Device and method for monitoring preamble for random access

Abstract

According to the present invention, a distributed unit (DU) may comprise at least one processor. The at least one processor is configured to: transmit, to a terminal, a system information block (SIB) including a physical random access channel (PRACH) configuration index indicating the format of a preamble for random access as format 0; monitor the preamble in a first time interval corresponding to the duration of a preamble sequence of format 0 and a second time interval corresponding to the duration, which is consecutively allocated following the first time interval; on the basis of the monitoring of the preamble in the first time interval and the second time interval, determine whether the signal quality for the preamble measured in the first time interval and the second time interval exceeds a threshold value; and in accordance with the determination that the signal quality exceeds the threshold value, transmit, to the terminal, a random access channel (RAR) responding to the preamble.

Description

Device and method for monitoring a preamble for random access

[0001] The following descriptions relate to an apparatus and method for monitoring a preamble for random access.

[0002] During the initial access procedure, the terminal can transmit a preamble to the base station for uplink synchronization. Repetition of the preamble sequence can be used for coverage extension. However, in the case of a short-sequence preamble format, there may be limitations to coverage extension due to the short length of the sequence. Additionally, in the case of a long-sequence preamble format, it may not be suitable for a TDD (time division duplex) structure due to the long length of the sequence.

[0003] The information described above may be provided as related art for the purpose of aiding understanding of the present disclosure. No claim or determination is made as to whether any of the foregoing may be applied as prior art related to the present disclosure.

[0004] A distributed unit (DU) is provided. The DU may include a communication circuit. The DU may include a memory that stores instructions and includes one or more storage media. The DU may include at least one processor that includes a processing circuit. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to transmit a system information block (SIB) to a terminal that includes a physical random access channel (PRACH) setting index indicating the format of a preamble for random access as format 0. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to monitor the preamble in a first time interval corresponding to the duration of the preamble sequence of format 0 and in a second time interval corresponding to the duration that is subsequently allocated after the first time interval. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine whether the signal quality for the preamble measured in the first time interval and the second time interval exceeds a threshold value based on monitoring the preamble in the first time interval and the second time interval. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to transmit a random access channel (RAR) responding to the preamble to the terminal upon the determination that the signal quality exceeds the threshold value.

[0005] A method performed by a distributed unit (DU) is provided. The method may include the operation of transmitting a system information block (SIB) to a terminal that includes a physical random access channel (PRACH) setting index indicating the format of a preamble for random access as format 0. The method may include the operation of monitoring the preamble in a first time interval corresponding to the duration of the preamble sequence of format 0 and in a second time interval corresponding to the duration that is subsequently allocated after the first time interval. The method may include the operation of determining whether the signal quality of the preamble measured in the first time interval and the second time interval exceeds a threshold value based on monitoring the preamble in the first time interval and the second time interval. The method may include the operation of transmitting a random access channel (RAR) responding to the preamble to the terminal in accordance with the determination that the signal quality exceeds the threshold value.

[0006] In relation to the description of the drawings, the same or similar reference numerals may be used for identical or similar components.

[0007] Figure 1 illustrates an example of a wireless communication system.

[0008] Figure 2 illustrates the interface between an upper network node and a lower network node.

[0009] Figure 3a illustrates the components of an upper network node.

[0010] Figure 3b illustrates the components of a sub-network node.

[0011] Figure 4 illustrates examples of resource structures in the time domain and frequency domain.

[0012] FIG. 5 illustrates signaling between a base station and a terminal for performing an initial connection.

[0013] Figure 6 illustrates a resource structure to explain an example of detecting a preamble.

[0014] Figure 7 is a flowchart showing the operations of a communication device for extending the coverage of a preamble.

[0015] Figure 8 is a diagram illustrating an example of detecting a preamble of format 0 for coverage expansion.

[0016] FIG. 9 is a flowchart showing the operations of a communication device for performing scheduling in the coverage extension of a preamble.

[0017] FIGS. 10a to 10c illustrate examples of downlink scheduling performed by a communication device.

[0018] The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression may include a plural expression unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by those skilled in the art described in this disclosure. Terms used in this disclosure that are defined in a general dictionary may be interpreted as having the same or similar meaning as they have in the context of the relevant technology, and are not to be interpreted in an ideal or overly formal sense unless explicitly defined in this disclosure. In some cases, even terms defined in this disclosure are not to be interpreted to exclude the embodiments of this disclosure.

[0019] In the various embodiments of the present disclosure described below, a hardware-based approach is described as an example. However, since the various embodiments of the present disclosure include techniques using both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0020] Terms referring to signals used in the following description (e.g., packet, message, signal, information, signaling), terms referring to resources (e.g., section, symbol, slot, subframe, radio frame, subcarrier, RE (resource element), RB (resource block), BWP (bandwidth part), occasion)), terms for operation states (e.g., step, operation, procedure)), terms referring to data (e.g., packet, message, user stream, information, bit, symbol, codeword)), terms referring to channels, terms referring to network entities (DU (distributed unit), RU (radio unit), CU (central unit), CU-CP (control plane), CU-UP (user plane), O-DU (O-RAN (open radio access network) DU), O-RU (O-RAN RU), O-CU (O-RAN CU), Terms such as O-CU-UP (O-RAN CU-CP), O-CU-CP (O-RAN CU-CP), and terms referring to components of the device are examples provided for convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used. Furthermore, terms such as '...part', '...device', '...object', '...body' used below may refer to at least one shape structure or a unit that processes a function.

[0021] Additionally, in this disclosure, expressions of "greater than" or "less than" may be used to determine whether a specific condition is satisfied or fulfilled; however, this is merely for the purpose of expressing an example and does not exclude descriptions of "greater than" or "less than." Conditions described as "greater than" may be replaced with "greater than," conditions described as "less than" may be replaced with "less than," and conditions described as "greater than and less than" may be replaced with "greater than and less than." Furthermore, "A" to "B" below refer to at least one of elements from A (including A) to B (including B). Below, "C" and / or "D" refers to including at least one of "C" or "D," i.e., {"C", "D", "C" and "D"}.

[0022] The present disclosure describes embodiments using terms used in some communication standards (e.g., 3GPP (3rd Generation Partnership Project)), but this is merely illustrative. The embodiments of the present disclosure may also be applied to other communication and broadcasting systems.

[0023] Figure 1 illustrates an example of a wireless communication system.

[0024] Referring to FIG. 1, FIG. 1 illustrates a base station (110) and a terminal (120) as part of nodes utilizing a wireless channel in a wireless communication system. FIG. 1 illustrates only one base station, but the wireless communication system may further include other base stations identical or similar to the base station (110). FIG. 1 illustrates only one terminal, but the wireless communication system may further include other terminals identical or similar to the terminal (120).

[0025] A base station (110) is a network infrastructure that provides wireless access to a terminal (120). The base station (110) has coverage defined based on the distance over which it can transmit signals. In addition to being a base station, the base station (110) may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5G node (5th generation node)', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having an equivalent technical meaning.

[0026] A terminal (120) is a device used by a user and communicates with a 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). Additionally, although not shown in FIG. 1, the terminal (120) and another terminal can 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 user involvement. For example, the terminal (120) may be a device that performs machine type communication (MTC) and may not be carried by the user. In addition, for example, the terminal (120) may be a narrowband (NB) IoT (internet of things) device.

[0027] The terminal (120) may be referred to 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 an equivalent technical meaning.

[0028] The base station (110) can perform beamforming with the terminal (120). 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). Additionally, 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) and a 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, beamforming may include transmit beamforming and receive beamforming. The base station (110) and the terminal (120) can assign directivity to the transmitted signal or the 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 a resource that is in a quasi-co-location (QCL) relationship with the resource that transmitted the serving beams.

[0029] If large-scale characteristics of the channel that transmitted the symbol on the first antenna port can be inferred from the channel that transmitted the symbol on the second antenna port, the first antenna port and the second antenna port can be evaluated as being in a QCL relationship. For example, the large-scale characteristics may include at least one of a delay spread, a Doppler spread, a Doppler shift, an average gain, an average delay, and a spatial receiver parameter.

[0030] In FIG. 1, it is described that both the base station (110) and the terminal (120) perform beamforming, but the embodiments of the present disclosure are not necessarily limited thereto. In some embodiments, the terminal may or may not perform beamforming. Also, the base station may or may not perform beamforming. That is, either the base station or the terminal may perform beamforming, or neither the base station nor the terminal may perform beamforming.

[0031] In the present disclosure, a beam refers to a spatial flow of a signal in a wireless channel, formed by one or more antennas (or antenna elements), and this formation process may be referred to as beamforming. Beamforming may include at least one of analog beamforming or digital beamforming (e.g., precoding). A reference signal transmitted based on beamforming may include, for example, a demodulation reference signal (DMRS), a channel state information-reference signal (CSI-RS), a synchronization signal / physical broadcast channel (SS / PBCH), or a sounding reference signal (SRS). Additionally, an IE such as a CSI-RS resource or an SRS-resource may be used as a configuration for each reference signal, and such a configuration may include information associated with the beam. Information associated with a beam may refer to whether the configuration (e.g., CSI-RS resource) uses the same spatial domain filter as other configurations (e.g., other CSI-RS resources within the same CSI-RS resource set) or a different spatial domain filter, or which reference signal it is quasi-colocated with, and if so, what type (e.g., QCL type A, B, C, D).

[0032] Conventionally, in communication systems with a relatively large cell radius of base stations, each base station was installed to include the functions of a digital processing unit (or DU (distributed unit)) and an RF (radio frequency) processing unit (RF processing unit, or RU (radio unit)). However, as high 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 required to cover a specific area has increased. Consequently, the burden of installation costs for operators to install base stations has also increased. To minimize base station installation costs, a structure has been proposed in which the DU and RU of a base station are separated, with one or more RUs connected to a single DU via a wired network, and one or more geographically distributed RUs deployed to cover a specific area. Below, with reference to FIG. 2, deployment structures and extension examples of base stations according to various embodiments of the present disclosure are described.

[0033] Figure 2 illustrates the interface between an upper network node and a lower network node.

[0034] The interface between the upper network node (210) and the lower network node (220) may include a fronthaul interface. Fronthaul refers to the space between entities between a wireless LAN and a base station, unlike backhaul between a base station and a core network. FIG. 2 illustrates an example of a fronthaul structure between an upper network node (210) and one lower network node (220), but this is merely for convenience of explanation and the present disclosure is not limited thereto. In other words, the embodiment of the present disclosure may also be applied to a fronthaul structure between one upper network node and a plurality of lower network nodes. For example, the embodiment of the present disclosure may be applied to a fronthaul structure between one upper network node and two lower network nodes. Additionally, the embodiment of the present disclosure may also be applied to a fronthaul structure between one upper network node and three lower network nodes.

[0035] For example, the upper network node (210) may include a digital unit / distributed unit (DU). The upper network node may be referred to as the DU (210). The lower network node (220) may include a radio unit (RU) or a massive MIMO unit (MMU). The lower network node (220) may be referred to as the RU or MMU.

[0036] Referring to FIG. 2, the base station (110) may include an upper network node (210) and a lower network node (220). The fronthole (215) between the upper network node (210) and the lower network node (220) may be operated via an Fx interface. For the operation of the fronthole (215), an interface such as eCPRI (enhanced common public radio interface) or ROE (radio over ethernet) may be used.

[0037] As communication technology develops, mobile data traffic increases, and consequently, the bandwidth requirements for the fronthaul between the digital unit and the wireless unit have increased significantly. In a deployment such as a C-RAN (centralized / cloud radio access network), the upper network node (210) performs functions for PDCP (packet data convergence protocol), RLC (radio link control), MAC (media access control), and PHY (physical), and the lower network node (220) can be implemented to perform functions for the PHY layer in addition to RF (radio frequency) functions.

[0038] The upper network node (210) may be responsible for upper layer functions of the wireless network. For example, the upper network node (210) may perform functions of the MAC layer and parts of the PHY layer. Here, parts of the PHY layer are functions of the PHY layer that are performed at a higher level, and may include, for example, channel encoding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), and layer mapping (or layer demapping). According to one embodiment, if the upper network node (210) conforms to the O-RAN standard, it may be referred to as an O-DU (O-RAN DU) (or DU). The upper network node (210) may be replaced and represented as a first network entity or DU for a base station (e.g., gNB) in the embodiments of the present disclosure as necessary.

[0039] The lower network node (220) can be responsible for lower layer functions of the wireless network. For example, the lower network node (220) can perform RF functions, which are part of the PHY layer. Here, part of the PHY layer refers to functions of the PHY layer that are performed at a relatively lower level than the upper network node (210), and may include, for example, iFFT transformation (or FFT transformation), CP (cyclic prefix) insertion (CP removal), and digital beamforming. Examples of such specific functional separation are described in detail in FIG. 4. The lower network node (220) may be referred to as an 'access unit (AU)', 'access point (AP)', 'transmission / reception point (TRP)', 'remote radio head (RRH)', 'radio unit (RU)', or other terms having an equivalent technical meaning. According to one embodiment, if the sub-network node (220) conforms to the O-RAN standard, it may be referred to as an O-RU (O-RAN RU) (or RU). The sub-network node (220) may be replaced with a second network entity or RU for a base station (e.g., gNB) in the embodiments of the present disclosure as needed.

[0040] In the above example, it is described that the upper network node (210) includes a DU and the lower network node (220) includes an RU, but the embodiments of the present disclosure are not limited thereto. A base station according to the embodiments may be implemented in a distributed deployment according to a centralized unit (CU) configured to perform the functions of the upper layers of the access network (e.g., packet data convergence protocol (PDCP), radio resource control (RRC)) and a distributed unit (DU) configured to perform the functions of the lower layers. In this case, the distributed unit (DU) may include a digital unit (DU) and a radio unit (RU). Between a core network (e.g., 5G core or next generation core (NGC)) and a radio network (RAN), the base station may be implemented in a structure in which the CU, DU, and RU are arranged in that order. The interface between the CU and the distributed unit (DU) may be referred to as the F1 interface.

[0041] For example, a centralized unit (CU) can be connected to one or more DUs and perform functions at a higher layer than the DUs. For instance, the CU can perform functions at the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, while the DU and RU can perform functions at lower layers. The DU can perform radio link control (RLC), media access control (MAC), and some functions of the physical (PHY) layer (high PHY), while the RU can perform the remaining functions of the PHY layer (low PHY). Additionally, as an example, a digital unit (DU) can be included in a distributed unit (DU) depending on the distributed deployment implementation of the base station. The following description describes the operations of DU and RU unless otherwise defined, but various embodiments of the present disclosure may be applied to both base station deployments including CU and deployments where DU is directly connected to the core network (i.e., implemented by integrating CU and DU into a single entity base station (e.g., NG-RAN node)).

[0042] Figure 3a illustrates the components of an upper network node.

[0043] The configuration exemplified in FIG. 3a can be understood as part of a base station and as a configuration of an upper network node (e.g., a distributed unit (DU)) of FIG. 2. Terms such as '...part', '...unit' used below refer to a unit that processes at least one function or operation, and this can be implemented in hardware or software, or a combination of hardware and software.

[0044] Referring to FIG. 3a, the upper network node (210) may include a transceiver (310), memory (320), and a processor (330).

[0045] The transceiver (310) can perform functions for transmitting and receiving signals in a wired communication environment. The transceiver (310) may include a wired interface for controlling a direct connection between a device and another device through a transmission medium (e.g., copper wire, optical fiber, etc.). For example, the transceiver (310) can transmit an electrical signal to another device through a copper wire or perform conversion between an electrical signal and an optical signal. An upper network node (210) can communicate with a lower network node (220) through the transceiver (310). The upper network node (210) can be connected to a core network or a centralized unit (CU) of a distributed arrangement through the transceiver (310).

[0046] The transceiver (310) can perform functions for transmitting and receiving signals in a wireless communication environment. For example, the transceiver (310) can perform conversion functions between baseband signals and bit sequences according to the physical layer specifications of the system. For example, when transmitting data, the transceiver (310) can generate complex symbols by encoding and modulating the transmitted bit sequence. For example, when receiving data, the transceiver (310) can restore the received bit sequence through decoding the baseband signal. For example, the transceiver (310) may include a plurality of transmission and reception paths. For example, the transceiver (310) may be connected to a core network or to other nodes (e.g., an integrated access backhaul (IAB)).

[0047] 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 receive a synchronization 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. FIG. 3a shows only the transceiver (310), but according to other implementation examples, the upper network node (210) may include two or more transceivers.

[0048] The transceiver (310) can transmit and receive signals as described above. Accordingly, all or part of the transceiver (310) may be referred to as a 'communication unit', 'transmitter unit', 'receiver unit', or 'transmitter / receiver unit'. Furthermore, in the following description, transmission and reception performed via a wireless channel may be used to mean that processing as described above is performed by the transceiver (310).

[0049] Although not illustrated in FIG. 3a, the transceiver (310) may further include a backhaul transceiver for connecting to a core network or another base station. For example, the backhaul transceiver may provide an interface for communicating with other nodes within the network. For example, the backhaul transceiver may convert a bit sequence transmitted from a base station to another node, e.g., another access node, another base station, an upper node, a core network, etc., into a physical signal, and convert a physical signal received from another node into a bit sequence.

[0050] The memory (320) can store data such as basic programs, applications, and configuration information for the operation of the upper network node (210). For example, the memory (320) may be referred to as a storage unit. For example, the memory (320) may be composed of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. For example, the memory (320) may provide stored data upon the request of the processor (330).

[0051] The processor (330) can control the overall operations of the upper network node (210). For example, the processor (330) may be referred to as a control unit. For example, the processor (330) can transmit and receive signals through the transceiver (310) (or through the backhaul communication unit). For example, the processor (330) can write and read data to and from memory (320). For example, the processor (330) can perform the functions of a protocol stack required by the communication standard. FIG. 3a shows only the processor (330), but according to other implementation examples, the upper network node (210) may include two or more processors.

[0052] The configuration of the upper network node (210) shown in FIG. 3a is merely an example, and the examples of upper network nodes performing embodiments of the present disclosure are not limited to the configuration shown in FIG. 3a. In some embodiments, some configurations may be added, deleted, or changed.

[0053] Figure 3b illustrates the components of a sub-network node.

[0054] The configuration exemplified in FIG. 3b can be understood as a configuration of a sub-network node (e.g., RU (radio unit)) of FIG. 2 as part of a base station. Terms such as '...part', '...unit' used below refer to a unit that processes at least one function or operation, which may be implemented in hardware or software, or a combination of hardware and software.

[0055] Referring to FIG. 3b, the sub-network node (220) may include an RF (radio frequency) transceiver (360), a fronthole transceiver (365), a memory (370), and a processor (380).

[0056] The RF transceiver (360) can perform functions for transmitting and receiving signals through a wireless channel. For example, the RF transceiver (360) can up-convert a baseband signal into an RF band signal and transmit it through an antenna, and down-convert an RF band signal received through an 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 digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc.

[0057] The RF transceiver (360) may include a plurality of transmission and reception paths. For example, the RF transceiver (360) may include an antenna section. For example, the RF transceiver (360) may include at least one antenna array composed of a plurality of antenna elements. For example, in terms of hardware, the RF transceiver (360) may be composed of a digital circuit and an analog circuit (e.g., a radio frequency integrated circuit (RFIC)). For example, the digital circuit and the analog circuit may be implemented in a single package. For example, the RF transceiver (360) may include a plurality of RF chains. For example, the RF transceiver (360) may perform beamforming. For example, the RF transceiver (360) may apply a beamforming weight to a signal to give directionality according to the settings of the processor (380) to the signal to be transmitted and received. For example, the RF transceiver (360) may include an RF block (or RF section).

[0058] For example, the RF transceiver (360) can transmit and receive signals over a radio access network. For example, the RF transceiver (360) can transmit a downlink signal. For example, the downlink signal may include a synchronization signal (SS), a reference signal (RS) (e.g., CRS (cell-specific reference signal), DM (demodulation)-RS), system information (e.g., MIB, SIB, RMSI (remaining system information), OSI (other system information)), a configuration message, control information, or downlink data. For example, the RF transceiver (360) can receive an uplink signal. For example, the uplink signal may include random access-related signals (e.g., random access preamble (RAP) (or Msg1 (message 1)), Msg3 (message 3)), reference signals (e.g., SRS (sounding reference signal), DM-RS), or power headroom reports (PHR), etc. FIG. 3b shows only an RF transceiver (360), but according to other embodiments, the sub-network node (220) may include two or more RF transceivers.

[0059] The fronthall transceiver (365) can transmit and receive signals. For example, the fronthall transceiver (365) can transmit and receive signals on the fronthall interface. For example, the fronthall transceiver (365) can receive management plane (M-plane) messages. For example, the fronthall transceiver (365) can receive synchronization plane (S-plane) messages. For example, the fronthall transceiver (365) can receive control plane (C-plane) messages. For example, the fronthall transceiver (365) can transmit user plane (U-plane) messages. For example, the fronthall transceiver (365) can receive user plane messages. FIG. 3b shows only a fronthole transceiver (365), but according to other implementation examples, the lower network node (220) may include two or more fronthole transceivers.

[0060] The RF transceiver (360) and the fronthall transceiver (365) can transmit and receive signals as described above. Accordingly, all or part of the RF transceiver (360) and the fronthall transceiver (365) may be referred to as a 'communication unit', 'transmitter unit', 'receiver unit', or 'transmitter unit'. In the following description, transmission and reception performed via a wireless channel may be used to mean that processing as described above is performed by the RF transceiver (360).

[0061] The memory (370) can store data such as basic programs, applications, and configuration information for the operation of the sub-network node (220). For example, the memory (370) may be referred to as a storage unit. For example, the memory (370) may be composed of volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. For example, the memory (370) provides stored data upon the request of the processor (380). For example, the memory (370) may include memory for conditions, commands, or configuration values ​​related to the SRS transmission method.

[0062] The processor (380) can control the overall operations of the sub-network node (220). For example, the processor (380) may be referred to as a control unit. For example, the processor (380) can transmit and receive signals through the RF transceiver (360) or the fronthall transceiver (365). For example, the processor (380) can write and read data to and from memory (370). For example, the processor (380) can perform the functions of the protocol stack required by the communication standard. FIG. 3b shows only the processor (380), but according to other implementation examples, the sub-network node (220) may include two or more processors. For example, the processor (380) may be a set of instructions or code stored in memory (370), at least temporarily resided in the processor (380), or a storage space storing instructions / code, or part of a circuitry constituting the processor (380). For example, the processor (380) may include various modules for performing communication. For example, the processor (380) may control a sub-network node (220) to perform operations according to the embodiments described below.

[0063] The configuration of the sub-network node (220) shown in FIG. 3b is merely an example, and the examples of sub-network nodes performing embodiments of the present disclosure are not limited to the configuration shown in FIG. 3b. In some embodiments, some configurations may be added, deleted, or changed.

[0064] Figure 4 illustrates examples of resource structures in the time domain and frequency domain.

[0065] FIG. 4 illustrates the basic structure of the time-frequency domain, which is a wireless resource area where data or control channels are transmitted in the downlink or uplink.

[0066] Referring to Fig. 4, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM (orthogonal frequency division multiplexing) symbol, OFDM symbols (401) are combined to form a slot (402). The length of the subframe is defined as 1.0 ms, and the length of the radio frame (403) is defined as 10 ms. The minimum transmission unit in the frequency domain is the subcarrier, and the carrier bandwidth constituting the resource grid is Dog (download link) or It consists of sub-carriers (407) of the uplink.

[0067] In the time-frequency domain, the basic unit of a resource is a resource element (hereinafter 'RE') (404), which can be represented by an OFDM symbol index and a subcarrier index. A resource block may include multiple resource elements. In an LTE system, a resource block (RB) (or physical resource block (hereinafter 'PRB')) is in the time domain 2 consecutive OFDM symbols and in the frequency domain It is defined by a number of consecutive subcarriers. In an NR system, the resource block (RB) (405) is defined in the frequency domain. It can be defined as a series of consecutive subcarriers (406). One RB (405) is in the frequency axis, It includes REs (404). Generally, the minimum transmission unit of data is RB, and the number of subcarriers = 12. The frequency domain may include common resource blocks (CRBs). Physical resource blocks (PRBs) may be defined in the bandwidth part (BWP) in the frequency domain. CRB and PRB numbers may be determined by subcarrier spacing. The data rate may increase in proportion to the number of RBs scheduled to the terminal.

[0068] In NR systems, for frequency division duplex (FDD) systems that operate downlink and uplink separately by frequency, the downlink transmission bandwidth and uplink transmission bandwidth may differ. Channel bandwidth represents the radio frequency (RF) bandwidth corresponding to the system transmission bandwidth. [Table 1] shows part of the correspondence between the system transmission bandwidth, subcarrier spacing (SCS), and channel bandwidth defined in NR systems in frequency bands lower than x GHz (e.g., frequency range 1 (410 MHz ~ 7125 MHz)). And [Table 2] shows part of the correspondence between the transmission bandwidth, subcarrier spacing, and channel bandwidth defined in NR systems in frequency bands higher than y GHz (e.g., FR2 (24250 MHz - 52600 MHz) or FR2-2 (52600 MHz ~ 71000 MHz)). For example, an NR system with a 100 MHz channel bandwidth and a 30 kHz subcarrier spacing has a transmission bandwidth consisting of 273 RBs. In [Table 1] and [Table 2], N / A may be a bandwidth-subcarrier combination that is not supported by the NR system.

[0069] Channel Bandwidth [MHz] SCS5 10 20 50 80 100 Transmission Bandwidth Configuration N RB 15kHz2552106207N / AN / A30kHz11245113321727360kHzN / A112465107135

[0070] Channel Bandwidth [MHz] SCS 50 100 200 400 Transmission Bandwidth Configuration N RB 60kHz66132264N / A120kHz3266132264

[0071] FIG. 5 illustrates signaling between a base station and a terminal for performing an initial access. The initial access procedure illustrated in FIG. 5 is illustrated as being performed by a base station (110), but the present disclosure is not limited thereto. For example, some of the operations of the base station (110) illustrated in FIG. 5 may be performed by an upper network node (210) (e.g., a distributed unit (DU)), and the remaining operations may be performed by a lower network node (220) (e.g., a radio unit (RU)). In another example, all of the operations of the base station (110) illustrated in FIG. 5 may be performed by an upper network node (210).

[0072] Referring to FIG. 5, in operation 501, a base station (110) according to one embodiment may transmit an SS / PBCH (synchronization signal physical broadcast channel) block to a terminal (120). For example, the SS / PBCH block may include a MIB (master information block). The MIB may include a parameter (e.g., subCarrierSpacingCommon) indicating the SCS (subcarrier spacing) for the initial connection procedure. For example, the parameter indicating the SCS may be 1 bit. In one example, the parameter indicating the SCS may be as shown in [Table 3] below.

[0073] 01FR115kHz30kHzFR260kHz120kHz

[0074] Referring to [Table 3], in one example, when an SS / PBCH block is received at FR (frequency range) 1 and the parameter indicates 0, the terminal (120) can identify that the SCS for the initial connection procedure is 15 kHz (kilohertz). In one example, when an SS / PBCH block is received at FR1 and the parameter indicates 1, the terminal (120) can identify that the SCS for the initial connection procedure is 30 kHz. In one example, when an SS / PBCH block is received at FR2 and the parameter indicates 0, the terminal (120) can identify that the SCS for the initial connection procedure is 60 kHz. In one example, when an SS / PBCH block is received at FR2 and the parameter indicates 1, the terminal (120) can identify that the SCS for the initial connection procedure is 120 kHz.

[0075] In operation 502, a base station (110) according to one embodiment may transmit a system information block (SIB) 1 to a terminal (120). For example, SIB 1 may include a physical random access channel (PRACH) configuration index. The PRACH configuration index may indicate a preamble format, a subframe number, a starting symbol, the number of PRACH slots within the subframe, the number of PRACH occasions within the PRACH slot, and / or a PRACH duration. In one example, the information indicated by the PRACH configuration index may be referenced from Tables 6.3.3.2-2 to 6.3.3.2-4 of 3GPP (3rd generation partnership project) TS (technical specification) 38.211. In one example, SIB 1 may be referred to as RMSI (remaining minimum system information) or another term having an equivalent technical / functional meaning.

[0076] In operation 503, a base station (110) according to one embodiment may receive a message (message, msg) 1 from a terminal (120). For example, the terminal (120) may transmit message 1 to the base station (110) based on SIB 1. Message 1 may be transmitted over a random access channel (RACH). The base station (110) may detect message 1 on a time-frequency resource (e.g., a RACH opportunity) for monitoring message 1. For example, the base station (110) may detect message 1 by identifying the sequence having the maximum correlation coefficient based on a correlation operation between the sequence of the received signal and candidate sequences. In one example, message 1 may be referred to as PRACH, preamble, random access preamble, or other terms having an equivalent technical / functional meaning.

[0077] In operation 504, a base station (110) according to one embodiment may transmit message 2 to a terminal (120). The base station (110) may transmit message 2 to the terminal (120) in response to message 1. Message 2 may be transmitted over a control channel marked with a cyclic redundancy check (CRC) as a random access-radio network temporary identifier (RA-RNTI). Message 2 may include a backoff indicator (BI), a random access preamble identifier (RAPID), a timing advance (TA), an uplink grant (UL), and / or a temporary cell-radio network temporary identifier (C-RNTI). The TA may be used to control the uplink transmission timing of the terminal (120) by compensating for propagation delay. In one example, message 2 may be referred to as RAR (random access response) or another term having an equivalent technical / functional meaning.

[0078] In operation 505, a base station (110) according to one embodiment may receive message 3 from a terminal (120). For example, the terminal (120) may transmit message 3 to the base station (110) on a time-frequency resource allocated by the UL grant of message 2. For example, the terminal (120) may transmit message 3 based on the TA value of message 2. For example, message 3 may be transmitted over a physical uplink shared channel (PUSCH). In one example, message 2 may be referred to as a radio resource control (RRC) connection request message or other terms having an equivalent technical / functional meaning.

[0079] In operation 506, a base station (110) according to one embodiment may transmit message 4 to a terminal (120). For example, message 4 may be transmitted over a physical downlink shared channel (PDSCH). In one example, message 4 may be referred to as a contention resolution message or another term having an equivalent technical / functional meaning.

[0080] Although a contention-based random access (CBRA) procedure is described in FIG. 5, the present disclosure is not limited thereto. The operations of the base station (110) (or DU) of the present disclosure may be performed based on a contention-free random access (CFRA) procedure. In a contention-free random access procedure, the base station (110) and the terminal (120) may not perform operations 505 and 506.

[0081] FIG. 6 illustrates a resource structure for explaining an example of detecting a preamble. The operations described in FIG. 6 may be performed by a communication device. For example, the communication device may be a base station (110) including an upper network node (210) (e.g., a DU (distributed unit)) and a lower network node (220) (e.g., a RU (radio unit)). For example, the communication device may be an upper network node (210). At least some of the operations of FIG. 6 may be controlled by a processor (330) of the upper network node (210).

[0082] Referring to FIG. 6, a terminal (120) may receive a system information block (SIB) 1 from a communication device. For example, SIB 1 may include a physical random access channel (PRACH) configuration index. For example, the PRACH configuration index may indicate format C2. Based on the PRACH configuration index included in SIB 1, the terminal (120) may transmit a preamble (601) of format C2 to the communication device. The preamble (601) of format C2 may include a cyclic prefix (CP), four preamble sequences, and a guard period (GP). That is, the repetition of the preamble sequences of format C2 may be four.

[0083] For example, the distance between the communication device and the terminal (120) may be a first distance. In one example, the first distance may be between 10 km (kilometers) and 20 km. Since the distance between the communication device and the terminal (120) is the first distance, the preamble (601) transmitted by the terminal (120) may be received by the communication device after a first delay. The preamble (601) received after a first delay may be the preamble (602) shown in FIG. 6.

[0084] For example, the distance between the communication device and the terminal (120) may be a second distance. In one example, the second distance may be between 20 km and 30 km. Since the distance between the communication device and the terminal (120) is a second distance, the preamble (601) transmitted by the terminal (120) may be received by the communication device after a second delay. The preamble (601) received after a second delay may be the preamble (603) shown in FIG. 6.

[0085] For example, the communication device may monitor the preamble (601) during a first time interval (610), a second time interval (620), a third time interval (630), and a fourth time interval (640). In one example, the time interval may be referred to as delay ambiguity.

[0086] For example, the communication device may measure the energy (e.g., SINR (signal to interference plus noise ratio)) of the preamble based on monitoring the preamble during a first time interval (610). The communication device may measure the energy (e.g., SINR) of the preamble based on monitoring the preamble during a second time interval (620). The communication device may determine the difference between the energy measured during the first time interval (610) and the energy measured during the second time interval (620). In one example, the difference between the energy measured during the first time interval (610) and the energy measured during the second time interval (620) may be determined according to [Equation 1] below.

[0087]

[0088] In [Mathematical Formula 1], is the difference between the energy measured during the first time interval (610) and the energy measured during the second time interval (620). is the energy measured during the first time interval (610). is the energy measured during the second time interval (620).

[0089] For example, the communication device may measure the energy (e.g., SINR) of the preamble based on monitoring the preamble during a third time interval (630). The communication device may measure the energy (e.g., SINR) of the preamble based on monitoring the preamble during a fourth time interval (640). The communication device may determine the difference between the energy measured during the third time interval (630) and the energy measured during the fourth time interval (640). In one example, the difference between the energy measured during the third time interval (630) and the energy measured during the fourth time interval (640) may be determined according to [Equation 2] below.

[0090]

[0091] In [Mathematical Formula 2], is the difference between the energy measured during the third time interval (630) and the energy measured during the fourth time interval (640). is the energy measured during the third time interval (630). is the energy measured during the fourth hour interval (640). Below, is referred to as the first energy, and It is referred to as secondary energy.

[0092] For example, the communication device may select the preamble (602) from the preamble (602) and the preamble (603) based on the determination that the first energy is greater than the second energy. Based on the selection of the preamble (602), the communication device may determine a timing advance (TA) to compensate for the propagation delay according to the time at which the preamble (602) is received. The communication device may transmit a random access response (RAR) containing the value of the TA to the terminal (120). In another example, the communication device may select the preamble (603) from the preamble (602) and the preamble (603) based on the determination that the second energy is greater than the first energy. Based on the selection of the preamble (603), the communication device may determine a timing advance (TA) to compensate for the propagation delay according to the time at which the preamble (603) is received. The communication device can transmit a RAR containing the value of TA to the terminal (120).

[0093] A communication device can detect a preamble even when the distance between the communication device and the terminal (120) is long, based on the method described above. The method described above may be applied when there are two or more repetitions of the preamble sequence. For example, the communication device and the terminal (120) may use the method based on short sequence formats (e.g., A1, A2, A3, B1, B2, B3, B4, C2) for coverage extension. For example, the communication device and the terminal (120) may use the method based on long sequence formats (e.g., 1, 2, 3) for coverage extension.

[0094] However, short sequence formats may have limitations in coverage extension because the sequence length is short. Long sequence formats may have the problem of being difficult to use in TDD (time division duplex) structures that include more downlink slots because the sequence length is long. Therefore, a preamble format 0 with a long sequence length and a sequence repetition count of 1 may be used. Below, a communication device for extending the coverage of a preamble using preamble format 0 and a method performed by the communication device are described.

[0095] FIG. 7 is a flowchart illustrating the operations of a communication device for extending the coverage of a preamble. The operations of FIG. 7 may be performed by the communication device. For example, the communication device may be a base station (110) including an upper network node (210) (e.g., a DU (distributed unit)) and a lower network node (220) (e.g., a RU (radio unit)). For example, the communication device may be an upper network node (210). At least some of the operations of FIG. 7 may be controlled by a processor (330) of the upper network node (210). In the following, each operation may be performed sequentially, but is not necessarily performed sequentially. For example, the order of each operation may be changed. For example, at least two operations may be performed in parallel. FIG. 7 describes the operations of a communication device for extending the coverage of a preamble.

[0096] Referring to FIG. 7, in operation 701, a communication device according to one embodiment can transmit a master information block (MIB) to a terminal (120).

[0097] In one embodiment, the communication device may transmit an SS / PBCH (synchronization signal physical broadcast channel) block to a terminal (120). For example, the SS / PBCH block may include a MIB (master information block). The MIB may include a parameter (e.g., subCarrierSpacingCommon) indicating the SCS (subcarrier spacing) for the initial connection procedure. For example, the parameter indicating the SCS may be 1 bit. In one example, the parameter indicating the SCS may be as described in [Table 3] above. In one example, when the SS / PBCH block is transmitted at FR (frequency range) 1 and the parameter indicates 0, the SCS for the initial connection procedure may be 15 kHz (kilohertz). In one example, when the SS / PBCH block is transmitted at FR1 and the parameter indicates 1, the SCS for the initial connection procedure may be 30 kHz. In one example, when an SS / PBCH block is transmitted from FR2 and a parameter indicates 0, the SCS for the initial connection procedure may be 60 kHz. In one example, when an SS / PBCH block is transmitted from FR2 and a parameter indicates 1, the SCS for the initial connection procedure may be 120 kHz. In FIG. 7, the communication device may transmit an SS / PBCH block containing a parameter indicating 0 to the terminal (120) from FR1. That is, the SCS for the initial connection procedure may be 30 kHz.

[0098] In operation 702, a communication device according to one embodiment may transmit a system information block (SIB) 1 to a terminal (120). SIB 1 may include a physical random access channel (PRACH) configuration index. The PRACH configuration index may indicate a preamble format, a subframe number, a starting symbol, the number of PRACH slots within the subframe, the number of PRACH occasions within the PRACH slot, and / or a PRACH duration. In one example, the information indicated by the PRACH configuration index may be referenced from Tables 6.3.3.2-2 to 6.3.3.2-4 of 3GPP (3rd generation partnership project) TS (technical specification) 38.211. In one example, SIB 1 may be referred to as RMSI (remaining minimum system information) or another term having an equivalent technical / functional meaning.

[0099] In one embodiment, the preamble format indicated by the PRACH setting index may be one of short sequence formats and long sequence formats. In one example, the short sequence formats may be as shown in [Table 4] below.

[0100] Short sequence format sequence duration A1 A2 A3 B1 B2 B3 B4 C0 C2

[0101] In [Table 4], Ts is the sampling period, and is the SCS of the preamble. In one example, the number of repetitions of the sequence in format A1 may be 2. In one example, the number of repetitions of the sequence in format A2 may be 4. In one example, the number of repetitions of the sequence in format A3 may be 6. In one example, the number of repetitions of the sequence in format B1 may be 2. In one example, the number of repetitions of the sequence in format B2 may be 4. In one example, the number of repetitions of the sequence in format B3 may be 6. In one example, the number of repetitions of the sequence in format B4 may be 12. In one example, the number of repetitions of the sequence in format C0 may be 1. In one example, the number of repetitions of the sequence in format C2 may be 4. Referring to [Table 4], short sequence formats can extend coverage by using sequence repetition. However, since short sequence formats have short sequence lengths, there may be limitations to coverage extension.

[0102] In one example, long sequence formats may be as shown in [Table 5] below.

[0103] Long sequence format sequence duration 0 1 2 3

[0104] Referring to [Table 5], the lengths of preamble format 1 and preamble format 2 are longer than the lengths of two slots (or one subframe) in the 30 kHz SCS for initial connection, so they may be difficult to use in a time division duplex (TDD) structure that includes more downlink slots. Preamble format 3 has a short sequence length, so there may be limitations in coverage expansion. Therefore, preamble format 0 can be used for coverage expansion. For example, a communication device can transmit SIB 1, which includes a PRACH setting index indicating format 0, to a terminal (120).

[0105] In operation 703, a communication device according to one embodiment may monitor a preamble in a first time interval and a second time interval. For example, the communication device may determine the first time interval and the second time interval. For example, the starting boundary of the first time interval may correspond to the time elapsed from the start symbol of the UL slot (e.g., UL slot (801) in FIG. 8) for the cyclic prefix (CP) duration of Format 0. The first time interval is the sequence duration of the preamble of Format 0 (e.g., 800 It can correspond to ). The first time interval may be a time interval for monitoring a preamble based on a minimum propagation delay. In one example, when a preamble is detected in the first time interval, the distance between the communication device and the terminal (120) may be between 0 km and 10 km. For example, the second time interval may be a time interval that is subsequently allocated to the first time interval. The second time interval is the sequence duration of the preamble of format 0 (e.g., 800 It can correspond to. The second time interval may be a time interval for monitoring a preamble based on the maximum propagation delay. In one example, when a preamble is detected in the second time interval, the distance between the communication device and the terminal (120) may be approximately 120 km. In one example, the second time interval may overlap with at least some of the symbols of the first UL slot (e.g., UL slot (802) in FIG. 8), all symbols of the first DL slot (e.g., DL slot (803) in FIG. 8), and at least some of the symbols of the second DL slot (e.g., DL slot (804) in FIG. 8). The CP length of Format 0 is 103.13 The sequence length of format 0 is 800 Therefore, considering a symbol length of 30 kHz SCS, the end boundary of the second time interval can be located within the 6th symbol of the second DL slot.

[0106] In operation 704, a communication device according to one embodiment can determine whether the received signal quality for the preamble in the first time interval and the second time interval exceeds a threshold value.

[0107] In one embodiment, the communication device may measure a first signal quality (e.g., energy, SINR (signal to interference plus noise ratio)) for the preamble based on monitoring the preamble during a first time interval. For example, the communication device may measure a second signal quality (e.g., energy, SINR) for the preamble based on monitoring the preamble during a second time interval. The communication device may determine a signal quality that is the sum of the first signal quality and the second signal quality. The communication device may determine whether the signal quality for the preamble in the first time interval and the second time interval exceeds a threshold value.

[0108] In operation 705, a communication device according to one embodiment may transmit a random access response (RAR) to a terminal (120). For example, the communication device may detect a preamble based on a determination that the received signal quality for the preamble in a first time interval and a second time interval exceeds a threshold value. Based on detecting the preamble, the communication device may determine a timing advance (TA) based on the time at which the preamble was received. The TA may be used to control the uplink transmission timing of the terminal (120) by compensating for the propagation delay. The communication device may transmit a RAR containing the value of the TA to the terminal (120). In one example, the RAR may be referred to as msg 2 (message 2) or another term having an equivalent technical / functional meaning.

[0109] In operation 706, a communication device according to one embodiment may monitor a preamble in the next time interval based on the determination that the quality of the received signal for the preamble in the first time interval and the second time interval is below a threshold value.

[0110] FIG. 8 is a diagram illustrating an example of detecting a preamble of format 0 for coverage expansion. The operations described in FIG. 8 may be performed by a communication device. For example, the communication device may be a base station (110) including an upper network node (210) (e.g., a DU (distributed unit)) and a lower network node (220) (e.g., a RU (radio unit)). For example, the communication device may be an upper network node (210). At least some of the operations of FIG. 8 may be controlled by a processor (330) of an upper network node (210).

[0111] Referring to FIG. 8, for example, a communication device may transmit an SS / PBCH (synchronization signal physical broadcast channel) block to a terminal (120). The SS / PBCH block may include a MIB (master information block). The MIB may include a parameter (e.g., subCarrierSpacingCommon) indicating the SCS (subcarrier spacing) for an initial access procedure. For example, the parameter indicating the SCS may be 1 bit. In one example, if the SS / PBCH block is transmitted at FR (frequency range) 1 and the parameter indicates 0, the SCS for the initial access procedure may be 15 kHz (kilohertz). In one example, if the SS / PBCH block is transmitted at FR1 and the parameter indicates 1, the SCS for the initial access procedure may be 30 kHz. In one example, when an SS / PBCH block is transmitted from FR2 and a parameter indicates 0, the SCS for the initial connection procedure may be 60 kHz. In one example, when an SS / PBCH block is transmitted from FR2 and a parameter indicates 1, the SCS for the initial connection procedure may be 120 kHz. In the example illustrated in FIG. 8, the communication device may transmit an SS / PBCH block containing a parameter indicating 0 from FR1 to the terminal (120). That is, the SCS for the initial connection procedure may be 30 kHz.

[0112] For example, a communication device may transmit a system information block (SIB) 1 to a terminal (120). SIB 1 may include a physical random access channel (PRACH) configuration index. The PRACH configuration index may indicate a preamble format. For example, the preamble formats may include short sequence formats and long sequence formats. Short sequence formats may have limitations in coverage extension because the sequence length is short. Some of the long sequence formats may not be suitable for a time division duplex (TDD) structure that includes more downlink slots, even though the sequence length is long. Therefore, a format 0 with a long sequence length may be used without using sequence repetition. In the example illustrated in FIG. 8, the communication device may transmit a SIB 1 containing a PRACH configuration index indicating format 0 to a terminal (120).

[0113] For example, the preamble may be received at different times depending on the distance between the communication device and the terminal (120). In one example, when the distance between the communication device and the terminal (120) is short, the preamble may be received across the UL (uplink) slot (801) and the UL slot (802). The preamble may include a CP (cyclic prefix) (811) and a sequence (812). In one example, when the distance between the communication device and the terminal (120) is long (e.g., 120 km), the preamble may be received across the UL slot (802), the DL (downlink) slot (803), and the DL slot (804). The preamble may include a CP (821) and a sequence (822).

[0114] For example, the communication device may determine a first time interval (810) and a second time interval (820) for monitoring the preamble of Format 0. For example, the starting boundary of the first time interval (810) may be the time elapsed by CP (811) from the start symbol of the UL slot (801). The first time interval (810) is the duration of the preamble sequence (812) of Format 0 (e.g., 800 It can correspond to ). The first time interval (810) may be a time interval for monitoring a preamble based on a minimum propagation delay. For example, the second time interval (820) may be a time interval continuously allocated subsequently to the first time interval (810). The second time interval (820) may be a duration of the preamble sequence (822) of format 0 (e.g., 800 It can correspond to ). The second time interval (820) may be a time interval for monitoring a preamble based on the maximum propagation delay. In one example, when the preamble is received in the second time interval (820), the distance between the communication device and the terminal (120) may be approximately 120 km. In one example, the preamble may be received with a delay of time (823). Time (823) may be included in the calculable range of the TA included in the RAR.

[0115] For example, a communication device may measure a first signal quality (e.g., energy, SINR (signal to interference plus noise ratio)) for a preamble based on monitoring the preamble during a first time interval. For example, a communication device may measure a second signal quality (e.g., energy, SINR) for a preamble based on monitoring the preamble during a second time interval. The communication device may determine a signal quality that is the sum of the first signal quality and the second signal quality. The communication device may determine whether the signal quality for the preamble in the first time interval and the second time interval exceeds a threshold value. Based on the determination that the signal quality for the preamble in the first time interval and the second time interval exceeds a threshold value, the communication device may detect the preamble. Based on detecting the preamble, the communication device may determine a timing advance (TA) according to the time at which the preamble was received. TA can be used to control the uplink transmission timing of the terminal (120) by compensating for propagation delay. The communication device can transmit a random access response (RAR) containing the value of TA to the terminal (120). The terminal (120) can transmit msg 3 (message 3) to the communication device based on the value of TA included in the RAR.

[0116] As described above, the communication device can extend the coverage of the preamble by monitoring the preamble of Format 0 in the first time interval (810) and the second time interval (820). However, as illustrated in FIG. 8, at least a portion of the second time interval (820) may overlap with the entire symbols of the DL slot (803) and some symbols of the DL slot (804). For example, the CP length of Format 0 is 103.13 The sequence length of format 0 is 800 Therefore, considering a symbol length with an SCS of 30 kHz, the end boundary of the second time interval (820) can be located within the 6th symbol of the DL slot (804). Thus, at least a portion of the second time interval (820) for monitoring the preamble, which is a UL signal, can overlap with all the symbols of the first slot (803) and some symbols of the DL slot (804). Below, a method for performing downlink scheduling is described when the time interval for monitoring the preamble, which is a UL signal, overlaps with at least a portion of the DL slots.

[0117] FIG. 9 is a flowchart illustrating the operations of a communication device for performing scheduling in the coverage extension of a preamble. The operations of FIG. 9 may be performed by a communication device. For example, the communication device may be a base station (110) including an upper network node (210) (e.g., a DU (distributed unit)) and a lower network node (220) (e.g., a RU (radio unit)). For example, the communication device may be an upper network node (210). At least some of the operations of FIG. 9 may be controlled by a processor (330) of an upper network node (210). In the following, each operation may be performed sequentially, but is not necessarily performed sequentially. For example, the order of each operation may be changed. For example, at least two operations may be performed in parallel. FIG. 9 describes the operations of a communication device for performing downlink (DL) scheduling in the coverage extension of a preamble described in FIG. 7. For example, the operations described in FIG. 9 can be performed in parallel with the operation 703 of FIG. 7.

[0118] Referring to FIG. 9, in operation 901, a communication device according to one embodiment may determine a time interval for monitoring a preamble. For example, the time interval may include a first time interval and a second time interval. For example, the starting boundary of the first time interval may be the time elapsed by a cyclic prefix (CP) from the starting symbol of the uplink (UL) slot (e.g., UL slot (801) in FIG. 8). The first time interval is the duration of the preamble sequence of format 0 (e.g., 800 It can correspond to ). The first time interval may be a time interval for monitoring a preamble based on the minimum propagation delay. For example, the second time interval may be a time interval continuously allocated subsequently to the first time interval. The second time interval is the duration of the preamble sequence of format 0 (e.g., 800 It can correspond to ). The second time interval may be a time interval for monitoring a preamble based on the maximum propagation delay. In one example, when a preamble is received in the second time interval, the distance between the communication device and the terminal (120) may be approximately 120 km. For example, in a time division duplex (TDD) structure, at least a portion of the second time interval may overlap with the entire symbols of the first downlink (DL) slot and some symbols of the second DL slot. For example, the CP length of format 0 is 103.13 The sequence length of format 0 is 800 Therefore, considering a symbol length of 30 kHz SCS, the end boundary of the second time interval can be located within the 6th symbol of the second DL slot.

[0119] In operation 902, a communication device according to one embodiment may determine whether the communication device supports full duplex (or a full duplex filter). For example, if the communication device supports full duplex, the communication device may perform downlink transmission and uplink reception simultaneously. In another example, if the communication device does not support full duplex, the communication device may perform either downlink transmission or uplink reception.

[0120] In operation 903, a communication device according to one embodiment may perform scheduling on DL symbols of a time interval. For example, the communication device may perform scheduling on DL symbols corresponding to a time interval for monitoring a preamble, depending on the determination that the communication device supports full duplex (or a full duplex filter). Since downlink transmission and uplink reception can be performed simultaneously when the communication device supports full duplex, the communication device may perform DL scheduling on DL symbols that overlap with a time interval for monitoring an uplink preamble. In one example, the communication device may transmit downlink control information (DCI) and / or DL ​​data on at least some of the DL symbols to a different terminal different from the terminal (120).

[0121] In operation 904, a communication device according to one embodiment may perform blanking on at least one symbol among the downlink symbols of a time interval. For example, the communication device may refrain from performing DL scheduling on DL symbols corresponding to a time interval for monitoring a preamble, based on a decision that the communication device does not support full duplex. Since DL transmission and UL reception cannot be performed simultaneously when the communication device does not support full duplex, the communication device may refrain from performing scheduling on DL symbols that overlap with a time interval for monitoring a preamble, which is a UL signal.

[0122] In one embodiment, the communication device may perform blanking on DL symbols that overlap with the time interval for monitoring the preamble. For example, the communication device may refrain from performing downlink scheduling on all symbols of the first DL slot and some symbols of the second DL slot that overlap with the time interval. The communication device may perform downlink scheduling on the remaining symbols of the second DL slot. For example, the PDSCH (physical downlink shared channel) mapping type for DL ​​scheduling may be as shown in [Table 6] below.

[0123] PDSCH Mapping Type SLS+L Type A0~33~143~14 Type B0~122, 4, 72~14

[0124] Since the end boundary of the second time interval for monitoring the preamble is located within the 6th symbol of the second DL slot, PDSCH type A with a start symbol of 0 to 3 cannot be used. Therefore, the communication device can perform DL scheduling for a different terminal different from the terminal (120) by using PDSCH mapping type B. In one example, the communication device can transmit downlink control information (DCI) for DL ​​scheduling to the terminal. The DCI may include a time domain resource assignment (TDRA) field indicating the start symbol of the physical downlink shared channel (PDSCH), the number of symbols, and / or PDSCH type B. The start symbol of the PDSCH indicated by the TDRA field may be a symbol after the 6th symbol of the second DL slot (e.g., 6 to 13 of symbols 0 to 13).

[0125] In one embodiment, if blanking is performed on the symbols of the second DL slot, DL throughput may be reduced and / or DL ​​scheduling for terminals that do not support PDSCH mapping type B may be impossible. To reduce DL throughput and / or to enable DL scheduling for terminals that do not support PDSCH mapping type B, the communication device may not perform blanking on the symbols of the second DL slot. The communication device may perform DL scheduling in the symbols of the second DL slot in a resource block (RB) region different from the RB for the preamble.

[0126] FIGS. 10a through 10c illustrate examples of downlink scheduling performed by a communication device. The operations described in FIGS. 10a through 10c may be performed by a communication device. For example, the communication device may be a base station (110) comprising an upper network node (210) (e.g., a DU (distributed unit)) and a lower network node (220) (e.g., a RU (radio unit)). For example, the communication device may be an upper network node (210). At least some of the operations of FIGS. 10a through 10c may be controlled by a processor (330) of the upper network node (210).

[0127] For example, a communication device may transmit an SS / PBCH (synchronization signal physical broadcast channel) block to a terminal (120). The SS / PBCH block may include a MIB (master information block). The MIB may include a parameter (e.g., subCarrierSpacingCommon) indicating the SCS (subcarrier spacing) for an initial access procedure. For example, the parameter indicating the SCS may be 1 bit. In one example, if the SS / PBCH block is transmitted at FR (frequency range) 1 and the parameter indicates 0, the SCS for the initial access procedure may be 15 kHz (kilohertz). In one example, if the SS / PBCH block is transmitted at FR1 and the parameter indicates 1, the SCS for the initial access procedure may be 30 kHz. In one example, when an SS / PBCH block is transmitted from FR2 and a parameter indicates 0, the SCS for the initial connection procedure may be 60 kHz. In one example, when an SS / PBCH block is transmitted from FR2 and a parameter indicates 1, the SCS for the initial connection procedure may be 120 kHz. In the examples illustrated in FIGS. 10a to 10c, the communication device may transmit an SS / PBCH block containing a parameter indicating 0 to the terminal (120) from FR1. That is, the SCS for the initial connection procedure may be 30 kHz.

[0128] For example, a communication device may transmit a system information block (SIB) 1 to a terminal (120). SIB 1 may include a physical random access channel (PRACH) configuration index. The PRACH configuration index may indicate a preamble format. For example, the preamble formats may include short sequence formats and long sequence formats. Short sequence formats may have limitations in coverage extension because the sequence length is short. Some of the long sequence formats may not be suitable for a time division duplex (TDD) structure that includes more downlink slots, even though the sequence length is long. Therefore, a format 0 with a long sequence length may be used without using sequence repetition. In the example illustrated in FIGS. 10a to 10c, the communication device may transmit a SIB 1 containing a PRACH configuration index indicating format 0 to a terminal (120).

[0129] Referring to FIGS. 10a through 10c, the communication device may determine a first time interval (1005) and a second time interval (1006) for monitoring a preamble. For example, the communication device may determine whether the sum of the first energy of the preamble measured in the first time interval (1005) (e.g., SINR (signal to interference plus noise ratio)) and the second energy of the preamble measured in the second time interval (1006) exceeds a threshold value. For example, the communication device may detect the preamble based on the determination that the sum of the energies exceeds the threshold value. Based on the detection of the preamble, the communication device may transmit a RAR (random access response) to the terminal (120). In another example, the communication device may monitor the preamble in the next monitoring time interval based on the determination that the sum of the energies is below the threshold value.

[0130] Referring to FIGS. 10a through 10c, the starting boundary of the first time interval (1005) may correspond to the time elapsed from the start symbol of the UL (uplink) slot (1001) by a cyclic prefix (CP) of Format 0. The first time interval (1005) is the duration of the preamble sequence of Format 0 (e.g., 800 It can correspond to ). The first time interval (1005) may overlap with at least some of the symbols of the UL slot (1001) and at least some of the symbols of the UL slot (1002). For example, the second time interval (1006) may be a time interval continuously allocated subsequently to the first time interval (1005). The second time interval (1006) is the duration of the preamble sequence of format 0 (e.g., 800 It can correspond to ). The second time interval (1006) may overlap with at least some of the symbols of the UL slot (1002), all of the symbols of the DL slot (1003), and at least some of the symbols of the DL slot (1004). For example, the CP length of format 0 is 103.13 The sequence length of format 0 is 800 Therefore, considering a symbol length of 30 kHz SCS, the end boundary of the second time interval (1006) can be located within the 6th symbol of the DL slot (1004). Below, a method for performing DL scheduling is described when the symbols of the DL slot overlap with the second time interval (1006) for monitoring the preamble, which is a UL signal.

[0131] Referring to FIG. 10a, the communication device may support full duplex (or a full duplex filter). A communication device supporting full duplex may perform DL transmission and UL reception simultaneously. Therefore, the communication device may perform scheduling for a terminal in the symbols of the DL slot (1003) and the symbols of the DL slot (1004). In one example, the communication device may transmit a signal to the terminal in the CORESET (control resource set) 0 (1012) of the DL slot (1003). The RB (resource block) range of the CORESET 0 (1012) may differ from the RB range of the preamble. The signal may be DCI (downlink control information), SIB (system information) 1, or a paging signal. However, this is merely to explain that downlink scheduling may be performed in the DL slot (1003), and the present disclosure is not limited thereto. The signal of the DL slot (1003) may be a different signal (e.g., SS / PBCH (synchronization signal physical broadcast channel) block, PDSCH) that is different from the signals described above. In one example, the communication device may transmit a signal to the terminal at CORESET 0 (1013) of the DL slot (1004). The RB range of CORESET 0 (1013) may be different from the RB range of the preamble. The signal may be a DCI, SIB 1, or paging signal. However, this is merely to explain that downlink scheduling may be performed in the DL slot (1004), and the present disclosure is not limited thereto. The signal scheduled in the DL slot (1003) may be a different signal (e.g., SS / PBCH block, PDSCH) that is different from the signals described above.For example, a communication device may perform PRB (physical resource block) blanking in the remaining symbols (1011) of the DL slot (1004). However, this is merely an example and the present disclosure is not limited thereto. For example, a communication device may schedule PDSCH in the remaining symbols (1011) for a terminal that supports PDSCH (physical downlink shared channel) mapping type B.

[0132] Referring to FIG. 10b, the communication device may not support full duplex (or a duplex filter). A communication device that does not support full duplex may perform either DL transmission or UL reception. A second time interval (1006) for monitoring the preamble, which is a UL signal, and all symbols of the DL slot (1003) and some symbols of the DL slot (1004) may overlap. Therefore, the communication device may perform slot blanking to monitor the preamble in an area (1021) that includes all symbols of the DL slot (1003) and some symbols of the DL slot (1004). For example, the communication device may refrain from performing DL scheduling in the area (1021). The communication device may perform downlink scheduling for the terminal in an area (1022) that includes the remaining symbols of the DL slot (1004). As described in [Table 6], since the end boundary of the second time interval (1006) is located within the 6th symbol of the DL slot (1004), PDSCH type A with a start symbol of 0 to 3 cannot be used. The communication device can perform DL scheduling for the terminal using PDSCH mapping type B. In one example, the communication device can transmit downlink control information (DCI) for DL ​​scheduling to the terminal. The DCI may include a time domain resource assignment (TDRA) field indicating the start symbol of the physical downlink shared channel (PDSCH), the number of symbols, and / or PDSCH type B. The start symbol of the PDSCH indicated by the TDRA field may be a symbol after the 6th symbol of the second DL slot (e.g., 6 to 13 of symbols 0 to 13).As described above, the communication device can improve DL throughput by performing DL scheduling for the area (1002).

[0133] Referring to FIG. 10c, full duplex (or full duplex filter) may not be supported. A communication device that does not support full duplex may perform either DL transmission or UL reception. A second time interval (1006) for monitoring the preamble, which is a UL signal, and all symbols of the DL slot (1003) and some symbols of the DL slot (1004) may overlap. Therefore, the communication device may perform slot blanking to monitor the preamble in an area (1031) that includes all symbols of the DL slot (1003). For example, the communication device may refrain from performing downlink scheduling in the area (1031). For example, if the terminal does not support PDSCH mapping type B, DL scheduling as described in FIG. 10b may not be possible. Therefore, the communication device may perform downlink scheduling for the terminal in the DL slot (1004) to improve DL throughput. In one example, a communication device may transmit a signal to a terminal in CORESET 0 (133) of a DL slot (1004). The RB range of CORESET 0 (1033) may differ from the RB range of the preamble. The signal may be a DCI, SIB 1, or paging signal. However, this is merely to illustrate that downlink scheduling may be performed in the DL slot (1004), and the present disclosure is not limited thereto. The signal scheduled in the DL slot (1003) may be a different signal (e.g., SS / PBCH block, PDSCH) that differs from the signals described above. For example, the communication device may perform PRB blanking to receive the preamble in the area (1032) of the DL slot (1004). However, this is merely an example, and the present disclosure is not limited thereto.For example, the communication device may not perform PRB blanking for symbols that do not overlap with the time interval for monitoring the preamble among the symbols of the DL slot (1004) in order to schedule PDSCH for a terminal supporting PDSCH mapping type B.

[0134] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure pertains.

[0135] A distributed unit (DU) as described above may include a communication circuit. The DU may include a memory that stores instructions and includes one or more storage media. The DU may include at least one processor that includes a processing circuit. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to transmit a system information block (SIB) to a terminal that includes a physical random access channel (PRACH) setting index indicating the format of a preamble for random access as format 0. When the instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to monitor the preamble in a first time interval corresponding to the duration of the preamble sequence of format 0 and in a second time interval corresponding to the duration that is subsequently allocated after the first time interval. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine whether the signal quality for the preamble measured in the first time interval and the second time interval exceeds a threshold value based on monitoring the preamble in the first time interval and the second time interval. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to transmit a random access channel (RAR) responding to the preamble to the terminal upon the determination that the signal quality exceeds the threshold value.

[0136] For example, when the above instructions are executed individually or collectively by the at least one processor, the DU may cause the terminal to transmit an SS / PBCH (synchronization signal physical broadcast channel) block containing a MIB (master information block) indicating a subcarrier spacing (SCS) of 30 kHz (kilohertz).

[0137] For example, at least a portion of the second time interval for monitoring the above preamble may overlap with all symbols of the first downlink slot and some of all symbols of the second downlink slot following the first downlink slot.

[0138] For example, when the above instructions are executed individually or collectively by the at least one processor, the DU may cause the terminal to transmit downlink control information (DCI) to a second terminal different from the terminal, the DCI including a time domain resource assignment field indicating a physical downlink shared channel (PDSCH) mapping type B in the remaining symbols of the second downlink slot.

[0139] For example, the start symbol indicated by the time domain resource allocation field above may be a symbol after the 6th symbol of the second downlink slot.

[0140] For example, when the above instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to refrain from performing downlink scheduling for terminals in all symbols of the first downlink slot and some of all symbols of the second downlink slot.

[0141] For example, when the above instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to refrain from performing downlink scheduling for terminals in all symbols of the first downlink slot. When the above instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to perform downlink scheduling for a second terminal different from the terminal in the symbols of the second downlink slot.

[0142] For example, the second terminal may not support PDSCH mapping type B.

[0143] For example, when the above instructions are executed individually or collectively by the at least one processor, the DU may cause downlink scheduling for a second terminal different from the terminal in the first downlink slot and the second downlink slot according to the identification that the DU supports a full duplex filter.

[0144] For example, when the above instructions are executed individually or collectively by the at least one processor, the DU may cause the DU to determine a timing advance (TA) representing the propagation delay of the preamble. The RAR may include the TA.

[0145] A method performed by a DU (distributed unit) as described above may include the operation of transmitting a SIB (system information block) to a terminal that includes a PRACH (physical random access channel) setting index indicating the format of a preamble for random access as format 0. The method may include the operation of monitoring the preamble in a first time interval corresponding to the duration of the preamble sequence of format 0 and in a second time interval corresponding to the duration that is continuously allocated following the first time interval. The method may include the operation of determining whether the signal quality of the preamble measured in the first time interval and the second time interval exceeds a threshold value based on monitoring the preamble in the first time interval and the second time interval. The method may include the operation of transmitting a RAR (random access channel) responding to the preamble to the terminal in accordance with the determination that the signal quality exceeds the threshold value.

[0146] For example, the above method may include the operation of transmitting an SS / PBCH (synchronization signal physical broadcast channel) block containing a MIB (master information block) indicating a 30 kHz (kilohertz) SCS (subcarrier spacing) to the terminal.

[0147] For example, at least a portion of the second time interval for monitoring the above preamble may overlap with all symbols of the first downlink slot and some of all symbols of the second downlink slot following the first downlink slot.

[0148] For example, the above method may include the operation of transmitting downlink control information (DCI) to a second terminal different from the terminal, the DCI including a time domain resource assignment field indicating a physical downlink shared channel (PDSCH) mapping type B in the remaining symbols of the second downlink slot.

[0149] For example, the start symbol indicated by the time domain resource allocation field above may be a symbol after the 6th symbol of the second downlink slot.

[0150] For example, the above method may include an operation of refraining from performing downlink scheduling for terminals in some of the entire symbols of the first downlink slot and the entire symbols of the second downlink slot.

[0151] For example, the method may include an operation of refraining from performing downlink scheduling for terminals in all symbols of the first downlink slot. The method may include an operation of performing downlink scheduling for a second terminal different from the terminal in the symbols of the second downlink slot.

[0152] For example, the second terminal may not support PDSCH mapping type B.

[0153] For example, the above method may include an operation of performing downlink scheduling for a second terminal different from the terminal in the first downlink slot and the second downlink slot, depending on the identification that the DU supports a full duplex filter.

[0154] For example, the above method may include an operation to determine a timing advance (TA) representing the propagation delay of the preamble. The RAR may include the TA.

[0155] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs.

[0156] For one or more embodiments, at least one of the components described in one or more of the prior art drawings may be configured to perform one or more operations, techniques, processes and / or methods as described in the present disclosure. For example, a processor (e.g., a baseband processor) described in the present disclosure in relation to one or more of the prior art drawings may be configured to operate according to one or more examples described in the present disclosure. As another example, circuits associated with user equipment (UE), a base station, a network element, etc., as described above in relation to one or more of the prior art drawings may be configured to operate according to one or more examples described herein.

[0157] Any of the embodiments described above may be combined with any other embodiment (or combination of embodiments) unless otherwise explicitly stated. The foregoing description of one or more embodiments is for illustrative and explanatory purposes only, and is not intended to limit or exhaust the scope of the embodiments in the exact form disclosed. Modifications and variations are possible in light of the foregoing teachings or may be obtained from the practice of various embodiments.

[0158] Methods according to the claims or embodiments described in the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0159] When implemented in software, a computer-readable storage medium (e.g., a non-transient computer-readable storage medium) storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the specification of this 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 product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or distributed online (e.g., download or upload) through an application store (e.g., Play Store™) or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created on a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0160] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disc storage devices, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0161] Additionally, the program may be stored on an attachable storage device that can be accessed via a communication network such as the Internet, Intranet, LAN (local area network), WAN (wide area network), or SAN (storage area network), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

[0162] In the specific embodiments of the present disclosure described above, the components included in the disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0163] According to the embodiments, one or more of the aforementioned components or operations may be omitted, or one or more other components or operations may be added. Generally or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the plurality of components in the same or similar manner as those performed by the corresponding component among the plurality of components prior to the integration. According to the embodiments, 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.

[0164] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is understood that various modifications are possible within the scope of the present disclosure.

Claims

1. In the case of a DU (distributed unit), Communication circuit; Memory for storing instructions and including one or more storage media; and It includes at least one processor comprising a processing circuit, and When the above instructions are executed individually or collectively by the at least one processor, the DU, Transmit a system information block (SIB) containing a physical random access channel (PRACH) setting index that indicates the format of the preamble for random access as format 0 to the terminal, and Monitoring the preamble in a first time interval corresponding to the duration of the preamble sequence of the above format 0 and in a second time interval corresponding to the duration that is continuously allocated following the first time interval, and Based on monitoring the preamble in the first time interval and the second time interval, determining whether the signal quality of the preamble measured in the first time interval and the second time interval exceeds a threshold value, and Causing the terminal to transmit a RAR (random access channel) in response to the preamble, based on the determination that the above signal quality exceeds the above threshold value, DU.

2. In Paragraph 1, When the above instructions are executed individually or collectively by the at least one processor, the DU, Causing to transmit to the terminal an SS / PBCH (synchronization signal physical broadcast channel) block containing a MIB (master information block) indicating a 30 kHz (kilohertz) SCS (subcarrier spacing), DU.

3. In Paragraph 2, At least a portion of the second time interval for monitoring the above preamble overlaps with all symbols of the first downlink slot and some of all symbols of the second downlink slot following the first downlink slot, DU.

4. In Paragraph 3, When the above instructions are executed individually or collectively by the at least one processor, the DU, Causing to transmit downlink control information (DCI) to a second terminal different from the terminal, the DCI including a time domain resource assignment field indicating a PDSCH (physical downlink shared channel) mapping type B in the remaining symbols of the second downlink slot. DU.

5. In Paragraph 4, The start symbol indicated by the time domain resource allocation field above is the symbol after the 6th symbol of the second downlink slot, DU.

6. In Paragraph 4, When the above instructions are executed individually or collectively by the at least one processor, the DU, Causing to refrain from performing downlink scheduling for terminals in some of the entire symbols of the first downlink slot and the entire symbols of the second downlink slot, DU.

7. In Paragraph 3, When the above instructions are executed individually or collectively by the at least one processor, the DU, Refrain from performing downlink scheduling for terminals in all symbols of the first downlink slot, and Causing to perform downlink scheduling for a second terminal different from the terminal in the symbols of the second downlink slot above, DU.

8. In Paragraph 7, The above second terminal does not support PDSCH mapping type B, DU.

9. In Paragraph 3, When the above instructions are executed individually or collectively by the at least one processor, the DU, Based on the identification that the above DU supports a full duplex filter, causing downlink scheduling for a second terminal different from the terminal to be performed in the first downlink slot and the second downlink slot, DU.

10. In Paragraph 1, When the above instructions are executed individually or collectively by the at least one processor, the DU, Causing to determine the TA (timing advance) representing the propagation delay of the above preamble, The above RAR includes the above TA, DU.

11. In a method performed by a DU (distributed unit), The operation of transmitting a system information block (SIB) to a terminal that includes a physical random access channel (PRACH) setting index indicating the format of the preamble for random access as format 0; An operation of monitoring the preamble in a first time interval corresponding to the duration of the preamble sequence of the above format 0, and in a second time interval corresponding to the duration that is continuously allocated following the first time interval; An operation to determine whether the signal quality of the preamble measured in the first time interval and the second time interval exceeds a threshold value based on monitoring the preamble in the first time interval and the second time interval; and The operation of transmitting a RAR (random access channel) responding to the preamble to the terminal in accordance with the determination that the signal quality exceeds the threshold value, method.

12. In Paragraph 11, further comprising the operation of transmitting to the terminal an SS / PBCH (synchronization signal physical broadcast channel) block including a MIB (master information block) indicating a 30kHz (kilohertz) SCS (subcarrier spacing), method.

13. In Paragraph 12, At least a portion of the second time interval for monitoring the above preamble overlaps with all symbols of the first downlink slot and some of all symbols of the second downlink slot following the first downlink slot, method.

14. In Paragraph 13, The operation further includes transmitting downlink control information (DCI) to a second terminal different from the terminal, the DCI including a time domain resource assignment field indicating a PDSCH (physical downlink shared channel) mapping type B in the remaining symbols of the second downlink slot. method.

15. In Paragraph 14, The start symbol indicated by the time domain resource allocation field above is the symbol after the 6th symbol of the second downlink slot, method.

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