Method and device for downlink transmission over non-terrestrial network

Abstract

A method performed by a terminal according to an embodiment of the present disclosure may comprise the steps of: receiving at least one of system information or control information from a base station that communicates with the terminal over a non-terrestrial network (NTN); acquiring information about physical downlink shared channel (PDSCH) repeated transmission on the basis of at least one of the system information or the control information; and receiving the PDSCH repeated transmission from the base station on the basis of the information about the PDSCH repeated transmission.

Description

Method and device for downlink transmission through a non-terrestrial network

[0001] The present disclosure relates to a method and apparatus for downlink transmission through a non-terrestrial network in a wireless communication system.

[0002] Communication networks (e.g., 5G communication networks, 6G communication networks, etc.) are being developed to provide communication services that are improved over existing communication networks (e.g., LTE (long term evolution), LTE-A (advanced), etc.). 5G communication networks (e.g., NR (new radio) communication networks) can support frequency bands above 6 GHz as well as frequency bands below 6 GHz. That is, 5G communication networks can support the FR1 band and / or FR2 band. 5G communication networks can support a wider variety of communication services and scenarios compared to LTE communication networks. For example, usage scenarios for 5G communication networks may include eMBB (enhanced Mobile BroadBand), URLLC (Ultra Reliable Low Latency Communication), mMTC (massive Machine Type Communication), etc.

[0003] 6G communication networks can support a wider variety of communication services and scenarios compared to 5G communication networks. 6G communication networks can meet the requirements for ultra-high performance, ultra-bandwidth, ultra-spatial, ultra-precision, ultra-intelligence, and / or ultra-reliability. 6G communication networks can support a variety of wide frequency bands and can be applied to various usage scenarios (e.g., terrestrial communication, non-terrestrial communication, sidelink communication, etc.).

[0004] Communication networks (e.g., 5G communication networks, 6G communication networks, etc.) can provide communication services to terminals located on the ground. There is an increasing demand for communication services for aircraft, drones, satellites, etc., located not only on the ground but also non-ground, and to meet this demand, technologies for non-terrestrial networks (NTNs) are being discussed. Non-terrestrial networks can be implemented based on 5G communication technology, 6G communication technology, etc. For example, in a non-terrestrial network, communication between a satellite and a communication node located on the ground or a communication node located non-terrestrial (e.g., an aircraft, a drone, etc.) can be performed based on 5G communication technology, 6G communication technology, etc. In a non-terrestrial network, a satellite can perform the function of a base station in a communication network (e.g., 5G communication networks, 6G communication networks, etc.).

[0005] Meanwhile, the technology forming the background of the invention is written to enhance understanding of the background of the invention and may include content that is not prior art already known to those skilled in the art to which this technology belongs.

[0006] The present disclosure aims to provide a method and apparatus for downlink transmission through a non-terrestrial network in a wireless communication system.

[0007] One embodiment of the present disclosure discloses a method performed by a terminal in a wireless communication system. The method may include the steps of receiving at least one of system information or control information from a base station communicating with the terminal via a Non-Terrestrial Network (NTN); obtaining information regarding a Physical Downlink Shared Channel (PDSCH) repetitive transmission based on at least one of the system information or the control information; and receiving a PDSCH repetitive transmission by the base station based on the information regarding the PDSCH repetitive transmission.

[0008] One embodiment of the present disclosure relates to a terminal performing communication in a wireless communication system. The terminal comprises at least one transceiver, at least one processor, and at least one memory connected to the at least one processor to be operable and storing instructions that, when executed by the processor, control the terminal to perform operations, wherein the operations may include receiving at least one of system information or control information from a base station communicating with the terminal via an NTN, obtaining information regarding a PDSCH repetitive transmission based on at least one of the system information or control information, and receiving a PDSCH repetitive transmission by the base station based on the information regarding the PDSCH repetitive transmission.

[0009] One embodiment of the present disclosure discloses a method performed by a base station in a wireless communication system. The method may include the steps of transmitting at least one of system information or control information to a terminal communicating with the base station via an NTN, and repeatedly transmitting a PDSCH associated with at least one of the system information or the control information.

[0010] One embodiment of the present disclosure relates to a base station that performs communication in a wireless communication system. The base station comprises at least one transceiver, at least one processor, and at least one memory connected to the at least one processor to be operable and storing instructions that control the base station to perform operations when executed by the processor, wherein the operations may include the step of transmitting at least one of system information or control information to a terminal communicating with the base station via an NTN, and the step of repeatedly transmitting a PDSCH associated with at least one of the system information or the control information.

[0011] According to one embodiment of the present disclosure, downlink communication can be effectively performed in a wireless communication system.

[0012] According to one embodiment of the present disclosure, downlink transmission through a non-terrestrial network can be effectively performed in a wireless communication system.

[0013] According to one embodiment of the present disclosure, PDSCH repetitive transmission can be effectively performed based on at least one of system information or control information transmitted from a base station to a terminal via NTN.

[0014] The effects according to the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art to which the technical configuration of the present disclosure applies from the description of the embodiments of the present disclosure below. That is, unintended effects resulting from implementing the configuration described in the present disclosure can also be derived by those skilled in the art from the embodiments of the present disclosure.

[0015] FIGS. 1A and FIGS. 1B are conceptual diagrams illustrating some embodiments of a non-ground network.

[0016] FIGS. 2A to 2C are conceptual diagrams illustrating some embodiments of a non-ground network.

[0017] FIG. 3 is a block diagram illustrating a first embodiment of a communication node constituting a non-terrestrial network.

[0018] FIG. 4 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0019] FIG. 5A is a block diagram illustrating a first embodiment of a transmission path, and FIG. 5B is a block diagram illustrating a first embodiment of a reception path.

[0020] FIG. 6 is a conceptual diagram illustrating an example of a system frame in a communication system.

[0021] FIG. 7 is a conceptual diagram illustrating an example of a subframe in a communication system.

[0022] FIG. 8 is a conceptual diagram illustrating an example of a slot in a communication system.

[0023] Figure 9 is a diagram showing the timing relationship between the uplink and downlink in a communication system.

[0024] FIG. 10A is a conceptual diagram illustrating a first embodiment of a protocol stack of the user plane in a transparent payload-based non-ground network, and FIG. 10B is a conceptual diagram illustrating a first embodiment of a protocol stack of the control plane in a transparent payload-based non-ground network.

[0025] FIG. 11A is a conceptual diagram illustrating a first embodiment of a protocol stack of the user plane in a regenerative payload-based non-terrestrial network, and FIG. 11B is a conceptual diagram illustrating a first embodiment of a protocol stack of the control plane in a regenerative payload-based non-terrestrial network.

[0026] FIG. 12 is a diagram showing an example of the process of a terminal connecting to an NTN cell according to one embodiment.

[0027] Figure 13 is a diagram showing an example of an explicit instruction process based on a Master Information Block (MIB).

[0028] FIG. 14 is a diagram showing an example of a PDCCH (Physical Downlink Control Channel)-based explicit instruction process for SIB1 (System Information Block 1).

[0029] Figure 15 is a diagram showing an example of an SIB-based explicit instruction process.

[0030] FIG. 16 is a diagram showing an example of a PDCCH-based explicit or implicit instruction process for MSG2.

[0031] FIG. 17 is a diagram showing an example of a PDCCH-based explicit or implicit instruction process for MSG4.

[0032] FIG. 18 is a diagram showing an example of an implicit instruction process based on the SSB (Synchronization Signal Block) period.

[0033] FIG. 19 is a diagram showing an example of an implicit instruction process based on the MSG3 PUSCH (Physical Uplink Shared Channel) repetition factor.

[0034] FIG. 20 is a diagram illustrating an example of a process of performing automatic repetitive transmission without explicit or implicit instructions.

[0035] FIG. 21 is a diagram showing an example of an implicit instruction process based on RSRP (Reference Signals Received Power).

[0036] FIG. 22 is a flowchart illustrating a method in which a terminal performs communication according to one embodiment.

[0037] FIG. 23 is a flowchart illustrating a method in which a base station performs communication according to one embodiment.

[0038] One embodiment of the present disclosure discloses a method performed by a terminal in a wireless communication system. The method may include the steps of receiving at least one of system information or control information from a base station communicating with the terminal via a Non-Terrestrial Network (NTN); obtaining information regarding a Physical Downlink Shared Channel (PDSCH) repetitive transmission based on at least one of the system information or the control information; and receiving a PDSCH repetitive transmission by the base station based on the information regarding the PDSCH repetitive transmission.

[0039] The present disclosure is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present disclosure to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present disclosure.

[0040] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present disclosure, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0041] In the present disclosure, "at least one of A and B" may mean "at least one of A or B" or "at least one of one or more combinations of A and B". Additionally, in the present disclosure, "at least one of A and B" may mean "at least one of A or B" or "at least one of one or more combinations of A and B".

[0042] In the present disclosure, (re)transmission may mean "transmission," "retransmission," or "transmission and retransmission"; (re)setting may mean "setting," "resetting," or "setting and resetting"; (re)connection may mean "connection," "reconnection," or "connection and reconnection"; and (re)connection may mean "connection," "reconnection," or "connection and reconnection".

[0043] When it is stated that a component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that a component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0044] The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit this disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, terms such as “comprising” or “having” are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0045] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which this disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this disclosure.

[0046] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. To facilitate an overall understanding of the present disclosure, the same reference numerals are used for identical components in the drawings, and redundant descriptions of identical components are omitted. Operations according to combinations of embodiments, extensions of embodiments, and / or modifications of embodiments may be performed, in addition to the embodiments explicitly described in the present disclosure. The performance of some operations may be omitted, and the order of operations may be changed.

[0047] In the embodiments, even when a method performed at a first communication node among the communication nodes (e.g., transmission or reception of a signal) is described, the corresponding second communication node may perform a method corresponding to the method performed at the first communication node (e.g., reception or transmission of a signal). That is, when the operation of a UE (user equipment) is described, the corresponding base station may perform an operation corresponding to the operation of the UE. Conversely, when the operation of a base station is described, the corresponding UE may perform an operation corresponding to the operation of the base station. In a non-terrestrial network (NTN) (e.g., a payload-based NTN), the operation of the base station may refer to the operation of a satellite, and the operation of the satellite may refer to the operation of the base station.

[0048] A base station may be referred to as Node B, evolved Node B, gNode B (next generation node B), gNB, device, apparatus, node, communication node, BTS (base transceiver station), RRH (radio remote head), TRP (transmission reception point), RU (radio unit), RSU (road side unit), radio transceiver, access point, access node, etc. A UE may be referred to as terminal, device, apparatus, node, communication node, end node, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, OBU (on-broad unit), etc.

[0049] In the present disclosure, signaling may be at least one of upper-layer signaling, MAC signaling, or PHY (physical) signaling. A message used for upper-layer signaling may be referred to as an "upper-layer message" or an "upper-layer signaling message." A message used for MAC signaling may be referred to as a "MAC message" or a "MAC signaling message." A message used for PHY signaling may be referred to as a "PHY message" or a "PHY signaling message." Upper-layer signaling may refer to the transmission and reception operations of system information (e.g., MIB (master information block), SIB (system information block)) and / or RRC messages. MAC signaling may refer to the transmission and reception operations of MAC CE (control element). PHY signaling may refer to the transmission and reception operations of control information (e.g., DCI (downlink control information), UCI (uplink control information), SCI (sidelink control information)).

[0050] In the present disclosure, "setting an operation (e.g., a transmission operation)" may mean that "setting information for said operation (e.g., an information element, a parameter)" and / or "information directing the performance of said operation" is signaled. "Setting an information element (e.g., a parameter)" may mean that said information element is signaled. In the present disclosure, "signal and / or channel" may mean a signal, a channel, or "signal and channel," and "signal" may be used to mean "signal and / or channel."

[0051] The communication system is at least among a terrestrial network, a non-terrestrial network, a 4G communication network (e.g., LTE (long-term evolution) communication network), a 5G communication network (e.g., NR (new radio) communication network), or a 6G communication network.

[0052] It may include one. Each of the 4G communication network, 5G communication network, and 6G communication network may include a terrestrial network and / or a non-terrestrial network. The non-terrestrial network may operate based on at least one of LTE communication technology, 5G communication technology, or 6G communication technology. The non-terrestrial network may provide communication services in various frequency bands.

[0053] The communication networks to which the embodiments are applied are not limited to those described below, and the embodiments may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the term "communication network" may be used interchangeably with "communication system."

[0054] FIG. 1A is a conceptual diagram illustrating a first embodiment of a non-ground network.

[0055] Referring to FIG. 1A, the non-ground network may include a satellite (110), a communication node (120), a gateway (130), a data network (140), etc. A unit including the satellite (110) and the gateway (130) may be a remote radio unit (RRU). The non-ground network depicted in FIG. 1A may be a transparent payload-based non-ground network. The satellite (110) may be a low earth orbit (LEO) satellite, a medium earth orbit (MEO) satellite, a geostationary earth orbit (GEO) satellite, a high elliptical orbit (HEO) satellite, or an unmanned aircraft system (UAS) platform. A UAS platform may include a high altitude platform station (HAPS). A non-GEO satellite may be a LEO satellite and / or an MEO satellite.

[0056] The communication node (120) may include a communication node located on the ground (e.g., UE, terminal) and a communication node located off the ground (e.g., airplane, drone). A service link may be established between the satellite (110) and the communication node (120), and the service link may be a radio link. The satellite (110) may be referred to as an NTN payload. The gateway (130) may support multiple NTN payloads. The satellite (110) may provide communication services to the communication node (120) using one or more beams. The shape of the beam footprint of the satellite (110) may be elliptical or circular.

[0057] In non-terrestrial networks, three types of service links can be supported as follows.

[0058] - Earth-fixed: Service links can be provided by beam(s) that continuously cover the same geographic area (e.g., GSO (Geosynchronous Orbit) satellites).

[0059] - Quasi-earth-fixed: Service links may be provided by beam(s) that cover one geographic area for a limited period and another geographic area for a different period (e.g., NGSO (non-GSO) satellites generating steerable beams).

[0060] - Earth-moving: Service links may be provided by beam(s) moving across the Earth's surface (e.g., NGSO satellites generating fixed beams or non-steeringable beams)

[0061] A communication node (120) can communicate with a satellite (110) (e.g., downlink communication, uplink communication) using 4G communication technology, 5G communication technology, and / or 6G communication technology. Communication between the satellite (110) and the communication node (120) can be performed using an NR-Uu interface and / or a 6G-Uu interface. If dual connectivity (DC) is supported, the communication node (120) can be connected to another base station (e.g., a base station supporting 4G functions, 5G functions, and / or 6G functions) as well as the satellite (110), and can perform DC operations based on the technology defined in the 4G specifications, 5G specifications, and / or 6G specifications.

[0062] The gateway (130) may be located on the ground, and a feeder link may be established between the satellite (110) and the gateway (130). The feeder link may be a wireless link. The gateway (130) may be referred to as a "non-terrestrial network (NTN) gateway." Communication between the satellite (110) and the gateway (130) may be performed based on an NR-Uu interface, a 6G-Uu interface, or a satellite radio interface (SRI). The gateway (130) may be connected to a data network (140). A "core network" may exist between the gateway (130) and the data network (140). In this case, the gateway (130) may be connected to the core network, and the core network may be connected to the data network (140). The core network may support 4G communication technology, 5G communication technology, and / or 6G communication technology. For example, the core network may include an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc. Communication between the gateway (130) and the core network may be performed based on an NG-C / U interface or a 6G-C / U interface.

[0063] As shown in the embodiment of FIG. 1B below, in a non-terrestrial network based on a transparent payload, a base station and a core network may exist between the gateway (130) and the data network (140).

[0064] FIG. 1B is a conceptual diagram illustrating a second embodiment of a non-ground network.

[0065] Referring to FIG. 1B, the gateway can be connected to a base station, the base station can be connected to a core network, and the core network can be connected to a data network. Each of the base station and the core network can support 4G communication technology, 5G communication technology, and / or 6G communication technology. Communication between the gateway and the base station can be performed based on an NR-Uu interface or a 6G-Uu interface, and communication between the base station and the core network (e.g., AMF, UPF, SMF) can be performed based on an NG-C / U interface or a 6G-C / U interface.

[0066] FIG. 2A is a conceptual diagram illustrating a third embodiment of a non-ground network.

[0067] Referring to FIG. 2A, the non-ground network may include satellite #1 (211), satellite #2 (212), a communication node (220), a gateway (230), a data network (1240), etc. The non-ground network illustrated in FIG. 2A may be a non-ground network based on a regenerative payload. For example, each of satellite #1 (211) and satellite #2 (212) may perform a regenerative operation (e.g., demodulation, decoding, re-coding, re-modulation, and / or filtering) on ​​a payload received from other entities constituting the non-ground network (e.g., communication node (220), gateway (230)), and may transmit the regenerated payload.

[0068] Satellite #1 (211) and Satellite #2 (212) may each be a LEO satellite, MEO satellite, GEO satellite, HEO satellite, or UAS platform. A UAS platform may include a HAPS. Satellite #1 (211) may be connected to Satellite #2 (212), and an inter-satellite link (ISL) may be established between Satellite #1 (211) and Satellite #2 (212). The ISL may operate in a radio frequency (RF) frequency or optical band. The ISL may be configured optionally. Communication nodes (220) may include communication nodes located on the ground (e.g., UE, terminal) and communication nodes located off the ground (e.g., airplane, drone). A service link (e.g., wireless link) may be established between Satellite #1 (211) and the communication nodes (220). Satellite #1 (211) may be referred to as an NTN payload. Satellite #1 (211) can provide communication services to a communication node (220) using one or more beams.

[0069] The communication node (220) can communicate with satellite #1 (211) (e.g., downlink communication, uplink communication) using 4G communication technology, 5G communication technology, and / or 6G communication technology. Communication between satellite #1 (211) and the communication node (220) can be performed using an NR-Uu interface or a 6G-Uu interface. If DC is supported, the communication node (220) can be connected to satellite #1 (211) as well as other base stations (e.g., base stations supporting 4G functions, 5G functions, and / or 6G functions), and can perform DC operations based on the technology defined in the 4G specifications, 5G specifications, and / or 6G specifications.

[0070] The gateway (230) may be located on the ground, and a feeder link may be established between satellite #1 (211) and the gateway (230), and a feeder link may be established between satellite #2 (212) and the gateway (230). The feeder link may be a wireless link. If an ISL is not established between satellite #1 (211) and satellite #2 (212), a feeder link between satellite #1 (211) and the gateway (230) may be established mandatorily. Communication between satellite #1 (211) and satellite #2 (212), respectively, and the gateway (230) may be performed based on an NR-Uu interface, a 6G-Uu interface, or SRI. The gateway (230) may be connected to a data network (240).

[0071] As shown in the embodiments of FIGS. 2B and FIGS. 2C below, a "core network" may exist between the gateway (230) and the data network (240).

[0072] FIG. 2B is a conceptual diagram illustrating a fourth embodiment of a non-ground network, and FIG. 2C is a conceptual diagram illustrating a fifth embodiment of a non-ground network.

[0073] Referring to FIGS. 2B and 2C, the gateway may be connected to a core network, and the core network may be connected to a data network. The core network may support 4G communication technology, 5G communication technology, and / or 6G communication technology. For example, the core network may include an AMF, UPF, SMF, etc. Communication between the gateway and the core network may be performed based on an NG-C / U interface or a 6G-C / U interface. The functions of a base station may be performed by a satellite. That is, the base station may be located on a satellite. The payload may be processed by the base station located on the satellite. Base stations located on different satellites may be connected to the same core network. A single satellite may have one or more base stations. In the non-terrestrial network of FIG. 2B, an ISL between satellites may not be established, while in the non-terrestrial network of FIG. 2C, an ISL between satellites may be established.

[0074] Meanwhile, entities constituting the non-terrestrial network illustrated in FIG. 1A, FIG. 1B, FIG. 2A, FIG. 2B, and / or FIG. 2C (e.g., satellite, base station, UE, communication node, gateway, etc.) may be configured as follows. In the present disclosure, an entity may be referred to as a communication node.

[0075] FIG. 3 is a block diagram illustrating a first embodiment of a communication node constituting a non-terrestrial network.

[0076] FIG. 3 is a drawing showing an example of a wireless device (300) in a wireless communication system according to one embodiment of the present disclosure. The wireless device (300) according to an embodiment of the present disclosure may be a mobile terminal such as a smartphone, tablet PC, or wearable device, but may not be limited thereto.

[0077] Referring to FIG. 3, the wireless device (300) may include at least one control unit (310), at least one memory (320), at least one power supply unit (330), at least one transceiver unit (340), at least one input unit (350), at least one output unit (360) and / or at least one antenna (370).

[0078] The control unit (310) can control the memory (320) and / or the transmission / reception unit (340) and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this disclosure. The memory (320) may be connected to the control unit (310) and may store various information related to the operation of the control unit (310). For example, the memory (320) may store software code including instructions for performing some or all of the controls controlled by the control unit (310) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this disclosure. The configuration of the memory is not limited in a particular way. For example, it may be configured as at least one of read-only memory (ROM) and random access memory (RAM).

[0079] At least one control unit (310) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. The descriptions, functions, procedures, proposals, methods, and / or flowcharts of operations disclosed in this disclosure may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions. Here, the firmware or software may execute other programs stored in memory (320), such as an OS. The control unit (310) may be implemented to support differently weighted beamforming or directional routing operations to effectively control the outgoing signal from at least one antenna (370) to a desired direction.

[0080] Additionally, at least one control unit (310) may be coupled with a backhaul or network interface. The wireless device (300) may communicate with other wireless devices through the backhaul or network interface. The control unit (310) may include at least one processor. The processor may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the methods according to embodiments of the present disclosure are performed.

[0081] At least one transceiver (340) may be connected to a control unit (310) and may transmit and / or receive a wireless signal through at least one antenna (370). The transceiver (340) may include a transmitter and / or a receiver. At least one transceiver (340) may transmit user data, control information, wireless signals / channels, etc., as described in the methods and / or operation flowcharts of the present disclosure to at least one other device. For example, at least one transceiver (340) may be connected to at least one control unit (310) and may transmit and receive wireless signals. Additionally, at least one control unit (310) may control at least one transceiver (340) to transmit user data, control information, or wireless signals to at least one other device. At least one transmitter (340) may receive a signal transmitted by another wireless device from at least one antenna (370). Additionally, at least one transceiver (24) can down-convert or up-convert the received signal to generate a baseband signal. At least one antenna (370) may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports).

[0082] The input unit (350) can acquire information such as user input, video, and audio, and may include various input means such as various mechanical / electronic input means, cameras, and microphones. The output unit (360) is intended to provide information to a user by generating output related to sight, hearing, or touch, and may include a display, speaker, vibration module, etc. The wireless device (300) supplies power through the power unit (330), and the power unit (330) may include a wired / wireless charging circuit, battery, etc.

[0083] Meanwhile, communication nodes performing communication in a communication network (e.g., a non-terrestrial network) may be configured as follows. The communication node shown in FIG. 4 may be a specific embodiment of the communication node shown in FIG. 3.

[0084] FIG. 4 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0085] Referring to FIG. 4, the first communication node (400a) and the second communication node (400b) may each be a base station or a UE. The first communication node (400a) may transmit a signal to the second communication node (400b). A transmission processor (411) included in the first communication node (400a) may receive data (e.g., a data unit) from a data source (410). The transmission processor (411) may receive control information from a controller (416). The control information may include at least one of system information, RRC setting information (e.g., information set by RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0086] The transmitting processor (411) can generate data symbol(s) by performing processing operations on data (e.g., encoding operations, symbol mapping operations, etc.). The transmitting processor (411) can generate control symbol(s) by performing processing operations on control information (e.g., encoding operations, symbol mapping operations, etc.). Additionally, the transmitting processor (411) can generate synchronization / reference symbol(s) for a synchronization signal and / or a reference signal.

[0087] The Tx MIMO processor (412) can perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or synchronization / reference symbol(s). The output of the Tx MIMO processor (412) (e.g., a symbol stream) can be provided to modulators (MODs) included in transceivers (413a to 413t). The modulators (MODs) can perform processing operations on the symbol stream to generate modulation symbols and perform additional processing operations on the modulation symbols (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations) to generate signals. The signals generated by the modulators (MODs) of the transceivers (413a to 413t) can be transmitted through antennas (414a to 414t).

[0088] Signals transmitted by the first communication node (400a) can be received at the antennas (464a to 464r) of the second communication node (400b). Signals received at the antennas (464a to 464r) can be provided to demodulators (DEMODs) included in the transceivers (463a to 463r). The demodulators (DEMODs) can obtain samples by performing processing operations on the signals (e.g., filtering, amplification, down-conversion, digital conversion). The demodulators (DEMODs) can obtain symbols by performing additional processing operations on the samples. The MIMO detector (462) can perform MIMO detection operations on the symbols. Receiving processor

[0089] The receiving processor (461) can perform processing operations on the symbols (e.g., deinterleaving operation, decoding operation). The output of the receiving processor (461) can be provided to the data sink (460) and the controller (466). For example, data can be provided to the data sink (460), and control information can be provided to the controller (466).

[0090] Meanwhile, the second communication node (400b) can transmit a signal to the first communication node (400a). The transmission processor (468) included in the second communication node (400b) can receive data (e.g., a data unit) from a data source (467) and can generate data symbol(s) by performing a processing operation on the data. The transmission processor (468) can receive control information from a controller (466) and can generate control symbol(s) by performing a processing operation on the control information. Additionally, the transmission processor (468) can generate reference symbol(s) by performing a processing operation on a reference signal.

[0091] The Tx MIMO processor (469) can perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or reference symbol(s). The output of the Tx MIMO processor (469) (e.g., a symbol stream) can be provided to modulators (MODs) included in transceivers (463a to 463t). The modulators (MODs) can perform processing operations on the symbol stream to generate modulated symbols and perform additional processing operations on the modulated symbols (e.g., analog conversion operations, amplification operations, filtering operations, upconversion operations) to generate signals. The signals generated by the modulators (MODs) of the transceivers (463a to 463t) can be transmitted through antennas (464a to 464t).

[0092] Signals transmitted by the second communication node (400b) can be received at the antennas (414a to 414r) of the first communication node (400a). Signals received at the antennas (414a to 414r) can be provided to demodulators (DEMODs) included in the transceivers (413a to 413r). The demodulators (DEMODs) can obtain samples by performing processing operations on the signals (e.g., filtering operation, amplification operation, down-conversion operation, digital conversion operation). The demodulators (DEMODs) can obtain symbols by performing additional processing operations on the samples. The MIMO detector (420) can perform MIMO detection operations on the symbols. The receiving processor (419) can perform processing operations on the symbols (e.g., deinterleaving operation, decoding operation). The output of the receiving processor (419) can be provided to the data sink (418) and the controller (416). For example, data can be provided to the data sink (418), and control information can be provided to the controller (416).

[0093] The memories (415 and 465) may store data, control information, and / or program code. The scheduler (417) may perform scheduling operations for communication. The processors (411, 412, 419, 461, 468, 469) and controllers (416, 466) shown in FIG. 4 may be the processor (310) shown in FIG. 3 and may be used to perform the methods described in this disclosure.

[0094] FIG. 5A is a block diagram illustrating a first embodiment of a transmission path, and FIG. 5B is a block diagram illustrating a first embodiment of a reception path.

[0095] Referring to FIGS. 5A and 5B, a transmission path (510) may be implemented at a communication node that transmits a signal, and a reception path (520) may be implemented at a communication node that receives a signal. The transmission path (510) may include a channel coding and modulation block (511), an S-to-P (serial-to-parallel) block (512), an N IFFT (Inverse Fast Fourier Transform) block (513), a P-to-S (parallel-to-serial) block (514), a CP (cyclic prefix) addition block (515), and an UC (up-converter) (UC) (516). The receiving path (520) may include a DC (down-converter) (521), a CP removal block (522), an S-to-P block (523), an N FFT block (524), a P-to-S block (525), and a channel decoding and demodulation block (526). Here, N may be a natural number.

[0096] Information bits in the transmission path (510) can be input to the channel coding and modulation block (511). The channel coding and modulation block (511) can perform coding operations (e.g., LDPC (low-density parity check) (LDPC) coding operations, polar coding operations, etc.) and modulation operations (e.g., QPSK (Quadrature Phase Shift Keying), QAM (Quadrature Amplitude Modulation), etc.) on the information bits. The output of the channel coding and modulation block (511) may be a sequence of modulation symbols.

[0097] The S-to-P block (512) can convert modulated symbols in the frequency domain into parallel symbol streams to generate N parallel symbol streams. N can be the IFFT size or the FFT size. The N IFFT block (513) can generate signals in the time domain by performing IFFT operations on the N parallel symbol streams. The P-to-S block (514) can convert the output of the N IFFT block (513) (e.g., parallel signals) into a serial signal to generate a serial signal.

[0098] The CP addition block (515) can insert CP into the signal. The UC (516) can up-convert the frequency of the output of the CP addition block (515) to an RF (radio frequency) frequency. Additionally, the output of the CP addition block (515) can be filtered in the baseband before up-conversion.

[0099] A signal transmitted from the transmission path (510) can be input into the reception path (520). The operation in the reception path (520) may be the inverse operation of the operation in the transmission path (510). The DC (521) may down-convert the frequency of the received signal to a baseband frequency. The CP removal block (522) may remove CP from the signal. The output of the CP removal block (522) may be a serial signal. The S-to-P block (523) may convert the serial signal into parallel signals. The NFFT block (524) may generate N parallel signals by performing an FFT algorithm. The P-to-S block (525) may convert the parallel signals into a sequence of modulation symbols. The channel decoding and demodulation block (526) may perform a demodulation operation on the modulation symbols and restore data by performing a decoding operation on the result of the demodulation operation.

[0100] In FIGS. 5A and 5B, Discrete Fourier Transform (DFT) and Inverse DFT (IDFT) may be used instead of FFT and IFFT. In FIGS. 5A and 5B, each of the blocks (e.g., components) may be implemented by at least one of hardware, software, or firmware. For example, in FIGS. 5A and 5B, some blocks may be implemented by software, and the remaining blocks may be implemented by hardware or a "combination of hardware and software." In FIGS. 5A and 5B, one block may be subdivided into multiple blocks, multiple blocks may be integrated into one block, some blocks may be omitted, and blocks supporting other functions may be added.

[0101] FIG. 6 is a conceptual diagram illustrating an example of a system frame in a communication system.

[0102] Referring to FIG. 6, time resources in a communication system can be divided into frames. For example, system frames can be set consecutively in the time domain of the communication system. The length of a system frame can be 10 ms (millisecond). The system frame number (SFN) can be set from #0 to #1023. In this case, 1024 system frames can be repeated in the time domain of the communication system. For example, the SFN of a system frame after system frame #1023 can be #0.

[0103] A single system frame may contain two half frames. The length of a single half frame may be 5ms. A half frame located at the beginning of the system frame may be referred to as "Half Frame #0", and a half frame located at the end of the system frame may be referred to as "Half Frame #1". A system frame may contain 10 subframes. The length of a single subframe may be 1ms. Within a single system frame, the 10 subframes may be referred to as "Subframe #0-9".

[0104] FIG. 7 is a conceptual diagram illustrating an example of a subframe in a communication system.

[0105] Referring to FIG. 7, one subframe may contain n slots, where n is a natural number. Thus, one subframe may consist of one or more slots.

[0106] FIG. 8 is a conceptual diagram illustrating an example of a slot in a communication system.

[0107] Referring to FIG. 8, a slot may contain one or more symbols. A slot illustrated in FIG. 8 may contain 14 symbols. The length of the slot may vary depending on the number of symbols included in the slot and the length of the symbols. Alternatively, the length of the slot may vary depending on the numerology.

[0108] Numerals applied to physical signals and channels in a communication system may be variable. Numerals may be variable to meet various technical requirements of the communication system. In a communication system where CP (cyclic prefix) based OFDM waveform technology is applied, numerals may include subcarrier spacing and CP length (or CP type). Table 1 may be an example of a method for configuring numerals for a CP-OFDM based communication system. Depending on the frequency band in which the communication system operates, at least some of the numerals in Table 1 may be supported. Additionally, numerals not listed in Table 1 may be further supported in the communication system.

[0109] [Table 1]

[0110]

[0111] When the subcarrier spacing is 15 kHz (e.g., μ=0), the slot length may be 1 ms. In this case, one system frame may contain 10 slots. When the subcarrier spacing is 30 kHz (e.g., μ=1), the slot length may be 0.5 ms. In this case, one system frame may contain 20 slots.

[0112] When the subcarrier spacing is 60 kHz (e.g., mu=2), the slot length may be 0.25 ms. In this case, one system frame may contain 40 slots. When the subcarrier spacing is 120 kHz (e.g., mu=3), the slot length may be 0.125 ms. In this case, one system frame may contain 80 slots. When the subcarrier spacing is 240 kHz (e.g., mu=4), the slot length may be 0.0625 ms. In this case, one system frame may contain 160 slots.

[0113] A symbol can be set as a downlink (DL) symbol, a flexible (FL) symbol, or an uplink (UL) symbol. A slot consisting only of a DL symbol may be referred to as a "DL slot," a slot consisting only of an FL symbol may be referred to as an "FL slot," and a slot consisting only of a UL symbol may be referred to as an "UL slot."

[0114] Figure 9 is a diagram showing the timing relationship between the uplink and downlink in a communication system.

[0115] There is one set of frames in the uplink, and there is also one set of frames in the downlink of each carrier. The uplink frame number i for transmission from the UE must begin before T_TA=(N_TA+N_TA,OFFSET+N^COMMON_TA,ADJ+N^UE_TA,ADJ)*T_C, and this must coincide with the start of the corresponding downlink frame observed by the UE.

[0116] Here, N_TA and N_TA,OFFSET can be provided by adjusting the transmission timing of the synchronization procedure. However, for msgA transmission in PUSCH (physical uplink shared channel), NTA = 0.

[0117] N^COMMON_TA,ADJ is derived from the upper layer parameters ta-Common, ta-CommonDrift, and ta-CommonDriftVariant, and if not configured, N^COMMON_TA,ADJ=0.

[0118] N^UE_TA,ADJ is calculated by the UE only when the UE's position and related upper-layer parameters are configured according to the transmission timing adjustment of the synchronization procedure; otherwise, N^UE_TA,ADJ=0.

[0119] As mentioned above, the timing of the downlink and uplink can be adjusted based on the transmission timing adjustment of the synchronization procedure.

[0120] The aforementioned TA (timing advance) can be determined based on the signal transmission and reception times of a random access procedure. For example, a base station can determine the TA based on the arrival time of a preamble transmitted by a terminal.

[0121] A terminal that has performed a random access procedure can receive configuration information from a base station and transmit PUSCH based on the configuration information.

[0122] The aforementioned PUSCH transmission can be controlled via a physical uplink control channel (PUCCH). In NR, the terminal transmits uplink control information (UCI) to the base station via the PUCCH. The control information may include at least one of a HARQ-ACK indicating whether demodulation / decoding of a transport block (TB) received by the terminal via PDSCH was successful, a scheduling request (SR) in which the terminal requests resource allocation from the PUSCH base station for uplink data transmission, and channel state information (CSI) which is information for reporting the channel status of the terminal.

[0123] PUCCH can be transmitted repeatedly.

[0124] Meanwhile, NTN reference scenarios can be defined as shown in Table 2 below.

[0125] [Table 2]

[0126]

[0127] In the non-ground network shown in FIG. 1A and / or FIG. 1B, if the satellite (110) is a GEO satellite (e.g., a GEO satellite supporting transparent functions), this may be referred to as “Scenario A”. In the non-ground network shown in FIG. 2A, FIG. 2B, and / or FIG. 2C, if satellite #1 (211) and satellite #2 (212) are each GEO satellites (e.g., GEO supporting regeneration functions), this may be referred to as “Scenario B”.

[0128] In the non-ground network depicted in FIG. 1A and / or FIG. 1B, if the satellite (110) is a LEO satellite having steerable beams, this may be referred to as “Scenario C1”. In the non-ground network depicted in FIG. 1A and / or FIG. 1B, if the satellite (110) is a LEO satellite having beams that move with the satellite, this may be referred to as “Scenario C2”. In the non-ground network depicted in FIG. 2A, FIG. 2B, and / or FIG. 2C, if satellite #1 (211) and satellite #2 (212) are each LEO satellites having steerable beams, this may be referred to as “Scenario D1”. In the non-ground network shown in FIG. 2A, FIG. 2B, and / or FIG. 2C, if satellite #1 (211) and satellite #2 (212) are each LEO satellites having beams moving with the satellite, this may be referred to as “Scenario D2”.

[0129] The parameters for the NTN reference scenarios defined in Table 2 can be defined as shown in Table 3 below.

[0130] [Table 3]

[0131]

[0132] In addition, in the NTN reference scenarios defined in Table 2 or Table 3, the delay constraint can be defined as shown in Table 4 below.

[0133] [Table 4]

[0134]

[0135] FIG. 10A is a conceptual diagram illustrating a first embodiment of a protocol stack of the user plane in a transparent payload-based non-ground network, and FIG. 10B is a conceptual diagram illustrating a first embodiment of a protocol stack of the control plane in a transparent payload-based non-ground network.

[0136] Referring to FIGS. 10A and 10B, user data can be transmitted and received between a UE and a core network (e.g., UPF), and control data (e.g., control information) can be transmitted and received between a UE and a core network (e.g., AMF). Each of the user data and control data can be transmitted and received via a satellite and / or gateway. The protocol stack of the user plane illustrated in FIG. 10A can be applied to a 6G communication network in the same or similar way. The protocol stack of the control plane illustrated in FIG. 10B can be applied to a 6G communication network in the same or similar way.

[0137] FIG. 11A is a conceptual diagram illustrating a first embodiment of a protocol stack of the user plane in a regenerative payload-based non-terrestrial network, and FIG. 11B is a conceptual diagram illustrating a first embodiment of a protocol stack of the control plane in a regenerative payload-based non-terrestrial network.

[0138] Referring to FIGS. 11A and 11B, user data and control data (e.g., control information), respectively, can be transmitted and received through an interface between a UE and a satellite (e.g., a base station). User data may refer to a user PDU (protocol data unit). A protocol stack of the SRI (satellite radio interface) can be used to transmit and receive user data and / or control data between the satellite and the gateway. User data can be transmitted and received through a GTP (general packet radio service (GPRS) tunneling protocol)-U tunnel between the satellite and the core network.

[0139] Accordingly, regarding non-terrestrial network (NTN) communication, a non-terrestrial network can be established to provide non-terrestrial NR access to the UE through an NTN payload and an NTN gateway. A service link refers to a connection between the NTN payload and the UE, and a feeder link may refer to a link between the NTN gateway and the NTN payload.

[0140] Meanwhile, in a non-terrestrial network, a base station may transmit system information (e.g., SIB19) containing satellite assistance information for NTN access. A UE may receive system information (e.g., SIB19) from a base station, verify the satellite assistance information included in the system information, and perform communication (e.g., non-terrestrial communication) based on the satellite assistance information. SIB19 may include information element(s) defined in Table 5 below.

[0141] [Table 5]

[0142]

[0143] The NTN-Config defined in Table 5 may include the information element(s) defined in Table 6 below.

[0144] [Table 6]

[0145]

[0146] EphemerisInfo defined in Table 6 may include the information element(s) defined in Table 7 below.

[0147] [Table 7]

[0148]

[0149] In addition, if there is a difference in NTN connection settings compared to TN connection, NTN-parameter may include information elements defined in Table 8 below to convey UE wireless connection capability parameters applied to NTN connection.

[0150] [Table 8]

[0151]

[0152] [RP-234078, New WID: Non-Terrestrial Networks (NTN) for NR Phase 3, RAN#102]

[0153] 1. Study and specify if beneficial downlink coverage enhancements targeting support for additional reference satellite payload parameters covering both GSO and NGSO constellations operating in FR1-NTN or FR2-NTN [RAN1, RAN2, RAN4]

[0154] Define additional reference satellite payload parameters assuming power sharing among satellite beams or different satellite beam patterns / size (i.e. wide or narrow) across the satellite footprint, such that satellite beams may not all be simultaneously active or may be active below the nominal EIRP density per satellite beam (see section 6.1.1 in TR 38.821) due to limited power and limited feeder link bandwidth.

[0155] Define the corresponding power sharing assumptions and necessary link level and system level evaluation methodology and relevant KPIs for evaluations of the coverage, to allow for identification of physical channels / signals and system-level aspects that need enhancements and the corresponding needed improvements.

[0156] Study and if needed specify solutions, including link level enhancements for FR1-NTN (eg for PDCCH, PDSCH) and / or system level enhancements for FR1-NTN and / or FR2-NTN, allowing dynamic and flexible power sharing between satellite beams or different satellite beam patterns / size (ie wide or narrow) across the satellite footprint.

[0157] One embodiment of the proposed technology relates to a signaling method for a repetition factor related to repeated transmission and a procedure related to repeated transmission for expanding NTN downlink coverage. Through the proposed technology, information instructions related to the repetition factor and the corresponding execution procedure are defined to support PDSCH repeated transmission during the process of terminals such as SIB1, SIB19, and Msg4 connecting to a cell in the NTN downlink, and based on this, it is possible to contribute to expanding NTN downlink coverage.

[0158] In the present disclosure, the "repetition factor" may be referred to in various ways, such as a repetition factor, a repetition factor, a repetition transmission factor, information regarding repetition transmission, or information regarding the number of PDSCH repetition transmissions.

[0159] In the present disclosure, "repetition enable / disable" may be referred to in various ways, such as Repetition Enabled / Disabled, information regarding repetitive transmission, or information regarding whether PDSCH repetitive transmission is performed.

[0160] FIG. 12 is a diagram showing an example of the process of a terminal connecting to an NTN cell according to one embodiment.

[0161] Cells supported by NTN (non-terrestrial network) base stations have a wider radius compared to cells supported by conventional TN (terrestrial network) stations. Additionally, in NTN, the distance from a terminal to a base station or to a satellite relaying signals between a base station and a terminal becomes relatively much longer than the distance from a terminal to a base station in TN. Accordingly, to increase coverage in both the uplink and downlink environments of NTN cells, repetition transmission, in which a specific symbol is transmitted multiple times across multiple time / frequency resources, may be applied.

[0162] Various discussions are currently underway to increase the coverage of the NTN downlink covered in the Release-19 standardization. Among these, discussions regarding link-level enhancement for the PDSCH (Physical Downlink Shared Channel) (PDSCH with SIB1 / SIB19) and the PDSCH with Msg4 (PDSCH with Msg4) received by a terminal during the process of connecting to a cell as shown in Fig. 12 have been conducted, and it has been agreed to perform repeated transmission for the PDSCH with SIB1 and the PDSCH with Msg4. The need for repeated transmission for SIB19 is also continuously being raised.

[0163] In order to proceed with PDSCH repeated transmissions for SIB1, SIB19, and Msg4, the Repetition Factor related to the transmission must be conveyed via explicit / implicit signaling or agreed upon between the base station and the terminal through methods / information via standards prior to the occurrence of the PDSCH repeated transmission. Accordingly, the present invention proposes methods for conveying and agreeing on the Repetition Factor to support PDSCH repeated transmissions that terminals such as SIB1, SIB19, Msg4, and MsgB must receive during the process of connecting to a cell, as well as related procedures. To this end, proposed techniques based on the conveying method are defined below, and each technique can be applied in conjunction with other techniques to separately indicate the Repetition Factor for the repeated transmission of multiple PDSCHs (e.g., PDSCH related to SIB1 and PDSCH related to SIB19). In addition, in the proposed techniques below, it is assumed that information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in iterative transmissions is standardized or transmitted via separate signaling.

[0164] [Example 1: MIB Based Explicit Indication]

[0165] Figure 13 is a diagram showing an example of an explicit instruction process based on a Master Information Block (MIB).

[0166] In Example 1, a method is proposed in which the repetition factor is explicitly indicated through the Master Information Block (MIB) as shown in FIG. 13. In this method, the repetition factor or whether to repeat transmission can be indicated by utilizing a field corresponding to a 1-bit spare bit among the 23 bits of the MIB based on the current Release-18 standard. In this case, two repetition factors can be indicated based on the 1-bit spare bit, and the repetition factor corresponding to the Bit 0 / Bit 1 mapping can be defined according to the standard specifications. (e.g., Bit 0 - No Repetition / Bit 1 – Repetition Factor 2, Bit 0 - No Repetition / Bit 1 – Repetition Factor 4) In addition, if the number of MIB bits is expanded, more than two repetition factors can be indicated by using a new bit field, and in this case, the repetition factor corresponding to each bit mapping can be defined according to the standard specifications. In this case, if (i) the maximum repeat factor is 2 or (ii) there are 2 candidates for the applicable repeat factor, the bit mapping may be mapped in the form of Repetition Disabled / Repetition Enabled rather than the transmission of the repeat factor. In this case, when mapped in the form of Repetition Disabled / Repetition Enabled, the repeat factor corresponding to Repetition Enabled may be determined through standardization or transmitted to the terminal through a separate field of the MIB.Alternatively, the repeat factor may be transmitted via MIB and the repeat enable / disable setting may be transmitted separately for each PDSCH. In this case, each terminal may determine whether the repeat transmission of each PDSCH is enabled or disabled through a separate message, and if the repeat transmission is enabled, apply the repeat factor determined through Example 1 (e.g., SIB1 Repetition Enabled / Disabled – MIB or PDCCH for SIB1, SIB19 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1, Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4). These repetition factor enable / disable settings can be defined and delivered individually for each supported PDSCH (e.g., using separate fields / signaling for SIB1 / SIB19 / Msg4) or commonly (e.g., Repetition Disabled / Enabled for SIB1 / SIB19 / Msg4 applied equally through a common field / signaling).

[0167] If the number of MIB bits is extended to allow for the instruction of repetition factors exceeding two, the repetition factors corresponding to each bit mapping can be defined in the following ways.

[0168] Example 1) [Indicate repetition factor at intervals of 1]

[0169] - (2 bits) 00: Repetition Factor 1, ie, no repetition, 01: Repetition Factor 2, 10: Repetition Factor 3, 11: Repetition Factor 4

[0170] - (3비트) 000: Repetition Factor 1, i.e., no repetition, 001: Repetition Factor 2, 010: Repetition Factor 3, 011: Repetition Factor 4, 100: Repetition Factor 5, 101: Repetition Factor 6, 110: Repetition Factor 7, 111: Repetition Factor 8

[0171] 예2) [반복 팩터를 2의 배수 간격으로 지시]

[0172] - (2비트) 00: Repetition Factor 1, i.e., no repetition, 01: Repetition Factor 2, 10: Repetition Factor 4, 11: Repetition Factor 8

[0173] - (3비트) 000: Repetition Factor 1, i.e., no repetition, 001: Repetition Factor 2, 010: Repetition Factor 4, 011: Repetition Factor 8, 100: Repetition Factor 16, 101: Repetition Factor 32, 110: Repetition Factor 64, 111: Repetition Factor 128

[0174] When an explicit instruction for a repeat factor is made via an MIB, the corresponding repeat factor may be applied to PDSCH methods that must be received after the MIB delivery / reception. Therefore, the repeat factor for PDSCH with SIB1 may be specified by an explicit instruction via an MIB. Alternatively, the repeat factor for PDSCH with SIB19 may be specified by an explicit instruction via an MIB. Alternatively, the repeat factor for PDSCH with Msg4 may be specified by an explicit instruction via an MIB. Or, the repeat factors for PDSCH with SIB1 and PDSCH with SIB19 may be specified simultaneously by an explicit instruction via an MIB. Alternatively, the repetition factors of PDSCH with SIB1 and PDSCH with Msg4 may be specified at once by explicit instructions via the MIB. Alternatively, the repetition factors of PDSCH with SIB19 and PDSCH with Msg4 may be specified at once by explicit instructions via the MIB. Alternatively, the repetition factors of PDSCH with SIB1, PDSCH with SIB19, and PDSCH with Msg4 may be specified at once by explicit instructions via the MIB. Whether any of the PDSCH transmission(s) transmitted after the delivery of the MIB containing the repetition factors perform the repetition transmission through the corresponding repetition factor may be defined by the standard specification.

[0175] If 2-Step Random Access is performed, the repetition factor for MsgB instead of Msg4 in Example 1 may be indicated. In this case, the contents for Msg4 in Example 1 may be performed identically for MsgB instead.

[0176] In this case, if repeated transmissions for multiple PDSCHs are supported, a repetition factor for a specific PDSCH may be defined, and the remaining PDSCHs may be defined to operate in the same manner. For example, a repetition factor for SIB1 may be defined, and the repeated transmission of SIB19 may be determined to operate according to the repetition factor of SIB1; a repetition factor for SIB1 may be defined, and the repeated transmission of Msg4 may be determined to operate according to the repetition factor of SIB1; and a repetition factor for SIB1 may be defined, and the repeated transmissions of SIB19 and Msg4 may be determined to operate according to the repetition factor of SIB1.

[0177] In this case, if repeated transmission for multiple PDSCHs is supported using the same field, the repetition factor for each PDSCH may be defined differently for the same bit mapping. For example, if Bit 0 corresponds to No Repetition and Bit 1 corresponds to Repetition, SIB1, SIB19, and Msg4 may perform repeated transmission for Bit 1 with different repetition factors. In this case, how each repetition factor is defined differently can be determined by the standard specification. In this case, the field where the repetition factor for multiple PDSCHs is transmitted is used commonly and may have the same size of n bits for each PDSCH. Furthermore, for a field with the same size of n bits, each PDSCH may use the same number of bits or a different number of bits to transmit the repetition factor. (e.g., total 2-bit field, SIB1 / SIB19 – using 2 bits for 00 / 01 / 10 / 11, Msg4 – using 1 bit for 0x / 1x or x0 / x1, etc.)

[0178] The terminal may receive the MIB to obtain a repeat factor, and then proceed with the reception process by assuming that a repeat transmission with the corresponding repeat factor is being performed for the PDSCH scheme(s) and other scheme(s) / channel(s) defined by the standard specification as applying the corresponding repeat factor. The terminal may proceed with subsequent procedures accordingly, depending on whether decoding is successful or unsuccessful during the reception process.

[0179] In Example 1, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive PDSCH in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0180] [Example 2: PDCCH for SIB1 Based Explicit Indication]

[0181] FIG. 14 is a diagram showing an example of a PDCCH (Physical Downlink Control Channel)-based explicit instruction process for SIB1 (System Information Block 1).

[0182] In Example 2, as shown in FIG. 14, a method is proposed in which a repetition factor is explicitly indicated through a PDCCH (Physical Downlink Control Channel) for SIB1. The PDCCH transmits DCI (Downlink Control Information) format 1_0 with CRC (Cyclic Redundancy Check) scrambled by SI (System Information)-RNTI (Radio Network Temporary Identifier). Since the DCI contains 15-bit or 17-bit reserved bits depending on the current Release-18 reference frequency band, a new bit field can be defined in that area to transmit the repetition factor. At this time, the repetition factor corresponding to each bit mapping can be defined according to standard specifications. (e.g., Bit 0 - No Repetition / Bit 1 – Repetition Factor 2, Bit 00 - No Repetition / Bit 01 – Repetition Factor 2 / Bit 10 – Repetition Factor 4 / Bit 11 – Repetition Factor 8, etc.) In this case, if (i) the maximum repeat factor is 2 or (ii) there are 2 candidates for applicable repeat factors, the bit mapping may be mapped in the form of repeat disable / repetition enable rather than the transmission of the repeat factor. In this case, if it is mapped in the form of repeat disable / enable, the repeat factor corresponding to repeat enable may be determined through standardization or transmitted to the terminal through a separate field of the MIB or PDCCH for SIB1.Alternatively, the repetition factor may be transmitted via PDCCH for SIB1 (PDCCH for SIB1), and repetition enable / disable may be transmitted separately for each PDSCH. In this case, each terminal may determine whether repetitive transmission is enabled or disabled via a separate message, and if repetitive transmission is enabled, apply the repetition factor identified through Example 2 (e.g., SIB1 Repetition Enabled / Disabled – MIB or PDCCH for SIB1, SIB19 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1, Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4). These repetition factors and / or repetition enable / disable may be defined and delivered individually for each supported PDSCH (e.g., using separate fields / signaling for SIB1 / SIB19 / Msg4) or commonly (e.g., Repetition Disabled / Enabled for SIB1 / SIB19 / Msg4 applied equally through common fields / signaling).

[0183] When an explicit instruction for a repeat factor is made via PDCCH for SIB1, the repeat factor may be applied to PDSCH methods that must be received after the transmission / reception of the PDCCH (DCI format 1_0 with CRC scrambled by SI-RNTI). Therefore, the repeat factor of PDSCH with SIB1 may be indicated by the explicit instruction via PDCCH for SIB1, or the repeat factor of PDSCH with SIB19 may be indicated by the explicit instruction via PDCCH for SIB1. Alternatively, the repeat factor of PDSCH with Msg4 may be indicated by the explicit instruction via PDCCH for SIB1. Alternatively, the repetition factors of PDSCH with SIB1 and PDSCH with SIB19 may be indicated at once by an explicit instruction via PDCCH for SIB1. Alternatively, the repetition factors of PDSCH with SIB1 and PDSCH with Msg4 may be indicated at once by an explicit instruction via PDCCH for SIB1. Alternatively, the repetition factors of PDSCH with SIB1 and PDSCH with Msg4 may be indicated at once by an explicit instruction via PDCCH for SIB1.Alternatively, the repetition factors of PDSCH with SIB1, PDSCH with SIB19, and PDSCH with Msg4 may be specified at once by an explicit instruction via PDCCH for SIB1. Whether any of the PDSCH transmission(s) transmitted after the delivery of PDCCH with SIB1 for SIB1 performs the repetition transmission through the corresponding repetition factor may be defined by the standard specification.

[0184] If two-step random access is performed, the repetition factor for MsgB instead of Msg4 in Example 2 may be indicated. In this case, the contents for Msg4 in Example 2 may be performed identically for MsgB instead.

[0185] In this case, when multiple PDSCHs are defined for repeated transmission and the repeated transmissions are transmitted through Example 2, each PDSCH may always have the same value, or a separate repeat factor may be defined and transmitted for each PDSCH. Accordingly, assuming that n bits are used for mapping the repeat factor, when the repeat factors of SIB1 and SIB19 are transmitted through the PDCCH for SIB1, the repeat factors for SIB1 and SIB19 may be transmitted in the same bit field using a total of n bits, or the repeat factors for SIB1 and SIB19 may be defined in separate bit fields using a total of 2n bits. Additionally, when the repeat factors of SIB1 and Msg4 are transmitted through the PDCCH for SIB1, the repeat factors for SIB1 and Msg4 may be transmitted in the same bit field using a total of n bits. Alternatively, the repetition factors for SIB1 and Msg4 may be defined in separate bit fields and transmitted using a total of 2n bits. Additionally, if the repetition factors for SIB19 and Msg4 are transmitted via PDCCH for SIB1, the repetition factors for SIB19 and Msg4 may be transmitted in the same bit field using a total of n bits. Alternatively, the repetition factors for SIB19 and Msg4 may be defined in separate bit fields and transmitted using a total of 2n bits. Additionally, if the repetition factors for SIB1, SIB19, and Msg4 are transmitted via PDCCH for SIB1, the repetition factors for SIB1, SIB19, and Msg4 may be transmitted in the same bit field using a total of n bits. Alternatively, the repetition factors for SIB1 and SIB19 may be transmitted in the same bit field, and the repetition factor for Msg4 may be transmitted in a separate bit field, using a total of 2n bits.Alternatively, the repetition factors for SIB1 and Msg4 may be transmitted in the same bit field, while the repetition factor for SIB19 may be transmitted in a separate bit field, using a total of 2n bits. Alternatively, the repetition factors for SIB19 and Msg4 may be transmitted in the same bit field, while the repetition factor for SIB1 may be transmitted in a separate bit field, using a total of 2n bits. Alternatively, the repetition factors for SIB1, SIB19, and Msg4 may be defined in separate bit fields, using a total of 3n bits. Whether separate repetition factors are used per PDSCH may be defined by standard specifications.

[0186] In this case, if repeated transmissions for multiple PDSCHs are supported, a repetition factor for a specific PDSCH may be defined, and the remaining PDSCHs may be defined to operate in the same manner. For example, a repetition factor for SIB1 may be defined, and the repeated transmission of SIB19 may be determined to operate according to the repetition factor of SIB1; a repetition factor for SIB1 may be defined, and the repeated transmission of Msg4 may be determined to operate according to the repetition factor of SIB1; and a repetition factor for SIB1 may be defined, and the repeated transmissions of SIB19 and Msg4 may be determined to operate according to the repetition factor of SIB1.

[0187] In this case, if repeated transmission for multiple PDSCHs is supported using the same field, the repetition factor for each PDSCH may be defined differently for the same bit mapping. For example, if Bit 0 corresponds to No Repetition and Bit 1 corresponds to Repetition, SIB1, SIB19, and Msg4 may perform repeated transmission for Bit 1 with different repetition factors. In this case, how each repetition factor is defined differently may be determined by the standard specification. In this case, the field where the repetition factor for multiple PDSCHs is transmitted is used commonly and may have the same size of n bits for each PDSCH. Furthermore, for a field with the same size of n bits, each PDSCH may use the same number of bits or a different number of bits to transmit the repetition factor. (e.g., total 2-bit field, SIB1 / SIB19 – using 2 bits for 00 / 01 / 10 / 11, Msg4 – using 1 bit for 0x / 1x or x0 / x1, etc.)

[0188] The terminal receives PDCCH for SIB1 and obtains a repeat factor, and then proceeds with the reception process by assuming that a repeat transmission with the corresponding repeat factor is being performed for PDSCH method(s) and other method(s) / channel(s) defined by standard specifications to apply the corresponding repeat factor. Depending on whether decoding is successful or unsuccessful during the reception process, the terminal may proceed with subsequent procedures accordingly.

[0189] In Example 2, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive PDSCHs in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0190] [Example 3: SIB Based Explicit Indication]

[0191] Figure 15 is a diagram showing an example of an SIB-based explicit instruction process.

[0192] Example 3 proposes a method in which the repetition factor is explicitly indicated by being included in SIB1 or SIB19 (i.e., PDSCH for SIB1 or PDSCH for SIB19) as shown in FIG. 15. In this case, the repetition factor corresponding to each bit mapping can be defined according to standard specifications. (e.g., Bit 0 - No Repetition / Bit 1 – Repetition Factor 2, Bit 00 - No Repetition / Bit 01 – Repetition Factor 2 / Bit 10 – Repetition Factor 4 / Bit 11 – Repetition Factor 8, etc.) In this case, if (i) the maximum repetition factor is 2 or (ii) there are 2 candidates for the applicable repetition factor, the bit mapping can be mapped in the form of repetition disabled / repetition enabled rather than the transmission of the repetition factor. In this case, when mapped in the form of repetitive disable / repetitive enable, the repetition factor corresponding to repetitive enable may be determined through standardization or transmitted to the terminal via a separate field transmitted prior or simultaneously, such as a PDCCH for MIB or SIB1 (PDCCH for SIB1) or SIB. Alternatively, the repetition factor may be transmitted via SIB and repetitive enable / disable may be transmitted separately for each PDSCH; in this case, each terminal may determine whether repetitive transmission of each PDSCH is applied through a separate message, and if repetitive transmission is applied, apply the repetition factor determined through Example 3 (e.g., SIB19 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1, Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4).These repetition factors and / or repetition enable / disable can be defined and delivered individually for each supported PDSCH (e.g., using separate fields / signaling per SSIB19 / Msg4) or commonly (e.g., Repetition Disabled / Enabled of SIB19 / Msg4 applied equally through common fields / signaling).

[0193] When an explicit instruction for a repeat factor is made via a SIB, that repeat factor may be applied to PDSCH methods that must be received after the delivery / reception of the corresponding SIB. Therefore, the repeat factor of SIB19 may be indicated by an explicit instruction via PDSCH for SIB1. Alternatively, the repeat factor of Msg4 may be indicated by an explicit instruction via PDSCH for SIB1, and the repeat factors of SIB19 and Msg4 may be indicated by an explicit instruction via PDSCH for SIB1. In addition, the repeat factor of Msg4 may be indicated by an explicit instruction via PDSCH for SIB19. Among the PDSCH methods transmitted after the delivery of the SIB containing the repeat factor, which PDSCH transmission(s) perform repeat transmission through the said repeat factor can be defined by the standard specification. In this case, since the repeat factor for SIB1 cannot be transmitted through SIB1, it may be transmitted separately through the MIB or PDCCH for SIB1 (PDCCH for SIB1) to perform repeat transmission for SIB1.

[0194] If two-step random access is performed, the repetition factor for MsgB instead of Msg4 in Example 3 may be indicated. In this case, the contents for Msg4 in Example 3 may be performed identically for MsgB instead.

[0195] In this case, when the repeated transmission of multiple PDSCHs is defined and the corresponding repeat factors are transmitted through Example 3, they may be transmitted such that they always have the same value for each PDSCH, or a separate repeat factor may be defined and transmitted for each PDSCH. Therefore, assuming that n bits are used for the mapping of the repeat factor, when the repeat factors for SIB19 and Msg4 are transmitted through PDSCH for SIB1, the repeat factors for SIB19 and Msg4 may be transmitted in the same bit field using a total of n bits. Alternatively, the repeat factors for SIB19 and Msg4 may be defined in separate bit fields and transmitted using a total of 2n bits. Whether such separate repeat factors are used for each PDSCH may be defined by standard specifications.

[0196] In this case, if repeated transmission for multiple PDSCHs is supported, a repetition factor can be defined for a specific PDSCH, and the remaining PDSCHs can be defined to operate in the same way. For example, when transmitting a repetition factor via SIB1, a repetition factor for SIB19 can be defined, and the repeated transmission of Msg4 can be determined to operate according to the repetition factor of SIB19.

[0197] In this case, if repeated transmission for multiple PDSCHs is supported using the same field, the repetition factor for each PDSCH may be defined differently for the same bit mapping. For example, when transmitting the repetition factor via SIB1, if Bit 0 corresponds to No Repetition and Bit 1 corresponds to Repetition, SIB19 and Msg4 may perform Repetition with different repetition factors for Bit 1. In this case, how each repetition factor is defined differently may be determined by the standard specification. In this case, the field transmitting the repetition factor for multiple PDSCHs may be used commonly and may have the same size of n bits for each PDSCH. Additionally, for fields of the same size of n bits, each PDSCH may use the same number of bits or a different number of bits for passing the repeat factor (e.g., a total 2-bit field, SIB19 – using 2 bits for 00 / 01 / 10 / 11, Msg4 – using 1 bit for 0x / 1x or x0 / x1, etc.).

[0198] The terminal may receive the SIB, obtain a repeat factor, and then proceed with the reception process by assuming that a repeat transmission with the corresponding repeat factor is being performed for the PDSCH scheme(s) and other scheme(s) / channel(s) defined by the standard specification as applying the corresponding repeat factor. The terminal may proceed with subsequent procedures accordingly, depending on whether decoding is successful or unsuccessful during the reception process.

[0199] In Example 3, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive a PDSCH in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0200] [Example 4: PDCCH for Msg2 (PDCCH for MsgB) Based Explicit / Implicit Indication]

[0201] FIG. 16 is a diagram showing an example of a PDCCH-based explicit / implicit instruction process for MSG2.

[0202] Example 4 proposes a method in which the repetition factor shown in Fig. 16 is explicitly or implicitly indicated through the PDCCH for Msg2. The PDCCH conveys DCI format 1_0 with CRC scrambled by RA (Random Access)-RNTI. Since the DCI contains 14 or more reserved bits depending on the current Release-18 reference frequency band, the repetition factor can be explicitly conveyed using this area. In this case, the repetition factor corresponding to each bit mapping can be defined according to standard specifications (e.g., Bit 0 - No Repetition / Bit 1 – Repetition Factor 2, Bit 00 - No Repetition / Bit 01 – Repetition Factor 2 / Bit 10 – Repetition Factor 4 / Bit 11 – Repetition Factor 8, etc.). Alternatively, it can be implicitly conveyed by interpreting the repetition factor based on the TB scaling value. In this case, if (i) the maximum repeat factor is 2 or (ii) there are 2 candidates for the applicable repeat factor, the bit mapping may be mapped in the form of repeat disable / enable rather than the transmission of the repeat factor. In this case, when mapped in the form of repeat disable / enable, the repeat factor corresponding to repeat enable may be determined through standardization or transmitted to the terminal through a separate field transmitted prior or simultaneously, such as PDCCH for MIB, PDCCH for SIB1, PDCCH for SIB, or PDCCH for Msg2. Alternatively, the repeat factor may be transmitted through PDCCH for Msg2, and the repeat enable / disable may be transmitted separately. In this case, each terminal may determine whether to transmit repeatedly through a separate message, and if repeated transmission is applied, apply the repeat factor determined through Example 4.(Example: Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4).

[0203] If two-stage random access is performed, Example 4 can be performed by replacing the DCI format 1_0 with CRC scrambled by RA-RNTI transmitted in the PDCCH for Msg2 of Example 4 with the DCI format 1_0 with CRC scrambled by MsgB-RNTI transmitted in the PDCCH for MsgB. This is because the DCI format 1_0 with CRC scrambled by MsgB-RNTI has the same format configuration as the DCI format 1_0 with CRC scrambled by RA-RNTI. In this case, the repetition factor for MsgB instead of Msg4 can be indicated via DCI format 1_0 with CRC scrambled by MsgB-RNTI, and thus the content for Msg4 in Example 4 can be replaced by the use of DCI format 1_0 with CRC scrambled by MsgB-RNTI, and the content of Example 4 can be performed in the same way for MsgB.

[0204] When a repetition factor is indicated via PDCCH for Msg2, the repetition factor may be applied to PDSCH methods that must be received after the transmission / reception of the PDCCH (DCI format 1_0 with CRC scrambled by RA-RNTI). Therefore, the repetition factor of PDSCH with Msg4 may be indicated by an explicit instruction via PDCCH for Msg2.

[0205] In the case of implicit transmission, the current TB (Transport Block) scaling field is assigned a Scaling Factor of 1 when Bit 00, 0.5 when Bit 01, and 0.25 when Bit 10; as the corresponding Scaling Factor decreases, transmission is configured to use a lower coding rate. Since a situation where a low coding rate is used for Msg2 can be considered as a situation requiring repeated transmission for Msg4, the repetition factor for Msg4 can be implicitly specified based on this. The specific method of interpreting the field can be illustrated with the following examples.

[0206] [Max Repetition Factor 2] Bit 0X (00, 01) -> (no repetition), Bit 1X (10, 11) -> Repetition Factor 2

[0207] [Maximum Repetition Factor 2] Bit 00 -> 1 (no repetition), Bit 01 & Bit 10 ->Repetition Factor 2, Bit 11 -> N / A

[0208] [Maximum Repetition Factor 2] Bit 00 / 01 -> 1 (no repetition), Bit 10 ->Repetition Factor 2, Bit 11 -> N / A

[0209] [Max Repetition Factor 4] Bit 00 -> 1 (no repetition), Bit 01 -> Repetition Factor 2, Bit 10 -> Repetition Factor 3, Bit 11 -> Repetition Factor 4

[0210] [Max Repetition Factor 4] Bit 00 -> 1 (no repetition), Bit 01 -> Repetition Factor 2, Bit 10 -> Repetition Factor 4, Bit 11 -> N / A

[0211] The terminal receives PDCCH for Msg2, obtains a repeat factor through a method defined in the standard or agreed upon in advance for use during explicit or implicit signaling, and then proceeds with the reception process by assuming that a repeat transmission with the corresponding repeat factor is being performed for PDSCH method(s) and other method(s) / channel(s) defined by standard specifications, such as PDSCH for Msg4, to apply the corresponding repeat factor. The terminal may proceed with subsequent procedures accordingly, depending on whether decoding is successful or unsuccessful during the reception process.

[0212] In Example 4, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive PDSCHs in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0213] [Example 5: PDCCH for Msg4 Based Explicit / Implicit Indication]

[0214] FIG. 17 is a diagram showing an example of a PDCCH-based explicit or implicit instruction process for MSG4.

[0215] Example 5 proposes a method in which the repetition factor is explicitly or implicitly indicated via the PDCCH for Msg4, as shown in FIG. 17. The PDCCH transmits DCI format 1_0 with CRC scrambled by TC(Temporary Cell)-RNTI. In the case of the DCI, explicit or implicit transmission using existing fields can be performed, or the repetition factor can be explicitly transmitted by defining a new field. In this case, the repetition factor corresponding to each bit mapping can be defined according to standard specifications (e.g., Bit 0 - No Repetition / Bit 1 – Repetition Factor 2, Bit 00 - No Repetition / Bit 01 – Repetition Factor 2 / Bit 10 – Repetition Factor 4 / Bit 11 – Repetition Factor 8, etc.). In this case, if (i) the maximum repeat factor is 2 or (ii) there are 2 candidates for the applicable repeat factor, the bit mapping may be mapped in the form of repeat disable / repeat enable rather than the transmission of the repeat factor. In this case, when mapped in the form of repeat disable / repeat enable, the repeat factor corresponding to repeat enable may be determined through standardization or transmitted to the terminal through a separate field transmitted prior to or simultaneously, such as PDCCH for MIB and SIB1, PDCCH for Msg2 and Msg4, or PDCCH for Msg4. Alternatively, the repeat factor may be transmitted through PDCCH for Msg4 and the repeat transmission enable / disable may be transmitted separately, in which case each terminal may determine whether to repeat transmission through a separate message.Subsequently, when repetitive transmission is applied, the terminal may apply the repetition factor identified through Example 5 (e.g., Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4).

[0216] When a repeat factor is indicated via PDCCH for Msg4, the repeat factor may be applied to PDSCH methods that must be received after the transmission / reception of the PDCCH (DCI format 1_0 with CRC scrambled by TC-RNTI). Therefore, the repeat factor of the PDSCH with Msg4 may be indicated by an explicit instruction via PDCCH for Msg4.

[0217] For explicit instructions using existing fields, the MCS (Modulation and Coding Scheme) field of DCI format 1_0 with CRC scrambled by TC-RNTI can be used. As of Release-18, MCS Indices 29, 30, and 31 of the MCS field are reserved and are not in use. Accordingly, when specifying the repetition factor for PDSCH with Msg4, the following definitions are possible. In each of the examples below, it is assumed that a lower MCS index is mapped to a lower repetition factor or a lower actual MCS index; however, this mapping can be applied in a different order, such as mapping a lower MCS index to a higher repetition factor.

[0218] 예1) MCS Index 29 – Equivalent to Original MCS Index 0 with Repetition Factor 2, MCS Index 30 –Equivalent to Original MCS Index 0 with Repetition Factor 3, MCS Index 31 – Equivalent to Original MCS Index 0 with Repetition Factor 4

[0219] 예2) MCS Index 29 – Equivalent to Original MCS Index 0 with Repetition Factor 2, MCS Index 30 –Equivalent to Original MCS Index 0 with Repetition Factor 4, MCS Index 31 – Equivalent to Original MCS Index 0 with Repetition Factor 8

[0220] 예3) MCS Index 29 – Equivalent to Original MCS Index 0 with Repetition Factor 2, MCS Index 30 –Equivalent to Original MCS Index 1 with Repetition Factor 2, MCS Index 31 – Equivalent to Original MCS Index 2 with Repetition Factor 2

[0221] For explicit / implicit instructions using existing fields, the DAI (Downlink Assignment Index) field can be used. The DAI field of DCI format 1_0 with CRC scrambled by TC-RNTI is 2 bits long and is used to transmit the repeat factor of the Msg4 HARQ (Hybrid Automatic Repeat Request)-ACK (Acknowledgement) based on Release-18 standards; specifically, code points 00, 01, 10, and 11 can be used sequentially depending on the number of repeat factor candidates that can be set in the Msg4 HARQ-ACK. Accordingly, the following explicit / implicit instructions for the PDSCH (PDSCH for Msg4) repeat factor for Msg4 are possible.

[0222] Example 1) Apply the same value as the repetition factor of Msg4 HARQ-ACK as the repetition factor of PDSCH for Msg4.

[0223] Example 2) If the repeat factor of Msg4 HARQ-ACK is greater than or equal to a specific value, repeat transmission is applied to PDSCH for Msg4. However, the repeat factor value of Msg4 HARQ-ACK operating as a threshold and the repeat factor of PDSCH for Msg4 determined accordingly are predetermined by the previously indicated cell-specific signaling or specifications. For example, the repeat factor of PDSCH for Msg4 may be set to the maximum value among the repeat factor candidates of Msg4 HARQ-ACK transmitted via SIB, or the repeat factor of PDSCH for Msg4 may be set to the minimum value excluding 1 among the repeat factor candidates of Msg4 HARQ-ACK transmitted via SIB.

[0224] Example 3) Use a fixed repetition factor based on the code point of the DAI field. For example, Bit 00 is defined as Repetition Factor 1 (No Repetition), Bit 01 as Repetition Factor 2, Bit 10 as Repetition Factor 4, and Bit 11 as Repetition Factor 8, and the number of repetition factors that can be used for PDSCH for Msg4 is determined according to the number of repetition factor candidates for Msg4 HARQ-ACK.

[0225] The terminal receives PDCCH for Msg4, obtains a repetition factor through a method among the above methods defined in the standard or agreed upon in advance for use, and then proceeds with the reception process by assuming that a repetition transmission with the corresponding repetition factor is being performed for PDSCH method(s) and other method(s) / channel(s) defined by standard specifications such as PDSCH for Msg4 to apply the corresponding repetition factor. The terminal may proceed with subsequent procedures accordingly, depending on whether decoding is successful or unsuccessful during the reception process.

[0226] In Example 5, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive PDSCHs in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0227] [Example 6: SSB Periodicity Based Implicit Indication]

[0228] FIG. 18 is a diagram showing an example of an implicit instruction process based on the SSB (Synchronization Signal Block) period.

[0229] Example 6 proposes a method in which a repetition factor is implicitly indicated according to the SSB period (Periodicity), as shown in Fig. 18. Although a Release-18 standard SSB period of 20ms is currently used, discussions on standardization are underway to utilize longer SSB periods, such as 160ms, to expand DL coverage. In this method, the SSB period and the repetition factor are applied in conjunction, so that the base station sets the repetition factor according to the period of the transmitted SSB, and the terminal estimates the SSB period and interprets and applies the repetition factor accordingly. Therefore, this method can be applied without additional signaling overhead for indication. At this time, the repetition enable / disabled status may be transmitted separately, and the terminal may identify and apply a separate repetition enable / disabled status for the repetition factor identified through Example 6 (e.g., SIB1 Repetition Enabled / Disabled – MIB or PDCCH for SIB1, SIB19 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1, Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4). These repetition factors and / or repetition enable / disable can be defined and delivered individually for each supported PDSCH (e.g., using separate fields / signaling for SIB1 / SIB19 / Msg4) or commonly (e.g., Repetition Disabled / Enabled for SIB1 / SIB19 / Msg4 applied equally through common fields / signaling).

[0230] When an implicit indication of an SSB period-based repetition factor is performed through Proposal 6, the corresponding repetition factor may be applied to PDSCH schemes that must be received after the terminal's SSB period estimation. Accordingly, the repetition factor of a PDSCH with SIB1 may be indicated by the SSB period-based implicit indication, or the repetition factor of a PDSCH with SIB19 may be indicated by the SSB period-based implicit indication, or the repetition factor of a PDSCH with Msg4 may be indicated by the SSB period-based implicit indication, or the repetition factors of a PDSCH with SIB1 and a PDSCH with SIB19 may be indicated at once by the SSB period-based implicit indication. Alternatively, the repetition factor of PDSCH with SIB1 and PDSCH with Msg4 may be indicated at once by an implicit indication based on the SSB period. Alternatively, the repetition factor of PDSCH with SIB19 and PDSCH with Msg4 may be indicated at once by an implicit indication based on the SSB period. Alternatively, the repetition factor of PDSCH with SIB1, PDSCH with SIB19, and PDSCH with Msg4 may be indicated at once by an implicit indication based on the SSB period. Whether the measurement of the SSB period and the repetition factor estimated thereby are applied to any of the subsequently transmitted PDSCH transmission(s) to perform repeated transmission may be defined by the standard specification.

[0231] If two-step random access is performed, the repetition factor for MsgB instead of Msg4 in Example 6 may be indicated. In this case, the contents for Msg4 in Example 6 may be performed identically for MsgB instead.

[0232] The interpretation of the repetition factor according to the SSB period can be determined in the manner of the following examples, and this can be specifically defined through standard specifications.

[0233] Example 1) SSB Periodicity ≤(<) Threshold: No Repetition, SSB Periodicity >(≥) Threshold: Repetition Factor 2

[0234] SSB Periodicity ≤20 ms: No Repetition (Repetition Factor 1), SSB Periodicity > Threshold: 20 ms

[0235] SSB Periodicity < 160ms: No Repetition (Repetition Factor 1), SSB Periodicity = 160ms: Repetition Factor 2

[0236] Example 2) Repetition factor increases with a given amount of ms

[0237] SSB Periodicity ≤20ms: No Repetition (Repetition Factor 1), Otherwise: Repetition Factor = SSB Periodicity / 20ms or 2^(SSB Periodicity / 20ms) or 2^(SSB Periodicity / 20ms - 1)

[0238] SSB Periodicity ≤40ms: No Repetition (Repetition Factor 1), Otherwise: Repetition Factor = SSB Periodicity / 40ms or 2^(SSB Periodicity / 40ms) or 2^(SSB Periodicity / 40ms - 1)

[0239] SSB Periodicity ≤80ms: No Repetition (Repetition Factor 1), Otherwise: Repetition Factor = SSB Periodicity / 80ms or 2^(SSB Periodicity / 80ms) or 2^(SSB Periodicity / 80ms - 1)

[0240] 예3) A different repetition factor for different interval of SSB periodicity

[0241] SSB Periodicity ≤20ms: No Repetition (Repetition Factor 1), 20ms < SSB Periodicity < 160ms: Repetition Factor 2, SSB Periodicity = 160ms: Repetition Factor 4

[0242] SSB Periodicity ≤40ms: No Repetition (Repetition Factor 1), 40ms < SSB Periodicity < 160ms: Repetition Factor 2, SSB Periodicity = 160ms: Repetition Factor 4

[0243] In this case, if repeated transmission for multiple PDSCHs is supported, different interpretation methods may be applied, such as defining the repetition factor of each PDSCH differently for the same SSB period. For example, SIB1, SIB19, and Msg4 may perform repetition with different repetition factors for the same SSB period * ms. In this case, how each repetition factor is defined differently can be determined by standard specifications, or instructions regarding the definition method for each PDSCH or a common method can be conveyed through cell-specific signaling such as PDCCH for MIB / SIB1 (PDCCH for SIB1) / SIB1.

[0244] After estimating the SSB period, the terminal obtains a repetition factor through a defined or transmitted interpretation method, and then proceeds with the reception process by assuming the progress of a repetitive transmission with the applied repetition factor for the PDSCH method(s) and other method(s) / channel(s) defined as applying the corresponding repetition factor according to standard specifications. Depending on whether decoding is successful or unsuccessful during the reception process, the terminal may proceed with the corresponding subsequent procedures.

[0245] For Example 6, the terminal needs to estimate the SSB period, which is defined as a capability and can be reported in the capability report. Additionally, it needs to estimate the repetition factor by applying each interpretation method to the estimated SSB period, which is defined as a capability and can be reported in the capability report. Furthermore, the calculation of the repetition factor based on the SSB period, considering both of the above simultaneously, is defined as a single capability and can be reported in the capability report.

[0246] In Example 6, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive a PDSCH in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0247] [Example 7: Msg3 PUSCH Repeat Factor-Based Implicit Indication]

[0248] Figure 19 shows an example of an implicit instruction process based on the MSG3 PUSCH (Physical Uplink Shared Channel) repetition factor.

[0249] Example 7 proposes a method in which the repetition factor for PDSCH for Msg4 is implicitly indicated from the repetition factor explicitly indicated for the repetition transmission of PUSCH for Msg3. Since the repetition transmission of PUSCH for Msg3 is based on a repetition factor delivery method already defined in Release-18, it can proceed without separate signaling overhead for indication. In this case, repetition enable / repetition disable can be delivered separately, and the terminal can identify and apply separate repetition enable / repetition disable based on the repetition factor identified through Example 7 (e.g., Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4).

[0250] The interpretation of the repetition factor of PDSCH for Msg4 based on the repetition factor of PUSCH for Msg3 can be determined in the manner of the following examples, and this can be specifically defined through standard specifications.

[0251] Example 2) Msg3 Repetition Factor ≤(<) Threshold: No Repetition, Msg3 Repetition Factor >(≥) Threshold: Repetition Factor 2

[0252] Msg3 Repetition Factor ≤1: No Repetition (Repetition Factor 1), Msg3 Repetition Factor > 1: Repetition Factor 2

[0253] Msg3 Repetition Factor ≤2: No Repetition (Repetition Factor 1), Msg3 Repetition Factor > 2: Repetition Factor 2

[0254] Msg3 Repetition Factor ≤4: No Repetition (Repetition Factor 1), Msg3 Repetition Factor > 4: Repetition Factor 2

[0255] Msg3 Repetition Factor ≤8: No Repetition (Repetition Factor 1), Msg3 Repetition Factor > 8: Repetition Factor 2

[0256] Example 2) Repetition factor increases with Msg3 repetition factor (*round function could be either floor or ceil function)

[0257] Msg3 Repetition Factor ≤4: No Repetition (Repetition Factor 1), Otherwise: Repetition Factor = round(Msg3 Repetition Factor / 4) or 2^(round(Msg3 Repetition Factor / 4)) or 2^(round(Msg3 Repetition Factor / 4)-1)

[0258] Msg3 Repetition Factor ≤8: No Repetition (Repetition Factor 1), Otherwise: Repetition Factor = round(Msg3 Repetition Factor / 8) or 2^(round(Msg3 Repetition Factor / 8)) or 2^(round(Msg3 Repetition Factor / 8)-1)

[0259] 예3) A different repetition factor for different range of Msg3 repetition factor

[0260] Msg3 Repetition Factor ≤ 1: No Repetition (Repetition Factor 1), 1 < Msg3 Repetition Factor ≤ 4: Repetition Factor 2, Msg3 Repetition Factor > 4: Repetition Factor 4

[0261] Msg3 Repetition Factor ≤ 2: No Repetition (Repetition Factor 1), 2 < Msg3 Repetition Factor ≤ 8: Repetition Factor 2, Msg3 Repetition Factor > 8: Repetition Factor 4

[0262] In this case, how the repetition factor of Msg4 is interpreted by the repetition factor of Msg3 can be determined by standard specifications, or instructions regarding the interpretation method can be conveyed through cell-specific signaling such as MIB / PDCCH for SIB1 / SIB1.

[0263] The terminal receives a repeat factor for PUSCH for Msg3, obtains the repeat factor through a method among the above methods defined in the standard or agreed upon in advance for use, and then proceeds with the reception process by assuming that a repeat transmission with the corresponding repeat factor is being performed for PDSCH method(s) and other method(s) / channel(s) defined by standard specifications, such as PDSCH for Msg4, to apply the corresponding repeat factor. The terminal may proceed with subsequent procedures accordingly, depending on whether decoding is successful or unsuccessful during the reception process.

[0264] In Example 7, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive PDSCH in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0265] [Example 8: Auto Repetition without Explicit / Implicit Indication]

[0266] FIG. 20 illustrates an example of a process for performing automatic repetitive transmission without explicit or implicit instructions.

[0267] Example 8 proposes an automatic repetition method in which a repeat transmission process is performed without explicit or implicit instructions regarding a separate repeat factor, as shown in FIG. 20. The base station performs repeat transmission without separate instructions for the PDSCH to which automatic repetition is applied, and the terminal proceeds with receiving operations and related procedures in preparation for automatic repeat transmission of the PDSCH under the assumption that repeat transmission is possible without receiving the repeat transmission status and the repeat factor from the base station / network in advance. At this time, the repetition disable / repetition enable may be transmitted separately, and the terminal may identify and apply a separate repetition disable / repetition enable for the repetition factor identified through Example 8, or determine whether to perform the process of Example 8 for each PDSCH according to the repetition disable / repetition enable (e.g., SIB1 Repetition Enabled / Disabled – MIB or PDCCH for SIB1, SIB19 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1, Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4). These repetition factors and / or repetition enable / disable can be defined and delivered individually for each supported PDSCH (e.g., using separate fields / signaling for SIB1 / SIB19 / Msg4) or commonly (e.g., Repetition Disabled / Enabled for SIB1 / SIB19 / Msg4 applied equally through common fields / signaling).

[0268] When automatic repetitive transmission is performed through Proposal 8, automatic repetitive transmission may be applied via signaling such as standard specifications or MIBs. Accordingly, depending on the application method, automatic repetitive transmission of PDSCH including SIB1 (PDSCH with SIB1) may be performed. Alternatively, automatic repetitive transmission of PDSCH including SIB19 (PDSCH with SIB19) may be performed. Alternatively, automatic repetitive transmission of PDSCH including Msg4 (PDSCH with Msg4) may be performed. Alternatively, automatic repetitive transmission of PDSCH including SIB1 (PDSCH with SIB1) and PDSCH including SIB19 (PDSCH with SIB19) may be performed. Alternatively, automatic repetitive transmission of PDSCH including SIB1 (PDSCH with SIB1) and PDSCH including Msg4 (PDSCH with Msg4) may be performed. Alternatively, automatic repeated transmission of PDSCH with SIB19 and PDSCH with Msg4 may be performed. Alternatively, automatic repeated transmission of PDSCH with SIB1, PDSCH with SIB19, and PDSCH with Msg4 may be performed.

[0269] If two-step random access is performed, the contents for Msg4 of Example 8 can be performed in the same way for MsgB instead.

[0270] For the operation of Example 8, the terminal requires the setting of a timer for receiving repeated transmissions. The timer is intended to define the maximum time for receiving repeated transmissions, and the terminal performs the operation to receive automatic repeated transmissions only within the timer and ignores repeated transmissions that may be received after the interval defined by the timer has ended. The timers for PDSCH for SIB1 and PDSCH for SIB19 may be set to an SSB period, a multiple of the SSB period, a multiple of the slot, or a multiple of the frame, and the length of such timers may be predetermined through standard specifications or indicated to the terminal through cell-specific signaling. In this case, the interval may operate starting from the reception time of the first SIB1 and the first SIB19 indicated by the PDCCH for SIB1, the reception time of the PDCCH for SIB1, or the reception time of the MIB. In this case, if automatic repeat transmission for both SIB1 and SIB19 is supported, the timers for each may be defined identically or differently. For the timer for the PDSCH for Msg4, the ra-ContentionResolutionTimer applied for the existing Msg4 and the interval defined thereby may be used for the operation of automatic repeat transmission.

[0271] The terminal may perform the following receiving operations for the automatic repeated transmission of Example 8. For example, the terminal may first proceed with receiving and decoding a PDSCH at a time and frequency resource corresponding to an initial transmission instructed in advance, such as a PDCCH, without assuming repeated transmission. If decoding of this initial transmission fails, the terminal may proceed with receiving and decoding by assuming a second PDSCH transmission at a time / frequency resource instructed in advance via a specification or signaling, and by combining the signals from that resource and the signals from the initial transmission through a process such as soft combining. If decoding of this second transmission fails, the terminal may similarly proceed with receiving and decoding by assuming a third PDSCH transmission and combining them, and this may continue until the interval according to a defined timer ends. If decoding is not successfully performed by this time, the terminal may assume that the PDSCH was not received normally and proceed with the next procedure following the decoding failure. If decoding is successful before the interval determined by the timer expires, the terminal can assume that the PDSCH has been received successfully and proceed to the next step.

[0272] Depending on the capabilities of the terminal, the preceding example of the reception process may proceed in parallel. For instance, if the reception and decoding process for the initial transmission is in progress, the terminal may, depending on its capabilities, simultaneously perform the reception and decoding process that combines the reception signal for the initial transmission with the next transmission, separately from the current process. This may continue until the interval determined by the defined timer expires; if decoding is not successfully performed by this time, the terminal assumes that the corresponding PDSCH was not received normally and proceeds to the next procedure following the decoding failure. If decoding is successful before the interval determined by the timer expires, the terminal assumes that the corresponding PDSCH was received normally, terminates the remaining parallel processes, and proceeds to the next procedure following the successful decoding.

[0273] During these processes, the terminal can infer, based on its capabilities, that the PDSCH transmission to be decoded—that is, the PDSCH repeated transmission—was not performed in the predicted time / frequency resource by using the correlation with the initial transmitted / received signal or noise estimation in the soft combining signal in the time / frequency resource where repeated transmission is predicted to have occurred. If it is inferred that repeated transmission was not performed in the predicted time / frequency resource, the terminal can proceed to the reception / decoding process considering the last repeated transmission where the PDSCH was determined to have been transmitted, and accordingly, the timer can be terminated early. If decoding is not successfully performed until the interval according to the defined timer ends, or until the early termination based on the inference of the end of the repeated transmission within the interval, the terminal can assume that the PDSCH was not received normally and proceed to the next procedure following the decoding failure. If decoding is successful before the interval determined by the timer ends, or before early termination based on the guess of the end of repeated transmission within the interval, the terminal can assume that the PDSCH has been received normally and proceed with the next procedure following the successful decoding.

[0274] For Example 8, the terminal must be able to perform the receiving operation defined above or the corresponding automatic repetitive transmission receiving operation when there is no instruction for a repetitive factor, and this may be additionally defined as a capability and reported during capability reporting. This capability may be additionally defined by PDSCH (SIB1, SIB19, Msg4) or by detailed functions (capable of performing automatic repetitive transmission, possible of parallel execution, estimation of non-performance of PDSCH repetitive transmission, etc.) and may be reported during capability reporting based on this. Additionally, if timers for PDSCH for SIB1 (PDSCH for SIB1) and PDSCH for SIB19 (PDSCH for SIB19) are defined in relation to the SSB period, the terminal needs to estimate the SSB period, and this may be defined as a capability and reported during capability reporting.

[0275] In Example 8, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive PDSCHs in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0276] [Example 9: RSRP Threshold Based Implicit Indication]

[0277] FIG. 21 is a diagram showing an example of an implicit instruction process based on RSRP (Reference Signals Received Power).

[0278] Example 9 proposes a method in which a repetition factor is implicitly indicated based on a given RSRP threshold and a measured RSRP, as shown in FIG. 21. Based on a standardized or pre-signaled RSRP threshold, the base station determines a repetition factor based on the RSRP of the terminal or the RSRP measured from terminals within the cell, and the terminal also interprets the repetition factor based on the estimated RSRP to proceed with receiving the repeated transmission of the PDSCH. Therefore, this method can be applied without additional signaling overhead for indication. At this time, the repetition disable / repetition enable may be transmitted separately, and the terminal may identify and apply a separate repetition disable / repetition enable for the repetition factor identified through Example 9 (e.g., SIB1 Repetition Enabled / Disabled – MIB or PDCCH for SIB1, SIB19 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1, Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4). These repetition factors and / or repetition enable / disable may be defined and delivered individually for each supported PDSCH (e.g., using separate fields / signaling for SIB1 / SIB19 / Msg4) or commonly (e.g., Repetition Disabled / Enabled for SIB1 / SIB19 / Msg4 applied equally through common fields / signaling).

[0279] When an implicit instruction of the RSRP threshold-based repetition factor is performed through this Proposal 9, the corresponding repetition factor may be applied to PDSCH schemes that must be received after the terminal's RSRP estimation. Accordingly, the repetition factor of PDSCH with SIB1 may be indicated by the RSRP threshold-based implicit instruction. Alternatively, the repetition factor of PDSCH with SIB19 may be indicated by the RSRP threshold-based implicit instruction. Alternatively, the repetition factor of PDSCH with Msg4 may be indicated by the RSRP threshold-based implicit instruction. Alternatively, the repetition factors of PDSCH with SIB1 and PDSCH with SIB19 may be indicated at once by the RSRP threshold-based implicit instruction. Alternatively, the repetition factor of PDSCH with SIB1 and PDSCH with Msg4 may be indicated at once by an implicit instruction based on an RSRP threshold. Alternatively, the repetition factor of PDSCH with SIB19 and PDSCH with Msg4 may be indicated at once by an implicit instruction based on an RSRP threshold. Alternatively, the repetition factor of PDSCH with SIB1, PDSCH with SIB19, and PDSCH with Msg4 may be indicated at once by an implicit instruction based on an RSRP threshold. Thus, whether the measurement of RSRP and the repetition factor estimated thereby are applied to any of the subsequently transmitted PDSCH transmission(s) to perform repetition may be defined by the standard specification.

[0280] If 2-Step Random Access is performed, the repetition factor for MsgB instead of Msg4 in Example 9 may be indicated. In this case, the contents for Msg4 in Example 9 may be performed identically for MsgB instead.

[0281] The interpretation of the RSRP threshold and the repetition factor based on the estimated RSRP can be determined in the manner shown in the following examples, and this can be specifically defined through standard specifications. In this case, the maximum value of the repetition factor applicable in each example is predefined through standard specifications to correct the repetition factor calculated according to the formula.

[0282] Example 1) Increase the repetition factor by 2 for every 3 dBm decrease in the difference between the estimated RSRP value and the RSRP Threshold (RSRP Threshold – RSRP).

[0283] ~0 dBm Difference: Repetition Factor 1 (no repetition), 0~3 dBm Difference: Repetition Factor 2, 3~6 dBm Difference: Repetition Factor 4, 6~9dBm Difference: Repetition Factor 8

[0284] ~3 dBm Difference: Repetition Factor 1 3~6 dBm Difference: Repetition Factor 2 6~9dBm Difference: Repetition Factor 4

[0285] Example 2) Definition of a function to calculate iteration factors based on the estimated RSRP value (RSRP Threshold – RSRP) relative to the RSRP Threshold

[0286] 10^(0.1*Difference) is 1 or less: No Repetition (Repetition Factor 1), 10^(0.1*Difference) is greater than 1 and less than or equal to 2: Repetition Factor 2, 10^(0.1*Difference) is greater than 2 and less than or equal to 3: Repetition Factor 3, … .

[0287] Example 3) Standardization of the conversion table based on the RSRP Threshold and estimated RSRP (Common or separate table standardization possible for each PDSCH)

[0288] In this case, if repeated transmission for multiple PDSCHs is supported, the repetition factor of each PDSCH may be defined or interpreted differently for the same RSRP threshold and estimated RSRP. For example, for the same RSRP threshold x dBm and estimated RSRP y dBm, SIB1, SIB19, and Msg4 may perform repeated transmission with different repetition factors. In this case, how each repetition factor is defined differently may be determined by standard specifications. Alternatively, instructions regarding the definition method for each PDSCH or a common method may be conveyed through cell-specific signaling, such as PDCCH / SIB1 for MIB / SIB1.

[0289] After estimating the RSRP, the terminal obtains a repetition factor by applying an interpretation method defined or transmitted through a pre-given RSRP threshold, and then proceeds with the reception process by assuming the progress of a repetitive transmission with the applied repetition factor for PDSCH method(s) and other method(s) / channel(s) defined by standard specifications to apply the corresponding repetition factor. The terminal may proceed with subsequent procedures accordingly, depending on whether decoding is successful or unsuccessful during the reception process.

[0290] For Example 9, the terminal needs to estimate the RSRP and estimate the repeat factor using the estimate and the RSRP threshold, which is defined as capability and can be reported during capability reporting.

[0291] The RSRP threshold used in Example 9 may be determined by a standard specification or through pre-signaling prior to the repetitive transmission (e.g., SIB1 Repetition Enabled / Disabled – MIB or PDCCH for SIB1, SIB19 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1, Msg4 Repetition Enabled / Disabled – MIB or PDCCH for SIB1 or SIB1 or SIB19 or PDCCH for Msg2 or PDCCH for Msg4). In this case, if Example 9 is supported for multiple PDSCHs, each PDSCH may have a common RSRP threshold, so a single value may be applied to the standard or indicated via signaling. Additionally, if Example 9 is supported for multiple PDSCHs, each PDSCH may have a separate RSRP threshold, so multiple values ​​may be applied to the standard, indicated via signaling, or some may be indicated by the standard specification and others by signaling.

[0292] In Example 9, information regarding the use of time / frequency resources (repeated transmission interval, time / frequency resource mapping, etc.) in repeated transmissions may be considered to be standardized or transmitted via separate signaling. For example, a terminal may expect to receive PDSCHs in a number of available slots equal to a set repetition factor, including at least the first slot in which the PDSCH was received.

[0293] FIG. 22 is a flowchart illustrating a method in which a terminal performs communication according to one embodiment.

[0294] The operations disclosed in the flowchart of FIG. 22 may be performed in combination with various embodiments of the present disclosure. In one example, the operations disclosed in the flowchart of FIG. 22 may be performed based on at least one of the devices shown in FIG. 1A through FIG. 4. In one example, the terminal of FIG. 22 may correspond to the second communication node (400b) of FIG. 4, and the base station may correspond to the first communication node (400a) of FIG. 4. In another example, the terminal of FIG. 22 may correspond to the first communication node (400a) of FIG. 4, and the base station may correspond to the second communication node (400b) of FIG. 4. In another example, the terminal of FIG. 22 may correspond to at least one of the terminals shown in FIG. 1A through FIG. 3, and the base station may correspond to at least one of the base stations shown in FIG. 1A through FIG. 3.

[0295] In step S2201, a terminal according to one embodiment may receive at least one of system information or control information from a base station communicating with the terminal via a Non-Terrestrial Network (NTN).

[0296] In one embodiment, the information regarding the PDSCH repeated transmission may represent at least one of information regarding whether the PDSCH repeated transmission is performed or information regarding the number of PDSCH repeated transmissions.

[0297] In one example, information regarding whether to perform PDSCH repeated transmissions may be identical, similar, or corresponding to “repetition enabled / repetition disabled” or “Repetition enabled / disabled” described throughout this disclosure.

[0298] In one example, information regarding the number of PDSCH repeated transmissions may be identical, similar, or corresponding to the “repetition factor” or “repetition factor” described throughout this disclosure.

[0299] In step S2202, a terminal according to one embodiment can obtain information regarding the repeated transmission of a PDSCH (Physical Downlink Shared Channel) based on at least one of the system information or the control information.

[0300] In step S2203, a terminal according to one embodiment can receive a PDSCH repetitive transmission by the base station based on information regarding the PDSCH repetitive transmission.

[0301] The step of a terminal according to one embodiment receiving at least one of the system information or control information may include the step of receiving the system information. In this case, the system information represents a Master Information Block (MIB), and the repeated transmission of the PDSCH by the base station may represent a repeated transmission of the PDSCH including System Information Block 1 (SIB1).

[0302] In one embodiment, the information regarding the PDSCH repeated transmission represents information regarding whether the PDSCH repeated transmission is performed, the information regarding whether the PDSCH repeated transmission is performed represents at least one bit of the MIB, and whether the PDSCH repeated transmission is performed can be determined by the at least one bit of the MIB.

[0303] The step of a terminal according to one embodiment receiving at least one of the system information or control information may include the step of receiving the control information. In this case, the control information represents Downlink Control Information (DCI), and the repeated transmission of the PDSCH by the base station may represent the repeated transmission of the PDSCH including MSG4.

[0304] In one embodiment, the DCI may represent DCI format 1_0.

[0305] In one embodiment, the DCI may represent a DCI transmitted through a PDCCH (Physical Downlink Control Channel) for the MSG4.

[0306] In one embodiment, the information regarding the PDSCH repeated transmission represents information regarding whether the PDSCH repeated transmission is performed, the information regarding whether the PDSCH repeated transmission is performed represents the Modulation and Coding Scheme (MCS) field of the DCI, and whether the PDSCH repeated transmission is performed can be determined by the MCS field of the DCI.

[0307] The step of a terminal according to one embodiment receiving at least one of the system information or control information may include the step of receiving the system information. In this case, the system information represents SIB1, and the PDSCH repeated transmission by the base station may represent the repeated transmission of a PDSCH including MSG4.

[0308] In one embodiment, the information regarding the PDSCH repeated transmission represents information regarding the number of PDSCH repeated transmissions, and the information regarding the number of PDSCH repeated transmissions may be included in the SIB1.

[0309] A terminal according to one embodiment may determine that the PDSCH repeated transmission by the base station is performed based on obtaining information regarding the number of PDSCH repeated transmissions.

[0310] A terminal according to one embodiment can transmit capability information of the terminal related to the PDSCH repeated transmission to the base station.

[0311] FIG. 23 is a flowchart illustrating a method in which a base station performs communication according to one embodiment.

[0312] The operations disclosed in the flowchart of FIG. 23 may be performed in combination with various embodiments of the present disclosure. In one example, the operations disclosed in the flowchart of FIG. 23 may be performed based on at least one of the devices shown in FIG. 1A through FIG. 4. In one example, the terminal of FIG. 23 may correspond to the second communication node (400b) of FIG. 4, and the base station may correspond to the first communication node (400a) of FIG. 4. In another example, the terminal of FIG. 23 may correspond to the first communication node (400a) of FIG. 4, and the base station may correspond to the second communication node (400b) of FIG. 4. In another example, the terminal of FIG. 23 may correspond to at least one of the terminals shown in FIG. 1A through FIG. 3, and the base station may correspond to at least one of the base stations shown in FIG. 1A through FIG. 3.

[0313] In step S2301, a base station according to one embodiment may transmit at least one of system information or control information to a terminal communicating with the base station via NTN.

[0314] In one embodiment, if the base station transmits at least one of system information or control information to the terminal in step S2301, the terminal may receive at least one of the system information or control information from the base station in step S2201.

[0315] In step S2302, a base station according to one embodiment may repeatedly transmit a PDSCH associated with at least one of the system information or the control information.

[0316] In one embodiment, if the base station repeatedly transmits PDSCH to the terminal in step S2302, the terminal can receive the repeated PDSCH transmission by the base station in step S2203.

[0317] The methods according to the present disclosure may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the computer-readable medium may be those specifically designed and configured for the present disclosure, or they may be those known and available to those skilled in the art of computer software.

[0318] Examples of computer-readable media include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

[0319] Some aspects of the present disclosure have been described in the context of a device, but may also be described according to a corresponding method, wherein a block or device corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may also be described according to a corresponding block or item or feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one of the most important method steps may be performed by such a device.

[0320] A programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described in this disclosure. A field-programmable gate array may operate with a microprocessor to perform one of the methods described in this disclosure. Generally, it is preferable that the methods be performed by some hardware device.

[0321] Although the present invention has been described with reference to the embodiments above, those skilled in the art will understand that various modifications and changes can be made to the present disclosure without departing from the spirit and scope of the disclosure as set forth in the following claims.

Claims

1. In a method performed by a terminal in a wireless communication system, A step of receiving at least one of system information or control information from a base station communicating with the terminal via a Non-Terrestrial Network (NTN); A step of obtaining information regarding the repeated transmission of a PDSCH (Physical Downlink Shared Channel) based on at least one of the above system information or the above control information; and A method comprising the step of receiving a PDSCH repetitive transmission by the base station based on information regarding the above PDSCH repetitive transmission.

2. In Paragraph 1, A method in which the information regarding the above-mentioned PDSCH repeated transmission indicates at least one of information regarding whether to perform PDSCH repeated transmission or information regarding the number of PDSCH repeated transmissions.

3. In Paragraph 2, The step of receiving at least one of the above system information or control information includes the step of receiving the above system information, and The above system information represents the MIB (Master Information Block), and A method in which the PDSCH repeated transmission by the above base station represents the repeated transmission of a PDSCH including SIB1 (System Information Block 1).

4. In Paragraph 3, The information regarding the above PDSCH repeated transmission indicates information regarding whether the above PDSCH repeated transmission is performed, and The information regarding whether to perform the above PDSCH repeated transmission indicates at least one bit of the above MIB, and A method in which whether to perform the above PDSCH repeated transmission is determined by the above at least one bit of the above MIB.

5. In Paragraph 2, The step of receiving at least one of the above system information or control information includes the step of receiving the control information, and The above control information represents DCI (Downlink Control Information), A method in which the PDSCH repeated transmission by the above base station represents the repeated transmission of a PDSCH including MSG4.

6. In Paragraph 5, The above DCI is a method representing DCI format 1_0.

7. In Paragraph 5, A method in which the above DCI represents a DCI transmitted via a PDCCH (Physical Downlink Control Channel) for the above MSG4.

8. In Paragraph 5, The information regarding the above PDSCH repeated transmission indicates information regarding whether the above PDSCH repeated transmission is performed, and The information regarding whether the above PDSCH repeated transmission is performed represents the MCS (Modulation and Coding Scheme) field of the above DCI, and A method in which whether to perform the above PDSCH repeated transmission is determined by the MCS field of the above DCI.

9. In Paragraph 2, The step of receiving at least one of the above system information or control information includes the step of receiving the above system information, and The above system information represents SIB1, and A method in which the PDSCH repeated transmission by the above base station represents the repeated transmission of a PDSCH including MSG4.

10. In Paragraph 9, The information regarding the above PDSCH repeated transmission represents information regarding the number of the above PDSCH repeated transmissions, and Information regarding the number of repeated PDSCH transmissions is a method included in the above SIB1.

11. In Paragraph 10, A method further comprising the step of determining that the PDSCH repeated transmission is performed by the base station based on obtaining information regarding the number of PDSCH repeated transmissions.

12. In Paragraph 1, A method further comprising the step of transmitting capability information of the terminal related to the above PDSCH repeated transmission to the base station.

13. In a terminal that performs communication in a wireless communication system, At least one transceiver; At least one processor; and It includes at least one memory connected to the above-mentioned at least one processor to enable operation, and storing instructions that control the terminal to perform operations when executed by the processor, The above operations are, A step of receiving at least one of system information or control information from a base station communicating with the terminal via NTN; A step of obtaining information regarding PDSCH iterative transmission based on at least one of the above system information or control information; and A terminal comprising the step of receiving a PDSCH repetitive transmission by the base station based on information regarding the above PDSCH repetitive transmission.

14. In Paragraph 13, A terminal in which the information regarding the above PDSCH repeated transmission indicates at least one of information regarding whether to perform PDSCH repeated transmission or information regarding the number of PDSCH repeated transmissions.

15. In a base station performing communication in a wireless communication system, At least one transmitter / receiver; At least one processor; and It includes at least one memory connected to the above-mentioned at least one processor to be operable, and storing commands that control the base station to perform operations when executed by the processor, The above operations are, A step of transmitting at least one of system information or control information to a terminal communicating with the base station via NTN; and A base station comprising the step of repeatedly transmitting a PDSCH associated with at least one of the system information or the control information.

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