RS can only add one CP to one OFDM symbol. Therefore, in order to generate an OFDM symbol of RIM-RS in which the first data symbol and the second data symbol are connected by the existing CP inserter, additional processing is required. The additional processing can be called a cyclic shift.

[0101] Reference Figure 7, RIM-RS 700 may include RIM-RS CP 710, a first RIM-RS symbol 721, and a second RIM-RS symbol 723. For example, the first RIM-RS symbol 721 may include 6 sample groups. Each sample group may include one or more time samples. The first RIM-RS symbol 721 may include sample group #0, sample group #1, sample group #2, sample group #3, sample group #4, and sample group #5. The second RIM-RS symbol 723 may include 6 sample groups. The second RIM-RS symbol 723 may include sample group #0, sample group #1, sample group #2, sample group #3, sample group #4, and sample group #5. The sample group of the second RIM-RS symbol 723 may be the same as the sample group of the first RIM-RS symbol 721. The RIM-RS CP 710 may be configured to be longer than the CP length of a conventional OFDM symbol. For example, the RIM-RS CP 710 may include some sample groups (eg, sample groups #4, #5) among the sample groups of the second RIM-RS symbol 723.

[0102] The CP inserter for conventional OFDM symbols inserts a sample group of data symbols in front. Here, conventional OFDM symbols refer to symbols used to transmit bits of other NR channels (e.g., PDSCH, PDCCH, PUSCH, PUCCH) in addition to RIM-RS. Data symbols refer to complex-valued symbols corresponding to data payloads and complex mapping has been performed on them. In order to implement RIM-RS CP 710 by the CP inserter for conventional OFDM symbols, cyclic shift needs to be performed before CP insertion.

[0103] The RU may perform a cyclic shift 750 on a portion of the data symbol. For example, a cyclic shift may be performed on sample group #5 located at the end of the six sample groups of the first data symbol 721. When a conventional OFDM symbol is assumed, the length of sample group #5 may correspond to the CP length of the second data symbol 723. After the first data symbol 721 of the RIM-RS is cyclically shifted backward by as much length as the CP length of the second data symbol 723, the RU may input the cyclically shifted first data symbol 760 to the CP inserter. Since the CP inserter inserts the last sample group of the input symbol in the front, sample group #4 is added to the cyclically shifted first data symbol 760. The CP inserter may output sample group #4, sample group #5, sample group #0, sample group #1, sample group #2, sample group #3, and sample group #4. The RU may input the second data symbol 723 to the CP inserter. Sample group #5 is added to the second data symbol 723. The CP inserter may output sample group #5, sample group #0, sample group #1, sample group #2, sample group #3, sample group #4, and sample group #5. Based on the CP inserter of the conventional OFDM symbol, the RU may generate the RIM-RS 700 by performing a cyclic shift on the first data symbol of the RIM-RS.

[0104] Since RIM-RS is used for the purpose of detecting remote interference signals, its OFDM symbol structure is different from the existing NR OFDM symbol structure, and its carrier frequency also operates differently from NR. Therefore, RIM-RS needs to perform independent resource mapping, IFFT, CP insertion, and carrier frequency modulation that are different from the existing NR channel. However, from a system perspective, having a separate processing chain for processing RIM-RS only is inefficient. Therefore, when the RU generates RIM-RS based on the processing chain of the existing NR channel (e.g., CP inserter), the cyclic shift according to the embodiment can improve the efficiency of the system.

[0105] Figure 8 The functional configuration of each network entity for downlink transmission is shown. The network entity may include a DU 310 or a RU 320 .

[0106] Reference Figure 8 In order to improve frequency utilization, RIM-RS and channels other than RIM-RS (hereinafter referred to as conventional NR channels) can be allocated to the same OFDM symbol using different frequency resources. For example, in the frequency domain 850, PDSCH 853 can be allocated to a frequency region other than the frequency region to which RIM-RS 851 is mapped.

[0107] In conventional functional splitting, DU 310 processes the signal in the frequency domain, and RU 320 processes the signal in the time domain after performing IFFT. Figure 7As shown, since the CP length and the data symbol length correspond to the time order, the cyclic shift can be performed based on the signal processing in the time domain in the RU 320. However, in the case where the RIM-RS 851 and the conventional NR channel (e.g., PDSCH) are mixed in the frequency domain 850, the cyclic shift for the RIM-RS needs to be selectively applied. However, it is not easy to separate frequency resources in the time domain. Therefore, it is necessary to selectively cyclically shift the RIM-RS through signal processing in the frequency domain. In the following, based on the processing chain for the conventional NR channel, the process of generating the RIM-RS 851 by the DU 310 and the RU 320 is described.

[0108] DU 310 may generate bit data 810 of RIM-RS. DU 310 may perform modulation 811. DU 310 may perform QPSK modulation on bit data 810 of RIM-RS. DU 310 may generate complex-valued symbols based on QPSK modulation. DU 310 may perform cyclic shift 813. DU 310 may perform cyclic shift on the complex-valued symbols. Therefore, it is a cyclic shift in the time domain, but corresponds to a phase rotation in the frequency domain. DU 310 may rotate the phase of the complex-valued symbol for each RE of RIM-RS. DU 310 may perform phase difference compensation 815. DU 310 may perform phase difference compensation on the cyclic shift result. Here, phase difference compensation refers to an operation of compensating for a phase difference caused by a difference between a carrier frequency of a conventional NR channel and a carrier frequency of RIM-RS. Thereafter, DU 310 may perform resource mapping 817.

[0109] Based on the result of resource mapping 817, DU 310 may send a modulation signal 830 to RU 320. Resource mapping modulation signal 830 refers to an IQ signal corresponding to RIM-RS. For example, resource mapping modulation signal 830 may include a 16-bit real part and a 16-bit imaginary part. Thereafter, RU 320 may perform IFFT and CP insertion 857. RU 320 may generate an OFDM baseband signal of RIM-RS by performing IFFT conversion and CP insertion on the received modulation signal 830. Although not in Figure 8 8, but RU 320 may perform precoding. RU 320 may generate an OFDM baseband signal of RIM-RS by performing precoding, IFFT conversion, and CP insertion on the received modulated signal 830.

[0110] exist Figure 6 In , a lossless compression scheme between DU-RU is described, where, except for the bit alignment for resource mapping, other functions of modulation (e.g. complex mapping, IQ signal generation) are performed in the RU. Figure 8In , a method for generating RIM-RS based on the processing chain of a conventional NR channel is described. Figure 8 Modulation, cyclic shift and phase difference compensation are performed in the DU, so it is difficult to achieve Figure 6 The lossless compression scheme shown in . Therefore, in order to generate RIM-RS through the processing chain of conventional NR channel and bit data according to the lossless compression technology, it is necessary to perform processing operations for RIM-RS in the RU. That is, in the modulation function, in addition to the bit alignment for resource mapping, other functions (e.g., complex mapping, IQ signal generation), cyclic shift, and phase difference compensation need to be performed in the RU.

[0111] In the following, Figure 9a and 9b In, the functionality for generating RIM-RS from bit data provided by a lossless compression scheme is described. Fig.10 In, the overall operation of DU and RU is described.

[0112] Figure 9a An example of a cyclic shifter according to an embodiment is shown. The cyclic shifter according to an embodiment may be implemented by RU (e.g., Figure 3a The cyclic shifter may be implemented in the form of hardware within the RU, software of a processor within the RU, or a combination of hardware and software. In order to reduce the required bandwidth between the DU-RU through a lossless compression scheme, the RU may perform a cyclic shift on the RIM-RS.

[0113] Reference Figure 9a , the cyclic shifter can output a cyclically shifted RIM-RS signal 911 by performing a phase rotation on the RIM-RS signal 901. In the case where the RIM-RS signal 901 is mixed with an NR channel (e.g., PDSCH) in the frequency domain, the cyclic shift of the RIM-RS signal 901 should be selectively applied. However, frequency resource segmentation is not possible in the time domain. Therefore, the cyclic shifter according to the embodiment can perform a phase rotation in the frequency domain instead of performing a cyclic shift in the time domain. The cyclic shifter of the RU can perform selective phase rotation on the RIM-RS by signal processing in the frequency domain. The cyclic shifter can rotate the phase of the RIM-RS signal 901 by multiplying the RIM-RS signal assigned to the kth RE by the complex value x(k) (903). For example, the complex value x(k) of the cyclic shifter can be determined based on the following formula.

[0114] [Formula 1]

[0115] x(k)=exp(-j*2*pi*n_cp_l1*k_prime / n_iFFT)

[0116] [Formula 2]

[0117] k_prime=(k+(n_iFFT-n_RB*6))%n_iFFT

[0118] n_cp_l1 represents the CP length of the second RIM-RS symbol of the RIM-RS, n_iFFT represents the iFFT size, and n_RB represents the total number of RBs (resource blocks) of the bandwidth including the RIM-RS. Each RB includes 12 REs. "k" represents the index of the corresponding RE within the bandwidth. exp(·) is an exponential function, and % represents a modulo operator.

[0119] In summary, the cyclic shifter can perform cyclic shift on the RIM-RS by phase rotation in the frequency domain. Through cyclic shifting, the RU can insert the CP of the RIM-RS (e.g., RIM-RS CP 710) into the RIM-RS symbol (e.g., the first RIM-RS symbol 721, the second RIM-RS symbol 723) based on the CP inserter of the conventional NR channel.

[0120] Figure 9b An example of a phase difference compensator according to an embodiment is shown. The phase difference compensator according to an embodiment can be configured by RU (e.g., Figure 3a The phase difference compensator may be implemented in the form of hardware within the RU, software of a processor within the RU, or a combination of hardware and software. In order to reduce the required bandwidth between the DU-RU through a lossless compression scheme, the RU may perform phase difference compensation on the RIM-RS.

[0121] Reference Figure 9b , by performing phase difference compensation on the cyclically shifted RIM-RS signal 951, the phase difference compensator can output a compensated RIM-RS signal 961. In the 5G wireless communication system, the phase of the carrier frequency at the starting point of the transmission OFDM symbol body is standardized to 0 degrees so that channel estimation can be performed even when the terminal receives a carrier frequency different from that of the base station. If the RIM-RS is transmitted based on the same modulation chain as the conventional NR channel, the RU transmits the RIM-RS at the carrier frequency of the conventional NR channel. Therefore, it is necessary to compensate for the phase difference between the carrier frequency of the conventional NR channel and the carrier frequency of the RIM-RS. In addition, the phase difference caused by the difference between the OFDM symbol lengths of the conventional NR channel and the RIM-RS also needs to be compensated. Therefore, the phase difference compensator of the RU can compensate for the phase difference by multiplying the cyclically shifted RIM-RS signal 951 by exp(-j*θ li ) to compensate the phase difference of the cyclically shifted RIM-RS signal 951. li represents the phase difference of the i-th symbol of RIM-RS. For example, θ l0The first OFDM symbol representing the RIM-RS (eg, Figure 7 The phase difference of the first RIM-RS symbol (721)). l1 represents the phase difference of the second RIM-RS symbol (eg, Figure 7 Here, regardless of the RE index, θ li has the same value within an OFDM symbol.

[0122] Fig.10 FIG. 3 shows a functional configuration of each network entity for RIM-RS transmission according to an embodiment. The network entity may include a DU 310 or a RU 320. Fig.10 In the invention, an apparatus and method are described for reducing the bandwidth required for the interface between DU and RU by transmitting RIM-RS based on a lossless compression scheme.

[0123] Reference Fig.10 , DU 310 may obtain RIM-RS bit data 1010. RIM-RS bit data 1010 may be determined based on parameters required to generate a RIM-RS sequence. For example, RIM-RS bit data 1010 may be configured as 2 bits. DU 310 may generate control information 1012. Control information 1012 may indicate a modulation method for bit data and a channel type for bit data so that RU 320 may generate a complex-valued symbol. Control information 1012 may indicate QPSK. Control information 1012 may indicate RIM-RS. For example, the index of the modulation scheme and the index of the channel type 663 may be determined by a predefined setting between DU 310 and RU 320 (e.g., pre-setting, M-plane of O-RAN). For example, the index "00" of the modulation scheme may refer to QPSK modulation. The index "101100" of the channel type may represent RIM-RS.

[0124] DU 310 may perform bit compression 1015 based on RIM-RS bit data 1010 and control information 1012. DU 310 may generate compressed bit data 1030 through bit compression 1015. DU 310 may perform resource mapping 1017 on the bits of the compressed bit data 1030. For resource mapping 1017, DU 310 may perform bit alignment on the bits of the compressed bit data 1030. Bit alignment refers to the operation of distinguishing bits into symbol units according to the modulation order so as to map bits to REs. According to an embodiment, when RIM-RS is transmitted, RUs may be aligned in units of two bits. Every two bits are allocated to one RE. That is, DU 310 may map the compressed bit data to the frequency-time resources allocated by the RIM-RS. The compressed bit data may include bits for the RIM-RS.

[0125] The DU 310 may transmit the compressed bit data 1030 to the RU 320. The compressed bit data 1030 may include the bit data 1010 of the RIM-RS. In some embodiments, the compressed bit data 1030 may include the control information 1012. Meanwhile, in some other embodiments, the compressed bit data 1030 may not include the control information 1012. In this case, the information indicated by the control information 1012 (e.g., channel type, modulation method) may be predefined between the DU 310 and the RU 320 or provided by the configuration information 1035 described below.

[0126] DU 310 may transmit configuration information 1035 to RU 320. Configuration information 1035 may be used by RU 320 instead of DU 310 to generate a complex symbol of RIM-RS from bit data of RIM-RS and to generate a RIM-RS baseband signal. RU 320 may generate a RIM-RS baseband signal based on configuration information 1035. According to an embodiment, a transmission frequency of configuration information 1035 may be the same as a transmission frequency of compressed bit data 1030. According to another embodiment, a transmission frequency of configuration information 1035 may be lower than a transmission frequency of compressed bit data 1030. Transmission of configuration information 1035 may be performed at a bandwidth lower than a bandwidth of compressed bit data 1030. Below, in order to generate a RIM-RS baseband signal, configuration information 1035 and each functional configuration of RU 320 are described in detail.

[0127] The RU 320 may perform complex mapping 1051. The RU 320 may generate an IQ signal corresponding to the bit data 1030. The RU 320 may obtain a modulation scheme (e.g., QPSK) and a channel type (e.g., RIM-RS) based on the control information 1012 of the compressed bit data 1030. Based on the modulation scheme (e.g., QPSK) and the channel type (e.g., RIM-RS), the RU 320 may generate a complex-valued symbol corresponding to the bit data 630. According to an embodiment, the configuration information 1035 may include information about a channel gain of the RIM-RS. Based on the channel gain, the RU 320 may generate a complex-valued symbol according to the modulation.

[0128] RU 320 may perform cyclic shift 1053. Since frequency resource partitioning is difficult in the time domain, RU 320 may perform phase rotation in the frequency domain to cyclically shift in the time domain. Hereinafter, cyclic shift may refer to phase rotation in the frequency domain. For phase rotation, configuration information 1305 may include various information.

[0129] According to an embodiment, the configuration information 1035 may include an indicator for indicating whether the symbol corresponding to the compressed bit data 1030 is the first symbol or the second symbol of the two symbols of the RIM-RS. In order to use the CP inserter for the conventional NR channel, the RU 320 according to an embodiment may perform a cyclic shift on the first RIM-RS. For example, Figure 7 As shown, the cyclic shift 750 is performed only on the first RIM-RS symbol 721. Depending on the symbol position of the RIM-RS, whether to perform the cyclic shift is different. The RU 320 can perform the cyclic shift of the RIM-RS symbol based on the indicator.

[0130] According to an embodiment, the configuration information 1035 may include resource allocation information. That is, the configuration information 1035 may include information related to the resource mapping 1017. The resource allocation information may indicate a time resource. For example, the resource allocation information may include a system frame number (SFN) for indicating a radio frame. For example, the resource allocation information may include a subframe number. For example, the resource allocation information may include a time slot index. For example, the resource allocation information may include a symbol index. The resource allocation information may indicate a frequency resource. For example, the resource allocation information may include frequency offset information of the RIM-RS. For example, the resource allocation information may include an RE index of the RIM-RS. According to an embodiment, a selective cyclic shift of the RIM-RS may be performed based on the resource allocation information. The RU 320 may perform a phase rotation based on identifying the RE to which the RIM-RS is allocated.

[0131] According to an embodiment, the configuration information 1035 may include cyclic shift information. For example, the configuration information 1035 may include information about the RIM-RS CP length. Here, the CP length refers to the CP length of the later RIM-RS symbol of the two RIM-RS symbols. At the position of the RE corresponding to the resource allocation information, the RU 320 may perform as many phase rotations as the RIM-RS CP length.

[0132] RU 320 may perform phase difference compensation 1055. Phase difference compensation refers to a process for compensating for the difference between the carrier frequency of the NR channel and the carrier frequency of the RIM-RS. According to an embodiment, the configuration information 1035 may include phase difference information. The phase difference information may include phase difference information of a first RIM-RS symbol and phase difference information of a second RIM-RS symbol. That is, the configuration information 1035 may include phase difference information for each symbol. The phase difference information between REs within the same symbol may be the same. According to another embodiment, the configuration information 1035 may include information about a reference point of the RIM-RS in each symbol. Based on the difference between the reference point of the RIM-RS and the carrier frequency of another NR channel, the RU may calculate the phase difference of the corresponding symbol.

[0133] RU 320 may perform IFFT and CP insertion 1057. RU 320 may generate RIM-RS symbols to be applied to modulated complex-valued symbols based on IFFT, and insert a cyclic prefix (CP) to generate an OFDM baseband signal. According to an embodiment, configuration information 1035 may include precoding information. RU 320 may apply precoding to the RIM-RS for which cyclic shift and phase difference compensation have been completed. According to an embodiment, the precoding matrix may be transmitted once through configuration information at system startup or updated when necessary. Based on the precoding information, RU 320 may apply the precoding matrix to the RS sequence. RU 320 may generate an OFDM baseband signal of the RIM-RS through precoding, IFFT, and CP insertion.

[0134] According to an embodiment, the control information 1012 including the modulation scheme and the channel type index may be removed from the compressed bit data 1030 to further reduce the bandwidth required between the DU-RU. If the control information 1012 is removed from the compressed bit data 1030, the configuration information 1035 may include the control information 1012 of the RIM-RS. In this case, the length of the compressed bit data may be reduced. For example, if the control information 1012 is included in the configuration information 1035 and is excluded from the compressed bit data 1030, the length of the compressed bit data 1030 may be reduced from 10 bits to 2 bits.

[0135] and Figure 6 Unlike the RU for the lossless compression scheme shown, in addition to the existing functions, the RU according to the embodiment of the present disclosure can generate a RIM-RS baseband signal by additionally performing cyclic shift and phase difference compensation. The RU according to the embodiment can reduce the RIM-RS bits on the fronthaul interface based on complex mapping, cyclic shift and phase difference compensation performed in the RU instead of the DU. Therefore, the bandwidth required between the DU and the RU can be reduced.

[0136] Fig.11 An example of RIM-RS mapping according to an embodiment is shown. RIM-RS can be transmitted on RIM-RS resources defined as ternary indexes in the time domain, frequency domain, and sequence domain. The complex-valued symbols of RIM-RS can be generated based on QPSK modulation of a pseudo-random sequence based on a length of 2 31 -1 gold sequence. Based on the ternary index, not only can the length of 2 used for RIM-RS be calculated 31 -1 QPSK modulated gold sequence, and the actual position in time and frequency can be calculated. Fig.11 The time-frequency resources are described on the resource grid in .

[0137] Reference Fig.11 , the resource grid 1100 may include multiple frequency-time resources. The frequency-time resources correspond to REs. The horizontal axis of the resource grid 1100 represents symbols arranged in ascending order of index. The vertical axis of the resource grid 1100 represents REs arranged in ascending order of index. According to the standard, up to 4 RIM-RS resources can be configured in the frequency domain (depending on the carrier bandwidth). A RIM-RS with a 15kHz subcarrier spacing (SCS) can occupy the entire carrier bandwidth or 96RB. The frequency resources of a RIM-RS with a 30khz subcarrier spacing can be limited to 48RB or 96RB.

[0138] DU 310 may map compressed bit data generated by bit compression to RE based on resource allocation information of RIM-RS. One modulation symbol may be mapped to one RE. RIM-RS may be generated from a pseudo-random sequence based on QPSK modulation. Therefore, one QPSK modulation symbol may include two bits 1110. That is, two bits 1110 may be mapped to one RE. However, since the DU according to the embodiment performs resource mapping before modulation, the DU may align the bits of the RIM-RS in units of two bits 1110. The aligned unit corresponds to one symbol.

[0139] Fig.12 FIG. 4 shows an operation flow of an RU for RIM-RS transmission according to an embodiment. Figure 3a According to an embodiment, the RU 320 may include an O-RU 353-1.

[0140] Reference Fig.12 In operation S1201, RU 320 may receive configuration information for RIM-RS. The configuration information may be in the form of Fig.10The configuration information 1035 of the present invention may be applied in the same or similar manner as described above. According to an embodiment, the configuration information may include channel gain information. The channel gain information may be used for complex mapping in RU 320. In addition, according to an embodiment, the configuration information may include an indicator for indicating whether the symbol corresponding to the compressed bit data 1030 is the first symbol or the second symbol of the two symbols of the RIM-RS. The indicator may be used for phase rotation and phase difference compensation in RU 320. In addition, according to an embodiment, the configuration information may include resource allocation information. The resource allocation information may be used for phase rotation and phase difference compensation in RU 320. In addition, according to an embodiment, the configuration information may include cyclic shift information. The cyclic shift information may be used for phase rotation in RU 320. In addition, according to an embodiment, the configuration information may include phase difference information. The phase difference information may be used for phase difference compensation in RU 320. In addition, according to an embodiment, the configuration information may include precoding information. It may be used for application of a precoding matrix in RU 320.

[0141] In operation S1203, RU 320 may receive a message including bit data for RIM-RS. According to an embodiment, the bit data for RIM-RS may include bits of RIM-RS. According to an embodiment, the bit data for RIM-RS may include bits of RIM-RS and control information for RIM-RS. The control information may indicate a channel type and a modulation scheme of the transmitted data. The control information may include information indicating that the bit is RIM-RS. The control information may include information indicating that the modulation scheme of the bit is QPSK. Meanwhile, according to another embodiment, the control information may be included in the configuration information of operation S1201 instead of being included in the bit data.

[0142] In operation S1205, RU 320 may generate a complex value symbol corresponding to the bit data for RIM-RS. RU 320 may obtain two bits of RIM-RS from the bit data. Two bits of RIM-RS may be used for QPSK modulation. RU 320 may generate an RS sequence by performing QPSK modulation based on two bits. RU 320 may apply a channel gain to the generated RS sequence. Here, the channel gain may be obtained from the configuration information in operation S1201. RU 320 may generate a complex value symbol by applying the channel gain to the generated RF sequence. For example, RU 320 may generate a complex value symbol by multiplying an amplitude scaling factor to control the RIM-RS transmission power.

[0143] In operation S1207, the RU 320 may generate a RIM-RS signal based on at least one of phase rotation and phase difference compensation. The RU 320 may perform phase rotation. Phase rotation refers to a cyclic shift in the time domain. Figure 7As described above, RU320 may perform phase rotation in the frequency domain to generate a baseband signal of the RIM-RS through a single CP inserter of the RU. The RIM-RS transmission may include two RIM-RS symbols (e.g., the total length of 3GPP TS 38.211 5.3.3 is Corresponds to κT C =T S , T S =1 / (Δf ref ·N f,ref ), Δf ref =15·10 3 Hz and N f,ref =2048). The phase rotation can be applied to the first RIM-RS symbol of the two RIM-RS symbols. However, the phase rotation cannot be applied to the second RIM-RS symbol of the two RIM-RS symbols.

[0144] The RU 320 may perform phase rotation based on the configuration information. According to an embodiment, the configuration information may indicate whether the symbol of the current bit data is the first RIM-RS symbol of the two RIM-RS symbols. The configuration information may indicate whether the symbol of the current bit data is the second RIM-RS symbol of the two RIM-RS symbols. The RU 320 may perform phase rotation based on recognizing that the symbol of the current bit data is the first RIM-RS symbol.

[0145] Phase rotation may be performed as much as the CP length of the second symbol in the two RIM-RS symbols of the RIM-RS transmission. The configuration information may include information for indicating the CP length of the second symbol. For example, the configuration information may include an index for indicating the CP length of the second symbol. In addition, for example, the configuration information may indicate a symbol index (a symbol index within a subframe). According to the 3GPP standard, the CP length varies according to the symbol index. The CP length according to the symbol index is as follows.

[0146] [Formula 3]

[0147]

[0148] represents the CP length at symbol index l when the parameter set is μ. Since RIM-RS is transmitted on SCS of 15 khz or 30 khz, one of the lengths according to the normal cyclic prefix (the second and third lines of the formula) can be used for phase rotation.

[0149] RU 320 may perform phase difference compensation. Modulation and up-conversion of a conventional NR channel (eg, PDSCH) are performed based on a carrier frequency f0. On the other hand, modulation and up-conversion of a RIM-RS are performed based on a reference point (f 0 RIM If the RIM-RS signal is transmitted through the same processing chain as the conventional NR channel implemented in the RU, the reference point (f 0 RIM ) and carrier frequency (f 0 ) to compensate for the difference between them.

[0150] Since modulation and up-conversion of the RIM-RS are performed in units of OFDM symbols, the RU 320 may identify phase difference information corresponding to the complex-valued symbol. If the complex-valued symbol is the first RIM-RS symbol of the two RIM-RS symbols, the RU 320 may identify first phase difference information corresponding to the first RIM-RS symbol. The RU 320 may perform phase difference compensation on the phase-rotated complex-valued symbol based on the first phase difference information. If the complex-valued symbol is the second RIM-RS symbol of the two RIM-RS symbols, the RU 320 may identify second phase difference information corresponding to the second RIM-RS symbol. The RU 320 may perform phase difference compensation on the complex-valued symbol based on the second phase difference information.

[0151] RU 320 may perform phase difference compensation based on the configuration information. The configuration information may identify the second phase difference information corresponding to the first RIM-RS symbol. The configuration information may identify the second phase difference information corresponding to the second RIM-RS symbol. According to another embodiment, the configuration information 1035 may include information of a reference point for the RIM-RS. The RU may calculate the phase difference of the corresponding symbol based on the difference between the reference point of the RIM-RS and the carrier frequency of another NR channel. The reference point may be set to be the same or different for each symbol.

[0152] In the S1209 operation, the RU 320 may generate a baseband signal based on IFFT and CP insertion. The RU 320 may apply IFFT to the RIM-RS signal. The RU 320 may perform CP insertion after applying IFFT. According to an embodiment, the processing chain of IFFT and CP insertion may be used not only for the RIM-RS signal, but also for generating an OFDM baseband signal for a conventional NR channel (e.g., PDSCH). Since the phase rotation and phase difference compensation of the S1207 operation have been completed, the RU 320 may generate a baseband signal corresponding to the RIM-RS signal through an IFFT operator and a CP inserter for a conventional NR channel.

[0153] although Fig.12Not shown, according to another embodiment, precoding may be performed before IFFT. A precoding matrix may be multiplied by the RIM-RS signal. In this case, the precoding matrix may be obtained from the configuration information of operation S1201.

[0154] Fig.13 FIG. 4 shows an operation flow of a RU for complex mapping of RIM-RS according to an embodiment. Figure 3a According to an embodiment, the RU 320 may include an O-RU 353-1. Fig.13 The operation can correspond to Fig.12 Operation 1205 is a complex-valued symbol generation operation.

[0155] Reference Fig.13 In operation S1301, the RU 320 may perform QPSK modulation for the RIM-RS. The RU 320 may perform QPSK modulation to map the bits of the RIM-RS to QPSK symbols based on the control information. The RU 320 may obtain the control information. The control information may indicate a channel type of the bit data. In addition, the control information may indicate a modulation scheme of the bit data. According to an embodiment, the control information may be included in the bit data. According to another embodiment, the control information may be included in the configuration information. The RU 320 may obtain an RS sequence by performing QPSK modulation.

[0156] In operation S1303, RU 320 may apply a channel gain. RU 320 may apply the channel gain to the RS sequence corresponding to the QPSK modulation result. For example, RU 320 may obtain a parameter according to the channel gain to control the transmission power of RIM-RS transmission. The parameter may include an amplitude scaling factor. RU 320 may obtain a channel gain value of RIM-RS based on the configuration information.

[0157] Fig.14 FIG. 4 shows an operation flow of an RU for RIM-RS phase rotation according to an embodiment. Figure 3a According to an embodiment, the RU 320 may include an O-RU 353-1. Fig.14 The operation can correspond to Fig.12 The phase rotation operation of operation 1207 is performed.

[0158] Reference Fig.14In operation S1401, the RU 320 may identify whether the symbol of the bit data is the first RIM-RS symbol. The RIM-RS transmission may be performed in units of two OFDM symbols. In addition to the RIM-RS CP, the RIM-RS transmission may include two RIM-RS symbols. The RU 320 may identify whether the symbol of the bit data is the first symbol of the two RIM-RS symbols. In the case where the symbol of the bit data is the first RIM-RS symbol, the RU 320 may perform operation S1403. Whether the symbol of the bit data is the first symbol of the two RIM-RS symbols may be based on Fig.12 The configuration information of operation S1201 is identified.

[0159] In operation S1403, the RU 320 may calculate a phase rotation value of the RE. The RU 320 may identify the RE used for RIM-RS transmission. The RU 320 may calculate a phase rotation value corresponding to the RE. The rotation of the phase in the frequency domain indicates a cyclic shift in the time domain. The RU 320 may calculate a phase rotation value (e.g., a complex value x(k) 903) of the RIM-RS signal assigned to the k-th RE. According to an embodiment, the RU 320 may calculate a phase rotation value corresponding to a CP length of a second symbol of two RIM-RS symbols used for RIM-RS transmission. Here, the CP length of the second symbol may be based on Fig.12 The configuration information of operation S1201 is identified.

[0160] In operation S1405, the RU 320 may perform phase rotation. Phase rotation means that the phase in the frequency domain is rotated. Among the modulation symbols, the RU 320 may perform phase rotation on the complex-valued symbol of the kth RE of the first RIM-RS symbol.

[0161] Fig.15 FIG. 4 shows an operation flow of an RU for phase difference compensation of a RIM-RS according to an embodiment. Figure 3a According to an embodiment, the RU 320 may include an O-RU 353-1.

[0162] Reference Fig.15 In operation S1501, the RU 320 may identify whether the bit data symbol is a first RIM-RS symbol. The first RIM-RS symbol may be a symbol for which the Fig.14The RU 320 may identify whether the symbol of the bit data is a first RIM-RS symbol based on the configuration information. The configuration information may indicate whether the symbol of the bit data is a first RIM-RS symbol. The configuration information may indicate whether the symbol of the bit data is a second RIM-RS symbol. The configuration information may indicate whether the symbol of the bit data is a first RIM-RS symbol or a second RIM-RS symbol.

[0163] In case the symbol of the bit data is the first RIM-RS symbol, the RU 320 may perform operation S1503. In case the symbol of the bit data is not the first RIM-RS symbol, the RU 320 may perform operation S1505.

[0164] In operation S1503, RU 320 may perform phase difference compensation on the first RIM-RS symbol. RU 320 may identify a first phase difference value for the first RIM-RS symbol. The phase difference information of the configuration information may indicate the first phase difference value for the first RIM-RS symbol. The phase difference compensator of RU 320 may utilize a modulation chain of a conventional NR channel. RU 320 may compensate for a phase difference of a carrier generated in the process of generating the RIM-RS. RU 320 may compensate for the phase difference θ of the first RIM-RS symbol. l0 The value of .

[0165] In operation S1505, the RU 320 may identify whether the symbol of the bit data is a second RIM-RS symbol. The RU 320 may identify whether the symbol of the bit data is a second RIM-RS symbol based on the configuration information. The configuration information may indicate whether the symbol of the bit data is a first RIM-RS symbol. The configuration information may indicate whether the symbol of the bit data is a second RIM-RS symbol. The configuration information may indicate whether the symbol of the bit data is a first RIM-RS symbol or a second RIM-RS symbol.

[0166] In case the symbol of the bit data is the second RIM-RS symbol, the RU 320 may perform operation S1507. When the symbol of the bit data is not the second RIM-RS symbol, the RU 320 may terminate the operation.

[0167] In operation S1507, RU 320 may perform phase difference compensation on the second RIM-RS. RU 320 may identify a second phase difference value of the second RIM-RS symbol. The phase difference information of the configuration information may indicate the second phase difference value of the second RIM-RS symbol. RU 320 may compensate the value θ of the second RIM-RS symbol. l1 .

[0168] Fig.16FIG. 4 shows an operation flow of a DU for RIM-RS transmission according to an embodiment. Figure 3a According to an embodiment, the RU 320 may include an O-DU 351.

[0169] Reference Fig.16 In operation S1601, the DU 310 may send configuration information about the RIM-RS. The DU 310 may send the configuration information about the RIM-RS to the RU 320. The application scheme of the configuration information may be the same as Fig.10 Configuration information 1035 or Fig.12 The configuration information of operation S1201 of the embodiment is the same or similar. According to an embodiment, the configuration information may be sent based on a C-plane message or an M-plane message of the O-RAN standard. According to another embodiment, the configuration information about the RIM-RS may be included in a defined message regardless of the O-RAN standard. The DU 310 may send the message to the RU 320.

[0170] In operation S1603, DU 310 may send a message including bit data about RIM-RS. DU 310 may send a message including bit data about RIM-RS to RU 320. According to an embodiment, the bit data about RIM-RS may include bits of RIM-RS. According to an embodiment, the bit data about RIM-RS may include bits of RIM-RS and control information for RIM-RS. The control information may indicate a channel type and a modulation scheme of the transmitted data. The control information may include information indicating that the bit is RIM-RS. The control information may include information indicating that the modulation scheme of the bit is QPSK. Meanwhile, according to another embodiment, the control information may be included in the configuration information of operation S1201 instead of being included in the bit data.

[0171] According to an embodiment, the bit data about the RIM-RS may be included in a U-plane message of the O-RAN standard. The DU 310 may send the U-plane message to the RU 320. According to another embodiment, the bit data about the RIM-RS may be included in a defined message regardless of the O-RAN standard. The DU 310 may send the message to the RU 320.

[0172] In an embodiment of the present disclosure, a device and method for reducing the required bandwidth of the interface between DU-RU are proposed by applying RU modulation lossless compression technology to RIM-RS. The device and method according to the embodiment of the present disclosure enable RIM-RS signals to be transmitted in an existing commercial RU modulation lossless compression function-splitting 5G system. RU modulation lossless compression technology refers to a technology that performs complex mapping, IQ signal generation and other functions (except bit alignment) in the modulation function in the RU to achieve lossless compression.

[0173] When the RU modulation lossless compression technology is applied to the RIM-RS, the effect of reducing the required bandwidth can be calculated differently according to the embodiment. Figure 6 As described above, the DU can compress the bit data 610b of the RIM-RS and the control information 612 into 10 bits and then transmit them to the RU. Since complex mapping is performed in the RU, the RU can generate a 16-bit complex value symbol, that is, the complex value symbol of the RIM-RS has a 16-bit real part and a 16-bit imaginary part. Compared with uncompressed, the required bandwidth between the DU and the RU is reduced to 31.25% (=10 / 32). As another embodiment, Fig.11 As shown, when only 2 bits of RIM-RS data are transmitted to the RU without control information, the bandwidth between the DU and the RU can be reduced to a maximum of 6.25% (= 2 / 32) compared to uncompressed. Since the configuration information sent from the DU to the RU at the time of setup is only transmitted once for the first time or can be updated as needed, it can be excluded from the bandwidth reduction rate calculation. That is, according to an embodiment, low-demand bandwidth can be operated between the DU-RU through complex mapping, phase rotation, and phase difference compensation in the RU. Unlike frequency domain cyclic shift and phase difference compensation performed in the DU for RIM-RS transmission, the DU and RU according to the embodiment perform frequency domain cyclic shift and phase difference compensation in the RU. In this way, bit compression can be achieved, and the RU can transmit the RIM-RS by utilizing a modulation chain with IFFT and CP insertion for conventional NR channels.

[0174] According to an embodiment, a method performed by a radio unit (RU) may include receiving configuration information for a remote interference management (RIM)-reference signal (RS) from a distributed unit (DU). The method may include receiving a message including bit data for the RIM-RS from the DU. The method may include generating a complex-valued symbol corresponding to the bit data for the RIM-RS. The method may include generating a RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex-valued symbol based on the configuration information. The method may include generating a baseband signal corresponding to the RIM-RS signal based on an inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU.

[0175] According to an embodiment, generating the complex-valued symbol may include obtaining two bits of bit data for the RIM-RS. Generating the complex-valued symbol may include performing quadrature phase shift keying (QPSK) modulation on the two bits.

[0176] According to an embodiment, generating the complex-valued symbol may include obtaining an RS sequence based on QPSK. Generating the complex-valued symbol may include generating the complex-valued symbol by applying a channel gain to the RS sequence. Information about the channel gain may be obtained through configuration information.

[0177] According to an embodiment, generating a RIM-RS signal may include identifying whether the bit data corresponds to a first RIM-RS symbol of two RIM-RS symbols. Generating a RIM-RS signal may include performing a phase rotation on the complex-valued symbol when the bit data corresponds to the first RIM-RS symbol. Generating a RIM-RS signal may include performing a first phase difference compensation to apply a first compensation value corresponding to the first RIM-RS symbol to the phase-rotated complex-valued symbol.

[0178] According to an embodiment, generating the RIM-RS signal may include identifying whether the bit data corresponds to a second RIM-RS symbol of the two RIM-RS symbols. Generating the RIM-RS signal may include performing a second phase difference compensation to apply a second compensation value corresponding to the second RIM-RS symbol to the complex-valued symbol when the bit data corresponds to the second RIM-RS symbol.

[0179] According to an embodiment, the first compensation value may be determined based on a difference between a reference point configured for the RIM-RS in the first RIM-RS symbol and a carrier frequency of an NR channel different from the RIM-RS. The second compensation value may be determined based on a difference between a reference point configured for the RIM-RS in the second RIM-RS symbol and a carrier frequency of an NR channel different from the RIM-RS.

[0180] According to an embodiment, the complex-valued symbol may be a first RIM-RS symbol of the two RIM-RS symbols. The phase rotation of the complex-valued symbol may be performed based on the CP length of the second RIM-RS symbol of the two RIM-RS symbols. The CP length of the second RIM-RS symbol may be determined based on the index of the second RIM-RS symbol within the time slot.

[0181] According to an embodiment, generating a baseband signal may include identifying a CP length of a first RIM-RS symbol. Generating a baseband signal may include performing as many CP insertions as the CP length of the first RIM-RS symbol based on a CP inserter for a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH). Generating a baseband signal may include performing as many CP insertions as the CP length of a second RIM-RS symbol based on the CP inserter.

[0182] According to an embodiment, the configuration information may include at least one of an indicator for indicating whether a symbol corresponding to the bit data is the first symbol or the second symbol of the two symbols of the RIM-RS, resource allocation information for indicating time resources and frequency resources through which the RIM-RS is transmitted, information for indicating the length of the CP of the second RIM-RS symbol of the two symbols of the RIM-RS, or compensation information for performing phase difference compensation in each symbol of the RIM-RS.

[0183] According to an embodiment, the bit data for RIM-RS may include a bit of RIM-RS and control information. The control information may include information indicating that a modulation scheme associated with the bit is quadrature phase shift keying (QPSK) and information indicating that the type of the bit corresponds to RIM-RS.

[0184] According to an embodiment, the electronic device of the radio unit (RU) may include a fronthaul transceiver, at least one radio frequency (RF) transceiver, and at least one processor coupled to the fronthaul transceiver and the at least one RF transceiver. At least one processor may be configured to receive configuration information for a remote interference management (RIM)-reference signal (RS) from a distributed unit (DU) through the fronthaul transceiver. At least one processor may be configured to receive a message including bit data for RIM-RS from the DU through the fronthaul transceiver. At least one processor may be configured to generate a complex-valued symbol corresponding to the bit data for RIM-RS. At least one processor may be configured to generate a RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex-valued symbol based on the configuration information. At least one processor may be configured to generate a baseband signal corresponding to the RIM-RS signal based on an inverse fast Fourier transform (IFFT) and a cyclic prefix (CP) insertion of the RU.

[0185] According to an embodiment, to generate a complex-valued symbol, at least one processor may be configured to obtain two bits of bit data for RIM-RS. To generate a complex-valued symbol, at least one processor may be configured to perform quadrature phase shift keying (QPSK) modulation on the two bits.

[0186] According to an embodiment, in order to generate a complex valued symbol, at least one processor may be configured to obtain an RS sequence based on QPSK. In order to generate a complex valued symbol, at least one processor may be configured to generate a complex valued symbol by applying a channel gain to the RS sequence. Information about the channel gain may be obtained through configuration information.

[0187] According to an embodiment, in order to generate a RIM-RS signal, at least one processor may be configured to identify whether the bit data corresponds to a first RIM-RS symbol of two RIM-RS symbols. In order to generate a RIM-RS signal, at least one processor may be configured to perform phase rotation on the complex valued symbol when the bit data corresponds to the first RIM-RS symbol. In order to generate a RIM-RS signal, at least one processor may be configured to perform a first phase difference compensation to apply a first compensation value corresponding to the first RIM-RS symbol to the phase-rotated complex valued symbol.

[0188] According to an embodiment, in order to generate a RIM-RS signal, at least one processor may be configured to identify whether the bit data corresponds to a second RIM-RS symbol of the two RIM-RS symbols. In order to generate a RIM-RS signal, at least one processor may be configured to, when the bit data corresponds to the second RIM-RS symbol, perform a second phase difference compensation to apply a second compensation value corresponding to the second RIM-RS symbol to the complex-valued symbol.

[0189] According to an embodiment, the first compensation value may be determined based on a difference between a reference point configured for the RIM-RS in the first RIM-RS symbol and a carrier frequency of an NR channel different from the RIM-RS. The second compensation value may be determined based on a difference between a reference point configured for the RIM-RS in the second RIM-RS symbol and a carrier frequency of an NR channel different from the RIM-RS.

[0190] According to an embodiment, the complex-valued symbol may be a first RIM-RS symbol of the two RIM-RS symbols. The phase rotation of the complex-valued symbol may be performed based on the CP length of the second RIM-RS symbol of the two RIM-RS symbols. The CP length of the second RIM-RS symbol may be determined based on the index of the second RIM-RS symbol within the time slot.

[0191] According to an embodiment, in order to generate a baseband signal, at least one processor may be configured to identify a CP length of a first RIM-RS symbol. In order to generate a baseband signal, at least one processor may be configured to perform as many CP insertions as the CP length of the first RIM-RS symbol based on a CP inserter for a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH). In order to generate a baseband signal, at least one processor may be configured to perform as many CP insertions as the CP length of a second RIM-RS symbol based on a CP inserter.

[0192] According to an embodiment, the configuration information may include at least one of an indicator for indicating whether a symbol corresponding to the bit data is the first symbol or the second symbol of the two symbols of the RIM-RS, resource allocation information for indicating time resources and frequency resources through which the RIM-RS is transmitted, information for indicating the length of the CP of the second RIM-RS symbol of the two symbols of the RIM-RS, or compensation information for performing phase difference compensation in each symbol of the RIM-RS.

[0193] According to an embodiment, the bit data for RIM-RS may include a bit of RIM-RS and control information. The control information may include information indicating that a modulation scheme associated with the bit is quadrature phase shift keying (QPSK) and information indicating that the type of the bit corresponds to RIM-RS.

[0194] According to an embodiment, a method performed by a distributed unit (DU) may include sending configuration information for a remote interference management (RIM)-reference signal (RS) to a radio unit (RU). The method may include sending a message including bit data for the RIM-RS to the RU. The configuration information may be used for at least one of phase rotation or phase difference compensation of a complex-valued symbol to generate a baseband signal by inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU. The complex-valued symbol may correspond to a modulation result of the bit data of the RIM-RS.

[0195] According to an embodiment, the electronic device of the 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 send configuration information for a remote interference management (RIM)-reference signal (RS) to a radio unit (RU) through the fronthaul transceiver. The at least one processor may be configured to send a message including bit data for the RIM-RS to the RU through the fronthaul transceiver. The configuration information may be used for at least one of phase rotation or phase difference compensation of a complex-valued symbol to generate a baseband signal by inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU. The complex-valued symbol may correspond to a modulation result of the bit data of the RIM-RS.

[0196] According to an embodiment, a non-transitory computer-readable storage medium is provided. The non-transitory computer-readable storage medium may store one or more programs. One or more programs may include instructions that, when executed by a processor of a radio unit (RU), cause the RU to receive configuration information for a remote interference management (RIM)-reference signal (RS) from a distributed unit (DU). One or more programs may include instructions that cause the RU to receive a message including bit data for the RIM-RS from the DU. One or more programs may include instructions that cause the RU to generate a complex-valued symbol corresponding to the bit data for the RIM-RS. One or more programs may include instructions that cause the RU to generate a RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex-valued symbol based on the configuration information. One or more programs may include instructions that cause the RU to generate a baseband signal corresponding to the RIM-RS signal based on the inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU.

[0197] According to an embodiment, a non-transitory computer-readable storage medium is provided. The non-transitory computer-readable storage medium may store one or more programs. One or more programs may include instructions that, when executed by a processor of a distributed unit (DU), cause the RU to send configuration information for a remote interference management (RIM)-reference signal (RS) to a radio unit (RU). One or more programs may include instructions that cause the RU to send a message including bit data for the RIM-RS to the RU. The configuration information may be used for at least one of phase rotation or phase difference compensation of a complex-valued symbol to generate a baseband signal by an inverse fast Fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU. The complex-valued symbol may correspond to a modulation result of the bit data for the RIM-RS.

[0198] The method according to the embodiment described in the claims or the specification of the present disclosure may be implemented in software, hardware, or a combination of hardware and software.

[0199] In the case of software implementation, a computer-readable storage medium for storing one or more programs (software modules) may be provided. 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. One or more programs include instructions for causing the electronic device to execute the method according to the embodiments described in the claims or description of the present disclosure.

[0200] Such programs (software modules, software) may 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 device, compact disk (CD-ROM), optical storage device (digital versatile disk (DVD) or other format) or magnetic tape. Alternatively, it may be stored in a memory configured with some or all of the combinations thereof. In addition, multiple configuration memories may also be included.

[0201] In addition, the program may be stored in a connectable storage device that can be accessed via a communication network (e.g., the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof). Such a storage device may be connected to the apparatus for executing the embodiments of the present disclosure via an external port. In addition, an independent storage device on a communication network may also be connected to the apparatus for executing the embodiments of the present disclosure.

[0202] In the above specific embodiments of the present disclosure, the components included in the present disclosure are expressed in the singular or plural according to the specific embodiments introduced. However, the expression of the singular or plural is appropriately selected according to the presented situation for the convenience of description, and the present disclosure is not limited to singular or plural elements, even if the element expressed in the plural can also be configured as a singular, or the element expressed in the singular can also be configured as a plural.

[0203] Meanwhile, specific embodiments have been described in the detailed description of the present disclosure. Of course, various modifications may be made without departing from the scope of the present disclosure.

Claims

1. A method performed by a radio unit RU, the method comprising: Receiving configuration information for remote interference management RIM-reference signal RS from the distributed unit DU; receiving, from the DU, a message including bit data for the RIM-RS; generating a complex-valued symbol corresponding to bit data for the RIM-RS; generating a RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex-valued symbol based on the configuration information; as well as Based on the inverse fast Fourier transform IFFT and cyclic prefix CP insertion of the RU, a baseband signal corresponding to the RIM-RS signal is generated.

2. The method according to claim 1, wherein: Generating the complex-valued symbol comprises: obtaining two bits of bit data for the RIM-RS; and Quadrature Phase Shift Keying QPSK modulation is performed on the two bits.

3. The method according to claim 2, wherein: Generating the complex-valued symbol comprises: Obtaining a RS sequence based on the QPSK; and generating the complex-valued symbol by applying a channel gain to the RS sequence, and The information about the channel gain is obtained through the configuration information.

4. The method according to claim 1, wherein: Generating the RIM-RS signal includes: identifying whether the bit data corresponds to a first RIM-RS symbol of two symbols for the RIM-RS; In a case where the bit data corresponds to the first RIM-RS symbol, performing phase rotation on the complex-valued symbol; and A first phase difference compensation is performed to apply a first compensation value corresponding to the first RIM-RS symbol to the phase-rotated complex-valued symbol.

5. The method according to claim 4, wherein: Generating the RIM-RS signal includes: identifying whether the bit data corresponds to a second RIM-RS symbol of two symbols used for the RIM-RS; and In a case where the bit data corresponds to the second RIM-RS symbol, a second phase difference compensation is performed to apply a second compensation value corresponding to the second RIM-RS symbol to the complex-valued symbol.

6. The method according to claim 5, in, The first compensation value is determined based on a difference between a reference point configured for a RIM-RS in the first RIM-RS symbol and a carrier frequency of an NR channel different from the RIM-RS, and The second compensation value is determined based on a difference between a reference point configured for the RIM-RS in the second RIM-RS symbol and a carrier frequency of an NR channel different from the RIM-RS.

7. The method according to claim 1, in, The complex-valued symbol is a first RIM-RS symbol of the two RIM-RS symbols, The phase rotation of the complex-valued symbol is performed based on the CP length of the second RIM-RS symbol of the two RIM-RS symbols, and The CP length of the second RIM-RS symbol is determined based on the index of the second RIM-RS symbol in the time slot.

8. The method according to claim 7, wherein: Generating the baseband signal comprises: identifying a CP length of the first RIM-RS symbol; and performing, based on a CP inserter for a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH), inserting as many CPs as the CP length of the first RIM-RS symbol; and Based on the CP inserter, as many CP insertions as the CP length of the second RIM-RS symbol are performed.

9. The method according to claim 1, in, The configuration information includes at least one of the following: An indicator for indicating whether a symbol corresponding to the bit data is a first symbol or a second symbol of two symbols of the RIM-RS; resource allocation information for indicating time resources and frequency resources through which the RIM-RS is transmitted; Information used to indicate a CP length of a second RIM-RS symbol of the two RIM-RS symbols; or The compensation information is used to perform phase difference compensation in each symbol of the RIM-RS.

10. The method according to claim 1, in, The bit data for the RIM-RS includes bits of the RIM-RS and control information, and The control information includes information for indicating that a modulation scheme associated with the bit is quadrature phase shift keying (QPSK) and information for indicating that the type of the bit corresponds to the RIM-RS.

11. An electronic device of a radio unit RU, comprising: fronthaul transceiver; at least one radio frequency (RF) transceiver; as well as at least one processor coupled to the fronthaul transceiver and the at least one RF transceiver, Wherein, the at least one processor is configured to: Receiving configuration information for remote interference management RIM-reference signal RS from the distributed unit DU through the fronthaul transceiver; receiving, by the fronthaul transceiver, from the DU a message including bit data for the RIM-RS; generating a complex-valued symbol corresponding to bit data for the RIM-RS; generating a RIM-RS signal by performing at least one of phase rotation or phase difference compensation on the complex-valued symbol based on the configuration information; as well as Based on the inverse fast Fourier transform IFFT and cyclic prefix CP insertion of the RU, a baseband signal corresponding to the RIM-RS signal is generated.

12. The electronic device according to claim 11, wherein: The at least one processor is configured to perform the method of any one of claims 2 to 10.

13. A method performed by a distributed unit DU, the method comprising: Sending configuration information for remote interference management RIM-reference signal RS to the radio unit RU; as well as sending a message including bit data for the RIM-RS to the RU, The configuration information is used to perform at least one of phase rotation or phase difference compensation on the complex-valued symbol to generate a baseband signal through an inverse fast Fourier transform IFFT and a cyclic prefix CP insertion of the RU, and The complex-valued symbol corresponds to a modulation result of the bit data used for the RIM-RS.

14. An electronic device of a distributed unit DU, the electronic device comprising: at least one transceiver, the at least one transceiver comprising a fronthaul transceiver; as well as at least one processor coupled to the at least one transceiver, Wherein, the at least one processor is configured to: Sending configuration information for remote interference management RIM-reference signal RS to a radio unit RU through the fronthaul transceiver; and sending a message including bit data for the RIM-RS to the RU through the fronthaul transceiver, The configuration information is used to perform at least one of phase rotation or phase difference compensation on the complex-valued symbol to generate a baseband signal through an inverse fast Fourier transform IFFT and a cyclic prefix CP insertion of the RU, and The complex-valued symbol corresponds to a modulation result of the bit data used for the RIM-RS.

15. A non-transitory computer-readable storage medium, the non-transitory computer-readable storage medium comprising a memory storing one or more programs, in, The one or more programs are configured to cause the radio unit RU to perform the method of any one of claims 1 to 10 or cause the distributed unit DU to perform the method of claim 13 .

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