Method and device for repeated pdsch transmission through non-terrestrial network

Abstract

One embodiment of the present disclosure provides a method by which a terminal performs communication in a wireless communication system. The method may comprise the steps of: receiving system information block 1 (SIB1) from a base station communicating with the terminal through a non-terrestrial network (NTN); determining the number of physical downlink shared channel (PDSCH) repeated transmissions on the basis of information about a candidate for the number of repeated PDSCH transmissions included in the SIB1; and receiving, on the basis of the determined number of PDSCH repeated transmissions, repeated PDSCH transmissions performed by the base station .

Description

PDSCH iterative transmission method and device over non-terrestrial network

[0001] The present disclosure relates to a non-terrestrial network (NTN) in a wireless communication system, and more specifically to a technique for performing PDSCH (Physical Downlink Shared Channel) repeated transmission.

[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 diverse and 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 not only on the ground but also for non-ground locations such as airplanes, drones, and satellites, and to meet this demand, technologies for non-terrestrial networks (NTNs) are being discussed. NTNs can be implemented based on 5G communication technologies, 6G communication technologies, etc. For example, in an NTN, communication between a satellite and a communication node located on the ground or a communication node located non-ground (e.g., airplanes, drones, etc.) can be performed based on 5G communication technologies, 6G communication technologies, etc. In an NTN, 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] One embodiment of the present disclosure provides a PDSCH iterative transmission method and apparatus through a non-terrestrial network in a wireless communication system.

[0007] One embodiment of the present disclosure provides a method and apparatus for repeatedly transmitting a PDSCH regarding MSG4 over a non-terrestrial network in a wireless communication system.

[0008] One embodiment of the present disclosure discloses a method for a terminal to perform communication in a wireless communication system. The method may include the steps of receiving a System Information Block (SIB1) from a base station communicating with the terminal via a Non-Terrestrial Network (NTN), determining a number of repeated transmissions of a Physical Downlink Shared Channel (PDSCH) based on information regarding a candidate number of repeated transmissions of a Physical Downlink Shared Channel (PDSCH) included in the SIB1, and receiving repeated transmissions of a PDSCH by the base station based on the determined number of repeated transmissions of a PDSCH.

[0009] One embodiment of the present disclosure discloses a terminal that performs 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 control the terminal to perform operations when executed by the processor, wherein the operations may include receiving a SIB1 from a base station communicating with the terminal via an NTN, determining a number of PDSCH repeat transmissions based on information regarding a candidate number of PDSCH repeat transmissions included in the SIB1, and receiving a PDSCH repeat transmission by the base station based on the determined number of PDSCH repeat transmissions.

[0010] One embodiment of the present disclosure discloses a method for a base station to perform communication in a wireless communication system. The method may include the step of transmitting SIB1 to a terminal communicating with the base station via an NTN, and the step of performing a PDSCH repeated transmission to the terminal based on information regarding a candidate number of PDSCH repeated transmissions included in the SIB1.

[0011] One embodiment of the present disclosure discloses 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 method of operation may include the steps of transmitting SIB1 to a terminal communicating with the base station via an NTN, and performing a PDSCH repeated transmission to the terminal based on information regarding a candidate number of PDSCH repeated transmissions included in the SIB1.

[0012] According to one embodiment of the present disclosure, the coverage of downlink communication through a non-terrestrial network can be expanded.

[0013] According to one embodiment of the present disclosure, PDSCH iterative transmission through a non-terrestrial network can be efficiently performed.

[0014] The effects obtainable from the embodiments of 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-terrestrial 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-terrestrial 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 illustrating an example of an NTN that provides non-terrestrial NR access to a UE through an NTN payload and an NTN gateway.

[0027] Figure 13 is a diagram illustrating the timing relationship between objects included in NTN.

[0028] Figure 14 shows an example illustrating the process of a terminal connecting to an NTN cell.

[0029] FIG. 15 illustrates a process in which the activation status of repeated transmission is conveyed to a terminal through cell-specific signaling in one embodiment.

[0030] FIG. 16 shows examples in which information regarding whether repeated transmission is enabled and / or the number of repeated transmissions is transmitted to a terminal through cell-specific signaling.

[0031] FIG. 17 illustrates a process in which information regarding whether repeated transmission is enabled and / or the number of repeated transmissions is transmitted to a terminal through terminal-specific signaling in one embodiment.

[0032] FIG. 18 shows examples in which information regarding whether repeated transmission is enabled and / or the number of repeated transmissions is transmitted to the terminal through terminal-specific signaling.

[0033] FIG. 19 illustrates a process in which information regarding a candidate number of repeated transmissions is transmitted to a terminal through cell-specific signaling in one embodiment.

[0034] Figure 20 shows examples in which information about the number of repeated transmissions can be transmitted to a terminal through cell-specific signaling.

[0035] FIG. 21 illustrates the process of a terminal receiving repeated transmissions through RSRP threshold signaling in one embodiment.

[0036] Figure 22 shows examples of a terminal receiving repeated transmissions through RSRP threshold signaling.

[0037] FIG. 23 is a flowchart illustrating a method in which a terminal performs communication according to one embodiment of the present disclosure.

[0038] FIG. 24 is a flowchart illustrating a method in which a base station performs communication according to one embodiment of the present disclosure.

[0039] One embodiment of the present disclosure discloses a method for a terminal to perform communication in a wireless communication system. The method may include the steps of receiving a System Information Block (SIB1) from a base station communicating with the terminal via a Non-Terrestrial Network (NTN), determining a number of repeated transmissions of a Physical Downlink Shared Channel (PDSCH) based on information regarding a candidate number of repeated transmissions of a Physical Downlink Shared Channel (PDSCH) included in the SIB1, and receiving repeated transmissions of a PDSCH by the base station based on the determined number of repeated transmissions of a PDSCH.

[0040] 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.

[0041] 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.

[0042] 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".

[0043] 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".

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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)).

[0051] In the present disclosure, "setting an operation (e.g., transmission operation)" may mean that "setting information for said operation (e.g., information element, parameter)" and / or "information directing the performance of said operation" is signaled. "Setting an information element (e.g., parameter)" may mean that said information element is signaled. In the present disclosure, "signal and / or channel" may mean signal, channel, or "signal and channel," and signal may be used to mean "signal and / or channel."

[0052] A communication system may include at least one of a terrestrial network, an NTN, a 4G communication network (e.g., an LTE (long-term evolution) communication network), a 5G communication network (e.g., an NR (new radio) communication network), or a 6G communication network. Each of the 4G communication network, the 5G communication network, and the 6G communication network may include a terrestrial network and / or an NTN. The NTN may be operated based on at least one of LTE communication technology, 5G communication technology, or 6G communication technology. The NTN may provide communication services in various frequency bands.

[0053] The communication networks to which the embodiments of the present disclosure 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] FIGS. 1A and 1B are conceptual diagrams illustrating some embodiments of a non-terrestrial network. FIGS. 1A and 1B illustrate the structure of a transparent-based NTN according to an embodiment of the present disclosure.

[0055] Referring to FIG. 1A, the NTN 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 referred to as a remote radio unit (RRU). 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 device located on the ground (e.g., UE, terminal) and a device 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 NTN, three types of service links can be supported as follows.

[0058] - Earth-fixed: Service links can be provided by beam(s) that always 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 standard, 5G standard, and / or 6G standard.

[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 an '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 FIG. 1B, in a transparent payload-based NTN, a base station and a core network may exist between the gateway (130) and the data network (140).

[0064] 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.

[0065] FIGS. 2A to 2C are conceptual diagrams illustrating some embodiments of a non-terrestrial network. FIGS. 2A to 2C illustrate the structure of a regenerative-based NTN according to an embodiment of the present disclosure.

[0066] Referring to FIG. 2A, the NTN may include a first satellite (211), a second satellite (212), a communication node (220), a gateway (230), a data network (1240), etc. Each of the first satellite (211) and the second satellite (212) may perform a regeneration operation (e.g., demodulation operation, decoding operation, re-encoding operation, re-modulation operation, and / or filtering operation) on a payload received from other entities constituting the NTN (e.g., communication node (220), gateway (230)), and may transmit the regenerated payload.

[0067] Each of the first satellite (211) and the second satellite (212) may be an LEO satellite, MEO satellite, GEO satellite, HEO satellite, or UAS platform. The UAS platform may include a HAPS. Satellite #1 (211) may be connected to the second satellite (212), and an inter-satellite link (ISL) may be established between the first satellite (211) and the second satellite (212). The ISL may operate in a radio frequency (RF) frequency or optical band. The ISL may be established optionally. The communication node (220) 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 (e.g., wireless link) may be established between Satellite #1 (211) and the communication node (220). The first satellite (211) may be referred to as an NTN payload. The first satellite (211) can provide communication services to the communication node (220) using one or more beams.

[0068] The communication node (220) can communicate (e.g., downlink communication, uplink communication) with the first satellite (211) using 4G communication technology, 5G communication technology, and / or 6G communication technology. Communication between the first satellite (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 the first satellite (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 standard, 5G standard, and / or 6G standard.

[0069] The gateway (230) may be located on the ground, and a feeder link may be established between the first satellite (211) and the gateway (230), and a feeder link may be established between the second satellite (212) and the gateway (230). The feeder link may be a wireless link. If an ISL is not established between the first satellite (211) and the second satellite (212), a feeder link between the first satellite (211) and the gateway (230) may be established mandatorily. Communication between the gateway (230) and each of the first satellite (211) and satellite #2 (212) 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).

[0070] As in the embodiments of FIGS. 2B and FIG. 2C, a core network may exist between the gateway (230) and the data network (240).

[0071] Referring to FIGS. 2B and 2C, the gateway can be connected to a core network, and the core network can be connected to a data network. The core network can 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 NTN of FIG. 2B, an ISL between satellites may not be established, while in the NTN of FIG. 2C, an ISL between satellites may be established.

[0072] Meanwhile, entities constituting the NTN 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.

[0073] FIG. 3 is a block diagram illustrating a first embodiment of a communication node constituting a non-terrestrial network. The structure exemplified in FIG. 3 can be understood as the structure of at least part of a communication node, base station, satellite, or core network entity. The wireless device (300) exemplified in FIG. 3 may be a mobile terminal such as a smartphone, tablet PC, or wearable device, but is not limited thereto.

[0074] 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).

[0075] 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).

[0076] At least one control unit (310) may be referred to as a processor, 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.

[0077] 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.

[0078] 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 (340) 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).

[0079] 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.

[0080] A more detailed example of the structure of the control unit (310) and / or the transceiver unit (340) is shown in FIG. 4. FIG. 4 is a block diagram illustrating a first embodiment of communication nodes performing communication. FIG. 4 illustrates the structure of a first communication node (400a) and a second communication node (400b) that transmit and / or receive signals. In FIG. 4, each of the first communication node (400a) and the second communication node (400b) may be a base station or a UE.

[0081] Referring to FIG. 4, the first communication node (400a) can transmit a signal to the second communication node (400b). The transmission processor (411) included in the first communication node (400a) can receive data (e.g., data unit) from the data source (410). The transmission processor (411) can receive control information from the 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).

[0082] The transmitting processor (411) can generate data symbol(s) by performing processing operations on data (e.g., encoding operation, symbol mapping operation, etc.). The transmitting processor (411) can generate control symbol(s) by performing processing operations on control information (e.g., encoding operation, symbol mapping operation, etc.). Additionally, the transmitting processor (411) can generate synchronization / reference symbol(s) for synchronization signals and / or reference signals.

[0083] 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 (e.g., symbol stream) of the Tx MIMO processor (412) 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 modulated symbols and perform additional processing operations on the modulated 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).

[0084] 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 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 (462) can perform MIMO detection operations on the symbols. 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).

[0085] 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., data unit) from the 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 the 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.

[0086] 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 (e.g., symbol stream) of the Tx MIMO processor (469) 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 (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations) on the modulated symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (463a to 463t) can be transmitted through antennas (464a to 464t).

[0087] 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).

[0088] 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.

[0089] 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.

[0090] Referring to FIGS. 5A and 5B, the transmission path (510) may be implemented at a communication node that transmits the signal, and the reception path (520) may be implemented at a communication node that receives the 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.

[0091] 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) 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.

[0092] The S-to-P block (512) can convert modulation 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] FIG. 6 is a conceptual diagram illustrating an example of a system frame in a communication system.

[0097] 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.

[0098] 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".

[0099] FIG. 7 is a conceptual diagram illustrating an example of a subframe in a communication system.

[0100] 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.

[0101] FIG. 8 is a conceptual diagram illustrating an example of a slot in a communication system.

[0102] 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.

[0103] 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.

[0104] Subcarrier Spacing 15kHz 30kHz 60kHz 120kHz 240kHz 480kHz OFDM Symbol Length [μs] 66.733.316.78.34.22.1 CP Length [μs] 4.762.381.190.600.300.151 Number of OFDM Symbols in ms 142856112224448

[0105] 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.

[0106] When the subcarrier spacing is 60 kHz (e.g., μ=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., μ=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., μ=4), the slot length may be 0.0625 ms. In this case, one system frame may contain 160 slots.

[0107] 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 can be referred to as a "DL slot," a slot consisting only of an FL symbol can be referred to as a "FL slot," and a slot consisting only of a UL symbol can be referred to as a "UL slot."

[0108] Figure 9 is a diagram showing the timing relationship between the uplink and downlink in a communication system.

[0109] There is one frame set in the uplink, and there is also one frame set in the downlink of each carrier. The uplink frame number I for transmission from the UE is T TA =(N TA +N TA,offset +N common TA,adj +N UE TA,adj )T C It must start previously, and this must coincide with the start of the corresponding downlink frame observed in the UE.

[0110] Here, N TA and N TA,offset This can be provided by adjusting the transmission timing of the synchronization procedure. However, for msgA transmission in PUSCH (physical uplink shared channel), NTA = 0.

[0111] N common TA,adj is derived from the upper layer parameters ta-Common, ta-CommonDrift, and ta-CommonDriftVariant, which is N if not configured. common TA,adj = 0.

[0112] 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, and otherwise N UE TA,adj = 0.

[0113] As described above, the timing of the downlink and uplink can be adjusted based on the transmission timing adjustment of the synchronization procedure.

[0114] 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.

[0115] A terminal that has performed a random access procedure can receive configuration information from a base station and transmit a PUSCH based on the configuration information. Specifically, the terminal can identify uplink resources and / or determine uplink transmission power based on control information and / or configuration information received from the base station. Then, the terminal can transmit a PUSCH using the determined power through the identified resources.

[0116] 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.

[0117] PUCCH can be transmitted repeatedly. Under given conditions, the terminal may perform repeated transmission of PUCCH based on configuration information from the base station. For example, if the terminal does not have a dedicated PUCCH resource configuration and has the ability to repeatedly transmit PUCCH containing HARQ-ACK information, the terminal may determine the number of slots for repeating PUCCH transmission containing HARQ-ACK information based on the upper layer configuration (e.g., numberOfPUCCHforMsg4HARQACK-RepetitionsList) and / or control information (e.g., the DAI (downlink assignment index) field of the DCI), and perform repeated PUCCH transmission in the determined number of slots. In this case, the terminal may apply frequency hopping.

[0118] Meanwhile, NTN reference scenarios can be defined as shown in [Table 2] below.

[0119] NTN illustrated in Fig. 1A, NTNGEO illustrated in Fig. 2A, Scenario A, BLEO (Adjustable Beam) Scenario C1, Scenario D1, LEO (Beam Moving with Satellite) Scenario C2, Scenario D2

[0120] In the NTN depicted 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 NTN depicted in FIG. 2A, FIG. 2B, and / or FIG. 2C, if the first satellite (211) and the second satellite (212) are each GEO satellites (e.g., GEO supporting regeneration functions), this may be referred to as “Scenario B”.

[0121] In the NTN 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 NTN 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 NTN depicted in FIG. 2A, FIG. 2B, and / or FIG. 2C, if the first satellite (211) and the second satellite (212) are each LEO satellites having steerable beams, this may be referred to as "Scenario D1". In the NTN depicted in FIG. 2A, FIG. 2B, and / or FIG. 2C, if the first satellite (211) and satellite #2 (212) are each LEO satellites having beams that move with the satellite, this may be referred to as "Scenario D2".

[0122] The parameters for the NTN reference scenarios defined in [Table 2] can be defined as shown in [Table 3] below.

[0123] Scenarios A and B Scenarios C and D Elevation 35,786 km 600 km 1,200 km Spectrum (Service Link) <6 GHz (e.g., 2 GHz) > 6 GHz (e.g., DL 20 GHz, UL 30 GHz) Maximum Channel Bandwidth Capacity (Service Link) 30 MHz for band < 6 GHz 1 GHz for band > 6 GHz Maximum Distance between Satellite and Communication Node (e.g., UE) at Minimum Elevation Angle 40,581 km 1,932 km (600 km altitude) 3,131 km (1,200 km altitude) Maximum RTD (Round Trip Delay) (Propagation Delay Only) Scenario A: 541.46 ms (Service and Feeder Links) Scenario B: 270.73 ms (Service Link Only) Scenario C: (Transparent Payload: Service and Feeder Links) -25.77 ms (600 km Altitude) -41.77ms (1200km altitude) Maximum differential delay within a single cell 10.3ms 3.12ms (600km altitude) 3.18ms (1200km altitude) Service Link NR or 6G Feeder Link 3GPP or non-3GPP defined radio interface

[0124] In addition, in the NTN reference scenario defined in [Table 2], the delay constraint can be defined as shown in [Table 4] below.

[0125] Scenario A Scenario B Scenario C1-2 Scenario D1-2 Satellite Altitude 35,768 km 600 km Maximum RTD at radio interface between base station and UE 541.75 ms (Worst case) 270.57 ms 28.41 ms 12.88 ms Minimum RTD at radio interface between base station and UE 477.14 ms 238.57 ms 8 ms 4 ms

[0126] FIG. 10A is a conceptual diagram illustrating a first embodiment of a protocol stack of the user plane in a transparent payload-based non-terrestrial 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-terrestrial network.

[0127] 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 identically or similarly to a 6G communication network. The protocol stack of the control plane illustrated in FIG. 10B can be applied identically or similarly to a 6G communication network.

[0128] 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.

[0129] 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 the 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.

[0130] In relation to NTN communication, an NTN may be configured to provide non-terrestrial NR access to the UE through an NTN payload and an NTN gateway. A service link refers to the connection between the NTN payload and the UE, and a feeder link may refer to the link between the NTN gateway and the NTN payload.

[0131] FIG. 12 is a diagram illustrating an example of an NTN providing non-terrestrial NR access to a UE through an NTN payload and an NTN gateway. FIG. 12 shows a service link between the NTN payload and the UE and a feeder link between the NTN gateway and the NTN payload.

[0132] The NTN payload transparently transmits the wireless protocol received from the UE via the service link to the NTN gateway via the feeder link, or vice versa. Here, the connectivity supported by the NTN payload is as follows.

[0133] - An NTN gateway can provide multiple NTN payloads.

[0134] - A single NTN payload can be provided by multiple NTN gateways.

[0135] - The NTN payload can change the carrier frequency before retransmission on the service link, or vice versa (at each feeder link).

[0136] In NTN, the following may apply in addition to the network identifier.

[0137] - A tracking area corresponds to a fixed geographical area. Each mapping is configured in the RAN.

[0138] - Mapped cell ID defined in Section 16.14.5.

[0139] Three types of service links are supported.

[0140] - Earth-fixed: Service links can be provided by beam(s) that always continuously cover the same geographic area (e.g., GSO (Geosynchronous Orbit) satellites).

[0141] - 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).

[0142] - 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).

[0143] A gNB operating as an NGSO satellite can provide a quasi-Earth fixed service link or an Earth moving service link, and a gNB operating as a GSO satellite can provide an Earth fixed service link.

[0144] Timing and synchronization are as follows.

[0145] Regarding scheduling and timing, downlink and uplink frames are aligned using an offset given by NTA,offset (see Section 4.2 of TS 38.213) at the uplink time synchronization reference point (RP). To accommodate the propagation delay of NTN, some timing relationships are reinforced by a common timing advance (TA) and two offsets, K_offset and k_mac.

[0146] - Common TA is a timing offset configured to be equal to the round trip time (RTT) between the RP and NTN payloads.

[0147] - K offset is a configured scheduling offset that must be greater than or equal to the sum of the service link RTT and the common TA.

[0148] - k mac is an offset configured to be approximately equal to the RTT between RP and gNB.

[0149] Scheduling offset K offset is used to allow the UE sufficient processing time between downlink reception and uplink transmission (see TS 38.213). Offset k mac It is used to delay the application of the downlink configuration dictated by the MAC CE instruction in PDSCH (see TS 38.213) and for estimating the UE-gNB RTT (see TS 38.321). If downlink and uplink frame timings are not aligned at the gNB, offset k mac It can be provided by the network. Also, offset k mac It is used to determine the RAR window / MsgB window start time after Msg1 / MsgA transmission in random access procedures (see TS 38.213). Service link RTT, feeder link RTT, RP, common TA, k mac and TTA are as shown in Fig. 13.

[0150] Figure 13 is a diagram illustrating the timing relationship between objects included in NTN.

[0151] The network can configure HARQ operations as follows.

[0152] - For downlinks, HARQ feedback can be enabled or disabled on a per-HARQ process basis. Disabling HARQ feedback allows scheduling the HARQ process before one HARQ RTT has elapsed since the last scheduling.

[0153] - For uplinks, a HARQ mode (e.g., HARQ Mode A or HARQ Mode B) can be configured per HARQ process. HARQ Mode B allows scheduling a HARQ process before one HARQ RTT has elapsed since the last scheduling.

[0154] For HARQ processes configured to enable / disable HARQ feedback, it depends on the network implementation to ensure the appropriate HARQ feedback configuration (e.g., enable all or disable all) for the HARQ processes used in the SPS configuration. For HARQ processes configured in HARQ mode, it depends on the network implementation to ensure the appropriate HARQ mode configuration (e.g., all HARQ modes A or all HARQ modes B) for the HARQ processes used in the CG (configured grant) configuration.

[0155] The mobility and state transitions for NTN are as follows.

[0156] Regarding mobility in the RRC_IDLE and RRC_INACTIVE states, the same principles applied in TN (e.g., TS 38.300 Section 9.2.1) apply to mobility in RRC_IDLE for NTN, and the same principles applied in TN (e.g., TS 38.300 Section 9.2.2) may apply to mobility in RRC_INACTIVE for NTN.

[0157] The network can broadcast multiple tracking area codes (TACs) per public land mobile network (PLMN) from NR NTN cells. Changes to TACs within the system information are under network control, and changes to TACs may not be accurately synchronized with the real-time illumination of the ground beam.

[0158] In NTN-TN mobility, the network can broadcast cell information regarding NR TN and EUTRA TN coverage areas in SIB25. This is supported for ground-fixed, semi-ground-fixed, and ground-mobile cells. The coverage information consists of a list of geographic TN areas, and relevant frequency information is also indicated. The UE can skip TN measurements based on the broadcast TN coverage information.

[0159] The UE can implicitly determine the network type (e.g., ground or non-ground) through the presence of cellBarredNTN in SIB1. NTN ephemeris is provided in SIB19. An NTN cell may include the NTN payload ephemeris of the serving cell and, optionally, the NTN payload astronomical clock of an adjacent cell.

[0160] Mobility in RRC_CONNECTED can be examined in terms of handover, conditional handover (CHO), satellite switch with re-sync, and measurement.

[0161] With respect to handover, the same principles applied to TN (e.g., Section 9.2.3.2 of TS 38.300) may apply to NTN unless otherwise specified in the following description. During movement between NTN and TN, the UE is not required to connect to both NTN and TN simultaneously. NTN-TN handover implies bidirectional mobility, that is, movement from NTN to TN (e.g., hand-in) and from TN to NTN (e.g., hand-out). The UE may support mobility between gNBs operating with NTN payloads in different orbits (e.g., GSOs and NGSOs at different altitudes). NTN may support RACH-less handover.

[0162] With respect to conditional handover, the same principles applied in TN (e.g., TS 38.300 Section 9.2.3.4) may be applied to NTN unless otherwise specified in the following description. NTN supports radio resource management (RRM) measurement-based event A4, time-based trigger conditions, and / or location-based trigger conditions as additional trigger conditions that allow a UE to perform a conditional handover to a candidate cell.

[0163] Time-based or location-based trigger conditions may be configured independently of the measurement conditions for the NTN's conditional handover in the minimum hard satellite switch case where the service discontinuity gap time length is assumed to be zero or negligible. Otherwise, the time-based or location-based trigger conditions are configured together with one of the measurement-based trigger conditions (e.g., conditional handover events A3 / A4 / A5). How the UE evaluates the time-based or location-based trigger conditions together with the RRM measurement-based events depends on the UE implementation. When a time-based trigger condition is used, the source base station may signal the corresponding parameters to a single target gNB via the Source NG-RAN Node to Target NG-RAN Node Transparent Container during an NG-C based handover (see TS 23.502). The source base station may signal the corresponding conditional handover configuration to the UE using an RRC reconfiguration message during the handover. When a time-based trigger condition is used, the source base station determines the start time for the initial data delivery to the target base station by considering the time instructed to the UE. In addition, time-based conditional handover can be performed in a RACH-less manner.

[0164] Meanwhile, in NTN, 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.

[0165] The proposed technology relates to signaling and transmission methods related to the repeated transmission of PDCCH CSS for expanding NTN downlink coverage. Through this proposed technology, relevant information transmission and transmission methods are defined to support the repeated transmission of PDCCH CSS during the process in which terminals such as SIB1, SIB19, and Msg4 connect to a cell in the NTN downlink, thereby contributing to the expansion of NTN downlink coverage.

[0166] In the present disclosure, “repetitive transmission” may be referred to in various ways, such as Repetition, Repeated transmission, etc.

[0167] In the present disclosure, "number of repeated transmissions" may be referred to in various ways, such as a repetition factor, repetition factor, repetition factor, repeated transmission factor, etc.

[0168] In the present disclosure, "repetition transmission count candidate" represents a candidate for a repetition transmission count that can be determined as a repetition transmission count. It may be referred to in various ways, such as Repetition factor Candidate(s), etc.

[0169] In the present disclosure, "enable / disable repetitive transmission" may be referred to in various ways, such as Repetition Enabled / Disabled, performing / not performing repetitive transmission, etc.

[0170] The proposed technology relates to signaling and related procedures for supporting repeated transmission of Msg4 (Message 4) to expand NTN downlink coverage. Through the proposed technology, specific procedures and operations regarding the necessity and support of repeated transmission of Msg4 by terminals in the NTN downlink are established, and based on this, it is possible to contribute to expanding NTN downlink coverage.

[0171] Cells supported by NTN (non-terrestrial network) base stations have a wider radius compared to cells supported by conventional TN (terrestrial network) base 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.

[0172] Figure 14 shows an example illustrating the process of a terminal connecting to an NTN cell.

[0173] Various discussions are currently underway to increase the coverage of the NTN downlink covered in the Release-19 standardization. Among these, as shown in Figure 1, discussions are being held regarding the repeated transmission of the Physical Downlink Shared Channel (PDSCH) and the Physical Downlink Control Channel (PDCCH) received by a terminal during the process of connecting to a cell. In particular, regarding the PDSCH, discussions have been held on link-level enhancement for the PDSCH related to SIB1 / SIB19 and the PDSCH related to Msg4. It was agreed to proceed with repeated transmission for the PDSCH related to SIB1 and the PDSCH related to Msg4, and the need for repeated transmission for SIB19 is also continuously being raised.

[0174] At this time, discussions are underway regarding methods in which a Capability Report or a repeat transmission request is transmitted from a terminal before the Msg4 repeat transmission is determined in order to proceed with the PDSCH repeat transmission for Msg4, and the base station determines the PDSCH repeat transmission for Msg4 based on this. To support the repeat transmission of Msg4, it is necessary to specifically define the procedures and necessary signaling for this process. Accordingly, the present invention proposes relevant procedures for the process of repeat transmission and determination / agreement on the number of repetitions to support the PDSCH repeat transmission regarding Msg4, and proposes methods and contents such as relevant terminal reports, including a Capability Report and a repeat transmission request, that may be required according to the procedures.

[0175] In the proposals below, it is assumed that information regarding the use of time / frequency resources (repetition interval, time / frequency resource mapping, etc.) in repetitive transmissions is standardized or conveyed via separate signaling.

[0176] FIG. 15 illustrates a process in which the activation status of repeated transmission is conveyed to a terminal through cell-specific signaling in one embodiment.

[0177] [Proposal 1: Cell-Specific Repetition Enable / Disable without Report]

[0178] Proposal 1 proposes a method in which the activation / deactivation status (or activation mode) of repetitive transmission is transmitted in a cell-specific manner, and the base station and terminal perform Msg4 Repetition based on this information without the transmission of information such as Capability Reports or repetitive transmission requests from the terminal. An example of this method is shown in Figure 2. Here, the repetitive transmission mode refers to the rules defined in the standard specification regarding the application of the Repetition Factor or Enable / Disable for Msg4 PDSCH repetitive transmission. (e.g., Mode 0 – supports non-repetitive transmission, applying only one of Repetition Factor 1 or {2, 4}; Mode 1 – supports repetitive transmission only, applying only Repetition Factors 2 and 4).

[0179] The basic procedure of the method can be defined as follows. First, the Enable / Disable value (or repeat transmission mode value) for Msg4 PDSCH Repetition is instructed to terminals from a specific base station via methods such as explicit or implicit instructions. The terminals determine whether the base station's Msg4 PDSCH is repeating based on the instructed value and do not send information, such as a separate Msg4 Repetition Capability Report or a repeat transmission request, to the base station until the Msg4 PDSCH reception process begins. Subsequently, when the Msg4 PDSCH reception process begins, depending on the determined Repetition status, the terminals may proceed with a reception process that does not assume Repetition, or a reception process that assumes Repetition for consecutive slots corresponding to the Repetition Factor.

[0180] The Enable / Disable value (or repeat transmission mode value) for Repetition of the Msg4 PDSCH in Proposal 1 can be represented through a 1-bit field (e.g., 0 – Enable, 1 – Disable or 0 – Disable, 1 – Enable or 0 – Mode 0, 1 – Mode 1). This value may indicate whether the base station's Msg4 PDSCH supports Repetition (e.g., Enable – Repetition possible, Disable – Repetition impossible / Mode 0 – Repetition possible, Mode 1 – Repetition impossible / Mode 0 – Repetition impossible, Mode 1 – Repetition possible) or may indicate the default operation related to Repetition of the base station's Msg4 PDSCH (e.g., Mode 0 – Repetition performed by default, Mode 1 – Repetition not performed by default / Mode 0 – Repetition not performed by default, Mode 1 – Repetition performed by default / Mode 0 – Non-repetitive transmission possible, Mode 1 – Non-repetitive transmission impossible / Mode 0 – Non-repetitive transmission impossible, Mode 1 – Non-repetitive transmission possible) The value may be explicitly transmitted by including it as a separate field in the MIB or PBCH Payload or SIB1 or SIB19, etc., or it may be implicitly transmitted by being standardized to be applied in the same way as the Repetition status of SIB1 PDSCH or SIB19 PDSCH, or it may be implicitly transmitted by being standardized to be applied in the same way as the Repetition status of Type-0 CSS PDCCH.

[0181] In this case, the Repetition Factor for the Repetition of Msg4 PDSCH can be determined in one of the following ways.

[0182] First, the Repetition Factor for the Repetition of Msg4 PDSCH may be transmitted via MIB, PBCH Payload, SIB1, or SIB19. In this case, the terminal can expect the transmission of Msg4 PDSCH with the corresponding Repetition Factor applied when Repetition Transmission is enabled / disabled, and may not specify the Repetition of Msg4 PDSCH when it is disabled. Alternatively, if a Repetition Transmission mode other than Repetition Transmission Enable / Disabled is transmitted, the terminal can expect whether the Repetition of Msg4 PDSCH with the transmitted Repetition Factor is applied according to that mode.

[0183] Next, it can be delivered UE-specifically to each individual terminal via Msg4 PDSCH. In this case, the terminal may interpret the Repetition Factor for the same field differently depending on whether repeat transmission is enabled or disabled according to the specification (e.g., for 1-bit signaling, bit 0 is Factor 2 and bit 1 is Factor 4 when Repetition is Enabled / for 1-bit signaling, Factor 1 regardless of the bit when Repetition is Disabled). The terminal can expect the transmission of Msg4 PDSCH applying the interpreted Repetition Factor. Alternatively, if a repeat transmission mode is transmitted instead of repeat transmission enable / disable, the terminal can expect whether the Msg4 PDSCH applies the Repetition Factor interpreted according to that mode (e.g., for 1-bit signaling in Mode 0, bit 0 is Factor 2 and bit 1 is Factor 4 / for 1-bit signaling in Mode 1, bit 0 is Factor 1 and bit 1 is Factor 2).

[0184] Next, a separate Repetition Factor may not be transmitted to the terminal. In this case, if Repetition is enabled, the terminal can proceed with the reception process under the assumption that repetition is possible for slots up to the maximum Repetition Factor defined for Msg4 PDSCH in the specification; at this stage, it may go through processes such as identifying slots where repetition has not been performed through calculations based on correlation or determining the Repetition Factor internally. If Repetition is disabled, the terminal may not expect Msg4 PDSCH repetition. Alternatively, if a repeat transmission mode is transmitted, the terminal can proceed with the reception process under the premise that specific Repetition Factors determined by the mode are possible.

[0185] FIG. 16 shows examples in which information regarding whether repeated transmission is enabled and / or the number of repeated transmissions is transmitted to a terminal through cell-specific signaling.

[0186] FIG. 16 illustrates examples of the implementation of this proposal 1. (1) of FIG. 16 illustrates an example of an explicit instruction for Enabling / Disabling (or an explicit instruction for a repeat transmission mode) and an explicit instruction for a Repetition Factor through a SIB, and (2) of FIG. 16 illustrates an example of an implicit instruction for Enabling / Disabling (or an implicit instruction for a repeat transmission mode) and an explicit instruction for a Repetition Factor through an Enabling / Disabling SIB1 PDSCH Repetition. Figure 16 (3) shows an example of an explicit instruction for Enabling / Disabling via SIB (or an explicit instruction for the repeat transmission mode) and an explicit instruction for the Repetition Factor via Msg4 PDCCH, and Figure 16 (4) shows an example of an operation procedure for an implicit instruction for Enabling / Disabling via Enabling / Disabling SIB1 PDSCH Repetition (or an implicit instruction for the repeat transmission mode) and an explicit instruction for the Repetition Factor via Msg4 PDCCH.

[0187] In FIG. 16, (1) illustrates an explicit indication of Enabling / Disabling via SIB (or an explicit indication of the repeat transmission mode) and an explicit indication of the Repetition Factor via SIB. (2) illustrates an implicit indication of Enabling / Disabling via Enabling / Disabling SIB1 PDSCH Repetition (or an implicit indication of the repeat transmission mode) and an explicit indication of the Repetition Factor via SIB. (3) illustrates an explicit indication of Enabling / Disabling via SIB (or an explicit indication of the repeat transmission mode) and an explicit indication of the Repetition Factor via Msg4 PDCCH. (4) illustrates an implicit indication of Enabling / Disabling via Enabling / Disabling SIB1 PDSCH Repetition (or an implicit indication of the repeat transmission mode) and an explicit indication of the Repetition Factor via Msg4 PDCCH.

[0188] FIG. 17 illustrates a process in which information regarding whether repeated transmission is enabled and / or the number of repeated transmissions is transmitted to a terminal through terminal-specific signaling in one embodiment.

[0189] [Proposal 2: UE-Specific Repetition Enable / Disable without Report]

[0190] Proposal 2 proposes a method in which the activation / deactivation status (or activation mode) of repetitive transmission is transmitted in a UE-specific manner, and the base station and terminal perform Msg4 Repetition based on this without the transmission of information such as Capability Reports or repetitive transmission requests from the terminal. An example of this method is shown in Figure 4. Here, the repetitive transmission mode refers to the rules defined in the standard specification regarding the application of the Repetition Factor or Enable / Disable for Msg4 PDSCH Repetition. (e.g., Mode 0 – supports non-repetitive transmission, applying only Repetition Factor 1 or one of {2, 4}; Mode 1 – supports repetitive transmission only, applying only Repetition Factors 2 and 4).

[0191] The basic procedure of the method can be defined as follows. First, the Enable / Disable value (or repeat transmission mode value) for Msg4 PDSCH Repetition is instructed to each individual terminal from a specific base station via methods such as explicit or implicit instructions. The terminals determine whether the base station's Msg4 PDSCH is repeating based on the instructed value and do not send information, such as a separate Msg4 Repetition Capability Report or a repeat transmission request, to the base station until the Msg4 PDSCH reception process begins. Subsequently, when the Msg4 PDSCH reception process begins, depending on the determined Repetition status, the terminals may proceed with a reception process that does not assume Repetition, or a reception process that assumes Repetition for consecutive slots corresponding to the Repetition Factor.

[0192] The Enable / Disable value (or repeat transmission mode value) for Repetition of the Msg4 PDSCH in Proposal 2 can be represented through a 1-bit field (e.g., 0 – Enable, 1 – Disable or 0 – Disable, 1 – Enable or 0 – Mode 0, 1 – Mode 1). This value may indicate whether the base station's Msg4 PDSCH supports Repetition (e.g., Enable – Repetition possible, Disable – Repetition impossible / Mode 0 – Repetition possible, Mode 1 – Repetition impossible / Mode 0 – Repetition impossible, Mode 1 – Repetition possible) or may indicate the default operation related to Repetition of the base station's Msg4 PDSCH (e.g., Mode 0 – Repetition performed by default, Mode 1 – Repetition not performed by default / Mode 0 – Repetition not performed by default, Mode 1 – Repetition performed by default / Mode 0 – Non-repetitive transmission possible, Mode 1 – Non-repetitive transmission is not possible / Mode 0 – Non-repetitive transmission is not possible, Mode 1 – Non-repetitive transmission is possible) The value may be included as a separate field in Msg2 PDCCH or Msg2 PDSCH or Msg4 PDCCH, etc. and transmitted explicitly.

[0193] In this case, the Repetition Factor for the Repetition of Msg4 PDSCH can be determined in one of the following ways.

[0194] First, the Repetition Factor for the Repetition of Msg4 PDSCH may be transmitted via MIB, PBCH Payload, SIB1, or SIB19. In this case, the terminal can expect the transmission of Msg4 PDSCH with the corresponding Repetition Factor applied when the repetition transmission is enabled or disabled, and may not specify the Repetition of Msg4 PDSCH when it is disabled. Alternatively, if a repetition transmission mode other than repetition transmission enable or disable is transmitted, the terminal can determine whether to apply the transmitted Repetition Factor to the repetition of Msg4 PDSCH according to that mode.

[0195] Next, it can be transmitted UE-specifically to each individual terminal via Msg4 PDCCH. In this case, the terminal may interpret the Repetition Factor for the same field differently depending on whether repeat transmission is enabled or disabled according to the standard (e.g., 1-bit signaling, where bit 0 is Factor 2 and bit 1 is Factor 4 when Repetition Enabled / 1-bit signaling, where Factor 1 is Factor 1 regardless of the bit when Repetition Disabled). Alternatively, using 2-bit signaling, it can be transmitted in the form of 00: repetition factor 1 (no repetition), 01: repetition factor 2, 10: repetition factor 4, 11: repetition factor 8, and the terminal can expect that if the transmitted repetition factor exceeds 1, the repetition of Msg4 PDSHC will be performed using that repetition factor. In this way, the terminal can expect the transmission of Msg4 PDSCH with the interpreted Repetition Factor applied. Alternatively, if a repeat transmission mode is transmitted rather than repeat transmission enable / disable, one can expect whether the repeat transmission of the Msg4 PDSCH is applied based on the Repetition Factor interpreted according to that mode. (e.g., 1-bit signaling, Mode 0: bit 0 is Factor 2, bit 1 is Factor 4 / 1-bit signaling, Mode 1: bit 0 is Factor 1, bit 1 is Factor 2)

[0196] Next, a separate Repetition Factor may not be transmitted to the terminal. In this case, if Repetition is enabled, the terminal can proceed with the reception process under the assumption that repetition is possible for slots up to the maximum Repetition Factor defined for Msg4 PDSCH in the specification; at this stage, it may go through processes such as identifying slots where repetition has not been performed through calculations based on correlation or determining the Repetition Factor internally. If Repetition is disabled, the terminal may not expect Msg4 PDSCH repetition. Alternatively, if a repeat transmission mode is transmitted, the terminal can proceed with the reception process under the premise that specific Repetition Factors determined by the mode are possible.

[0197] When a UE-specific Repetition Factor is transmitted to the terminal via Msg4 PDCCH, etc., the terminal can determine whether to repeat transmission based on the Repetition Factor; therefore, the Enable / Disable message (or repeat transmission mode) may not be transmitted separately or may be ignored. In other words, the transmission of a UE-specific Repetition Factor can replace the transmission of a UE-specific Enable / Disable (or repeat transmission mode) message.

[0198] FIG. 18 shows examples in which information regarding whether repeated transmission is enabled and / or the number of repeated transmissions is transmitted to the terminal through terminal-specific signaling.

[0199] Figure 18 below shows examples of the implementation procedures for this proposal 2. Figure 18 (1) shows an example of the explicit instruction of the Repetition Factor (or the explicit instruction of the repetitive transmission mode) via SIB and the explicit instruction of Enabling / Disabling via Msg4 PDCCH, and Figure 18 (2) shows an example of the operation procedure for the explicit instruction of Enabling / Disabling (or the repetitive transmission mode) and the Repetition Factor via Msg4 PDCCH.

[0200] In FIG. 18, (1) illustrates an explicit indication of the Repetition Factor (or an explicit indication of the repeat transmission mode) via SIB and an explicit indication of Enabling / Disabling via Msg4 PDCCH. (2) illustrates an explicit indication of the Enabling / Disabling (or repeat transmission mode) and Repetition Factor via Msg4 PDCCH.

[0201] FIG. 19 illustrates a process in which information regarding a candidate number of repeated transmissions is transmitted to a terminal through cell-specific signaling in one embodiment.

[0202] [Proposal 3: Cell-Specific Repetition Factor Candidates without Report]

[0203] Proposal 3 proposes a method in which candidates for Repetition Factors configurable at the base station are transmitted in a cell-specific manner, and the base station and terminal perform Msg4 Repetition based on this without transmitting information such as Capability Reports or requests for repeated transmission from a separate terminal. An example of this method is shown in Figure 6.

[0204] The basic procedure of the method can be defined as follows. First, at a specific base station, candidates for the Repetition Factors for the Repetition of Msg4 PDSCH are cell-specifically instructed to terminals via SIB1 or SIB19, etc. The terminals determine whether the base station's Msg4 PDSCH Repetition is applicable based on the instructed values ​​(e.g., if only 1 is set as the candidate for the number of repeated transmissions – Repetition is never performed; if only a value of 2 or more is set as the candidate for the number of repeated transmissions – Repetition is always performed; if multiple values ​​including 1 are set as the candidate for the number of repeated transmissions – Repetition is performed or not performed depending on the situation), and the terminals also do not send information such as a separate Msg4 Repetition Capability Report or a request for repeated transmission to the base station until the Msg4 PDSCH reception process begins. Subsequently, when the Msg4 PDSCH reception process begins, depending on whether a repetition is determined, a reception process that does not assume repetition may be performed, or a reception process that assumes repetition for consecutive slots corresponding to the repetition factor may be performed.

[0205] In Proposal 3, the value for the candidate for the number of repeated transmissions in Msg4 PDSCH can be explicitly transmitted through a separate field in the MIB, PBCH Payload, SIB1, or SIB19, thereby allowing one or multiple candidates for the number of repeated transmissions to be transmitted. When a single Repetition Factor Candidate is transmitted, terminals can interpret the value to enable / disable repeated transmission or a specific repeated transmission mode (e.g., if only 1 is set – Repetition Disable, if only a value of 2 or higher is set – Repetition Enable), and can obtain the Repetition Factor without separate transmission. When multiple candidates for the number of repeated transmissions are transmitted, terminals can determine the Repetition status and the Repetition Factor, etc., through a separate message / field for determining the Repetition Factor and the Repetition Enable / Disable (or repeated transmission mode).

[0206] Additionally, the candidates for the number of repeated transmissions may always include only the Repetition Factor to be applied when Msg4 Repetition is performed (e.g., Repetition Factor Candidates = {2} or {4}, Enable / Disable, or determine whether to repeat based on the repeated transmission mode). That is, 1 may not be included in the candidates for the number of repeated transmissions regardless of whether Non-Repetition is actually applied. This may be determined by the definition of the candidates for the number of repeated transmissions (whether they include all possible Repetition Factors, or whether they include only the values ​​to be applied during repeated transmissions, excluding the case of non-repetition transmission).

[0207] In this case, if there are multiple Repetition Factors applicable to Msg4 PDSCH Repetition (e.g., multiple Repetition Factor Candidates are included, or if the specification does not specify 1 for the Candidate but the Repetition Factor Candidate is configured), the Repetition status and Repetition Factor of Msg4 PDSCH may be determined by one of the following methods. If there is a single applicable Repetition Factor (e.g., Example 1: if all possible candidates including Repetition Factor 1 are to be included in the Repetition Factor Candidate, Example 2: if Repetition Factor 1 is to be excluded from the Repetition Factor Candidate but the Repetition Factor Candidate is not configured), the method below may not be applied, and operation may always be performed according to a given single Repetition Factor.

[0208] First, the UE-specific status of enabling or disabling repeat transmission (or the repeat transmission mode value) can be transmitted to each individual terminal via Msg4 PDCCH. This case may involve a situation where the repeat transmission count candidates include two values, one of which is 1, corresponding to Non-repetition (e.g., Repetition Factor Candidates = {1, 2} or {1, 4}, etc.). Alternatively, the repeat transmission count candidates may always include only the Repetition Factor to be used when Repetition is performed (e.g., Repetition Factor Candidates = {2} or {4}, determining whether to repeat or not based on Enable / Disable). In this case, if Repetition Enable is transmitted, the terminal may interpret the remaining value other than Repetition Factor 1 as the Repetition Factor to be applied to it and proceed with the Msg4 PSDCH reception process. If Repetition Disable is transmitted, the terminal may not expect Repetition from Msg4 PDSCH. Alternatively, if a repeat transmission mode is transmitted rather than repeat transmission enable / disable, one can expect whether the repeat transmission of the transmitted Repetition Factor Msg4 PDSCH is applied according to that mode.

[0209] Next, there is a case where the Repetition Factor is transmitted UE-specifically to each individual terminal via Msg4 PDCCH. This case may involve a situation where the Repetition Factors Candidates contain more than two values ​​(e.g., Repetition Factor Candidates = {1, 2, 4} or {1, 2, 4, 8} or {2, 4, 8} or {2, 4}, etc.). In this case, the terminal can proceed with the reception process of the Msg4 PDSCH according to the received Repetition Factor. In this case, when transmitting the Repetition Factor, the mapping of each field may be indicated by absolute values ​​(e.g., 2-bit signaling, 00 – Repetition Factor 1, 01 – Repetition Factor 2, 10 – Repetition Factor 4, 11 – Repetition Factor 8) or may be indicated based on values ​​included in the candidates for the number of repeated transmissions (e.g., 2-bit signaling, 00 – 1st candidates, 01 – 2nd candidate, 10 – 3rd candidates, 11 – 4th candidates / e.g., 2-bit signaling, 00 – Repetition Factor 1, 01 – 1st candidate, 10 – 2nd candidates, 11 – 3rd candidate, etc.).

[0210] Next, a separate Repetition Factor may not be transmitted to the terminal. In this case, the terminal can proceed with the reception process under the assumption that repeated transmission of Msg4 PDSCH is possible based on the possible Repetition Factor values ​​identified through the candidate transmission counts and specifications. At this time, the terminal may go through processes such as finding slots where repetition has not been performed through calculations based on correlation, or determining the Repetition Factor independently.

[0211] Figure 20 shows examples in which information about the number of repeated transmissions can be transmitted to a terminal through cell-specific signaling.

[0212] FIG. 20 illustrates examples of the implementation procedures for Proposal 3. (1) in FIG. 20 is an example of Repetition through the indication of candidate repeat transmission counts via SIB and the explicit indication of Enabling / Disabling via Msg4 PDCCH (or the explicit indication of repeat transmission mode), in which the specification defines that the candidate repeat transmission counts may include Repetition Factor 1 if necessary. (2) in FIG. 20 is an example of Non-Repetition through the indication of candidate repeat transmission counts via SIB and the explicit indication of Enabling / Disabling via Msg4 PDCCH (or the explicit indication of repeat transmission mode), in which the specification defines that the candidate repeat transmission counts may include only those exceeding Repetition Factor 1. In the case of (3) in FIG. 20, it is an example of Repetition through the instruction of candidate repeat transmission counts via SIB and the instruction of Repetition Factor via Msg4 PDCCH, in which the specification defines that Repetition Factor 1 may be included in the candidate repeat transmission counts if necessary. FIG. 20 (4) shows an example of a procedure for Non-Repetition through the instruction of candidate repeat transmission counts via SIB and the instruction of Repetition Factor via Msg4 PDCCH, in which the specification defines that Repetition Factor 1 may be included in the candidate repeat transmission counts if necessary.

[0213] In FIG. 20, (1) illustrates Repetition through a candidate for the number of repeated transmissions via SIB [defined in the specification to include Repetition Factor 1] and an explicit indication of Enabling / Disabling via Msg4 PDCCH (or an explicit indication of the repeated transmission mode). (2) illustrates Non-Repetition through a candidate for the number of repeated transmissions via SIB [defined in the specification to include only those exceeding Repetition Factor 1] and an explicit indication of Enabling / Disabling via Msg4 PDCCH (or an explicit indication of the repeated transmission mode). (3) illustrates Repetition through a candidate for the number of repeated transmissions via SIB [defined in the specification to include Repetition Factor 1] and an indication of the Repetition Factor via Msg4 PDCCH. (4) illustrates the number of repeated transmissions via SIB [defined in the specification to include Repetition Factor 1] and the non-repetition via the Repetition Factor indication via Msg4 PDCCH.

[0214] FIG. 21 illustrates the process of a terminal receiving repeated transmissions through RSRP threshold signaling in one embodiment.

[0215] [Proposal 4: RSRP Threshold with Report]

[0216] Proposal 4 proposes a method in which a base station sets an RSRP Threshold, a terminal sends a report based on the interpretation method of the RSRP Threshold, and the terminal sets the Repetition Status and Repetition Factor for individual terminals based on this. An example of this method is shown in Fig. 21.

[0217] The basic procedure of this method can be defined as follows. First, the RSRP threshold for Msg4 PDSCH repetition is cell-specifically instructed to terminals from a specific base station via SIB1 or SIB19, etc. Terminals measure their RSRP based on the instructed value and transmit a report to the base station accordingly. Based on this report, the base station determines whether a specific terminal is experiencing Msg4 PDSCH repetition and the repetition factor, and instructs the terminal accordingly. The terminal then proceeds with the Msg4 PDSCH reception process based on the instruction result regarding the Msg4 PDSCH repetition.

[0218] The RSRP Threshold for Msg4 PDSCH Repetition used in Proposal 4 can be transmitted Cell-Specifically through a separate field in SIB1 or SIB19. Additionally, the RSRP Threshold for Msg4 PDSCH Repetition can be specified to use the RSRP Threshold value already standardized for Msg4 HARQ-ACK Repetition. In this case, the RSRP Threshold value for Msg4 HARQ-ACK Repetition can be used as is as the RSRP Threshold for Msg4 PDSCH Repetition, or the RSRP Threshold for Msg4 PDSCH Repetition can be calculated by considering the transmission power difference between the satellite and the terminal in addition to the RSRP Threshold for Msg4 HARQ-ACK Repetition. Alternatively, a value corresponding to the difference between the RSRP Threshold of Msg4 HARQ-ACK Repetition and the RSRP Threshold of Msg4 PDSCH Repetition may be transmitted.

[0219] In the application scenario of this method, whether the Msg4 PDSCH repetition is enabled or disabled (or the repetition mode value) can be additionally transmitted cell-specifically, separately from the RSRP Threshold. In this case, if Msg4 PDSCH Repetition is enabled, the terminal and base station can operate according to the basic procedure; if Msg4 PDSCH Repetition is disabled, the terminal and base station operate under the assumption that Msg4 PDSCH Repetition is not supported, so the terminal can skip the report regardless of the existence of the RSRP Threshold, and the base station can skip procedures such as the repetition status / repetition factor configuration for each terminal. Alternatively, even if Msg4 PDSCH Repetition is disabled, the terminal can transmit the report if the RSRP Threshold exists. In this case, the Enable / Disable value for Repetition in the Msg4 PDSCH can be expressed through a 1-bit field (e.g., 0 – Enable, 1 – Disable or 0 – Disable, 1 – Enable). This value can indicate whether the base station's Msg4 PDSCH supports Repetition (e.g., Enable – Repetition can be performed, Disable – Repetition cannot be performed) or indicate the default behavior related to Repetition of the base station's Msg4 PDSCH (e.g., Enable – Repetition is performed by default, Disable – Repetition is not performed by default).Alternatively, if a repeat transmission mode is transmitted, the corresponding Mode may indicate whether the base station’s Msg4 PDSCH supports Repetition (e.g., Mode 0 – Repetition possible, Mode 1 – Repetition impossible / Mode 0 – Repetition impossible, Mode 1 – Repetition possible) or indicate the default operation related to Repetition of the base station’s Msg4 PDSCH (e.g., Mode 0 – Repetition performed by default, Mode 1 – Repetition not performed by default / Mode 0 – Repetition not performed by default, Mode 1 – Repetition performed by default / Mode 0 – Non-repetitive transmission possible, Mode 1 – Non-repetitive transmission impossible / Mode 0 – Non-repetitive transmission impossible, Mode 1 – Non-repetitive transmission possible). Depending on these Modes, if it is determined by the standard that Msg4 PDSCH Repetition is not supported or that a report does not need to be sent, the terminal may omit the report, and if Msg4 PDSCH Repetition is supported If it is determined according to the specifications or if it is determined that a report must be sent, the terminal may transmit the report. The value may be explicitly transmitted by including it as a separate field in the MIB or PBCH Payload or SIB1 or SIB19, or it may be implicitly transmitted by being standardized to be applied in the same way as the repetition status of SIB1 PDSCH or SIB19 PDSCH, or it may be implicitly transmitted by being standardized to be applied in the same way as the repetition status of Type-0 CSS PDCCH.

[0220] Additionally, the RSRP Threshold for Msg4 PDSCH Repetition can be used to implicitly indicate whether repetition is enabled or disabled (or the repetition mode value). For example, if the RSRP Threshold for Msg4 PDSCH Repetition is Absent, it can be interpreted as Repetition Disable (or a specific repetition mode), or if the RSRP Threshold for Msg4 PDSCH Repetition is Config, it can be interpreted as Repetition Enable (or a specific repetition mode).

[0221] In the application scenario of this method, information regarding candidate iteration counts applicable to Msg4 PDSCH can be separately and additionally transmitted in a Cell-Specific manner. In this case, if only 1 is included in the Msg4 PDSCH repeat transmission count candidates, it is interpreted as Repetition Disabled; consequently, the terminal may not send the report according to the conditions defined in the specification, and the RSRP Threshold for Msg4 PDSCH Repetition may not be configured. (Example 1: Only 1 included in the repeat transmission count candidates -> Report not sent and repeat transmission not applied; Example 2: Only 1 included in Repetition Factor Candidates & RSRP Threshold not configured -> Report not sent and repeat transmission not applied) Additionally, if only one value exceeding 1 is included in the Repetition Factor Candidates, it is interpreted as Repetition Always Enabled; consequently, the terminal may not send the report according to the conditions defined in the specification, and the RSRP Threshold for Msg4 PDSCH Repetition may not be configured. (Example 1: Only one value exceeding 1 included in Repetition Factor Candidates -> Report not sent and repeat transmission of that value applied; Example 2: In the repeat transmission count candidates Includes only one value exceeding 1 & RSRP Threshold is not configured -> Report not sent and repeated transmission of the value is applied) Also, regardless of the value included in the repeated transmission count candidates and the number of Candidates, the terminal can always deliver the Report according to the given procedure.

[0222] Additionally, the candidates for the number of repeated transmissions may always include only the Repetition Factor to be applied when Msg4 Repetition is performed (e.g., Repetition Factor Candidates = {2} or {4}, Enable / Disable, or determine whether to repeat transmission based on the repeated transmission mode). That is, 1 may not be included in the candidates for the number of repeated transmissions regardless of whether Non-Repetition is actually applied. This may be determined by the definition of the candidates for the number of repeated transmissions (whether they include all possible Repetition Factors, or whether they include only the values ​​to be applied during repeated transmission, excluding the case of non-repetition transmission).

[0223] The values ​​for the repeat count candidates of this Msg4 PDSCH may be explicitly transmitted through a separate field in the MIB, PBCH Payload, SIB1, or SIB19, or implicitly transmitted through the same field as the repeat count candidates of the Msg4 HARQ-ACK. In the case of such implicit transmission, the candidate set may be determined to be the same as that of the repeat count candidates of the Msg4 HARQ-ACK, or the repeat count candidates of the Msg4 PDSCH may be calculated by interpreting them from the repeat count candidates of the Msg4 HARQ-ACK using standardized calculation rules (e.g., conversion using the difference between terminal transmit power and satellite transmit power).

[0224] In Proposal 4, the terminal may transmit a Capability Report, a Repetition Transmission Request, or a Repetition Factor Request as the content of the Report transmission. The transmission scenarios for this can be classified as follows.

[0225] First, consider a scenario where the terminal transmits either a Capability Report or a Repetition Request as 2-state information. In other words, in this scenario, the Capability Report and the Repetition Request represent the same 2-state information; for the sake of convenience of description, this is referred to as the Capability Report. In this scenario, the terminal may transmit the Capability Report as Negative if it is unable to handle the Msg4 PDSCH Repetition, such as when it cannot proceed with the reception process for the Repetition or cannot measure the RSRP. In this case, the base station may not configure the Msg4 PDSCH Repetition for the terminal based on the report. Alternatively, if the terminal can handle the Msg4 PDSCH Repetition but determines that the Repetition is not necessary because the RSRP measurement result is above (or exceeds) the RSRP Threshold, the terminal may send the Capability Report as Negative. In this case, the base station may not configure the Msg4 PDSCH Repetition for the terminal based on the report. Alternatively, if the terminal can process Msg4 PDSCH Repetition and the RSRP measurement result is below (or less than) the RSRP Threshold, the terminal may send a Capability Report as Positive. In this case, the base station may configure Msg4 PDSCH Repetition for the terminal based on the Report.

[0226] Next is a scenario where the terminal transmits both the Capability Report and the Repetition Request separately, with each defined as 2-state information. In this case, regarding the Capability Report, the terminal may transmit it as Positive if it can handle the repetition, or Negative if it cannot, considering its Msg4 PDSCH Repetition processing capability. Additionally, regarding the Repetition Request, if the RSRP measurement result is above (or exceeds) the RSRP Threshold and it is determined that Repetition is not necessary, the terminal may transmit the Repetition Request as Negative; if it is below (or less than) the RSRP Threshold and it is determined that Repetition is necessary, the terminal may transmit the Repetition Request as Positive. The base station may determine whether to configure PDSCH Repetition and the Repetition Factor for the terminal based on the relevant Capability Report and Repetition Request. For example, if both the Capability Report and the Repetition Request are Positive, Repetition may be configured, but if either one is Negative, Repetition may not be configured. As another example, if the Capability Report is Positive, the Repetition may be configured by considering the terminal's repeated transmission request and the base station's own additional judgment, and if the Capability Report is Negative, the Repetition may not be configured.

[0227] Next is a scenario where the terminal sends a Repetition Factor Request. In the relevant scenario, the Repetition Factor Request can be defined as an absolute value (e.g., 2-bit signaling, 00 – Repetition Factor 1, 01 – Repetition Factor 2, 10 – Repetition Factor 4, 11 – Repetition Factor 8; e.g., 2-bit signaling, 00 – Repetition Factor 1, 01 – Repetition Factor 2, 10 – Repetition Factor 3, 11 – Repetition Factor 4) or can be indicated based on values ​​included in the repeat transmission count candidates (e.g., 2-bit signaling, 00 – 1st candidates, 01 – 2nd candidate, 10 – 3rd candidates, 11 – 4th candidate / e.g., 2-bit signaling, 00 – Repetition Factor 1, 01 – 1st candidate, 10 – 2nd candidates, 11 – 3rd candidate, etc.), and the terminal itself If you have the capability to process Msg4 PDSCH Repetition, you can determine and transmit the required Repetition Factor based on the difference between the RSRP measurement result and the RSRP Threshold. For example, you can determine the required number of repetitions by quantizing the difference between the RSRP measurement result and the RSRP Threshold in 3dB increments, and transmit that number of repetitions, or transmit the value closest to that number of repetitions among the candidates for the number of repetitions or the Repetition Factors supported by the system specifications.If the terminal is unable to process Msg4 PDSCH Repetition (e.g., inability to process repeated transmission reception or inability to compare RSRP, etc.), it may transmit Repetition Factor 1 without performing the process, or even if Msg4 PDSCH repeated transmission reception is impossible, it may calculate and transmit a value for a Repetition Factor Request to provide information for reference to the base station. The base station may determine whether to configure Msg4 PDSCH Repetition and the Repetition Factor for the terminal by considering the relevant Capability Report and the repeated transmission request. For example, the value reported by the terminal may be applied to the terminal as is, or the base station may determine whether to configure Msg4 PDSCH Repetition and the Repetition Factor for the terminal and issue instructions based on the value reported by the terminal through additional processing steps.

[0228] Next, the terminal transmits a Capability Report, which includes the difference value from the RSRP Threshold. If the terminal has the capability to handle Msg4 PDSCH Repetition, or if reporting a Capability Report is required by the standard regardless of processing capability, the terminal transmits the difference value from the RSRP Threshold based on the RSRP measurement result to the base station via the Capability Report. If the terminal lacks the capability to handle Msg4 PDSCH Repetition (e.g., inability to process repeated transmissions or receptions, or inability to compare RSRP), it may not perform the process and transmit information corresponding to the dB value for cases where Repetition is not required. The base station can determine whether to configure Msg4 PDSCH Repetition and the Repetition Factor for the terminal by considering the dB difference between the RSRP Threshold transmitted in the Capability Report and the measured RSRP.

[0229] In this Proposal 4, the Report sent by the terminal can be transmitted via Msg1 or separately via Msg3 via Explicit. When the Report is transmitted via Msg1, it can be distinguished by the Preamble Index. That is, the entire Preamble Indices can be divided into subsets of multiple Preamble Indices, and each subset can be determined to represent specific content of the Report (e.g., sending only the Capability Report, dividing the Preamble into two sets, with each set indicating Positive / Negative). Alternatively, it can be transmitted separately via Msg3 using separate fields such as PHY, MAC CE, or RRC Message. Or, it can be transmitted together using the same fields as the Capability Report (Repetition Request) for the existing Msg4 HARQ-ACK. In this case, the terminal can generate and transmit information in the same manner as the existing Msg4 HARQ-ACK Repetition Capability Report generation process without performing a separate process for Msg4 PDSCH Repetition, and the base station can interpret the information as the Capability Reports for Msg4 PDSCH Repetition and Msg4 HARQ-ACK Repetition appearing simultaneously with the same value and proceed with the remaining process.

[0230] A base station that receives a report from a terminal may transmit information to the terminal regarding the determined repeat transmission enable / disable (or repeat transmission mode) and Repetition Factor, etc. Such information may be transmitted as follows, in accordance with the specifications.

[0231] First, the UE-specific status of enabling or disabling repeat transmission (or repeat transmission mode) can be conveyed to each individual terminal via Msg4 PDCCH. This case may involve a situation where repeat transmission count candidates are configured and contain two values, one of which is 1, corresponding to Non-repetition (e.g., Repetition Factor Candidates = {1, 2} or {1, 4}, etc.). Alternatively, the repeat transmission count candidates may always include only the Repetition Factor to be used when Repetition is performed (e.g., Repetition Factor Candidates = {2} or {4}, determining whether to repeat based on Enable / Disable or Repeat Transmission Mode). In this case, if Repetition Enable is conveyed, the terminal may interpret the remaining value other than Repetition Factor 1 as the Repetition Factor to be applied to it and proceed with the Msg4 PSDCH reception process. If Repetition Disable is conveyed, the terminal may not expect Repetition from Msg4 PDSCH. Alternatively, if a repeat transmission mode is transmitted rather than repeat transmission enable / disable, one can expect whether the repeat transmission of Msg4 PDSCH with a specific Repetition Factor interpreted according to that mode is applied.

[0232] Next, there is a case where the Repetition Factor is transmitted UE-specifically to each individual terminal via Msg4 PDCCH. This case may occur when the Repetition Factors Candidates are not standardized or configured, or when the Candidates contain more than two values ​​(e.g., Repetition Factor Candidates = {1, 2, 4} or {1, 2, 4, 8} or {2, 4, 8} or {2, 4}, etc.). In this case, the terminal can proceed with the reception process of the Msg4 PDSCH according to the received Repetition Factor. In this case, when transmitting the Repetition Factor, the mapping of each field may be indicated by absolute values ​​(e.g., 2-bit signaling, 00 – Repetition Factor 1, 01 – Repetition Factor 2, 10 – Repetition Factor 4, 11 – Repetition Factor 8) or may be indicated based on values ​​included in the candidates for the number of repeated transmissions (e.g., 2-bit signaling, 00 – 1st candidates, 01 – 2nd candidate, 10 – 3rd candidates, 11 – 4th candidate / e.g., 2-bit signaling, 00 – Repetition Factor 1, 01 – 1st candidate, 10 – 2nd candidates, 11 – 3rd candidate, etc.).

[0233] Next, the Repetition Factor and Enable / Disable status (or repetitive transmission mode) may not be separately conveyed to the terminal. In this case, the terminal may proceed with the reception process under the assumption that repetitive transmission of Msg4 PDSCH is possible for all possible Repetition Factor values ​​identified through the repetition count candidates and specifications; at this time, it may go through processes such as finding slots where repetition has not been performed through calculations based on correlation, etc., or determining the Repetition Factor independently. Alternatively, if the repetition count candidates are not standardized or configured, the terminal may proceed with the reception process under the assumption that repetitive transmission of Msg4 PDSCH is possible for all possible values ​​for the Msg4 PDSCH Repetition defined in the specifications; at this time, it may go through processes such as finding slots where repetition has not been performed through calculations based on correlation, etc., or determining the Repetition Factor independently.

[0234] Figure 22 shows examples of a terminal receiving repeated transmissions through RSRP threshold signaling.

[0235] FIG. 22 illustrates examples of the implementation procedures for this Proposal 4. Figure 22 (1) is an example of the procedure for transmitting the RSRP Threshold via SIB, the 2-state Capability Report, and the Repetition Factor instruction via Msg4 PDCCH. Figure 22 (2) shows an example of the procedure for transmitting the RSRP Threshold and Repetition Factor Candidate via SIB, and the instruction to enable / disable repetition transmission via the 2-state Capability Report and Msg4 PDCCH. Figure 22 (3) shows an example of the instruction to enable / disable the RSRP Threshold and repetition transmission (or repetition transmission mode) via SIB, and the instruction to enable / disable UE-specific repetition transmission or Repetition Factor via the 2-state Capability Report and Msg4 PDCCH. Figure 22 (4) shows an example of the RSRP Threshold and repeat transmission enable / disable (or repeat transmission mode) and Repetition Factor Candidate instructions via SIB and Capability Report based on the difference from the RSRP Threshold and UE-Specific repeat transmission enable / disable instructions via Msg4 PDCCH. Figure 22 (5) shows an example of the procedure for the RSRP Threshold and repeat transmission enable / disable (or repeat transmission mode) and Repetition Factor Candidate instructions via SIB and Capability Report based on the difference from the RSRP Threshold, without instructions for UE-Specific repeat transmission enable / disable (or repeat transmission mode) via Msg4 PDCCH.Figure 22 (6) shows an example of the implementation procedure for RSRP Threshold and repeat transmission enable / disable (or repeat transmission mode) instructions via SIB, Repetition Factor Request, and UE-Specific Repetition Factor instructions via Msg4 PDCCH.

[0236] In FIG. 22, (1) illustrates the transmission of the RSRP Threshold via SIB, the 2-state Capability Report, and the Repetition Factor instruction via Msg4 PDCCH. (2) illustrates the transmission of the RSRP Threshold and Repetition Factor Candidate via SIB, the 2-state Capability Report, and the instruction to enable / disable repetition transmission via Msg4 PDCCH. (3) illustrates the transmission of the RSRP Threshold and the instruction to enable / disable repetition transmission (or repetition mode) via SIB, the 2-state Capability Report, and the instruction to enable / disable UE-specific repetition transmission or Repetition Factor via Msg4 PDCCH. (4) illustrates the transmission of the RSRP Threshold and the instruction to enable / disable repetition transmission (or repetition mode) and the Repetition Factor Candidate via SIB, the Capability Report based on the difference from the RSRP Threshold, and the instruction to enable / disable UE-specific repetition transmission via Msg4 PDCCH. (5) shows the RSRP Threshold and Repetition Factor Candidate (or Repetition Mode) instructions via SIB and the Capability Report based on the difference from the RSRP Threshold (no UE-Specific Repetition Factor Enable / Disable (or Repetition Mode) instructions via Msg4 PDCCH). (6) shows the RSRP Threshold and Repetition Factor Enable / Disable (or Repetition Mode) instructions via SIB and the Repetition Factor Request and UE-Specific Repetition Factor instructions via Msg4 PDCCH.

[0237] [Proposal 5: Selective Application of Msg4 Repetition Method]

[0238] Proposal 5 describes the method of applying the methods of Proposals 1-4 mentioned earlier.

[0239] First, only one of the methods from Proposal 1 to Proposal 4 may be defined in the standard and used. Alternatively, two or more of the methods from Proposal 1 to Proposal 4 may be defined in the standard and used selectively depending on the conditions. Through this, Proposal 1 and Proposal 2 may be used selectively, or Proposal 1 and Proposal 3 may be used selectively, or Proposal 1 and Proposal 4 may be used selectively, or Proposal 1, Proposal 2 and Proposal 3 may be used selectively, or Proposal 1, Proposal 2 and Proposal 4 may be used selectively, or Proposal 1, Proposal 3 and Proposal 4 may be used selectively, or Proposal 2, Proposal 3 and Proposal 4 may be used selectively, or Proposal 1, Proposal 2 and Proposal 3 and Proposal 4 may be used selectively.

[0240] Criteria for such selective use can be determined in the following ways.

[0241] First, a bit field that explicitly indicates which method to use may be included in the MIB, PBCH Payload, SIB1, SIB19, PDCCH for Msg2, Msg2 PDSCH, etc. In this case, up to two methods can be selectively applied when using 1-bit (2-state) signaling, or up to four methods can be selectively applied when using 2-bit (4-state) signaling. The terminal can identify the method to be applied by interpreting the corresponding bit field and then expect the Msg4 PDSCH Repetition procedure according to that method.

[0242] Next, depending on the message transmitted including MIB, PBCH Payload, SIB1, SIB19, PDCCH for Msg2, Msg2 PDSCH, etc., a specific method of transmission can be implicitly identified. For example, if an RSRP Threshold is included in a Cell-Specific message and transmitted, the terminal can expect the application of Proposal 4; if a repeat transmission enable / disable (or repeat transmission mode) is included and transmitted, the terminal can expect the application of Proposal 1; if a candidate for the number of repeat transmissions is included and transmitted, the terminal can expect the application of Proposal 3; and if nothing is included and transmitted, the terminal can expect the application of Proposal 2. Alternatively, if an RSRP Threshold exists, the terminal can expect the application of Proposal 4; and if an RSRP Threshold does not exist or is located at a specific value, the terminal can expect the application of Proposal 1 / Proposal 2 / Proposal 3 or other methods defined in the specifications. When two or more pieces of information among RSRP Threshold, repeat transmission enable / disable (or repeat transmission mode), and repeat transmission count candidates are transmitted, the terminal may expect the application of a specific technique according to the interpretation rules defined in the standard.

[0243] Next, it can be implicitly determined based on the status of SSB Periodicity, SIB1 PDSCH Repetition, and Type-0 CSS PDCCH Repetition. For example, if information regarding SSB Periodicity 20ms or 160ms is transmitted or can be identified by the terminal, the application of a specific technique may be determined according to the standard based on the value, or the application of a specific technique may be determined according to the standard based on whether there is SIB1 PDSCH Repetition, or the application of a specific technique may be determined according to the standard based on whether there is Type-0 CSS PDCCH Repetition, or the application of a specific technique may be determined according to a combination of SSB Periodicity and SIB PDSCH Repetition, or the application of a specific technique may be determined according to a combination of SSB Periodicity and Type-0 CSS PDCCH Repetition, or the application of a specific technique may be determined according to a combination of SIB PDSCH Repetition and Type-0 CSS PDCCH Repetition, or the application of a specific technique may be determined according to a combination of SSB Periodicity, SIB PDSCH Repetition, and Type-0 CSS PDCCH Repetition.

[0244] Next, it may be determined according to time information / resources such as periods. For example, the terminal may expect the application of Proposal 4 only when it corresponds to a specific period or specific time resource determined for the degradation of UL Control Information, and in the case of a period or time resource that does not correspond to the application of Proposal 4, the terminal may expect the application of Proposal 1 / Proposal 2 / Proposal 3 or other methods defined in the standard. As another example, methods such as Proposal 4 and Proposal 1, Proposal 4 and Proposal 2, or Proposal 4 and Proposal 3 may be used alternately in a periodic manner. Such application methods based on specific periods or time resources may be transmitted explicitly through MIB, PBCH Payload, SIB1, SIB19, PDCCH for Msg2, Msg2 PDSCH, etc., or may be transmitted by implicitly interpreting from existing information contained in MIB, PBCH Payload, SIB1, SIB19, PDCCH for Msg2, Msg2 PDSCH, etc., or may be defined to be determined without signaling through the standard.

[0245] FIG. 23 is a flowchart illustrating a method in which a terminal performs communication according to one embodiment of the present disclosure.

[0246] 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.

[0247] In step S2301, a terminal according to one embodiment can receive SIB1 (System Information Block 1) from a base station communicating with the terminal through a Non-Terrestrial Network (NTN).

[0248] In step S2302, a terminal according to one embodiment can determine the number of PDSCH (Physical Downlink Shared Channel) repeated transmissions based on information regarding the number of PDSCH repeated transmissions candidate included in SIB1.

[0249] In one embodiment, the PDSCH repeat transmission count candidate may be referred to in various ways, such as Repetition Factor Candidate(s).

[0250] In one example, the information regarding the candidate number of PDSCH repeated transmissions may indicate various sets of numbers as candidates for the candidate number of PDSCH repeated transmissions, such as {1}, {1, 2}, {1, 4}, {1, 2, 4}, {1, 8}, {1, 2, 8}, {1, 4, 8}, {1, 2, 4, 8}, {2}, {4}, {2, 4}, {2, 8}, {4, 8}, or {2, 4, 8}.

[0251] In one example, the terminal can determine the number of PDSCH repeated transmissions based on the various sets of numbers indicated by the information regarding the candidate number of PDSCH repeated transmissions.

[0252] In step S2303, a terminal according to one embodiment can receive a PDSCH repeated transmission by the base station based on the determined number of PDSCH repeated transmissions.

[0253] In one embodiment, the PDSCH repetitive transmission may represent a repetitive transmission of the PDSCH associated with MSG4.

[0254] In one embodiment, the PDSCH repeat transmission may be enabled based on the fact that the terminal receives information regarding the candidate number of PDSCH repeat transmissions through the SIB1.

[0255] In one embodiment, the information for the candidate number of PDSCH repeat transmissions may include 2 or 4.

[0256] In one embodiment, based on information regarding the candidate number of PDSCH repeated transmissions, the PDSCH repeated transmission can be enabled based on the fact that the candidate number of PDSCH repeated transmissions is set to 2 or 4 times.

[0257] In one embodiment, the information for the candidate number of PDSCH repeated transmissions may include 2 and 4.

[0258] In one embodiment, the PDSCH repeated transmission may be enabled based on the information for the candidate number of PDSCH repeated transmissions including 2 and 4.

[0259] A terminal according to one embodiment can transmit terminal capability information indicating the receiving capability of the terminal for the PDSCH repeated transmission to the base station.

[0260] In one embodiment, the terminal capability information can be transmitted to the base station through a PUSCH (Physical Uplink Shared Channel) associated with MSG3.

[0261] According to one embodiment, the terminal can receive Downlink Control Information (DCI) from the base station. Whether the PDSCH repeated transmission is enabled can be indicated by the DCI.

[0262] In one embodiment, the DCI may represent DCI format 1_0.

[0263] According to one embodiment of the present disclosure, the coverage of downlink communication through a non-terrestrial network can be expanded.

[0264] According to one embodiment of the present disclosure, PDSCH iterative transmission through a non-terrestrial network can be efficiently performed.

[0265] According to one embodiment of the present disclosure, MSG4 PDSCH repetitive transmission over a non-terrestrial network can be efficiently performed.

[0266] FIG. 24 is a flowchart illustrating a method in which a base station performs communication according to one embodiment of the present disclosure.

[0267] The operations disclosed in the flowchart of FIG. 24 may be performed in combination with various embodiments of the present disclosure. In one example, the operations disclosed in the flowchart of FIG. 24 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. 24 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. 24 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. 24 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.

[0268] In step S2401, a base station according to one embodiment can transmit SIB1 to a terminal communicating with the base station via NTN.

[0269] In step S2402, a base station according to one embodiment can perform PDSCH repeated transmission to the terminal based on information regarding the number of PDSCH repeated transmission candidates included in SIB1.

[0270] In one embodiment, the PDSCH repetitive transmission may represent a repetitive transmission of the PDSCH associated with MSG4.

[0271] In one embodiment, the PDSCH repeat transmission may be enabled based on the fact that the terminal receives information regarding the candidate number of PDSCH repeat transmissions through the SIB1.

[0272] In one embodiment, the information for the candidate number of PDSCH repeat transmissions may include 2 or 4.

[0273] In one embodiment, based on information regarding the candidate number of PDSCH repeated transmissions, the PDSCH repeated transmission can be enabled based on the fact that the candidate number of PDSCH repeated transmissions is set to 2 or 4 times.

[0274] In one embodiment, the information for the candidate number of PDSCH repeated transmissions may include 2 and 4.

[0275] In one embodiment, the PDSCH repeated transmission may be enabled based on the information for the candidate number of PDSCH repeated transmissions including 2 and 4.

[0276] A base station according to one embodiment can receive terminal capability information from the terminal indicating the terminal's ability to receive the PDSCH repeated transmission.

[0277] In one embodiment, the terminal capability information can be transmitted to the base station through a PUSCH (Physical Uplink Shared Channel) associated with MSG3.

[0278] According to one embodiment, the terminal can receive Downlink Control Information (DCI) from the base station. Whether the PDSCH repeated transmission is enabled can be indicated by the DCI.

[0279] In one embodiment, the DCI may represent DCI format 1_0.

[0280] 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., 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.

[0281] 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.

[0282] 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 a 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 a 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.

[0283] 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.

[0284] 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 for a terminal to perform communication in a wireless communication system, A step of receiving SIB1 (System Information Block 1) from a base station communicating with the terminal via NTN (Non-Terrestrial Network); A step of determining the number of PDSCH repeated transmissions based on information regarding the number of PDSCH (Physical Downlink Shared Channel) repeated transmissions candidate included in the above SIB1; and A method comprising the step of receiving a PDSCH repeated transmission by the base station based on the number of PDSCH repeated transmissions determined above.

2. In Paragraph 1, The above PDSCH repetitive transmission is a method representing a PDSCH repetitive transmission associated with MSG4.

3. In Paragraph 1, A method in which the PDSCH repeated transmission is activated based on the fact that the terminal receives information regarding the candidate number of PDSCH repeated transmissions through the SIB1.

4. In Paragraph 1, The information regarding the candidate number of PDSCH repeated transmissions above includes 2 or 4, a method.

5. In Paragraph 4, A method in which the PDSCH repeated transmission is enabled based on information regarding the PDSCH repeated transmission count candidate, and the PDSCH repeated transmission count candidate is set to 2 or 4 times.

6. In Paragraph 1, The information on the above PDSCH repeat transmission count candidates includes 2 and 4, a method.

7. In Paragraph 6, A method in which the PDSCH repeated transmission is enabled based on the information regarding the number of PDSCH repeated transmission candidates including 2 and 4.

8. In Paragraph 1, A method further comprising the step of transmitting terminal capability information indicating the receiving capability of the terminal for the PDSCH repetitive transmission to the base station.

9. In Paragraph 8, A method in which the above terminal capability information is transmitted to the base station via a PUSCH (Physical Uplink Shared Channel) associated with MSG3.

10. In Paragraph 1, The method further includes the step of receiving DCI (Downlink Control Information) from the base station, A method in which the activation status of the above PDSCH repeated transmission is indicated by the above DCI.

11. In Paragraph 10, The above DCI is a method representing DCI format 1_0.

12. 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, wherein The above operations are, A step of receiving SIB1 from a base station communicating with the terminal via NTN; A step of determining the number of PDSCH repeated transmissions based on information regarding the candidate number of PDSCH repeated transmissions included in the above SIB1; and A terminal comprising the step of receiving a PDSCH repeated transmission by the base station based on the number of PDSCH repeated transmissions determined above.

13. In Paragraph 12, The above PDSCH repetitive transmission is a terminal representing a PDSCH repetitive transmission associated with MSG4.

14. In Paragraph 12, A terminal in which the PDSCH repeat transmission is activated based on the fact that the terminal receives information regarding the candidate number of PDSCH repeat transmissions through the SIB1.

15. In a base station performing 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 be operable, and storing instructions that control the base station to perform operations when executed by the processor, wherein The above method of operation is, A step of transmitting SIB1 to a terminal communicating with the base station via NTN; and A base station comprising the step of performing a PDSCH repeated transmission to the terminal based on information regarding the number of PDSCH repeated transmission candidates included in the above SIB1.

Images