Electronic device and method for identifying beamforming parameter set

Abstract

According to an embodiment, an electronic device executed by a distributed unit (DU) may comprise: at least one transceiver including a fronthaul transceiver; a memory that stores instructions; and a processor. The instructions, when executed by the processor, may cause the electronic device to transmit, to a radio unit (RU), information including a plurality of synchronization signal / physical broadcast channel (SS / PBCH) blocks. The instructions, when executed by the processor, may cause the electronic device to receive, within a first association period from among a plurality of association periods, a physical random access channel (PRACH) signal regarding an SS / PBCH block selected by a terminal from among the plurality of SS / PBCH blocks, on the basis of a first beamforming parameter set from among a plurality of beamforming parameter sets. The instructions, when executed by the processor, may cause the electronic device to receive, within a second association period, the PRACH signal regarding the selected SS / PBCH block on the basis of a second beamforming parameter set.

Description

Electronic device and method for identifying a set of beamforming parameters

[0001] The present disclosure relates to an electronic device and method for identifying a set of beamforming parameters.

[0002] As transmission capacity increases in wireless communication systems, functional splitting, which functionally separates base stations, is being implemented. Through functional splitting, base stations can be divided into distributed units (DUs) and radio units (RUs). A fronthaul interface is defined for communication between DUs and RUs.

[0003] The above information may be provided as background art to aid in understanding the present disclosure. No claim or determination is made as to whether any of the above is applicable as prior art related to the present disclosure.

[0004] According to one embodiment, an electronic device executed by a distributed unit (DU) may include at least one transceiver including a fronthaul transceiver, a memory storing instructions, and a processor. The instructions, when executed by the processor, may cause the electronic device to transmit information including a plurality of synchronization signal / physical broadcast channel (SS / PBCH) blocks to a radio unit (RU). The instructions, when executed by the processor, may cause the electronic device to receive, through the RU, a physical random access channel (PRACH) signal for an SS / PBCH block selected by a terminal from among the plurality of SS / PBCH blocks within a first association period from among a plurality of association periods set for the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among a plurality of beamforming parameter sets. The instructions, when executed by the processor, may cause the electronic device to receive, through the RU, the PRACH signal for the selected SS / PBCH block within a second association period, distinct from the first association period, among the plurality of association periods, based on a second beamforming parameter set, distinct from the first beamforming parameter set, among the plurality of beamforming parameter sets.

[0005] According to one embodiment, an electronic device executed by a radio unit (RU) may include at least one transceiver including a fronthaul transceiver, a memory storing instructions, and a processor. The instructions, when executed by the processor, may cause the electronic device to transmit a plurality of synchronization signal / physical broadcast channel (SS / PBCH) blocks to a terminal based on information including the SS / PBCH blocks received from a distributed unit (DU). The instructions, when executed by the processor, may cause the electronic device to receive, within a first association period among a plurality of association periods set for the plurality of SS / PBCH blocks, a physical random access channel (PRACH) signal for an SS / PBCH block selected by the terminal from among the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among a plurality of beamforming parameter sets. The instructions, when executed by the processor, may cause the electronic device to receive the PRACH signal for the selected SS / PBCH block within a second association period, distinct from the first association period, among the plurality of association periods, based on a second beamforming parameter set, distinct from the first beamforming parameter set, among the plurality of beamforming parameter sets.

[0006] According to one embodiment, a method performed by a distributed unit (DU) may include transmitting information including a plurality of SS / PBCH (synchronization signal / physical broadcast channel) blocks to a radio unit (RU). The method may include receiving, through the RU, a physical random access channel (PRACH) signal for an SS / PBCH block selected by a terminal from among the plurality of SS / PBCH blocks within a first association period from among a plurality of association periods set for the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among a plurality of beamforming parameter sets. The method may include an operation of receiving, through the RU, the PRACH signal for the selected SS / PBCH block within a second association period, which is distinct from the first association period, among the plurality of association periods, based on a second beamforming parameter set, which is distinct from the first beamforming parameter set, among the plurality of beamforming parameter sets.

[0007] According to one embodiment, a method performed by a radio unit (RU) may include transmitting a plurality of synchronization signal / physical broadcast channel (SS / PBCH) blocks to a terminal based on information including the SS / PBCH blocks received from a distributed unit (DU). The method may include receiving, within a first association period among a plurality of association periods set for the plurality of SS / PBCH blocks, a physical random access channel (PRACH) signal for an SS / PBCH block selected by the terminal from among the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among a plurality of beamforming parameter sets. The method may include an operation of receiving, within a second association period among the plurality of association periods, which is distinct from the first association period, the PRACH signal for the selected SS / PBCH block based on a second beamforming parameter set among the plurality of beamforming parameter sets, which is distinct from the first beamforming parameter set.

[0008] Figure 1 illustrates a wireless communication system.

[0009] Figure 2a illustrates a front-hole interface.

[0010] Figure 2b illustrates the fronthaul interface of an O(open)-RAN(radio access network).

[0011] Figure 3a illustrates the functional configuration of a distributed unit (DU).

[0012] Figure 3b illustrates the functional configuration of a RU (radio unit).

[0013] Figure 4 illustrates an example of function split between DU and RU.

[0014] Figure 5a illustrates an example in which a base station transmits a single SSB (synchronization signal block).

[0015] Figure 5b illustrates an example in which a base station transmits multiple SSBs.

[0016] Figure 6 shows an example of SSB transmitted from a base station.

[0017] Figure 7 illustrates an example of a RACH (physical random access channel) space.

[0018] Figure 8 illustrates an example of an operation for performing PRACH detection according to a receiving path.

[0019] Figure 9 illustrates an example of multiple LBs (logical beams) configured to receive PRACH.

[0020] Figure 10 illustrates an example of multiple association periods for receiving a PRACH signal.

[0021] Figure 11a illustrates an example of the operation of a base station for performing PRACH detection for each receiving path.

[0022] Figure 11b illustrates an example of the operation of a base station to perform PRACH detection for each receiving path.

[0023] Figure 12 shows an example of the operation of a base station and a terminal.

[0024] Figure 13 shows a flowchart regarding the operation of DU.

[0025] Figure 14 shows a flowchart regarding the operation of RU.

[0026] The terms used in this disclosure are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. The singular expression may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this disclosure. Terms defined in general dictionaries among the terms used in this disclosure may be interpreted as having the same or similar meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this disclosure. In some cases, even if a term is defined in this disclosure, it cannot be interpreted to exclude embodiments of the present disclosure.

[0027] The various embodiments of the present disclosure described below illustrate a hardware-based approach as an example. However, since the various embodiments of the present disclosure include techniques utilizing both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0028] In the following description, terms referring to signals (e.g., signal, information, message, signaling), terms referring to resources (e.g., symbol, slot, subframe, radio frame, subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), occasion), terms for operational states (e.g., step, operation, procedure), terms referring to data (e.g., packet, user stream, information, bit, symbol, codeword), terms referring to channels, terms referring to network entities, terms referring to components of devices, etc. are examples for convenience of description. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0029] In addition, in the present disclosure, expressions such as "more than" or "less than" may be used to determine whether a specific condition is satisfied or fulfilled, but this is merely a description for expressing an example and does not exclude descriptions such as "more than" or "less than." A condition described as "more than" may be replaced with "more than," a condition described as "less than" may be replaced with "less than," and a condition described as "more than and less than" may be replaced with "more than and less than." In addition, hereinafter, "A" to "B" mean at least one of elements from A (including A) to B (including B). hereinafter, "C" and / or "D" mean at least one of "C" or "D," that is, including {"C", "D", "C" and "D"}.

[0030] Although the present disclosure describes various embodiments using terms used in some communication standards (e.g., 3rd Generation Partnership Project (3GPP), extensible radio access network (xRAN), open-radio access network (O-RAN), etc.), these are merely examples for explanation. The various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0031] Figure 1 illustrates a wireless communication system.

[0032] Referring to FIG. 1, FIG. 1 illustrates a base station (110) and a terminal (120) as some of the nodes utilizing a wireless channel in a wireless communication system. Although FIG. 1 illustrates only one base station, the wireless communication system may further include other base stations identical or similar to the base station (110).

[0033] The base station (110) is a network infrastructure that provides wireless access to the terminal (120). The base station (110) has coverage defined based on the distance at which a signal can be transmitted. In addition to the base station, the base station (110) may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5th generation node', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having equivalent technical meanings.

[0034] The terminal (120) is a device used by a user and communicates with the base station (110) via a wireless channel. The link from the base station (110) to the terminal (120) is referred to as a downlink (DL), and the link from the terminal (120) to the base station (110) is referred to as an uplink (UL). In addition, although not shown in FIG. 1, the terminal (120) and another terminal may communicate with each other via a wireless channel. In this case, the link between the terminal (120) and another terminal (device-to-device link, D2D) is referred to as a sidelink, and the sidelink may be used interchangeably with the PC5 interface. In some other embodiments, the terminal (120) may be operated without the involvement of a user. According to one embodiment, the terminal (120) is a device that performs machine type communication (MTC) and may not be carried by the user. Additionally, according to one embodiment, the terminal (120) may be an NB (narrowband)-IoT (internet of things) device.

[0035] The terminal (120) may be referred to as a terminal, or other terms such as 'user equipment (UE),' 'customer premises equipment (CPE),' 'mobile station,' 'subscriber station,' 'remote terminal,' 'wireless terminal,' 'electronic device,' or 'user device,' or other terms having equivalent technical meanings.

[0036] The base station (110) and the terminal (120) can perform beamforming. The base station (110) and the terminal (120) can transmit and receive wireless signals in a relatively low frequency band (e.g., FR 1 (frequency range 1) of NR). In addition, the base station (110) and the terminal (120) can transmit and receive wireless signals in a relatively high frequency band (e.g., FR 2 (or, FR 2-1, FR 2-2, FR 2-3), FR 3 of NR), millimeter wave (mmWave) band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz)). To improve channel gain, the base station (110) and the terminal (120) can perform beamforming. Here, the beamforming can include transmission beamforming and reception beamforming. The base station (110) and the terminal (120) can impart directionality to the transmitted or received signal. To this end, the base station (110) and the terminal (120) can select serving beams through a beam search or beam management procedure. After the serving beams are selected, subsequent communication can be performed through resources that have a QCL relationship with the resource that transmitted the serving beams.

[0037] If large-scale characteristics of a channel carrying a symbol on a first antenna port can be inferred from a channel carrying a symbol on a second antenna port, the first antenna port and the second antenna port can be evaluated to have a QCL relationship. For example, the large-scale characteristics may include at least one of delay spread, Doppler spread, Doppler shift, average gain, average delay, and a spatial receiver parameter.

[0038] Although both the base station (110) and the terminal (120) are described as performing beamforming in FIG. 1, the embodiments of the present disclosure are not necessarily limited thereto. In some embodiments, the terminal may or may not perform beamforming. Furthermore, the base station may or may not perform beamforming. That is, either only one of the base station and the terminal may perform beamforming, or neither the base station nor the terminal may perform beamforming.

[0039] In the present disclosure, a beam refers to a spatial flow of a signal in a wireless channel, and is formed by one or more antennas (or antenna elements), and this forming process may be referred to as beamforming. Beamforming may include at least one of analog beamforming and digital beamforming (e.g., precoding). Reference signals transmitted based on beamforming may include, for example, a demodulation-reference signal (DM-RS), a channel state information-reference signal (CSI-RS), a synchronization signal / physical broadcast channel (SS / PBCH), and a sounding reference signal (SRS). In addition, as a configuration for each reference signal, an IE such as a CSI-RS resource or an SRS-resource may be used, and this configuration may include information associated with the beam. Information associated with a beam may mean whether the configuration (e.g., a CSI-RS resource) uses the same spatial domain filter as another configuration (e.g., another CSI-RS resource within the same CSI-RS resource set) or a different spatial domain filter, or whether it is quasi-co-located (QCL) with a reference signal, and if so, what type it is (e.g., QCL type A, B, C, D).

[0040] In the past, in communication systems with relatively large cell radius of base stations, each base station was installed to include the functions of a digital processing unit (or distributed unit (DU)) and a radio frequency (RF) processing unit (or radio unit (RU)). However, as higher frequency bands are used in 4G (4th generation) and / or subsequent communication systems (e.g., 5G) and the cell coverage of base stations decreases, the number of base stations to cover a specific area has increased. The installation costs for operators to install base stations have also increased. In order to minimize the installation costs of base stations, a structure has been 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. Hereinafter, the deployment structure and expanded examples of base stations according to various embodiments of the present disclosure are described through FIGS. 2A and 2B.

[0041] FIG. 2A illustrates a fronthaul interface. Unlike the backhaul between a base station and a core network, fronthaul refers to the connection between entities between a wireless LAN and a base station. FIG. 2A illustrates an example of a fronthaul structure between a DU (210) and one RU (220), but this is merely for convenience of explanation and the present disclosure is not limited thereto. In other words, embodiments of the present disclosure can also be applied to a fronthaul structure between one DU and multiple RUs. For example, embodiments of the present disclosure can be applied to a fronthaul structure between one DU and two RUs. Furthermore, embodiments of the present disclosure can also be applied to a fronthaul structure between one DU and three RUs.

[0042] Referring to FIG. 2A, a base station (110) may include a DU (210) and an RU (220). A fronthaul (215) between the DU (210) and the RU (220) may be operated via an FX interface. For operation of the fronthaul (215), an interface such as an enhanced common public radio interface (eCPRI) or radio over ethernet (ROE) may be used, for example.

[0043] As communications technology advances, mobile data traffic increases, significantly increasing the bandwidth requirements for the fronthaul between the digital unit and the radio unit. In deployments such as C-RAN (centralized / cloud radio access network), the DU performs functions for the packet data convergence protocol (PDCP), radio link control (RLC), media access control (MAC), and physical layer (PHY), while the RU can be implemented to perform additional functions for the PHY layer in addition to its radio frequency (RF) functions.

[0044] DU (210) may be responsible for upper layer functions of a wireless network. For example, DU (210) may perform functions of the MAC layer and a part of the PHY layer. Here, a part of the PHY layer refers to functions performed at a higher level among the functions of the PHY layer, and may include, for example, channel encoding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), and layer mapping (or layer demapping). According to an embodiment, if DU (210) complies with the O-RAN standard, it may be referred to as O-DU (O-RAN DU). DU (210) may be replaced with a first network entity for a base station (e.g., gNB) in embodiments of the present disclosure, if necessary.

[0045] The RU (220) may be responsible for lower layer functions of a wireless network. For example, the RU (220) may perform a part of the PHY layer, an RF function. Here, a part of the PHY layer refers to functions of the PHY layer that are performed at a relatively lower level than the DU (210), and may include, for example, iFFT transformation (or FFT transformation), CP (cyclic prefix) insertion (CP removal), and digital beamforming. An example of such specific functional separation is described in detail in FIG. 4. The RU (220) may be referred to as an 'access unit (AU)', an 'access point (AP)', a 'transmission / reception point (TRP)', a 'remote radio head (RRH)', a 'radio unit (RU)', or other terms having an equivalent technical meaning thereto. In one embodiment, if RU (220) complies with the O-RAN standard, it may be referred to as O-RU (O-RAN RU). RU (220) may be replaced with a second network entity for a base station (e.g., gNB) in embodiments of the present disclosure, if necessary.

[0046] Although FIG. 2A illustrates that the base station (110) includes a DU (210) and a RU (220), the embodiments of the present disclosure are not limited thereto. The base station according to the embodiments may be implemented in a distributed deployment according to a centralized unit (CU) configured to perform functions of upper layers of an access network (e.g., packet data convergence protocol (PDCP), radio resource control (RRC)) and a distributed unit (DU) configured to perform functions of lower layers. In this case, the distributed unit (DU) may include the digital unit (DU) and radio unit (RU) of FIG. 1. Between a core (e.g., 5GC (5G core) or NGC (next generation core)) network and a radio network (RAN), the base station may be implemented in a structure in which CU, DU, and RU are arranged in that order. The interface between CU and DU (distributed unit) can be referred to as the F1 interface.

[0047] A centralized unit (CU) can be connected to one or more DUs and can be responsible for functions at a higher layer than the DU. For example, the CU can be responsible for functions at the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, while the DU and RU can be responsible for functions at lower layers. The DU can perform some functions (high PHY) of the radio link control (RLC), media access control (MAC), and physical (PHY) layers, while the RU can be responsible for the remaining functions (low PHY) of the PHY layer. In addition, for example, a digital unit (DU) can be included in a distributed unit (DU) depending on the implementation of a distributed deployment of the base station. Hereinafter, unless otherwise defined, the operations of DU (digital unit) and RU are described, but various embodiments of the present disclosure can be applied to both a base station deployment including CU and a deployment in which DU is directly connected to the core network (i.e., a base station in which CU and DU are integrated as a single entity (e.g., NG-RAN node)).

[0048] Figure 2b illustrates the fronthaul interface of an open RAN (radio access network). A base station (110) according to a distributed deployment is exemplified as an eNB or gNB.

[0049] Referring to FIG. 2b, the base station (110) may include an O-DU (251) and O-RUs (253-1, ..., 253-n). Hereinafter, for convenience of explanation, the operation and function of the O-RU (253-1) may be understood as a description of each of the other O-RUs (e.g., O-RU (253-n)).

[0050] The O-DU (251) is a logical node that includes functions, excluding functions exclusively assigned to the O-RU (253-1), among the functions of a base station (e.g., eNB, gNB) according to FIG. 4 described below. The O-DU (251) can control the operation of the O-RUs (253-1, ..., 253-n). The O-DU (251) may be referred to as an LLS (lower layer split) CU (central unit). The O-RU (253-1) is a logical node that includes a subset of the functions of a base station (e.g., eNB, gNB) according to FIG. 4 described below. Real-time aspects of control plane (C-plane) communication and user plane (U-plane) communication with the O-RU (253-1) can be controlled by the O-DU (251).

[0051] The O-DU (251) can communicate with the O-RU (253-1) through an LLS interface. The LLS interface corresponds to a fronthaul interface. The LLS interface refers to a logical interface between the O-DU (251) and the O-RU (253-1) that utilizes lower layer functional split (i.e., intra-PHY based functional split). The LLS-C between the O-DU (251) and the O-RU (253-1) provides the C-plane through the LLS interface. The LLS-U between the O-DU (251) and the O-RU (253-1) provides the U-plane through the LLS interface.

[0052] In FIG. 2B, to explain the O-RAN, entities of the base station (110) are described as O-DU and O-RU. However, these names are not to be construed as limiting the embodiments of the present disclosure. In the embodiments described below, it is obvious that the operations of the DU (210) can be performed by the O-DU (251). The description of the DU (210) can be applied to the O-DU (251). Similarly, in the embodiments described below, it is obvious that the operations of the RU (220) can be performed by the O-RU (253-1). The description of the RU (220) can be applied to the O-DU (253-1).

[0053] Fig. 3a illustrates the functional configuration of a DU (distributed unit). The configuration illustrated in Fig. 3a can be understood as the configuration of the DU (210) of Fig. 2a (or the O-DU (250) of Fig. 2b) as part of a base station. Terms such as "...unit" and "...unit" used hereinafter mean a unit that processes at least one function or operation, and this can be implemented by hardware, software, or a combination of hardware and software.

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

[0055] The transceiver (310) can perform functions for transmitting and receiving signals in a wired communication environment. The transceiver (310) can include a wired interface for controlling direct connections between devices via a transmission medium (e.g., copper wire, optical fiber). For example, the transceiver (310) can transmit electrical signals to other devices via copper wire, or perform conversion between electrical signals and optical signals. The DU (210) can communicate with a radio unit (RU) via the transceiver (310). The DU (210) can be connected to a core network or a CU in a distributed arrangement via the transceiver (310).

[0056] The transceiver (310) may perform functions for transmitting and receiving signals in a wireless communication environment. For example, the transceiver (310) may perform a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the transceiver (310) generates complex symbols by encoding and modulating the transmitted bit stream. In addition, when receiving data, the transceiver (310) restores the received bit stream by demodulating and decoding the baseband signal. In addition, the transceiver (310) may include multiple transmission and reception paths. Furthermore, according to one embodiment, the transceiver (310) may be connected to the core network or other nodes (e.g., an integrated access backhaul (IAB).

[0057] The transceiver (310) can transmit and receive signals. For example, the transceiver (310) can transmit a management plane (M-plane) message. For example, the transceiver (310) can transmit a management plane (S-plane) message. For example, the transceiver (310) can transmit a control plane (C-plane) message. For example, the transceiver (310) can transmit a user plane (U-plane) message. For example, the transceiver (310) can receive a user plane message. Although only the transceiver (310) is illustrated in FIG. 3A, in other implementations, the DU (210) may include two or more transceivers.

[0058] The transceiver (310) transmits and receives signals as described above. Accordingly, all or part of the transceiver (310) may be referred to as a "communication unit," a "transmitter," a "receiver," or a "transmitter-receiver unit." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean that the transceiver (310) performs the processing described above.

[0059] Although not illustrated in FIG. 3A, the transceiver (310) may further include a backhaul transceiver for connection to the core network or other base stations. The backhaul transceiver provides an interface for communicating with other nodes within the network. That is, the backhaul transceiver converts a bit stream transmitted from the base station to other nodes, such as other access nodes, other base stations, upper nodes, the core network, etc., into a physical signal, and converts a physical signal received from other nodes into a bit stream.

[0060] The memory (320) stores data such as basic programs, application programs, and setting information for the operation of the DU (210). The memory (320) may be referred to as a storage unit. The memory (320) may be composed of volatile memory, nonvolatile memory, or a combination of volatile memory and nonvolatile memory. In addition, the memory (320) provides stored data upon request from the processor (330).

[0061] The processor (330) controls the overall operations of the DU (210). The processor (380) may be referred to as a control unit. For example, the processor (330) transmits and receives signals through the transceiver (310) (or through the backhaul communication unit). In addition, the processor (330) records and reads data from the memory (320). In addition, the processor (330) may perform the functions of the protocol stack required by the communication standard. Although only the processor (330) is illustrated in FIG. 3A, the DU (210) may include two or more processors according to other implementation examples.

[0062] The configuration of DU (210) illustrated in FIG. 3A is merely an example, and examples of DUs performing embodiments of the present disclosure are not limited to the configuration illustrated in FIG. 3A. In some embodiments, some configurations may be added, deleted, or changed.

[0063] Fig. 3b illustrates the functional configuration of a radio unit (RU). The configuration illustrated in Fig. 3b can be understood as a configuration of the RU (220) of Fig. 2b or the O-RU (253-1) of Fig. 2b as part of a base station. Terms such as "...unit" and "...unit" used hereinafter mean a unit that processes at least one function or operation, and this can be implemented by hardware, software, or a combination of hardware and software.

[0064] Referring to FIG. 3b, the RU (220) includes an RF transceiver (360), a fronthaul transceiver (365), a memory (370), and a processor (380).

[0065] The RF transceiver (360) performs functions for transmitting and receiving signals via a wireless channel. For example, the RF transceiver (360) upconverts a baseband signal into an RF band signal and transmits it via an antenna, and downconverts an RF band signal received via the antenna into a baseband signal. For example, the RF transceiver (360) may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

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

[0067] According to one embodiment, the RF transceiver (360) can transmit and receive signals on a radio access network. For example, the RF transceiver (360) can transmit a downlink signal. The downlink signal can 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., a MIB, a SIB, remaining system information (RMSI), other system information (OSI)), a configuration message, control information, or downlink data. In addition, for example, the RF transceiver (360) can receive an uplink signal. The uplink signal may include a random access related signal (e.g., a random access preamble (RAP) (or Msg1 (message 1)), Msg3 (message 3)), a reference signal (e.g., a sounding reference signal (SRS), DM-RS), or a power headroom report (PHR). Although only the RF transceiver (360) is illustrated in FIG. 3b, in other implementation examples, the RU (220) may include two or more RF transceivers.

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

[0069] The fronthaul transceiver (365) can transmit and receive signals. According to one embodiment, the fronthaul transceiver (365) can transmit and receive signals on the fronthaul interface. For example, the fronthaul transceiver (365) can receive a management plane (M-plane) message. For example, the fronthaul transceiver (365) can receive a management plane (S-plane) message. For example, the fronthaul transceiver (365) can receive a control plane (C-plane) message. For example, the fronthaul transceiver (365) can transmit a user plane (U-plane) message. For example, the fronthaul transceiver (365) can receive a user plane message. Although only the fronthaul transceiver (365) is shown in FIG. 3b, according to other implementation examples, the RU (220) may include two or more fronthaul transceivers.

[0070] The RF transceiver (360) and the fronthaul transceiver (365) transmit and receive signals as described above. Accordingly, all or part of the RF transceiver (360) and the fronthaul transceiver (365) may be referred to as a 'communication unit', a 'transmitter unit', a 'receiver unit', or a 'transmitter-receiver unit'. In addition, in the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the RF transceiver (360). In the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the RF transceiver (360).

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

[0072] The processor (380) controls the overall operations of the RU (220). The processor (380) may be referred to as a control unit. For example, the processor (380) transmits and receives signals through the RF transceiver (360) or the fronthaul transceiver (365). In addition, the processor (380) records and reads data in the memory (370). In addition, the processor (380) may perform functions of a protocol stack required by a communication standard. Although only the processor (380) is illustrated in FIG. 3B, the RU (220) may include two or more processors according to other implementation examples. The processor (380) may be a set of instructions or codes stored in the memory (370), or may be a storage space that stores instructions / codes or instructions / codes that are at least temporarily residing in the processor (380), or may be a part of the circuitry that constitutes the processor (380). Additionally, the processor (380) may include various modules for performing communication. The processor (380) may control the RU (220) to perform operations according to the embodiments described below.

[0073] The configuration of RU (220) illustrated in FIG. 3b is merely an example, and examples of RUs performing embodiments of the present disclosure are not limited to the configuration illustrated in FIG. 3b. In some embodiments, some configurations may be added, deleted, or changed.

[0074] Figure 4 illustrates an example of function split between DUs and RUs. As wireless communication technologies advance (e.g., the introduction of 5G (5th generation) communication systems (or NR (new radio) communication systems), the frequency bands used have increased further. As the cell radius of a base station has become significantly smaller, the number of RUs required for installation has also increased further. Furthermore, in 5G communication systems, the amount of data transmitted has increased by a factor of up to ten, significantly increasing the transmission capacity of the wired network transmitted to the fronthaul. Due to the factors described above, the installation cost of the wired network in the 5G communication system may increase significantly. Therefore, in order to lower the transmission capacity of the wired network and reduce the installation cost of the wired network, 'function split' can be utilized, which transfers some of the functions of the modem of the DU to the RU to lower the transmission capacity of the fronthaul.

[0075] To reduce the burden on the DU, the role of the RU, which is traditionally solely responsible for RF functions, can be expanded to include some physical layer functions. As the RU performs higher-layer functions, its throughput increases, which can increase transmission bandwidth in the fronthaul while reducing latency requirements due to response processing. However, as the RU performs higher-layer functions, virtualization gains decrease, and the RU's size, weight, and cost increase. Considering the trade-offs between the advantages and disadvantages described above, implementing an optimal functional separation is required.

[0076] Referring to Figure 4, the functional separation in the physical layer below the MAC layer is illustrated. For the downlink (DL) that transmits a signal to a terminal through a wireless network, the base station can sequentially perform channel encoding / scrambling, modulation, layer mapping, antenna mapping, RE mapping, digital beamforming (e.g., precoding), iFFT transform / CP insertion, and RF transform. For the uplink (UL) that receives a signal from a terminal through a wireless network, the base station can sequentially perform RF transform, FFT transform / CP removal, digital beamforming (pre-combining), RE demapping, channel estimation, layer demapping, demodulation, and decoding / descrambling. The separation of uplink and downlink functions can be defined in various types depending on the needs of vendors, discussions in standards, etc., according to the above-mentioned trade-offs.

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

[0078] In one embodiment, when a large amount of signal processing is expected, such as in the FR 1 MMU, functional separation at a relatively high layer (e.g., the fourth functional separation (420b)) may be required to reduce fronthaul capacity. In addition, functional separation at too high a layer (e.g., the sixth functional separation (430)) may complicate the control interface and cause a burden on the implementation of the RU due to the inclusion of a large number of PHY processing blocks within the RU. Therefore, appropriate functional separation may be required depending on the arrangement and implementation method of the DU and the RU.

[0079] In one embodiment, if the precoding of data received from the DU cannot be processed (i.e., if the precoding capability of the RU is limited), the third functional separation (420a) or a lower functional separation (e.g., the second functional separation (410)) may be applied. Conversely, if the DU has the capability to process the precoding of data received from the DU, the fourth functional separation (420b) or a higher functional separation (e.g., the sixth functional separation (430)) may be applied.

[0080] Hereinafter, embodiments in the present disclosure are described based on the third functional separation (420a) (which may be referred to as category A (CAT-A)) or the fourth functional separation (420b) (which may be referred to as category B (CAT-B)) for performing beamforming processing in an RU unless otherwise specified. The O-RAN standard distinguishes the types of O-RUs depending on whether the precoding function is located at the interface of the O-DU or the O-RU interface. An O-RU that does not perform precoding (i.e., has low complexity) may be referred to as a CAT-A O-RU. An O-RU that performs precoding may be referred to as a CAT-B O-RU.

[0081] Hereinafter, the term "upper-PHY" refers to physical layer processing handled in the DU of the fronthaul interface. For example, the upper-PHY may include FEC encoding / decoding, scrambling, and modulation / demodulation. Hereinafter, the term "lower-PHY" refers to physical layer processing handled in the RU of the fronthaul interface. For example, the lower-PHY may include FFT / iFFT, digital beamforming, PRACH (physical random access channel) extraction, and filtering. However, the above-described criteria do not exclude embodiments through other functional separations. The functional configuration, signaling, or operation of the embodiments described below may be applied not only to the third functional separation (420a) or the fourth functional separation (420b), but also to other functional separations.

[0082] Embodiments of the present disclosure exemplarily describe the standards of eCPRI and O-RAN as fronthaul interfaces when transmitting messages between a DU (e.g., DU (210) of FIG. 2a) and an RU (e.g., RU (220) of FIG. 2a). The Ethernet payload of the message may include an eCPRI header, an O-RAN header, and additional fields. Hereinafter, various embodiments of the present disclosure are described using standard terms of eCPRI or O-RAN, but other expressions having equivalent meanings to each term may be used instead in various embodiments of the present disclosure. Hereinafter, various embodiments of the present disclosure are described using standard terms of eCPRI or O-RAN, but are not limited thereto. For example, in various embodiments of the present disclosure, the CPRI standard may be used as the fronthaul interface.

[0083] The fronthaul transport protocol can use Ethernet and eCPRI, which are easy to share with networks. The Ethernet payload can include an eCPRI header and an O-RAN header. The eCPRI header can be located at the beginning of the Ethernet payload. The contents of the eCPRI header are as follows.

[0084] 1) ecpriVersion (4 bits): This parameter indicates the eCPRI protocol version.

[0085] 2) ecpriReserved (3 bits): This parameter is reserved for further use by eCPRI.

[0086] 3) ecpriConcatenation (1 bit): This parameter indicates when eCPRI concatenation is in use.

[0087] 4) ecpriMessage (1 byte): This parameter indicates the type of service carried by the message type. For example, the parameter indicates an IQ data message, a real-time control data message, or a transmission network delay measurement message.

[0088] 5) ecpriPayload (2 bytes): This parameter indicates the byte size of the payload portion of the eCPRI message.

[0089] 6) ecpriRtcid / ecpriPcid (2 bytes): This parameter is the eAxC (extended antenna-carrier) identifier (eAxC ID) and identifies a specific data flow associated with each C-plane (ecpriRtcid) or U-plane (ecpriPcid) message.

[0090] 7) ecpriSeqid (2 bytes): This parameter provides unique message identification and ordering at both levels. The first octet of this parameter is a sequence ID used to identify the order of messages within the eAxC message stream. The sequence ID is used to ensure that all messages are received and to reorder out-of-order messages. The second octet of this parameter is a subsequence ID. The subsequence ID is used to ensure ordering and implement reordering when radio-transport-level (eCPRI or IEEE-1914.3) fragmentation occurs.

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

[0092] 1) DU_port ID: The DU_port ID is used to distinguish processing units (e.g., different baseband cards) in the O-DU. The O-DU is expected to allocate bits for the DU_port ID, and the O-RU is expected to append the same value to the UL U-plane message carrying the same sectionId data.

[0093] 2) BandSector_ID: Aggregated cell identifier (band and sector distinction supported by O-RU).

[0094] 3) CC_ID: CC_ID identifies the carrier component supported by the O-RU.

[0095] 4) RU_port ID: The RU_port ID specifies logical flows such as data layer or spatial streams, and signaling channels that require separate numerologies (e.g. PRACH) or special antenna allocation such as SRS.

[0096] The application protocol of the fronthaul may include a control plane (C-plane), a user plane (U-plane), a synchronization plane (S-plane), and a management plane (M-plane).

[0097] The control plane may be configured to provide scheduling information and beamforming information via control messages. The control plane refers to real-time control between DUs and RUs. The user plane may include IQ sample data transmitted between DUs and RUs. The user plane may include user downlink data (IQ data or SSB / RS), uplink data (IQ data or SRS / RS), or PRACH data. A weight vector of the beamforming information described above may be multiplied by the user's data. The synchronization plane generally refers to traffic between DUs and RUs for a synchronization controller (e.g., IEEE grand master). The synchronization plane may be related to timing and synchronization. The management plane refers to non-real-time control between DUs and RUs. The management plane may be related to initial setup, non-realtime reset or reset, and non-realtime report.

[0098] Control plane messages, or C-plane messages, can be encapsulated based on a two-layer header approach. The first layer can consist of the eCPRI common header or the IEEE 1914.3 common header, which contains fields used to indicate the message type. The second layer is the application layer, which contains fields necessary for control and synchronization. Within the application layer, sections define the characteristics of U-plane data transmitted or received on a beam with a single pattern ID. The following section types are supported within the C-plane:

[0099] Section Type can indicate the purpose of control messages transmitted on the control plane. For example, the purposes of each Section Type are as follows.

[0100] 1) sectionType=0: Used to indicate resource blocks or symbols not used in DL or UL.

[0101] 2) sectionType=1: Used for most DL / UL wireless channels. Here, "most" refers to channels that do not require time or frequency offsets, such as those required for mixed numerology channels.

[0102] 3) sectionType=2: reserved for further use

[0103] 4) sectionType=3: PRACH and mixed-numerology channels. Channels that require a time or frequency offset or differ from the nominal SCS value(s).

[0104] 5) sectionType=4: reserved for further use

[0105] 6) sectionType=5: UE scheduling information. Transmits UE scheduling information so that the RU can perform real-time BF weight calculations (O-RAN optional BF method).

[0106] 7) sectionType=6: Transmits UE-specific channel information. Periodically transmits UE channel information to enable the RU to perform real-time BF weight calculations (O-RAN optional BF method).

[0107] 8) sectionType=7: Used for LAA support

[0108] According to one embodiment, a base station (110) (e.g., DU) may transmit a synchronization signal / physical broadcast channel (SS / PBCH) (hereinafter, a synchronization signal block (SSB)) to a terminal (120). The base station (110) may transmit an SSB so that the terminal (120) may access the base station (110) (or cell). The base station (110) may transmit a single SSB or multiple SSBs to the terminal (120). FIG. 5A will illustrate an example in which the base station (110) transmits one SSB (or a single SSB) to the terminal (120). FIG. 5B will illustrate an example in which the base station (110) transmits multiple SSBs to the terminal (120).

[0109] Figure 5a illustrates an example in which a base station transmits a single SSB (synchronization signal block).

[0110] Figure 5b illustrates an example in which a base station transmits multiple SSBs.

[0111] The base station (110) (or DU) may periodically transmit an SSB (or SS / PBCH) (511). The base station (110) may transmit the SSB (511) based on a designated time interval. For example, the base station (110) may transmit the SSB (511) so that a terminal (120) within the system can access a cell related to the base station (110).

[0112] For example, the period at which SSB (511) is transmitted can be set in various ways. For example, the period at which SSB (511) is transmitted can be set to one of 5 ms (milliseconds), 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms.

[0113] Referring to FIG. 5a, a base station (110) can transmit one SSB (511) to a terminal (120). The terminal (120) can receive the SSB (511) transmitted from the base station (110). The terminal (120) can obtain downlink frequency synchronization and / or time synchronization through the received SSB (511).

[0114] For example, the base station (110) can generate (or configure) an SSB (511) using a beam. The base station (110) can generate (or configure) the SSB (511) using one beamforming parameter set. The base station (110) can transmit the SSB (511) generated using one beamforming parameter set to the terminal (120). The terminal (120) can obtain downlink frequency synchronization and / or time synchronization based on RSRP (reference signal received power) for the SSB (511). For example, the terminal (120) can obtain downlink frequency synchronization and / or time synchronization based on identifying that the RSRP for the SSB (511) is greater than or equal to a threshold value.

[0115] The terminal (120) can obtain a master information block (MIB) based on the received SSB (511). The MIB can include essential information about the cell. For example, the MIB can include information about the numerology of the system information block 1 (SIB1) and information about the configuration of the SIB1. Although not illustrated, the terminal (120) can receive the SSB (511) and then, based on the SSB (511), receive the SIB1. The SIB1 can include information (or parameters) for initial random access. The terminal (120) can transmit a PRACH signal (512) to the base station (110) to perform initial random access based on the SIB1. Depending on the embodiment, the information (or parameters) for random access may be included in the SIB2. For example, in the NR standard, information (or parameters) for random access may be included in SIB1. For example, in the LTE standard, information (or parameters) for random access may be included in SIB2.

[0116] The terminal (120) can transmit a PRACH signal (512) to the base station (110) in a RACH (random access channel) space (occasion) regarding the SSB (511). A specific example of the RACH space will be described later in FIG. 7.

[0117] Referring to FIG. 5B, the base station (110) can transmit a plurality of SSBs (520) to the terminal (120). The base station (110) can sequentially transmit the plurality of SSBs (520) to the terminal (120). The plurality of SSBs (520) can form a single SS burst set (synchronization signal burst set). For example, the base station (110) can configure a plurality of SSBs (520) corresponding to a plurality of beams, respectively. The base station (110) can configure a plurality of SSBs (520) corresponding to a plurality of beamforming parameter sets. For example, the plurality of SSBs (520) included in the SS burst set can be transmitted continuously or discontinuously.

[0118] For example, the base station (110) can generate (or configure) a plurality of SSBs (520) using a plurality of beams. The base station (110) can generate (or configure) the plurality of SSBs (520) using a plurality of beamforming parameter sets. Each of the plurality of beamforming parameter sets can correspond to a plurality of SSBs (520). For example, the plurality of SSBs (520) can include a first SSB (521), a second SSB (522), a third SSB (523), and a fourth SSB (524). The first SSB (521) can be generated (or configured) based on the first beamforming parameter set. The second SSB (522) can be generated (or configured) based on the second beamforming parameter set. The third SSB (523) can be generated (or configured) based on the third beamforming parameter set. The fourth SSB (524) can be generated (or configured) based on the fourth beamforming parameter set.

[0119] FIG. 5B illustrates an example in which the number of SSBs included in the plurality of SSBs (520) is 4, but is not limited thereto. The number of SSBs included in the plurality of SSBs (520) may be set to various values. For example, within a 3 GHz frequency band, the maximum number of SSBs included in the plurality of SSBs (520) may be set to 4. The base station (110) may perform beam sweeping for 4 beams within the 3 GHz frequency band. For example, within a frequency band between 3 GHz and 6 GHz, the maximum number of SSBs included in the plurality of SSBs (520) may be set to 8. The base station (110) may perform beam sweeping for 8 beams within a frequency band between 3 GHz and 6 GHz. For example, within FR (frequency range) 2, the maximum number of SSBs included in the plurality of SSBs (520) can be set to 64. The base station (110) can perform beam sweeping for 64 beams within FR (frequency range) 2.

[0120] Referring to FIG. 5B, the terminal (120) can perform measurements on a plurality of SSBs (520). For example, the terminal (120) can obtain RSRP (reference signal received power) for each of the plurality of SSBs (520) (e.g., the first SSB (521) to the fourth SSB (524)). The terminal (120) can select (or determine, identify) an SSB with the highest RSRP among the plurality of SSBs (520). The terminal (120) can transmit a PRACH signal (531) to a RACH space corresponding to the selected SSB. The base station (110) can acquire the RSRP (reference signal received power) for each of the plurality of SSBs (520) (e.g., the first SSB (521) to the fourth SSB (524)). th Based on the reception of a PRACH signal (531) in the RACH space corresponding to the SSB, the selected SSB (or SSBRI (SSB resource indicator)) can be identified. For example, the terminal (120) can obtain an MIB based on the selected SSB, as shown in FIG. 5A. The terminal (120) can receive SIB1 based on the MIB. The terminal (120) can transmit a PRACH signal (531) to the RACH space corresponding to the selected SSB based on SIB1.

[0121] Referring to FIGS. 5A and 5B, when multiple SSBs (520) are transmitted, different beams may be assigned to each SSB. When multiple SSBs (520) are transmitted, different beamforming parameter sets may be applied to each SSB. The latency when multiple SSBs (520) are transmitted may be longer than the latency when one SSB (511) is transmitted, but when multiple SSBs (520) are transmitted, the coverage may be expanded because the multiple SSBs (520) are transmitted through sharp beams.

[0122] Figure 6 shows an example of SSB transmitted from a base station.

[0123] Referring to FIG. 6, the SSB (600) may include a primary synchronization signal (PSS) (610), a secondary synchronization signal (SSS) (620), and a physical broadcast channel (PBCH) (630). Although not illustrated, the SSB (600) may further include a demodulate reference signal (DMRS) for the PBCH (630). The symbols of the PBCH (630) may include a self-frequency-multiplexed DMRS. For example, the SSB (600) may be referred to as SS / PBCH.

[0124] SSB (600) may be composed of four consecutive OFDM symbols. SSB (600) may occupy 240 subcarriers. PSS (610) may be transmitted through the first symbol. PSS (610) may occupy 127 subcarriers. For example, PSS (610) may be composed of one of three sequences.

[0125] The SSS (620) may be transmitted via the third symbol. The SSS (620) may occupy 127 subcarriers, similar to the PSS (610). In the third symbol, no signal may be mapped to the 8 and 9 subcarriers on both sides of the SSS (620).

[0126] The PBCH (630) may be transmitted through the second and fourth symbols among the four symbols constituting the SSB (600). Additionally, the PBCH (630) may be transmitted through 48 subcarriers on each side of the SSS (620) of the third symbol. For example, quadrature phase shift keying (QPSK) modulation may be used for the PBCH (630). For example, polar coding may be used for the PBCH (630).

[0127] For example, the possible temporal positions of SSBs (600) within a half-frame can be determined by the subcarrier spacing and the period of the half-frame. Network-configured SSBs can be transmitted within a half-frame. During a half-frame, different SSBs can be transmitted in different spatial directions.

[0128] For example, multiple SSBs may be transmitted within a subcarrier's frequency range. The physical layer cell identifiers (PCIs) of SSBs transmitted at different frequency locations may not be unique. Different SSBs within a frequency domain may have different PCIs.

[0129] For example, if the SSB (600) is associated with the remaining minimum system information (RMSI), the SSB (600) may be referred to as a CD-SSB (cell-defining SSB). The PCell (primary cell) may always be associated with a CD-SSB in the synchronization raster.

[0130] Figure 7 illustrates an example of a RACH (physical random access channel) space.

[0131] Referring to FIG. 7, six RACH spaces (occasions) (hereinafter, ROs) may be included within a PRACH configuration period (710). One RO may correspond to one or more SSBs.

[0132] In one embodiment, one RO may correspond to one SSB. For example, if a first SSB, a second SSB, a third SSB, and a fourth SSB are transmitted from the base station (110), the first SSB may correspond to RO #0. The second SSB may correspond to RO #1. The third SSB may correspond to RO #2. The fourth SSB may correspond to RO #3.

[0133] According to one embodiment, one RO may correspond to multiple SSBs. For example, when the first to eighth SSBs are transmitted from the base station (110), the first and second SSBs may correspond to RO #0. The third and fourth SSBs may correspond to RO #1. The fifth and sixth SSBs may correspond to RO #2. The seventh and eighth SSBs may correspond to RO #3. For example, when 'ssb-perRACH-OccasionAndCB-PreamblesPerSSB' is set to '2', two SSBs may be mapped to one RO. For example, when 'ssb-perRACH-OccasionAndCB-PreamblesPerSSB' is set to '1 / 2 (one-half)', one SSB may be mapped to two ROs.

[0134] For example, the terminal (120) can transmit a PRACH signal to the base station (110) using at least one of the plurality of ROs. The terminal (120) can select (or determine, identify) an SSB having the highest RSRP among the plurality of received SSBs. The terminal (120) can transmit the PRACH signal to the base station (110) through the RO corresponding to the selected SSB. The base station (110) can identify the selected SSB (or SSBRI (SSB resource indicator)) based on the RO corresponding to the selected SSB. For example, when two or more SSBs are mapped to the RO where the PRACH signal is transmitted, the base station (110) can identify a preamble index (or sequence). The base station (110) can identify one of the two or more SSBs mapped to the RO where the PRACH signal is transmitted based on the preamble index.

[0135] According to one embodiment, one RO may correspond to one SSB. The base station (110) may transmit eight SSBs. Since four ROs are included in the PRACH configuration period (710), the PRACH configuration period may not be sufficient to indicate eight SSBs. Therefore, the PRACH configuration period (720) may be used to indicate the remaining SSBs. Eight SSBs may be indicated using the PRACH configuration period (710) and the PRACH configuration period (720). Each of the eight ROs included in the PRACH configuration period (710) and the PRACH configuration period (720) may correspond to eight SSBs. The PRACH configuration period (710) and the PRACH configuration period (720) may be referred to as an association period (730). The association period (730) may mean a period for indicating (or mapping) all SSBs transmitted from the base station (110).

[0136] FIG. 7 illustrates examples of PRACH configuration periods (e.g., PRACH configuration periods (710, 720)) and association periods (e.g., association periods (730)), but is not limited thereto. For example, the PRACH configuration periods and association periods may be configured as shown in the table below.

[0137] PRACH configuration period (msec) Associated period value 10{1, 2, 4, 8, 16} 20{1, 2, 4, 8} 40{1, 2, 4} 80{1, 2} 160{1}

[0138] Referring to Table 1, the PRACH configuration period can be set to one of 10 [msec], 20 [msec], 40 [msec], 80 [msec], and 160 [msec]. The association period value can be set based on the PRACH configuration period. For example, the length of the association period can be set to 160 [msec] or less. The association period value can be configured so that the length of the association period is set to 160 [msec] or less.

[0139] For example, if the PRACH configuration period is 10 [msec], the association period value can be set to one of 1, 2, 4, 8, and 16. If the association period value is 1, the length of the association period can be set to 10 [msec]. If the association period value is 8, the length of the association period can be set to 80 [msec].

[0140] For example, if the PRACH configuration period is 80 [msec], the association period value can be set to either 1 or 2. If the association period value is 1, the length of the association period can be set to 80 [msec]. If the association period value is 2, the length of the association period can be set to 160 [msec].

[0141] Figure 8 illustrates an example of an operation for performing PRACH detection according to a receiving path.

[0142] Referring to FIG. 8, a base station (110) (e.g., DU (210) of FIG. 2a) can receive a PRACH signal from an RO. For example, the PRACH signal can correspond to an SSBRI. The PRACH signal can be transmitted through an RO corresponding to the SSBRI.

[0143] A base station (110) may include one or more receiving paths (800). The one or more receiving paths (800) may refer to paths between a DU (e.g., DU (210) of FIG. 2A) and an RU (e.g., RU (220) of FIG. 2A) included in the base station (110). The one or more receiving paths (800) may refer to the number of streams configured between the DU and the RU.

[0144] For example, a base station (110) (e.g., DU (210)) can receive a PRACH signal through one or more reception paths (800). The base station (110) can perform a PRACH detection operation based on one or more reception paths (800). For example, the base station (110) can perform a PRACH signal detection operation on a first reception path (800-1). The base station (110) can identify a preamble index (or sequence) for the PRACH signal on the first reception path (800-1). The base station (110) can perform a PRACH signal detection operation on a second reception path (800-2). The base station (110) can identify a preamble index (or sequence) for the PRACH signal on the second reception path (800-2). The base station (110) can perform a PRACH signal detection operation on the n-1th reception path (800-(n-1)). The base station (110) can identify a preamble index (or sequence) for the PRACH signal on the n-1th reception path (800-(n-1)). The base station (110) can perform a PRACH signal detection operation on the nth reception path (800-n). The base station (110) can identify a preamble index (or sequence) for the PRACH signal on the nth reception path (800-n).

[0145] The base station (110) can identify the covariance between a sequence for a preamble index among one or more receiving paths (800) and a reference sequence corresponding to the corresponding SSB. The base station (110) can identify a preamble index having the largest covariance. The base station (110) can identify an SSBRI based on the identified preamble index. The base station (110) can determine one SSB among a plurality of SSBs based on the identified preamble index. The base station (110) can perform a physical random access operation based on the determined SSB.

[0146] For example, before a physical random access procedure is initiated, Layer 1 may receive a set of SS / PBCH block indices from upper layers and provide the corresponding RSRP measurement set to the upper layers. Before a physical random access procedure is initiated, Layer 1 may receive an indication to perform a Type-1 random access procedure or a Type-2 random access procedure.

[0147] Before the physical random access procedure begins, Layer 1 may receive the following information from upper layers:

[0148] - Configuration of PRACH transmission parameters (e.g., PRACH preamble format, time resources, frequency resources for PRACH transmission)

[0149] - Parameters for determining the root sequence and its cyclic shift in the PRACH preamble sequence set (index to the logical root sequence table, index to the cyclic shift (NCS) and set type (no restriction, restricted set A or restricted set B)).

[0150] From a physical layer perspective, a Type-1 L1 random access procedure includes a Random Access Response (RAR) transmission including a random access preamble (Msg1) and a physical downlink control channel (PDCCH) / physical downlink shared channel (PDSCH) (Msg2) on a PRACH, and a Type-1 L1 random access procedure may include transmission of a PUSCH scheduled by an RAR UL grant and a PDSCH for contention resolution, if applicable.

[0151] From a physical layer perspective, a Type-2 L1 random access procedure includes transmission of a random access preamble on PRACH and PUSCH (MsgA) and reception of a RAR message containing PDCCH / PDSCH (MsgB), and the Type-2 L1 random access procedure may include transmission of a physical uplink shared channel (PUSCH) scheduled by a fallback RAR UL grant, if applicable, and transmission of a PDSCH for contention resolution.

[0152] When a random access procedure is initiated by a PDCCH order to the UE, the PRACH transmission may be performed using the same subcarrier spacing (SCS) as the PRACH transmission initiated by the upper layer.

[0153] If the UE is configured with two UL carriers for the serving cell and the UE detects the PDCCH order, the UE can use the UL / SUL indicator field value from the detected PDCCH order to determine the UL carrier for the corresponding PRACH transmission.

[0154] When multiple SSBs (520) are transmitted using multiple beams, as shown in FIG. 5b, the overhead of the SSBs may increase. Downlink throughput may decrease due to resource occupancy of the multiple SSBs.

[0155] When multiple SSBs (520) are transmitted using multiple beams as shown in FIG. 5b, the latency may increase by the connection time for measurement of the multiple SSBs (520). In addition, the latency may increase by the time the terminal (120) waits for the RACH space corresponding to the selected SSB.

[0156] When multiple SSBs (520) are transmitted as in FIG. 5b, coverage may increase, but as described above, delay time may increase. In the following specification, an embodiment for receiving a PRACH through multiple beams (or multiple beamforming parameter sets) when multiple SSBs (520) are transmitted as in FIG. 5b will be described.

[0157] In addition, as the number of the one or more receiving paths (800) described above increases, the SINR (signal to interference plus noise ratio) of the beam based on each of the one or more receiving paths (800) can be secured, but the number of the one or more receiving paths (800) may be limited depending on the setting (or capability) of the base station (110). If the number of the one or more receiving paths (800) is insufficient, it may be difficult to obtain beamforming gain through a plurality of SSBs (520). Therefore, in the following specification, an embodiment for setting a beam (or receiving beam, LB (logical beam)) differently according to time in order to obtain beamforming gain by space will be described.

[0158] Figure 9 illustrates an example of multiple LBs (logical beams) configured to receive PRACH.

[0159] Referring to FIG. 9, the base station (110) can transmit multiple SSBs (not shown). For example, if the number of one or more receiving paths of the base station (110) is less than the number of LBs described below, multiple SSBs can be transmitted.

[0160] For example, a DU (e.g., DU (210) of FIG. 2A) may transmit information including a plurality of SSBs (or SS / PBCH blocks) to a terminal (120) via an RU (e.g., RU (220) of FIG. 2A). The RU may transmit information including a plurality of SSBs (or SS / PBCH blocks) received from the DU to the terminal (120). For example, the plurality of SSBs may be referred to as multiple SSBs. The plurality of SSBs may be sequentially transmitted to the terminal (120). The plurality of SSBs may constitute one SS burst set (synchronization signal burst set). The plurality of SSBs may correspond to the plurality of SSBs (520) of FIG. 5B.

[0161] The terminal (120) can receive multiple SSBs from the base station (110). The terminal (120) can measure (or obtain, identify) the RSRP (reference signal received power) for each of the multiple SSBs. Based on the RSRP for each of the multiple SSBs, the terminal (120) can select (or decide) one of the multiple SSBs. For example, the terminal (120) can select the SSB with the highest RSRP among the multiple SSBs.

[0162] After receiving a plurality of SSBs, the terminal (120) may receive SIB1 from the base station (110). SIB1 may include information about a preamble. The terminal (120) may transmit a PRACH signal (910) to the base station (110) in a RACH space corresponding to the selected SSB. For example, the terminal (120) may transmit a PRACH signal (910) including a preamble to inform the base station (110) of the selected SSB (or SSBRI). The base station (110) may identify the SSB (or SSBRI) selected by the terminal (120) based on the RACH space and / or the preamble in which the PRACH signal (910) is transmitted.

[0163] The base station (110) can receive the PRACH signal (910) using different logical beams (LBs) over time. The logical beams (LBs) can be configured based on a set of beamforming parameters. For example, the LBs can mean beams (or reception beams) for receiving the PRACH signal (910) (or uplink signals). For example, multiple LBs can be used to receive PRACH signals for the same SSBRI.

[0164] The base station (110) can receive the PRACH signal (910) using multiple LBs (or multiple beamforming parameter sets). The base station (110) can identify the LB that most accurately receives the PRACH signal (910). For example, the multiple LBs can include LB #0, LB #1, LB #2, LB #3, LB #4, LB #5, LB #6, and LB #7. The base station (110) can identify that the PRACH signal can be most accurately received through LB #2.

[0165] For example, the base station (110) can identify one of the plurality of LBs based on the covariance between the sequence (or preamble) and the reference sequence according to the PRACH signal detected in each of the plurality of LBs. The base station (110) can transmit a downlink signal (e.g., an RAR signal) to the terminal (120) using a beamforming parameter set corresponding to the identified LB. The operation of the base station (110) to identify the reception path that most accurately receives the PRACH signal (910) will be described later in FIG. 11A or FIG. 11B.

[0166] As shown in FIG. 7, an association period may be set to indicate all of the multiple SSBs. By repeating the association period at a designated period, multiple association periods may be set. One association period may be configured to receive a PRACH signal based on multiple LBs. For example, a first association period may include a RACH space for receiving a PRACH signal for a first SSB based on LB #0. The first association period may include a RACH space for receiving a PRACH signal for a second SSB based on LB #0. For example, a second association period may include a RACH space for receiving a PRACH signal for the first SSB based on LB #1. The second association period may include a RACH space for receiving a PRACH signal for the second SSB based on LB #1.

[0167] A specific example of multiple related cycles, such as the example described above, will be described later in Fig. 10.

[0168] In FIG. 9, an example of receiving a PRACH signal (910) using eight LBs (or eight beamforming parameter sets) is illustrated, but the present invention is not limited thereto. For example, the number of multiple LBs may be set in various ways. The number of multiple LBs may be set to be equal to or less than the number of reception paths between the DU and RU of the base station (110).

[0169] Figure 10 illustrates an example of multiple association periods for receiving a PRACH signal.

[0170] Referring to FIG. 10, the base station (110) can receive a PRACH signal corresponding to an SSB selected by the terminal (120) among a plurality of SSBs. The base station (110) can receive the PRACH signal using a plurality of LBs (or a plurality of beamforming parameter sets).

[0171] The base station (110) may set a plurality of association periods to receive a PRACH signal. For example, the plurality of association periods may include a first association period (1010-1) to an n-th association period (1010-n).

[0172] One association period (e.g., the first association period (1010-1)) may include RACH spaces (RACH occasions, hereinafter, ROs) for multiple SSBs (or multiple SSBRIs) using one LB (e.g., LB #0). The number of ROs included in one association period may correspond to the number of multiple SSBs.

[0173] According to one embodiment, the number of multiple LBs may be set to n, and the number of multiple SSBs may be set to M.

[0174] For example, a first association period (1010-1) may include a plurality of ROs for receiving a PRACH signal using LB #0. The first association period (1010-1) may include RO #0 to RO #(M-1). RO #0 in the first association period (1010-1) may refer to a time and frequency band for receiving a PRACH signal regarding SSBRI #0 using LB #0. RO #1 in the first association period (1010-1) may refer to a time and frequency band for receiving a PRACH signal regarding SSBRI #1 using LB #0. RO #(M-1) in the first association period (1010-1) may refer to a time and frequency band for receiving a PRACH signal regarding SSBRI #(M-1) using LB #0.

[0175] For example, the second association period (1010-2) may include a plurality of ROs for receiving a PRACH signal using LB #1. The second association period (1010-2) may include RO #0 to RO #(M-1). RO #0 in the second association period (1010-2) may refer to a time and frequency band for receiving a PRACH signal for SSBRI #0 using LB #1. RO #1 in the second association period (1010-2) may refer to a time and frequency band for receiving a PRACH signal for SSBRI #1 using LB #1. RO #(M-1) in the second association period (1010-2) may refer to a time and frequency band for receiving a PRACH signal for SSBRI #(M-1) using LB #1.

[0176] For example, the nth association period (1010-n) may include a plurality of ROs for receiving a PRACH signal using LB #(n-1). The nth association period (1010-n) may include RO #0 to RO #(M-1). RO #0 in the nth association period (1010-n) may denote a time and frequency band for receiving a PRACH signal regarding SSBRI #0 using LB #(n-1). RO #1 in the nth association period (1010-n) may denote a time and frequency band for receiving a PRACH signal regarding SSBRI #1 using LB #(n-1). RO #(M-1) in the nth association period (1010-n) may denote a time and frequency band for receiving a PRACH signal regarding SSBRI #(M-1) using LB #(n-1).

[0177] The associated periodic index, SSBRI, and LBID (logical beam identifier) ​​according to the above-described example can be set as shown in the table below.

[0178]

[0179] Referring to Table 2, the association period index can indicate multiple association periods. For example, the association period index #0 can indicate the first association period (1010-1). 'Wide beam ID mapping' can indicate an SSBRI within the association period. 'Narrow beam ID mapping' can indicate an LBID set within the association period. The LBID can mean a narrow beam ID defined for the same SSB (or SSBRI). The LBID is the number of SSBRIs (N SSBRI ) can be constructed through modular operations performed using .

[0180] According to one embodiment, the length of each of the plurality of associated periods may be set to 160 [ms] or less.

[0181] Figure 11a illustrates an example of the operation of a base station for performing PRACH detection for each receiving path.

[0182] Referring to FIG. 11a, the base station (110) can receive a PRACH signal for an SSB selected by the terminal (120) from among a plurality of SSBs from the terminal (120). The base station (110) can receive the PRACH signal through a plurality of receiving paths (1110). The plurality of receiving paths (1110) can correspond to one LB. The plurality of receiving paths (1110) can correspond to one beamforming parameter set.

[0183] For example, the plurality of LBs may include n LBs. The plurality of LBs may include LB #0 to LB #n-1. The plurality of association periods may include n association periods. The plurality of association periods may include the first association period to the nth association period.

[0184] Each of the multiple LBs can be indicated by an LBID (logical beam identifier). The LBID corresponding to SSBRI (or SSBRI n) can be set as shown in the following mathematical formula.

[0185]

[0186] Referring to Mathematical Formula 1, 'LBID' is a value indicating LB. 'Association period index' is a value indicating an association period. Each of multiple association periods can be indicated by the value of 'association period index' (or 'associated period index). N SSBRIis the number of SSBRIs (or the number of multiple SSBs). The % operation is a modulo operation. 'LBID' is the 'association period index' of N SSBRI It is the remainder after dividing by . The 'association period index' can be set as shown in the mathematical formula below.

[0187]

[0188] Referring to mathematical expression 2, SFN is the system frame number. 'Association Period' is the number of RACH configuration periods for mapping all of the multiple SSBs transmitted from the base station (110). 'Association Period' may be an example of the association period value in Table 1. x is the RACH configuration period. represents the largest integer less than or equal to a. represents the floor function.

[0189] According to one embodiment, the terminal (120) can transmit a PRACH signal for a selected SSB among a plurality of SSBs to the base station (110).

[0190] For example, in a first association period, the base station (110) (e.g., DU (210) of FIG. 2A) may receive a PRACH signal using LB #0 through a plurality of reception paths. In the first association period, the base station (110) (e.g., DU (210) of FIG. 2A) may receive a PRACH signal based on a first beamforming parameter set through a plurality of reception paths. For example, in the first association period, the base station (110) (e.g., DU (210) of FIG. 2A) may receive a PRACH signal using LB #0 configured according to the first beamforming parameter set through a plurality of reception paths. The base station (110) may identify a preamble index based on the PRACH signal received using LB #0 configured according to the first beamforming parameter set. For example, the base station (110) can identify a reception path corresponding to a PRACH signal having the largest covariance between a sequence (or preamble) according to a PRACH signal detected in each of a plurality of reception paths (1110) and a reference sequence (or reference preamble). For example, the reference sequence may mean a sequence corresponding to a preamble index. The sequence according to the PRACH signal identified in each of the plurality of reception paths (1110) may be obtained differently from the reference sequence depending on a communication status. The base station (110) can obtain the covariance between the sequence according to the PRACH signal detected in each of the plurality of reception paths (1110) and the reference sequence. The base station (110) can identify a preamble index based on identifying the PRACH signal having the largest covariance.

[0191] For example, in the second association period, the base station (110) (e.g., DU (210) of FIG. 2A) may receive a PRACH signal using LB #1 through a plurality of reception paths. In the second association period, the base station (110) (e.g., DU (210) of FIG. 2A) may receive a PRACH signal based on a second beamforming parameter set through a plurality of reception paths. For example, in the second association period, the base station (110) (e.g., DU (210) of FIG. 2A) may receive a PRACH signal using LB #1 configured according to the second beamforming parameter set through a plurality of reception paths. The base station (110) may identify a preamble index based on the PRACH signal received using the configured LB #1.

[0192] For example, in the n-th association period, the base station (110) (e.g., DU (210) of FIG. 2A) can receive a PRACH signal using LB #(n-1) through a plurality of reception paths. In the n-th association period, the base station (110) (e.g., DU (210) of FIG. 2A) can receive a PRACH signal based on an n-th beamforming parameter set through a plurality of reception paths. For example, in the n-th association period, the base station (110) (e.g., DU (210) of FIG. 2A) can receive a PRACH signal using LB #(n-1) configured according to the n-th beamforming parameter set through a plurality of reception paths. The base station (110) can identify a preamble index based on the PRACH signal received using the configured LB #(n-1).

[0193] The base station (110) can identify, among a plurality of LBs, an LB (or LBID) having the highest covariance between a sequence and a reference sequence according to a PRACH signal detected in each of the plurality of receiving paths (1110). The base station (110) can identify a beamforming parameter set for configuring the identified LB. The base station (110) can transmit a downlink signal (e.g., an RAR signal) to the terminal (120) using the identified beamforming parameter set.

[0194] According to an embodiment, the base station (110) can identify a beamforming parameter set corresponding to LB #0 for configuring a downlink signal based on whether the covariance between the sequence according to the PRACH signal detected in each of the plurality of reception paths (1110) and the reference sequence satisfies a specified condition within a first association period. The base station (110) can also identify a beamforming parameter set corresponding to LB #0 for configuring a downlink signal based on whether the covariance between the sequence according to the PRACH signal detected in each of the plurality of reception paths (1110) and the reference sequence satisfies a specified condition within a first association period, even before receiving the PRACH signal in the second association period to the n-th association period.

[0195] According to one embodiment, the base station (110) may transmit a downlink signal to the terminal (120) through the identified beamforming parameter set (or LB). For example, the downlink signal may include a random access response (RAR) signal corresponding to a PRACH signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal.

[0196] For example, a downlink signal may be configured based on applying a weight to at least one antenna according to an identified set of beamforming parameters. The base station (110) may configure a downlink signal by applying a weight to at least one antenna of the transceiver based on the identified set of beamforming parameters, and transmit the downlink signal to the terminal (120).

[0197] Figure 11b illustrates an example of the operation of a base station to perform PRACH detection for each receiving path.

[0198] Referring to FIG. 11b, the base station (110) can receive a PRACH signal for an SSB selected by the terminal (120) from among a plurality of SSBs from the terminal (120). The base station (110) can receive the PRACH signal through a plurality of reception paths (1110).

[0199] Unlike FIG. 11a, some of the plurality of receiving paths (1110) may correspond to some of the plurality of LBs. Some of the plurality of receiving paths (1110) may correspond to at least one beamforming parameter set.

[0200] For example, two LBs may correspond to one association period. The base station (110) may receive a PRACH signal using LB #0 and LB #1 within the first association period. The base station (110) may receive the PRACH signal using LB #0 through first reception paths (1111) among the plurality of reception paths (1110). The base station (110) may receive the PRACH signal using LB #1 through second reception paths (1112) among the plurality of reception paths (1110). The base station (110) may receive the PRACH signal using LB #2 and LB #3 within the second association period. The base station (110) may receive the PRACH signal using LB #2 through first reception paths (1111) among the plurality of reception paths (1110). The base station (110) can receive a PRACH signal using LB #3 through the second receiving paths (1112) among the plurality of receiving paths (1110).

[0201] In the first association period, the base station (110) (e.g., DU (210) of FIG. 2A) can receive a PRACH signal through the first reception paths (1111) based on the first beamforming parameter set. In the first association period, the base station (110) can receive a PRACH signal through the second reception paths (1112) based on the second beamforming parameter set.

[0202] In the second association period, the base station (110) (e.g., DU (210) of FIG. 2A) may receive a PRACH signal through the first receiving paths (1111) based on the third beamforming parameter set. In the second association period, the base station (110) may receive a PRACH signal through the second receiving paths (1112) based on the fourth beamforming parameter set.

[0203] In Fig. 11a, an example is shown where one LB corresponds to one association period. However, as in Fig. 11b, two or more LBs may correspond to one association period. For example, if two LBs out of n correspond to one association period, n / 2 association periods may be configured.

[0204] The base station (110) can identify, among a plurality of LBs, an LB (or LBID) having the highest covariance between a sequence and a reference sequence according to a PRACH signal detected through some of the plurality of receiving paths (1110). The base station (110) can identify a beamforming parameter set for configuring the identified LB. The base station (110) can transmit a downlink signal (e.g., an RAR signal) to the terminal (120) using the identified beamforming parameter set.

[0205] According to an embodiment, when the number of the plurality of reception paths (1110) of the base station (110) is less than the number of the plurality of LBs described below, multiple SSBs may be transmitted. According to an embodiment, when the number of the plurality of reception paths (1110) of the base station (110) is greater than or equal to the number of the plurality of LBs, a single SSB may be transmitted. However, this is not limited thereto.

[0206] Figure 12 shows an example of the operation of a base station and a terminal.

[0207] Referring to FIG. 12, in operation 1201, the base station (110) may transmit multiple SSBs (or multiple SS / PBCH blocks). The base station (110) may transmit multiple SSBs based on a specified period (e.g., 20 ms).

[0208] In operation 1202, the terminal (120) may select one SSB from among multiple SSBs. For example, the terminal (120) may receive multiple SSBs from the base station (110). For example, the terminal (120) may select the SSB with the highest RSRP among the multiple SSBs. The terminal (120) may obtain downlink frequency synchronization and / or time synchronization through the selected SSB.

[0209] The terminal (120) can obtain a master information block (MIB) based on the selected SSB. For example, the MIB can include information regarding the numerology of the system information block 1 (SIB1) and information regarding the configuration of the SIB1. The terminal (120) can receive the SIB1 based on the selected SSB. The SIB1 can include information (or parameters) for initial random access.

[0210] According to one embodiment, a base station (110) may include a DU (e.g., DU (210) of FIG. 2A) and an RU (e.g., RU (220) of FIG. 2A). Multiple receive paths (or a plurality of streams) may be established between the DU and the RU. The base station (110) may receive an RPACH signal through the multiple receive paths. The base station (110) may receive a PRACH signal using one of the multiple LBs (or the multiple receive beams) within one association period. The base station (110) may receive a PRACH signal using one of the multiple LBs (or the multiple receive beams) via the multiple receive paths within one association period. In operations 1203 to 1208, operations of the base station (110) and the terminal (120) performed within the multiple association periods will be described.

[0211] Operations 1203 and 1204 may be performed within a first association period among a plurality of association periods. The terminal (120) may transmit a PRACH signal to the base station (110) within the first association period based on the selected SSB. The terminal (120) may identify an RO (RACH occasion) corresponding to the SSB selected according to operation 1202 within the first association period. For example, the first association period may include ROs corresponding to a plurality of SSBs. The base station (110) may identify an RO corresponding to the selected SSB among the plurality of ROs within the first association period. The terminal (120) may transmit a PRACH signal to the base station (110) through the RO corresponding to the selected SSB. The RU of the base station (110) may receive the PRACH signal from the terminal (120) through the RO. The DU may identify an SSBRI based on the RO.

[0212] For example, the base station (110) can receive a PRACH signal based on LB #0. The first association period can be set to receive the PRACH signal using LB #0. Accordingly, the base station (110) can receive the PRACH signal based on LB #0 within the first association period. In the first association period, the base station (110) can receive the PRACH signal using LB #0 configured according to the first beamforming parameter set. The base station (110) can identify a preamble index based on the PRACH signal received using LB #0.

[0213] Operations 1205 and 1206 may be performed within a second association period among a plurality of association periods. The terminal (120) may transmit a PRACH signal to the base station (110) within the second association period based on the selected SSB. The terminal (120) may identify an RO (RACH occasion) corresponding to the SSB selected according to operation 1202 within the second association period. For example, the second association period may include ROs corresponding to a plurality of SSBs. The base station (110) may identify an RO corresponding to the selected SSB among the plurality of ROs within the second association period. The terminal (120) may transmit a PRACH signal to the base station (110) through the RO corresponding to the selected SSB. The RU of the base station (110) may receive the PRACH signal from the terminal (120) through the RO. The DU may identify an SSBRI based on the RO.

[0214] For example, the base station (110) can receive a PRACH signal based on LB #1. The second association period can be set to receive the PRACH signal using LB #1. Accordingly, the base station (110) can receive the PRACH signal based on LB #1 within the second association period. In the second association period, the base station (110) can receive the PRACH signal using LB #1 configured according to the second beamforming parameter set. The base station (110) can identify a preamble index based on the PRACH signal received using LB #1.

[0215] Although not illustrated for convenience of explanation, a third association period to the (n-1)th association period may be established after the second association period. In the third association period to the (n-1)th association period, operations identical to or similar to operations 1203 and 1204 may be performed.

[0216] Operations 1207 and 1208 may be performed within an n-th association period among a plurality of association periods. The terminal (120) may transmit a PRACH signal to the base station (110) within the n-th association period based on the selected SSB. The terminal (120) may identify an RO (RACH occasion) corresponding to the SSB selected according to operation 1202 within the n-th association period. For example, the n-th association period may include ROs corresponding to a plurality of SSBs. The base station (110) may identify an RO corresponding to the selected SSB among the plurality of ROs within the n-th association period. The terminal (120) may transmit a PRACH signal to the base station (110) through the RO corresponding to the selected SSB. The RU of the base station (110) may receive the PRACH signal from the terminal (120) through the RO. The DU may identify an SSBRI based on the RO.

[0217] For example, the base station (110) can receive a PRACH signal based on LB #(n-1). The n-th association period can be set to receive the PRACH signal using LB #(n-1). Therefore, the base station (110) can receive the PRACH signal based on LB #(n-1) within the n-th association period. In the n-th association period, the base station (110) can receive the PRACH signal using LB #(n-1) configured according to the n-th beamforming parameter set. The base station (110) can identify a preamble index based on the PRACH signal received using LB #(n-1).

[0218] Although not shown, the base station (110) can determine one LB among the plurality of LBs. For example, the base station (110) can identify an LB (or LBID) having the highest covariance between a sequence according to a PRACH signal detected in each of the plurality of receiving paths (1110) and a reference sequence among the plurality of LBs. The base station (110) can identify a set of beamforming parameters for configuring the identified LB. The base station (110) can transmit a downlink signal (e.g., an RAR signal) to the terminal (120) using the identified set of beamforming parameters.

[0219] According to one embodiment, the base station (110) may include a DU and an RU. The specific operations of the DU and RU according to the above-described embodiment will be described in the following FIGS. 13 and 14.

[0220] Figure 13 shows a flowchart regarding the operation of DU.

[0221] Referring to FIG. 13, in operation 1310, a DU (e.g., DU (210) of FIG. 2A) included in a base station (110) may transmit information including a plurality of SS / PBCH blocks (or a plurality of SSBs) to a terminal (120) via an RU. For example, the DU may control the RU to transmit a plurality of SS / PBCH blocks. For example, the DU may control the RU to transmit a plurality of SS / PBCH blocks based on a specified period (e.g., 20 ms).

[0222] In operation 1320, the DU may receive, through the RU, a PRACH signal for an SS / PBCH block selected from among a plurality of SS / PBCH blocks in a first association period among a plurality of association periods, based on a first beamforming parameter set among a plurality of beamforming parameter sets.

[0223] For example, the terminal (120) may select one of the plurality of SS / PBCH blocks based on receiving the plurality of SS / PBCH blocks. The terminal (120) may transmit a PRACH signal to the RU (or DU) in the RACH space corresponding to the selected SS / PBCH block. The DU may identify that the PRACH signal is received in the RACH space corresponding to the SS / PBCH block selected by the terminal (120). The DU may identify that the terminal (120) has selected the SS / PBCH block indicated by the PRACH signal among the plurality of SS / PBCH blocks based on identifying that the PRACH signal is received in the RACH space corresponding to the SS / PBCH block selected by the terminal (120). The DU may identify the SSBRI based on identifying that the PRACH signal is received in the RACH space corresponding to the selected SS / PBCH block.

[0224] For example, multiple association periods may be configured for receiving PRACH signals. Each of the multiple association periods may include multiple RACH spaces. The multiple RACH spaces may correspond to each of the multiple SS / PBCH blocks.

[0225] For example, a plurality of association periods may be respectively associated with a plurality of beamforming parameter sets. For example, a first association period among the plurality of association periods may be configured to receive a PRACH signal for an SS / PBCH block selected by the terminal (120) using a first beamforming parameter set. For example, a second association period among the plurality of association periods may be configured to receive a PRACH signal for an SS / PBCH block selected by the terminal (120) using a second beamforming parameter set.

[0226] In operation 1330, the DU may receive, through the RU, a PRACH signal for an SS / PBCH block selected from among a plurality of SS / PBCH blocks in a second association period among a plurality of association periods, based on a second beamforming parameter set among a plurality of beamforming parameter sets.

[0227] For example, the second association period can be distinguished from the first association period. The second association period can be set after the first association period. For example, the second beamforming parameter set can be distinguished from the first beamforming parameter set. A beam (or, a reception beam, LB (logical beam)) configured by the second beamforming parameter set can be distinguished from a beam configured by the first beamforming parameter set. However, the present invention is not limited thereto.

[0228] According to one embodiment, the DU may receive a PRACH signal based on each of a plurality of beamforming parameter sets. For example, the DU may receive a PRACH signal based on each of a plurality of beamforming parameter sets within a plurality of associated periods. The DU may identify one of the plurality of beamforming parameter sets based on a result of receiving the PRACH signal. The DU may control the RU to transmit a downlink signal to the terminal (120) through the identified parameter set. For example, the DU may identify a beamforming parameter set having the highest covariance between a sequence according to a PRACH signal detected in each of the plurality of associated periods and a reference sequence. The DU may transmit a downlink signal (e.g., an RAR signal) to the terminal (120) through the RU using the identified beamforming parameter set.

[0229] For example, a downlink signal may be configured based on weighting applied to at least one antenna of the transceiver according to a set of identified beamforming parameters.

[0230] For example, the downlink signal may include a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal. As an example, the DU may control the RU to transmit an RAR signal corresponding to the PRACH signal to the terminal (120) through an identified beamforming parameter set.

[0231] Figure 14 shows a flowchart regarding the operation of RU.

[0232] Referring to FIG. 14, in operation 1410, an RU included in a base station (110) may transmit a plurality of SS / PBCH blocks to a terminal (120). For example, the RU may transmit a plurality of SS / PBCH blocks to the terminal (120) based on information received from a DU and including a plurality of SS / PBCH blocks. For example, the RU may transmit a plurality of SS / PBCH blocks based on a specified period (e.g., 20 ms).

[0233] In operation 1420, the RU may receive a PRACH signal for an SS / PBCH block selected from among a plurality of SS / PBCH blocks by the terminal (120) within a first association period among a plurality of association periods, based on a first beamforming parameter set among a plurality of beamforming parameter sets.

[0234] For example, the terminal (120) may select one of the plurality of SS / PBCH blocks based on receiving the plurality of SS / PBCH blocks. The terminal (120) may transmit a PRACH signal to the RU in the RACH space corresponding to the selected SS / PBCH block. The RU may transmit the PRACH signal received in the RACH space corresponding to the SS / PBCH block to the DU. The DU may identify that the terminal (120) has selected the SS / PBCH block indicated by the PRACH signal among the plurality of SS / PBCH blocks based on identifying that the PRACH signal is received in the RACH space corresponding to the SS / PBCH block selected by the terminal (120).

[0235] For example, multiple association periods may be configured for receiving PRACH signals. Each of the multiple association periods may include multiple RACH spaces. The multiple RACH spaces may correspond to each of the multiple SS / PBCH blocks.

[0236] For example, a plurality of association periods may be respectively associated with a plurality of beamforming parameter sets. For example, a first association period among the plurality of association periods may be configured to receive a PRACH signal for an SS / PBCH block selected by the terminal (120) using a first beamforming parameter set. For example, a second association period among the plurality of association periods may be configured to receive a PRACH signal for an SS / PBCH block selected by the terminal (120) using a second beamforming parameter set.

[0237] At operation 1430, the RU may receive a PRACH signal for a selected SS / PBCH block within a second association period among the plurality of association periods, based on a second beamforming parameter set among the plurality of beamforming parameter sets.

[0238] For example, the second association period can be distinguished from the first association period. The second association period can be set after the first association period. For example, the second beamforming parameter set can be distinguished from the first beamforming parameter set. A beam (or, a reception beam, LB (logical beam)) configured by the second beamforming parameter set can be distinguished from a beam configured by the first beamforming parameter set. However, the present invention is not limited thereto.

[0239] According to one embodiment, the RU may receive a PRACH signal based on each of a plurality of beamforming parameter sets. For example, the RU may receive a PRACH signal based on each of a plurality of beamforming parameter sets within a plurality of associated periods. The RU may receive one beamforming parameter set among the plurality of beamforming parameter sets received from the DU. The RU may transmit a downlink signal (e.g., an RAR signal) to the terminal (120) through the received beamforming parameter set.

[0240] For example, a downlink signal may be configured based on weighting applied to at least one antenna of the transceiver according to a set of identified beamforming parameters.

[0241] For example, the downlink signal may include a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal. As an example, the RU may transmit an RAR signal corresponding to the PRACH signal to the terminal (120) through a beamforming parameter set received from the DU.

[0242] According to one embodiment, an electronic device performed by a distributed unit (DU) may include at least one transceiver including a fronthaul transceiver, a memory storing instructions and including one or more storage media, and at least one processor including a processing circuit. The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to transmit information including a plurality of SS / PBCH (synchronization signal / physical broadcast channel) blocks to a radio unit (RU). The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to receive, via the RU, a physical random access channel (PRACH) signal for an SS / PBCH block selected by a terminal from among the plurality of SS / PBCH blocks within a first association period from among a plurality of association periods set for the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among a plurality of beamforming parameter sets. The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to receive, via the RU, the PRACH signal for the selected SS / PBCH block within a second association period from among the plurality of association periods, the second beamforming parameter set being distinct from the first beamforming parameter set from among the plurality of beamforming parameter sets.

[0243] According to one embodiment, each of the plurality of association periods may include a plurality of RACH spaces. The plurality of RACH spaces may respectively correspond to the plurality of SS / PBCH blocks.

[0244] According to one embodiment, the instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to receive the PRACH signal through the RU based on each of the plurality of beamforming parameter sets. The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to identify one beamforming parameter set from the plurality of beamforming parameter sets based on a result of receiving the PRACH signal. The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to control the RU to transmit a downlink signal to the terminal through the identified beamforming parameter set.

[0245] According to one embodiment, the downlink signal may include a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal.

[0246] According to one embodiment, the plurality of associated periods may be respectively (respectively) related to the plurality of beamforming parameter sets.

[0247] According to one embodiment, each of the plurality of association periods may be set to 160 ms (milliseconds) or less.

[0248] According to one embodiment, an electronic device performed by a radio unit (RU) may include at least one transceiver including a fronthaul transceiver, a memory storing instructions and including one or more storage media, and at least one processor including a processing circuit. The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to transmit a plurality of synchronization signal / physical broadcast channel (SS / PBCH) blocks to a terminal based on information including the plurality of SS / PBCH blocks received from a distributed unit (DU). The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to receive, within a first association period among a plurality of association periods set for the plurality of SS / PBCH blocks, a physical random access channel (PRACH) signal for an SS / PBCH block selected by the terminal from among the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among a plurality of beamforming parameter sets. The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to receive, within a second association period among the plurality of association periods, the PRACH signal for the selected SS / PBCH block, based on a second beamforming parameter set from among the plurality of beamforming parameter sets, the second beamforming parameter set being distinct from the first beamforming parameter set.

[0249] According to one embodiment, each of the plurality of association periods may include a plurality of RACH spaces. The plurality of RACH spaces may respectively correspond to the plurality of SS / PBCH blocks.

[0250] According to one embodiment, the instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to receive the PRACH signal based on each of the plurality of beamforming parameter sets. The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to receive, from the DU, one of the plurality of beamforming parameter sets identified based on a result of receiving the PRACH signal. The instructions, when individually and / or collectively executed by the at least one processor, may cause the electronic device to transmit a downlink signal to the terminal via the identified beamforming parameter set.

[0251] According to one embodiment, the downlink signal may include a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal.

[0252] According to one embodiment, a method performed by a distributed unit (DU) may include transmitting information including a plurality of SS / PBCH (synchronization signal / physical broadcast channel) blocks to a radio unit (RU). The method may include receiving, through the RU, a physical random access channel (PRACH) signal for an SS / PBCH block selected by a terminal from among the plurality of SS / PBCH blocks within a first association period from among a plurality of association periods set for the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among a plurality of beamforming parameter sets. The method may include an operation of receiving, through the RU, the PRACH signal for the selected SS / PBCH block within a second association period, which is distinct from the first association period, among the plurality of association periods, based on a second beamforming parameter set, which is distinct from the first beamforming parameter set, among the plurality of beamforming parameter sets.

[0253] According to one embodiment, each of the plurality of association periods may include a plurality of RACH spaces. The plurality of RACH spaces may respectively correspond to the plurality of SS / PBCH blocks.

[0254] According to one embodiment, the method may include an operation of receiving the PRACH signal through the RU based on each of the plurality of beamforming parameter sets. The method may include an operation of identifying one beamforming parameter set among the plurality of beamforming parameter sets based on a result of receiving the PRACH signal. The method may include an operation of controlling the RU to transmit a downlink signal to the terminal through the identified beamforming parameter set.

[0255] According to one embodiment, the downlink signal may include a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal.

[0256] According to one embodiment, the plurality of associated periods may be respectively (respectively) related to the plurality of beamforming parameter sets.

[0257] According to one embodiment, each of the plurality of association periods may be set to 160 ms (milliseconds) or less.

[0258] According to one embodiment, a method performed by a radio unit (RU) may include transmitting a plurality of synchronization signal / physical broadcast channel (SS / PBCH) blocks to a terminal based on information including the SS / PBCH blocks received from a distributed unit (DU). The method may include receiving, within a first association period among a plurality of association periods set for the plurality of SS / PBCH blocks, a physical random access channel (PRACH) signal for an SS / PBCH block selected by the terminal from among the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among a plurality of beamforming parameter sets. The method may include an operation of receiving, within a second association period among the plurality of association periods, which is distinct from the first association period, the PRACH signal for the selected SS / PBCH block based on a second beamforming parameter set among the plurality of beamforming parameter sets, which is distinct from the first beamforming parameter set.

[0259] According to one embodiment, each of the plurality of association periods may include a plurality of RACH spaces. The plurality of RACH spaces may respectively correspond to the plurality of SS / PBCH blocks.

[0260] According to one embodiment, the method may include an operation of receiving the PRACH signal based on each of the plurality of beamforming parameter sets. The method may include an operation of receiving, from the DU, one of the plurality of beamforming parameter sets identified based on a result of receiving the PRACH signal. The method may include an operation of transmitting a downlink signal to the terminal through the identified beamforming parameter set.

[0261] According to one embodiment, the downlink signal may include a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal.

[0262] According to the above-described embodiments, multiple beams (e.g., logical beams (LBs)) can be applied to multiple receiving paths. Therefore, coverage can be secured. However, in order to sufficiently secure the SINR of the beam in each of the multiple receiving paths, the number of the multiple receiving paths must be large. However, if the number of the multiple receiving paths is insufficient, it may be difficult to obtain beamforming gain by the multiple beams at the same time. According to the above-described embodiments, when it is difficult to obtain beam gain by space (or beam direction), beams (e.g., receiving beams, LBs) can be arranged differently according to time. According to the above-described embodiments, there is an effect of obtaining beamforming gain by using multiple beams without changing the existing standards for SSB and PRACH.

[0263] According to the above-described embodiment, multiple beams can be used even when the number of reception paths is insufficient. The above-described embodiment can also be applied when the number of LBs for the same SSB is limited or when coverage is limited due to a limitation in the number of reception paths available per LB.

[0264] According to the above-described embodiment, the number of multiple SSBs can be reduced, thereby reducing downlink overhead. According to the above-described embodiment, an SSB can be defined as a single wide beam. An LB can be defined as a narrow beam configured within an SSB.

[0265] According to the above-described embodiment, by distributing the allocation of beams (e.g., LBs) in the time domain, different LBIDs can be allocated for the same SSBRI.

[0266] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0267] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure. The one or more programs may be provided as a computer program product. The computer program product may be traded between a seller and a buyer as a commodity. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) via an application store (e.g., Play Store™) or directly between two user devices (e.g., smart phones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created in a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0268] These 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 disc storage devices, compact disc-ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in memories formed by a combination of some or all of these. In addition, each configuration memory may include multiple copies.

[0269] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0270] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0271] According to embodiments, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0272] Meanwhile, although the detailed description of the present disclosure has described specific embodiments, it is obvious that various modifications are possible within the scope of the present disclosure.

Claims

1. In an electronic device performed by a DU (distributed unit), At least one transceiver comprising a front-haul transceiver; and A memory storing instructions and including one or more storage media; and comprising at least one processor including a processing circuit; The above instructions, when individually and / or collectively executed by the at least one processor, cause the electronic device to: Transmits information including multiple SS / PBCH (synchronization signal / physical broadcast channel) blocks to the RU (radio unit), Within a first association period among a plurality of association periods set for the plurality of SS / PBCH blocks, a PRACH (physical random access channel) signal for an SS / PBCH block selected by a terminal among the plurality of SS / PBCH blocks is received through the RU based on a first beamforming parameter set among a plurality of beamforming parameter sets, Causing to receive, through the RU, the PRACH signal for the selected SS / PBCH block, within a second association period, which is distinct from the first association period, among the plurality of association periods, based on a second beamforming parameter set, which is distinct from the first beamforming parameter set, among the plurality of beamforming parameter sets. Electronic devices.

2. In the first paragraph, each of the plurality of associated periods, Contains multiple RACH (random access channel) spaces, The above multiple RACH spaces are, Each of the above multiple SS / PBCH blocks (respectively) corresponds to, Electronic devices.

3. In the first paragraph, when the instructions are individually and / or collectively executed by the at least one processor, the electronic device, Based on each of the plurality of beamforming parameter sets, the PRACH signal is received through the RU, Based on the reception result of the PRACH signal, one beamforming parameter set among the plurality of beamforming parameter sets is identified, Causing the RU to be controlled to transmit a downlink signal to the terminal via the identified beamforming parameter set. Electronic devices.

4. In the third paragraph, the downlink signal includes a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal. Electronic devices.

5. In the first paragraph, the plurality of associated cycles are: Respectively related to the above multiple beamforming parameter sets, Electronic devices.

6. In the first paragraph, each of the plurality of associated periods, Set to 160 ms (milliseconds) or less, Electronic devices. In an electronic device performed by a 7.RU (radio unit), At least one transceiver comprising a front-haul transceiver; and A memory storing instructions and including one or more storage media; and comprising at least one processor including a processing circuit; The above instructions, when individually and / or collectively executed by the at least one processor, cause the electronic device to: Based on information including multiple SS / PBCH (synchronization signal / physical broadcast channel) blocks received from a DU (distributed unit), the multiple SS / PBCHs are transmitted to the terminal, Within a first association period among a plurality of association periods set for the plurality of SS / PBCH blocks, a PRACH (physical random access channel) signal for an SS / PBCH block selected by the terminal among the plurality of SS / PBCH blocks is received based on a first beamforming parameter set among a plurality of beamforming parameter sets, Causing to receive the PRACH signal for the selected SS / PBCH block within a second association period, which is distinct from the first association period, among the plurality of association periods, based on a second beamforming parameter set, which is distinct from the first beamforming parameter set, among the plurality of beamforming parameter sets. Electronic devices.

8. In the 7th paragraph, each of the plurality of associated periods, Contains multiple RACH (random access channel) spaces, The above multiple RACH spaces are, Each of the above multiple SS / PBCH blocks (respectively) corresponds to, Electronic devices.

9. In the 7th paragraph, the instructions, when individually and / or collectively executed by the at least one processor, the electronic device, Based on each of the plurality of beamforming parameter sets, the PRACH signal is received, Receive one beamforming parameter set from the DU among the plurality of beamforming parameter sets identified based on the reception result of the PRACH signal, Causing the terminal to transmit a downlink signal through the above identified beamforming parameter set. Electronic devices.

10. In the 9th paragraph, the downlink signal includes a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal. Electronic devices. In a method performed by 11.DU (distributed unit), An operation of transmitting information including multiple SS / PBCH (synchronization signal / physical broadcast channel) blocks to a RU (radio unit); An operation of receiving, through the RU, a PRACH (physical random access channel) signal for an SS / PBCH block selected by a terminal from among the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among the plurality of beamforming parameter sets, within a first association period from among the plurality of association periods set for the plurality of SS / PBCH blocks; and An operation including receiving, through the RU, the PRACH signal for the selected SS / PBCH block, within a second association period, which is distinct from the first association period, among the plurality of association periods, based on a second beamforming parameter set, which is distinct from the first beamforming parameter set, among the plurality of beamforming parameter sets. method.

12. In paragraph 11, each of the plurality of associated periods, Contains multiple RACH (random access channel) spaces, The above multiple RACH spaces are, Each of the above multiple SS / PBCH blocks (respectively) corresponds to method.

13. In the 11th paragraph, the method, An operation of receiving the PRACH signal through the RU based on each of the plurality of beamforming parameter sets; An operation of identifying one beamforming parameter set among the plurality of beamforming parameter sets based on the reception result of the PRACH signal; and Further comprising an operation of controlling the RU to transmit a downlink signal to the terminal through the identified beamforming parameter set. method.

14. In the 13th paragraph, the downlink signal includes a random access response (RAR) signal, a physical downlink control channel (PDCCH) signal, or a physical downlink shared channel (PDSCH) signal corresponding to the PRACH signal. method. In a method performed by 15.RU (radio unit), An operation of transmitting a plurality of SS / PBCH (synchronization signal / physical broadcast channel) blocks to a terminal based on information including the plurality of SS / PBCH blocks received from a DU (distributed unit); An operation of receiving a PRACH (physical random access channel) signal for an SS / PBCH block selected by the terminal from among the plurality of SS / PBCH blocks, based on a first beamforming parameter set from among the plurality of beamforming parameter sets, within a first association period from among the plurality of association periods set for the plurality of SS / PBCH blocks; and An operation including receiving, in a second association period among the plurality of association periods, the PRACH signal for the selected SS / PBCH block based on a second beamforming parameter set among the plurality of beamforming parameter sets, the second beamforming parameter set being distinct from the first beamforming parameter set. method.

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