Method and apparatus for carrying out wireless communication in non-terrestrial network

Abstract

The present embodiments provide a method for a terminal to carry out wireless communication in a non-terrestrial network (NTN), the method comprising the steps of: receiving discontinuous beam pattern configuration information from a network node; receiving, from the network node, activation indication information for a discontinuous reception operation based on the discontinuous beam pattern configuration information; and when the discontinuous reception operation is activated, receiving a downlink signal from the network node.

Description

Method and device for performing wireless communication in a non-terrestrial network

[0001] The present embodiments propose a method and device for performing wireless communication in a non-terrestrial network in a 3rd Generation Partnership Project (3GPP) wireless access network (hereinafter referred to as “5G” or “NR [New Radio]”) or a next-generation wireless access network (hereinafter referred to as “5G-Advanced or 6G”).

[0002] Mobile communication technologies, offering ultra-high speeds, ultra-low latency, and hyper-connectivity, are being utilized across diverse industries. This expansion of mobile communication technologies is standardizing Non-Terrestrial Networks (NTNs), enabling communication services via satellites, High Altitude Air Platforms (HAPS), and Low Earth Orbit (LEO) satellites. Satellite-based communications, in particular, offer the advantage of providing coverage in environments unreachable by terrestrial networks, such as oceans, mountains, deserts, polar regions, and air and sea vehicles.

[0003] Meanwhile, next-generation mobile communication technologies are expected to further expand the scope of NTN applications, necessitating technologies such as satellite-terrestrial network integration, high-speed handover, low-latency connectivity, and AI-based network optimization. However, in NTN environments, existing terrestrial network-based communication methods alone may struggle to ensure efficient connection quality.

[0004] Therefore, a technology is required that enables a terminal to effectively control reception operations according to changes in the satellite's beam pattern and traffic-based resource scheduling, and a control structure on the satellite or network node side to support this.

[0005] As part of this aspect, specific designs are needed to more efficiently improve coverage in environments such as non-terrestrial networks.

[0006] The present embodiments can provide a method and apparatus for performing wireless communication in a non-terrestrial network that can improve downlink coverage and provide efficient satellite-terminal communication with low power from a system perspective.

[0007] In one aspect, the present embodiments may provide a method for a terminal to perform wireless communication in a non-terrestrial network (NTN), the method including the steps of: receiving discontinuous beam pattern configuration information from a network node; receiving activation instruction information for a discontinuous reception operation according to the discontinuous beam pattern configuration information from the network node; and receiving a downlink signal from the network node when the discontinuous reception operation is activated.

[0008] In another aspect, the present embodiments may provide a method for a network node to perform wireless communication in a non-terrestrial network (NTN), the method including the steps of transmitting non-continuous beam pattern configuration information to a terminal, transmitting activation instruction information for non-continuous reception operation according to the non-continuous beam pattern configuration information to the terminal, and transmitting a downlink signal to the terminal when the non-continuous reception operation is activated.

[0009] In another aspect, the present embodiments provide a terminal for performing wireless communication in a non-terrestrial network (NTN), including a transmitter, a receiver, and a control unit for controlling operations of the transmitter and the receiver, wherein the control unit receives discontinuous beam pattern configuration information from a network node, receives activation instruction information for discontinuous reception operation according to the discontinuous beam pattern configuration information from the network node, and, when the discontinuous reception operation is activated, provides a terminal for receiving a downlink signal from the network node.

[0010] In another aspect, the present embodiments provide a network node that performs wireless communication in a non-terrestrial network (NTN), including a transmitter, a receiver, and a control unit that controls operations of the transmitter and the receiver, wherein the control unit transmits non-continuous beam pattern configuration information to a terminal, transmits activation instruction information for non-continuous reception operation according to the non-continuous beam pattern configuration information to the terminal, and transmits a downlink signal to the terminal when the non-continuous reception operation is activated.

[0011] According to the present embodiments, a method and apparatus for performing wireless communication in a non-terrestrial network can be provided that can improve downlink coverage and provide efficient satellite-terminal communication with low power from a system perspective.

[0012] FIG. 1 is a schematic diagram illustrating the structure of an NR wireless communication system to which the present embodiment can be applied.

[0013] FIG. 2 is a drawing for explaining a frame structure in an NR system to which the present embodiment can be applied.

[0014] FIG. 3 is a diagram for explaining a resource grid supported by a wireless access technology to which the present embodiment can be applied.

[0015] FIG. 4 is a diagram for explaining a bandwidth part supported by a wireless access technology to which the present embodiment can be applied.

[0016] FIG. 5 is a diagram illustrating an example of a synchronization signal block in a wireless access technology to which the present embodiment can be applied.

[0017] FIG. 6 is a diagram for explaining a random access procedure in a wireless access technology to which the present embodiment can be applied.

[0018] Figure 7 is a drawing for explaining CORESET.

[0019] FIG. 8 is a diagram illustrating a procedure for a terminal to perform wireless communication in a non-terrestrial network according to one embodiment.

[0020] FIG. 9 is a diagram illustrating a procedure in which a network node performs wireless communication in a non-terrestrial network according to one embodiment.

[0021] FIG. 10 is a diagram illustrating an example of a non-terrestrial network architecture to which the present embodiment can be applied.

[0022] FIG. 11 and FIG. 12 are drawings for explaining the mapping of beams and cells according to one embodiment.

[0023] FIGS. 13 to 15 are drawings for explaining a method of configuring a beam pattern according to one embodiment.

[0024] FIG. 16 and FIG. 17 are drawings for explaining a method of grouping beams according to one embodiment.

[0025] Fig. 18 is a diagram showing the configuration of a user terminal according to another embodiment.

[0026] Fig. 19 is a diagram showing the configuration of a network node according to another embodiment.

[0027] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to exemplary drawings. When adding reference numerals to components in each drawing, identical components may have the same numerals as much as possible even if they are shown in different drawings. In addition, when describing the present embodiments, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the technical idea of ​​the present invention, the detailed description may be omitted. When "includes," "has," "consists of," etc. are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it may include a case in which the plural is included unless specifically stated otherwise.

[0028] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of the present disclosure. These terms are only intended to distinguish the components from other components, and the nature, order, sequence, or number of the components are not limited by the terms.

[0029] In a description of the positional relationship of components, when it is described that two or more components are "connected," "combined," or "connected," it should be understood that the two or more components may be directly "connected," "combined," or "connected," but that the two or more components may also be further "interposed" with another component to be "connected," "combined," or "connected." Here, the other component may be included in one or more of the two or more components that are "connected," "combined," or "connected" to each other.

[0030] In the description of the temporal flow relationship related to components, operation methods, or manufacturing methods, for example, when the temporal or flow relationship is described as “after”, “following”, “next to”, “before”, etc., it may also include cases where it is not continuous, unless “immediately” or “directly” is used.

[0031] Meanwhile, when numerical values ​​or corresponding information (e.g., levels, etc.) for components are mentioned, even without separate explicit description, the numerical values ​​or corresponding information may be interpreted as including an error range that may occur due to various factors (e.g., process factors, internal or external impact, noise, etc.).

[0032] The wireless communication system in this specification refers to a system for providing various communication services such as voice, data packets, etc. using wireless resources, and may include a terminal, a base station, or a core network.

[0033] The embodiments disclosed below can be applied to wireless communication systems using various wireless access technologies. For example, the embodiments can be applied to various wireless access technologies such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), or NOMA (non-orthogonal multiple access). In addition, the wireless access technology may not only refer to a specific access technology, but also to each generation of communication technologies established by various communication agreement organizations such as 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, and ITU. For example, CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented in wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e.UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTSterrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink. Thus, the present embodiments can be applied to currently disclosed or commercialized wireless access technologies, as well as wireless access technologies currently under development or to be developed in the future.

[0034] Meanwhile, the term "terminal" in this specification is a comprehensive concept that refers to a device that includes a wireless communication module that performs communication with a base station in a wireless communication system, and should be interpreted as a concept that includes not only UE (User Equipment) in WCDMA, LTE, NR, HSPA, and IMT-2020 (5G or New Radio), but also MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), and wireless device in GSM. In addition, the terminal may be a user portable device such as a smartphone depending on the usage type, and in a V2X communication system, it may mean a vehicle, a device including a wireless communication module in the vehicle, etc. In addition, in the case of a Machine Type Communication system, it may mean an MTC terminal, M2M terminal, URLLC terminal, etc. that is equipped with a communication module to perform machine type communication.

[0035] The base station or cell in this specification refers to an end that communicates with a terminal in terms of a network, and includes various coverage areas such as Node-B, eNB (evolved Node-B), gNB (gNode-B), LPN (Low Power Node), Sector, Site, various types of antennas, BTS (Base Transceiver System), Access Point, Point (e.g., Transmission Point, Reception Point, Transmission / Reception Point), Relay Node, Mega Cell, Macro Cell, Micro Cell, Pico Cell, Femto Cell, RRH (Remote Radio Head), RU (Radio Unit), and Small Cell. In addition, a cell may mean including a BWP (Bandwidth Part) in the frequency domain. For example, a serving cell may mean an Activation BWP of a terminal.

[0036] Since the various cells listed above have a base station that controls one or more cells, the base station can be interpreted in two meanings. 1) It can be a device itself that provides a mega cell, macro cell, micro cell, pico cell, femto cell, or small cell in relation to a wireless area, or 2) it can indicate the wireless area itself. In 1), all devices that provide a given wireless area are controlled by the same entity or that interact to cooperatively configure the wireless area are all indicated as a base station. Depending on how the wireless area is configured, a point, a transceiver point, a transmission point, a reception point, etc. can be an embodiment of a base station. In 2), the wireless area itself that receives or transmits a signal from the perspective of a user terminal or a neighboring base station can also be indicated as a base station.

[0037] In this specification, a cell may mean a component carrier having coverage of a signal transmitted from a transmission / reception point or a transmission / reception point itself.

[0038] Uplink (UL, or uplink) refers to a method of transmitting and receiving data from a terminal to a base station, and downlink (DL, or downlink) refers to a method of transmitting and receiving data from a base station to a terminal. Downlink may refer to communication or a communication path from multiple transmission / reception points to a terminal, and uplink may refer to communication or a communication path from a terminal to multiple transmission / reception points. In this case, in the downlink, the transmitter may be part of the multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in the uplink, the transmitter may be part of the terminal, and the receiver may be part of the multiple transmission / reception points.

[0039] Uplink and downlink transmit and receive control information through control channels such as PDCCH (Physical Downlink Control CHannel) and PUCCH (Physical Uplink Control CHannel), and transmit and receive data by configuring data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel). Hereinafter, the situation in which signals are transmitted and received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH is also expressed in the form of 'transmitting and receiving PUCCH, PUSCH, PDCCH, and PDSCH.'

[0040] For clarity of explanation, the technical idea of ​​this invention is described below mainly with reference to the 3GPP LTE / LTE-Ack / NackR (New RAT) communication system, but the technical features of this invention are not limited to the communication system.

[0041] After researching 4G (4th-Generation) communication technology, 3GPP develops 5G (5th-Generation) communication technology to meet the requirements of the next-generation wireless access technology of the ITU-R. Specifically, 3GPP develops LTE-A pro, which is an enhancement of LTE-Advanced technology to meet the requirements of the ITU-R, as a 5G communication technology, and NR, a new communication technology separate from 4G communication technology. Both LTE-A pro and NR refer to 5G communication technology, and in the following, 5G communication technology will be explained with NR as the focus, unless a specific communication technology is specified.

[0042] The operating scenario in NR defines various operation scenarios by adding considerations for satellites, automobiles, and new verticals to the existing 4G LTE scenario, and in terms of service, it supports the eMBB (Enhanced Mobile Broadband) scenario, the mMTC (Massive Machine Communication) scenario that has high terminal density but is deployed over a wide area and requires low data rate and asynchronous access, and the URLLC (Ultra Reliability and Low Latency) scenario that requires high responsiveness and reliability and can support high-speed mobility.

[0043] To meet these scenarios, NR introduces a wireless communication system that incorporates new waveform and frame structure technologies, low latency technologies, support for ultra-high frequency bands (mmWave), and forward compatibility technologies. In particular, NR systems offer various technological changes in terms of flexibility to ensure forward compatibility. The key technical features of NR are described below with reference to the drawings.

[0044] <NR 시스템 일반>

[0045] Figure 1 is a schematic diagram illustrating the structure of an NR system to which the present embodiment can be applied.

[0046] Referring to Fig. 1, the NR system is divided into 5GC (5G Core Network) and NR-RAN parts, and the NG-RAN is composed of gNBs and ng-eNBs that provide user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol termination for UE (User Equipment). gNBs or gNBs and ng-eNBs are interconnected via the Xn interface. gNBs and ng-eNBs are each connected to the 5GC via the NG interface. The 5GC can be configured to include an AMF (Access and Mobility Management Function) that is responsible for the control plane such as terminal access and mobility control functions, and an UPF (User Plane Function) that is responsible for the control function for user data. NR includes support for both frequency bands below 6 GHz (FR1, Frequency Range 1) and frequency bands above 6 GHz (FR2, Frequency Range 2).

[0047] gNB refers to a base station that provides NR user plane and control plane protocol termination to terminals, and ng-eNB refers to a base station that provides E-UTRA user plane and control plane protocol termination to terminals. The base station described in this specification should be understood to encompass both gNB and ng-eNB, and may also be used to refer to gNB or ng-eNB separately as needed.

[0048] <NR 웨이브 폼,뉴머롤러지 및 프레임 구조>

[0049] NR uses the CP-OFDM waveform with a cyclic prefix for downlink transmission, and CP-OFDM or DFT-s-OFDM for uplink transmission. OFDM technology is easily combined with MIMO (Multiple Input Multiple Output) and offers the advantages of high spectral efficiency and low-complexity receivers.

[0050] Meanwhile, in NR, the requirements for data rates, latency, and coverage differ across the three scenarios mentioned above. Therefore, it is necessary to efficiently satisfy these requirements across the frequency bands that comprise any NR system. To this end, technologies have been proposed to efficiently multiplex radio resources based on multiple different numerologies.

[0051] Specifically, the NR transmission numerator is determined based on the sub-carrier spacing and the cyclic prefix (CP), and is changed exponentially using the μ value as an exponent value of 2 based on 15 kHz, as shown in Table 1 below.

[0052] μsubcarrier intervalCyclic prefixSupported for dataSupported for synch015NormalYesYes130NormalYesYes260Normal, ExtendedYesNo3120NormalYesYes4240NormalNoYes

[0053] As shown in Table 1 above, the numerology of NR can be divided into five types according to the subcarrier spacing. This is different from the fixed 15 kHz subcarrier spacing of LTE, one of the 4G communication technologies. Specifically, the subcarrier spacing used for data transmission in NR is 15, 30, 60, and 120 kHz, and the subcarrier spacing used for synchronization signal transmission is 15, 30, 120, and 240 kHz. In addition, the extended CP is applied only to the 60 kHz subcarrier spacing. Meanwhile, the frame structure in NR is defined as a 10 ms frame consisting of 10 subframes of the same length of 1 ms. One frame can be divided into 5 ms half frames, and each half frame contains 5 subframes. In the case of a 15 kHz subcarrier spacing, one subframe consists of one slot, and each slot consists of 14 OFDM symbols. FIG. 2 is a diagram for explaining the frame structure in an NR system to which the present embodiment can be applied.

[0054] Referring to Fig. 2, a slot is fixedly composed of 14 OFDM symbols in the case of a normal CP, but the length of the slot in the time domain may vary depending on the subcarrier spacing. For example, in the case of a numerology with a 15 kHz subcarrier spacing, a slot is composed of 1 ms in length, which is the same length as a subframe. In contrast, in the case of a numerology with a 30 kHz subcarrier spacing, a slot is composed of 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms. In other words, subframes and frames are defined with fixed time lengths, while slots are defined by the number of symbols, and their time lengths may vary depending on the subcarrier spacing.

[0055] Meanwhile, NR defines slots as the basic scheduling unit and also introduces mini-slots (or sub-slots, or non-slot-based scheduling) to reduce transmission delay in the wireless section. Using wider subcarrier spacing reduces transmission delay in the wireless section by shortening the length of each slot inversely. Mini-slots (or sub-slots) are designed to efficiently support URLLC scenarios and allow scheduling in units of 2, 4, or 7 symbols.

[0056] Furthermore, unlike LTE, NR defines uplink and downlink resource allocation at the symbol level within a single slot. To reduce HARQ delay, a slot structure was defined that allows HARQ ACK / NACKs to be transmitted directly within the transmission slot. This slot structure is referred to as a self-contained structure and will be described in detail.

[0057] NR is designed to support a total of 256 slot formats, of which 62 are used in 3GPP Rel-15. It also supports a common frame structure that configures FDD or TDD frames through various combinations of slots. For example, it supports a slot structure in which all symbols in a slot are set to downlink, a slot structure in which all symbols are set to uplink, and a slot structure in which downlink and uplink symbols are combined. NR also supports data transmission being distributed and scheduled across one or more slots. Therefore, a base station can use a slot format indicator (SFI) to inform a UE whether a slot is a downlink slot, an uplink slot, or a flexible slot. The base station can indicate the slot format by indicating an index of a table configured through UE-specific RRC signaling using the SFI, and can also indicate it dynamically through DCI (Downlink Control Information) or statically or semi-statically through RRC.

[0058] <NR 물리 자원 >

[0059] In relation to physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, and bandwidth parts are considered.

[0060] Antenna ports are defined such that the channel through which a symbol on an antenna port is carried can be inferred from the channel through which another symbol on the same antenna port is carried. Two antenna ports are said to be quasi co-located (or quasi co-located) if the large-scale properties of the channel through which a symbol on one antenna port is carried can be inferred from the channel through which a symbol on the other antenna port is carried. Here, the large-scale properties include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

[0061] FIG. 3 is a diagram for explaining a resource grid supported by a wireless access technology to which the present embodiment can be applied.

[0062] Referring to Figure 3, a resource grid may exist for each numeral, as NR supports multiple numerals on the same carrier. Furthermore, resource grids may exist based on antenna ports, subcarrier spacing, and transmission direction.

[0063] A resource block (RB) consists of 12 subcarriers and is defined solely in the frequency domain. Furthermore, a resource element (RE) consists of one OFDM symbol and one subcarrier. Therefore, as shown in Figure 3, the size of a single RB can vary depending on the subcarrier spacing. NR also defines "Point A," which serves as a common reference point for the RB grid, as well as common RBs and virtual RBs.

[0064] FIG. 4 is a diagram for explaining a bandwidth part supported by a wireless access technology to which the present embodiment can be applied.

[0065] Unlike LTE, where the carrier bandwidth is fixed at 20 MHz, NR sets the maximum carrier bandwidth from 50 MHz to 400 MHz for each subcarrier interval. Therefore, it is not assumed that all terminals will use the entire carrier bandwidth. Accordingly, NR allows terminals to designate bandwidth parts (BWPs) within the carrier bandwidth, as illustrated in Figure 4. Furthermore, bandwidth parts are associated with a single numerology, consist of a subset of consecutive common resource blocks, and can be dynamically activated over time. Each terminal is configured with up to four bandwidth parts for both the uplink and downlink, and data is transmitted and received using the bandwidth parts activated at a given time.

[0066] In the case of a paired spectrum, the uplink and downlink bandwidth parts are set independently, and in the case of an unpaired spectrum, the downlink and uplink bandwidth parts are set in pairs so that they can share a center frequency to prevent unnecessary frequency re-tuning between downlink and uplink operations.

[0067] <NR 초기 접속>

[0068] In NR, a terminal performs cell search and random access procedures to connect to a base station and perform communication.

[0069] Cell search is a procedure in which a terminal synchronizes to the cell of a corresponding base station, obtains a physical layer cell ID, and obtains system information using a synchronization signal block (SSB) transmitted by the base station.

[0070] FIG. 5 is a diagram illustrating an example of a synchronization signal block in a wireless access technology to which the present embodiment can be applied.

[0071] Referring to FIG. 5, SSB is composed of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), each occupying 1 symbol and 127 subcarriers, and a PBCH spanning 3 OFDM symbols and 240 subcarriers.

[0072] The terminal receives SSB by monitoring SSB in the time and frequency domain.

[0073] SSB can be transmitted up to 64 times in 5ms. Multiple SSBs are transmitted in different transmission beams within 5ms, and the terminal performs detection assuming that SSBs are transmitted every 20ms based on a specific beam used for transmission. The number of beams that can be used for SSB transmission within 5ms can increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted below 3GHz, up to 8 in the frequency band between 3GHz and 6GHz, and up to 64 different beams can be used for SSB transmission in the frequency band above 6GHz.

[0074] SSB contains two symbols in one slot, and the starting symbol and number of repetitions within the slot are determined as follows depending on the subcarrier spacing.

[0075] Meanwhile, unlike SS in conventional LTE, SSB is not transmitted at the center frequency of the carrier bandwidth. This means that SSB can be transmitted even in locations other than the center of the system bandwidth, and when supporting wideband operation, multiple SSBs can be transmitted in the frequency domain. Accordingly, the terminal monitors SSB using the synchronization raster, which is a candidate frequency location for monitoring SSB. The carrier raster, which is the center frequency location information of the channel for initial access, and the synchronization raster are newly defined in NR. The synchronization raster has a wider frequency interval than the carrier raster, which can support the terminal's fast SSB search.

[0076] A UE can obtain the MIB through the PBCH of the SSB. The MIB (Master Information Block) includes the minimum information required for the UE to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, the PBCH may include information on the position of the first DM-RS symbol in the time domain, information for the UE to monitor SIB1 (e.g., SIB1 numerology information, information related to SIB1 CORESET, search space information, PDCCH-related parameter information, etc.), offset information between the common resource block and the SSB (the absolute position of the SSB within the carrier is transmitted through SIB1), etc. Here, the SIB1 numerology information is also applied equally to some messages used in the random access procedure for the UE to access the base station after completing the cell search procedure. For example, the numerology information of SIB1 may be applied to at least one of messages 1 to 4 for the random access procedure.

[0077] The aforementioned RMSI may refer to SIB1 (System Information Block 1), and SIB1 is broadcast periodically (e.g., every 160 ms) in the cell. SIB1 contains information necessary for the UE to perform the initial random access procedure and is periodically transmitted via PDSCH. In order for the UE to receive SIB1, it must receive numerology information used for SIB1 transmission and CORESET (Control Resource Set) information used for SIB1 scheduling via PBCH. The UE checks scheduling information for SIB1 using SI-RNTI in CORESET and acquires SIB1 on PDSCH according to the scheduling information. The remaining SIBs, excluding SIB1, may be transmitted periodically or upon request of the UE.

[0078] FIG. 6 is a diagram for explaining a random access procedure in a wireless access technology to which the present embodiment can be applied.

[0079] Referring to FIG. 6, once cell search is complete, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted via the PRACH. Specifically, the random access preamble is transmitted to the base station via the PRACH, which consists of consecutive radio resources in a specific slot that is periodically repeated. Generally, when a terminal initially accesses a cell, a contention-based random access procedure is performed, and when performing random access for beam failure recovery (BFR), a non-contention-based random access procedure is performed.

[0080] The terminal receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), an UL Grant (uplink radio resource), a temporary C-RNTI (Temporary Cell - Radio Network Temporary Identifier), and a TAC (Time Alignment Command). Since one random access response may include random access response information for one or more terminals, the random access preamble identifier may be included to indicate which terminal the included UL Grant, temporary C-RNTI, and TAC are valid for. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the terminal to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, i.e., an RA-RNTI (Random Access - Radio Network Temporary Identifier).

[0081] Upon receiving a valid random access response, the terminal processes the information contained in the random access response and performs scheduled transmission to the base station. For example, the terminal applies TAC and stores a temporary C-RNTI. Furthermore, using the UL Grant, the terminal transmits data stored in its buffer or newly generated data to the base station. In this case, information that identifies the terminal must be included.

[0082] Finally, the terminal receives a downlink message for contention resolution.

[0083] <NR CORESET>

[0084] The downlink control channel in NR is transmitted in a CORESET (Control Resource Set) with a length of 1 to 3 symbols, and transmits uplink / downlink scheduling information, SFI (Slot format Index), and TPC (Transmit Power Control) information.

[0085] To ensure system flexibility, NR introduced the CORESET concept. CORESET (Control Resource Set) refers to time-frequency resources for downlink control signals. A terminal can decode control channel candidates using one or more search spaces within the CORESET time-frequency resources. A QCL (Quasi CoLocation) assumption is established for each CORESET, which is used to inform the characteristics of analog beam direction in addition to the delay spread, Doppler spread, Doppler shift, and average delay assumed by the conventional QCL.

[0086] Figure 7 is a drawing for explaining CORESET.

[0087] Referring to Figure 7, a CORESET can exist in various forms within the carrier bandwidth within a single slot, and in the time domain, a CORESET can consist of up to three OFDM symbols. In addition, a CORESET is defined as a multiple of six resource blocks up to the carrier bandwidth in the frequency domain.

[0088] The first CORESET is indicated via the MIB as part of the initial bandwidth part configuration, allowing the terminal to receive additional configuration and system information from the network. After establishing a connection with the base station, the terminal can receive and configure one or more CORESET information via RRC signaling.

[0089] Wider bandwidth operations

[0090] Existing LTE systems supported scalable bandwidth operation for any LTE Component Carrier (CC). That is, depending on the deployment scenario, any LTE operator could configure a single LTE CC with a bandwidth ranging from a minimum of 1.4 MHz to a maximum of 20 MHz, and a normal LTE terminal supported transmission and reception capabilities of 20 MHz bandwidth for a single LTE CC.

[0091] However, in the case of NR, the design is made to support NR terminals with different transmission and reception bandwidth capabilities through a single wideband NR CC, and accordingly, it is required to configure one or more bandwidth parts (BWP, bandwidth part(s)) consisting of segmented bandwidths for any NR CC, and to support flexible wider bandwidth operation through different bandwidth part configurations and activations for each terminal.

[0092] Specifically, in NR, one or more bandwidth parts can be configured through one serving cell configured from the terminal's perspective, and the terminal is defined to activate one downlink bandwidth part (DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) in the serving cell to use them for uplink / downlink data transmission and reception. In addition, when multiple serving cells are configured in the terminal, that is, for the terminal to which CA is applied, it is defined to activate one downlink bandwidth part and / or uplink bandwidth part for each serving cell to use the radio resources of the serving cell to use them for uplink / downlink data transmission and reception.

[0093] Specifically, an initial bandwidth part for an initial access procedure of a terminal in an arbitrary serving cell is defined, one or more UE-specific bandwidth part(s) are configured for each terminal through dedicated RRC signaling, and a default bandwidth part for a fallback operation can also be defined for each terminal.

[0094] However, it can be defined that multiple downlink and / or uplink bandwidth parts can be activated and used simultaneously depending on the capability and bandwidth part(s) configuration of the terminal in any serving cell, but in NR rel-15, it is defined that only one downlink bandwidth part (DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) can be activated and used in any terminal at any time.

[0095] In this specification, the terms frequency, frame, subframe, resource, resource block, region, band, subband, control channel, data channel, synchronization signal, various reference signals, various signals or various messages related to NR (New Radio) may be interpreted in the past or present meaning or in various meanings used in the future.

[0096] Non-Terrestrial Network (NTN)

[0097] A non-terrestrial network (NTN) refers to a network or segment of a network that uses RF resources mounted on a satellite (or UAS (Unmanned Aircraft System platform).

[0098] NTN can be implemented in various ways, as follows:

[0099] Scenario A: Transparent GEO (Geostationary orbit) (NTN beam foot print fixed on earth)

[0100] Scenario B: Regenerative GEO (NTN beam footprint fixed on earth)

[0101] Scenario C1: Transparent LEO (NTN beam foot print fixed on earth)

[0102] Scenario C2: Transparent LEO (NTN beam foot print moving on earth)

[0103] Scenario D1: Regenerative LEO (NTN beam footprint fixed on earth)

[0104] Scenario D2: Regenerative LEO (NTN beam foot print moving on earth)

[0105] Here, transparent payload and regenerative payload are defined as follows.

[0106] Transparent payload: Radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the transparent payload remains unchanged.

[0107] Regenerative payload: Demodulation / decoding, switching and / or routing, coding / modulation, as well as radio frequency filtering, frequency conversion, and amplification. This is essentially equivalent to having all or part of the base station functions (e.g., gNB) on board a satellite (or UAS platform).

[0108] A satellite generates multiple beams for a given service area bounded by the satellite's field of view. The beam's ground footprint is typically elliptical in shape.

[0109]

[0110] The present disclosure proposes a method for an NTN base station or network to perform cell / beam DTX (Discontinuous Transmission) / DRX (Discontinuous Reception) and provide and transmit necessary configuration information to a terminal in order to improve the system level through power consumption reduction and efficient communication of satellites and terminals in a Non Terrestrial Network (NTN) operating based on a 3rd Generation Partnership Project (3GPP) radio access network (hereinafter referred to as "5G" or "NR [New Radio]" in this disclosure) or a next-generation radio access network (hereinafter referred to as "5G-Advanced or 6G" in this disclosure).

[0111] 3GPP is researching non-terrestrial network (NTN) technology to provide broadband Internet services to users by utilizing GEO (Geostationary Earth Orbit) and NGSO (Non-Geostationary Satellite Orbit) satellites deployed in high, medium, and low Earth orbits, ground-based gateways, 5G / 6G RAN / Core, and terminal-to-terminal communications.

[0112] 3GPP is currently standardizing two services and technologies: "NR-NTN," which supports NTN in NR, and "IoT-NTN," which supports NTN in NB-IoT / eMTC. The NTN technologies studied in 3GPP Releases 15 through 18 are summarized in Table 2 below.

[0113] Key ContentsRelease 15· Research for 5G NR-based NTN support - Channel model, Deployment scenario, Key impactRelease 16· Research on RAN architecture and interface for satellite access· Derivation of NTN use-case and requirementsRelease 17· Classification and standardization of 'NR-NTN' and 'IoT-NTN'· Mobility (HO) support for NTN-TN service continuityRelease 18· NR-NTN advancement - UL coverage improvement, NTN-NTN mobility improvement, etc.· IoT-NTN advancement - HARQ-feedback disabling, mobility improvement, etc.Release 19· NR NTN Evolution - Regenerative payload support - DL coverage improvement - UL Cell Throughput improvement - Signaling definition for MBS broadcast service· IoT NTN Evolution - UL capacity improvement - Store & Forward support (only Regenerative) Full gNB )

[0114] According to TR 38.821, 3GPP defines the characteristics of NTN satellites by orbit as shown in Table 3 below. Furthermore, from a frequency perspective, discussions are underway on FR1 / FR2 and the L-band (1-2 GHz), S-band (2-4 GHz), Ku-band (12-18 GHz), and Ka-band (25.6-40 GHz) frequency bands.

[0115] Satellite PlatformsAltitude rangeMax Propagation Delay [ms]Typical beamfootprint sizeLEO300-1500 km25.77 (600km)100 - 1000 km41.77 (1200km)MEO7000-25000 km95.19 (10000km)100 - 1000 kmGEO35,786 km541.46200 - 3500 km

[0116] A work item may be undertaken to define a solution that enables New Radio (NR) and NG-RAN to support non-terrestrial networks (NTNs). Furthermore, enhancements to NR NTNs may be introduced. Furthermore, a new work item may be proposed to define additional enhancements to NG-RAN-based non-terrestrial networks. The objectives of this work item are as follows:

[0117] Given NTN deployment constraints such as limited satellite payload power, large satellite footprint, and limited feeder link bandwidth, the goal is to provide optimized performance, particularly for downlink coverage targeting terminals (e.g., smartphones with -5.5 dBi antenna gain). The downlink coverage enhancement is necessary to accommodate the case where satellite payload constraints prevent all beams from being activated at a given point in time with the "normal" equivalent isotropically radiated power (EIRP) density per beam. This can be due to limited power and limited feeder link bandwidth. Therefore, maximizing the number of beams that can be activated simultaneously ensures that all user terminals are served across the satellite footprint, maximizing overall satellite throughput, while keeping all satellite radio cells alive even when traffic is absent to prevent new users from accessing them or impacting end-user quality of service (QoS).

[0118] Downlink coverage enhancement can be considered at two levels:

[0119] Link Level: To accommodate the EIRP reduction in FR1-NTN, the link margin of selected physical channels can be improved. For example, link margin improvements for physical channels (such as PDSCH and PDCCH) can be considered without affecting the SSB design.

[0120] System level: Capable of supporting efficient, dynamic and flexible power sharing between beams or beam patterns / sizes (e.g. wide beam or narrow beam) across the satellite footprint of FR1-NTN and FR2-NTN.

[0121] Multiplexing techniques can provide optimized capacity performance in the uplink. This can be motivated by the following:

[0122] NTN satellites have very wide coverage, and given their high terminal density, it's expected that a large number of user equipment (UEs) will be within satellite coverage. In particular, for Low Earth Orbit (LEO) satellites, multiple UEs within coverage must be able to successfully transmit desired data during the satellite coverage period, necessitating rapid access and release of satellite resources.

[0123] The overall frequency resources available in the network may be limited, especially in the early stages of NR NTN deployment.

[0124] Some users may require more resources than others, depending on their traffic patterns. Therefore, increased granularity in resource multiplication can significantly improve system capacity efficiency.

[0125] To better support VoNR / VoIP services in coverage-limited scenarios, it is possible to allocate more resources per user terminal.

[0126] Multi-broadcast service (MBS) capabilities can provide significant added value to NR NTN systems, as they leverage the broader coverage of NTN compared to terrestrial networks (TN). While 5G standards will likely provide the same terrestrial MBS capabilities for NR NTN, in some cases, the intended service area is expected to be smaller than the coverage of Uu cells. Therefore, some enhancements may be required to notify the service area of ​​broadcast services.

[0127] It can support a non-terrestrial network architecture (i.e., replay payload) with 5G system capabilities on NTN payload.

[0128] Support for architectures that implement 5G system functions on non-terrestrial network payloads (i.e., regenerative payloads) can provide new architectural options beyond transparent payloads, allowing for more flexible deployment of non-terrestrial networks. Support for regenerative payloads can benefit radio resource handling on the Uu interface and coordination between gNBs via Inter-Satellite Links (ISLs). To support real-time connectivity between two user equipment (UEs) or between a network and a user equipment (UEs) over space segments, with or without ISLs, regenerative payloads (5G system functions on satellites) may be required.

[0129] RedCap UE support in FR1 NTN

[0130] By supporting RedCap devices (e.g., portable terminals and IoT devices) operating on FR1-band NR-NTN networks, we can provide improved service capabilities (broadband / ultra-wideband) compared to IoT-NTN while ensuring low-complexity devices. Global coverage can provide a clear advantage to RedCap devices.

[0131] The above work item may be aimed at specifying further enhancements to NG-RAN based Non-Terrestrial Networks (NTNs) based on the following assumptions:

[0132] Geosynchronous Orbit (GSO) and Non-Geosynchronous Orbit (NGSO) satellites. NGSO may include Low Earth Orbit (LEO) and Medium Earth Orbit (MEO) satellites.

[0133] Earth-fixed tracking area. For NGSO, both Earth-fixed and Earth-moving cells can be considered.

[0134] FDD mode.

[0135] User equipment (UE) with GNSS (Global Navigation Satellite Systems) capabilities.

[0136] In the frequency bands above 10 GHz, both terminal type 1 (electronic steering antenna) and terminal type 2 (mechanical steering antenna) may be considered for geostationary satellites (GSOs) and non-geostationary satellites (NGSOs).

[0137] If required, it may include implicit compatibility to support High Altitude Platform Station (HAPS) and Air To Ground (ATG) scenarios.

[0138] A "VSAT (Very Small Aperture Terminal)" device with an external antenna on a mobile platform is equivalent to a device operating from a moving platform, and may be referred to as an ESIM (Earth Station In Motion).

[0139] For geostationary satellite (GSO) and non-geostationary satellite (NGSO) constellations operating in FR1-NTN or FR2-NTN, it is possible to study and, if necessary, specify whether downlink coverage enhancements to support additional reference satellite payload parameters would be beneficial.

[0140] Additional baseline satellite payload parameters can be defined that assume power sharing between satellite beams or different satellite beam patterns / sizes (e.g., wide beam or narrow beam) across the satellite footprint. This includes cases where limited power and limited feeder link bandwidth may prevent all satellite beams from being activated simultaneously, or where individual satellite beams may be activated at less than their nominal EIRP density.

[0141] For coverage assessment, the power sharing assumptions, required link-level and system-level evaluation methodologies, and related Key Performance Indicators (KPIs) can be defined. This allows for the identification of physical channel / signal and system-level elements requiring improvement, and corresponding improvements can be derived.

[0142] If necessary, solutions can be explored and defined that include link-level enhancements for FR1-NTN (e.g., PDCCH, PDSCH) and / or system-level enhancements for FR1-NTN and / or FR2-NTN. This would enable dynamic and flexible power sharing across satellite beams or between different beam patterns / sizes (e.g., wide beam or narrow beam) across the satellite footprint.

[0143] Uplink capacity / cell throughput enhancements for FR1-NTN

[0144] When PUSCH repetitions are used, orthogonal cover codes (OCCs) for DFT-s-OFDM PUSCH can be specified for multiplexing for at least two or four user equipment (UEs).

[0145] The required signaling can be specified.

[0146] If necessary, RF requirements can be updated accordingly.

[0147] This enhancement does not target improvements / impacts of Multi-User Multiple Input Multiple Output (MU-MIMO) functionality.

[0148] This enhancement is not for PUSCH DMRS.

[0149] Improvements to initial access are not included.

[0150] Enhancements to PRACH are out of scope.

[0151] This feature can also be applied to user terminals operating on terrestrial networks based on a common design.

[0152] Regulations for signaling the intended service area of ​​broadcasting services (e.g. MBS broadcasting) via NR NTN

[0153] If the satellite footprint covers a larger area, System Information Block (SIB) signaling may be specified to indicate the intended service area.

[0154] It can specify the required signaling between the core network (CN) and NG-RAN.

[0155] Support for regenerative payloads

[0156] Support for satellite-mounted gNBs can be specified.

[0157] Enhancements to intra- and inter-gNB mobility may be specified, if required, particularly with respect to Xn interfaces via feeder links or inter-satellite links (ISLs). [RAN3]

[0158] Note: If additional stage-3 specifications such as NGAP are identified as requiring impact, RAN3 may address this.

[0159] Support for eRedCap UE supporting NR NTN operating in FR1-NTN band

[0160] For full-duplex and half-duplex FDD RedCap and eRedCap UEs, RF and RRM requirements can be defined.

[0161] For HD-FDD RedCap UEs and eRedCap UEs, enhancements can be defined to mitigate issues arising from mismatches between the TA (Timing Advance) assumed by the gNB and the TA actually used by the UE.

[0162] The above enhancements target the following HD crash cases (Case 3 and Case 4).

[0163] When a semi-statically configured DL reception and a semi-statically configured UL transmission collide.

[0164] When dynamically scheduled DL reception and dynamically scheduled UL transmission collide.

[0165] Improvements for other HD crash cases are not targeted. However, it is possible that improvements for Cases 3 and 4 could improve other HD crash cases.

[0166] RedCap / eRedCap UE can support GNSS (Global Navigation Satellite Systems) functions and simultaneous operation of GNSS and NR-NTN.

[0167]

[0168] As mentioned above, 3GPP has defined the necessity and scope of research on downlink coverage enhancement as one of the NR-NTN evolution technologies. Research is underway on ways to leverage characteristics such as power sharing mechanisms between satellite beams with different beam patterns / sizes to improve the downlink coverage of Geo Stationary Orbit (GSO) and Non-GSO (NGSO) constellation satellite constellations in FR1 / FR2-based NTN networks, thereby enhancing link and system-level performance.

[0169] As described above in Table 2, a single satellite can be composed of dozens of beams or footprints, and the radii of each beam / footprint range from hundreds to thousands of kilometers. Therefore, satellites have limited EIRP (Equivalent Isotropic Radiated Power) per beam, as shown in Table 4 below, due to limited power and feeder link bandwidth. In other words, it is difficult for a single satellite to activate all beams simultaneously. Even if a single satellite activates all beams simultaneously, the EIRP density must be set below a threshold due to limited power and bandwidth. This limits the power that can be allocated per beam / footprint, which can cause problems from a system perspective.

[0170] Satellite orbit(Altitude)GEO(Altitude: 35786 km)LEO(Altitude: 1200 km)LEO(Altitude: 600 km)Satellite EIRP DensityS-band(ie 2 GHz)59 dBW / MHz40 dBW / MHz34 dBW / MHzka-band(ie 20 GHz for DL)40 dBW / MHz10 dBW / MHz4 dBW / MHz

[0171] Currently, there is no technology for efficient satellite operation due to the limited satellite power and feeder link bandwidth described above. To address this, there have been suggestions to introduce Network Energy Saving (NES) technology to NTNs. However, the consensus was that NES technology, which performs cell-based ON / OFF switching, requires further discussion for its application to NTNs, and the details of this approach have not yet been defined.

[0172] Hereinafter, a method for performing wireless communication in a non-terrestrial network will be specifically described with reference to relevant drawings. As mentioned above, the present disclosure aims to improve downlink coverage and efficiently use power in a non-terrestrial network environment. In addition, general matters related to wireless communication between network nodes and terminals in a non-terrestrial network environment, as well as general matters related to discontinuous transmission and reception, are known in the art, and a detailed description thereof will be omitted below.

[0173] FIG. 8 is a diagram illustrating a procedure (800) in which a terminal performs wireless communication in a non-terrestrial network according to one embodiment.

[0174] Referring to FIG. 8, the terminal can receive non-continuous beam pattern configuration information from a network node (S810).

[0175] For example, a network node may refer to any one of a base station, a network, or a satellite base station (also referred to as a satellite in this disclosure). That is, the technical concepts of the present disclosure are not limited to specific devices on a non-terrestrial network, as long as they can perform the embodiments of the present disclosure so that they can be substantially equally applied.

[0176] The satellite's footprint (referred to as ground coverage, satellite coverage area, etc. in this disclosure) can range from several hundred kilometers, and the satellite must transmit by covering dozens of beams based on a limited EIRP value. Therefore, the network node can configure a transmission pattern for each beam or beam group to ensure efficient NTN downlink transmission. The terminal can receive information about the non-continuous beam pattern configuration for each beam or beam group set by the network node from the network node.

[0177] For example, the discontinuous beam pattern configuration information may include ON / OFF status and period information for each beam or beam group, or may include Equivalent Isotropically Radiated Power (EIRP) and period information.

[0178] The discontinuous beam pattern configuration information can be configured to have different ON / OFF states and periods for each beam or beam group, i.e., to have different patterns. Considering the limited power of the satellite payload, the discontinuous beam pattern configuration information can be configured to have different ON / OFF states for different time intervals for each beam or beam group, and the periods can also be set to be different.

[0179] In this case, for example, when the network node configures different patterns for each beam or beam group, the total amount of time intervals for each beam or beam group may be set to be equally allocated. For example, in the case of three beams, Beam #1, Beam #2, and Beam #3 may be set to different ON / OFF states and cycles, but the total amount of time intervals for the ON states may be set to be the same. Alternatively, the ON / OFF states may be configured regardless of the total amount of time intervals.

[0180] Alternatively, the discontinuous beam pattern configuration information may be configured such that EIRP and period are set for each beam or beam group. In this case, the value of EIRP may be set to a fixed value or may be set flexibly. However, even in this case, the pattern may be configured such that the sum of the EIRPs for each beam or beam group has the same value. For example, Beam #1, Beam #2, and Beam #3 may be configured with different fixed or flexible EIRP values ​​and periods, but the total EIRPs of the transmitted states may be set to be the same. Alternatively, the pattern may be configured regardless of the total amount of EIRP.

[0181] In one example, the non-continuous beam pattern configuration information may be set based on at least one of the traffic amount of each beam or beam group, the traffic priority, or the power of the network node.

[0182] That is, when configuring different ON / OFF patterns for each beam or beam group, the network node can dynamically change or configure the ON / OFF state and cycle by considering the amount of traffic to be transmitted per beam or beam group or the traffic priority. For example, if the traffic volume of Beam #1 is the largest, it can be changed or configured to have the longest ON state cycle in the Beam #1 area.

[0183] Similarly, network nodes can be configured based on traffic volume or traffic priority per beam or beam group, even when configured with different EIRP values ​​and periods for each beam or beam group. For example, the EIRP can be dynamically changed or configured to increase or allocate longer time intervals for beams or beam groups with the highest traffic volume.

[0184] For example, the discontinuous beam pattern configuration information may be set to correspond to a beam index or a synchronization signal block index, respectively. In this case, for example, the discontinuous beam pattern configuration information may be received via a cell-specific or terminal-specific signal.

[0185] For example, a terminal in an area where a specific beam, Beam #1, is transmitted must know in advance the discontinuous beam pattern configuration information (i.e., discontinuous transmission (DTx) / discontinuous reception (DRx) pattern information) of beam #1 that it should receive, so that it can perform a DRx operation in synchronization with the DTx operation and receive data. Accordingly, a network node can provide mapping information to the terminal to identify the beam pattern that the terminal should receive and perform DRx. According to an example, the mapping information may also be included in the discontinuous beam pattern configuration information. Alternatively, the mapping information may be configured separately.

[0186] Accordingly, the network node can transmit non-continuous beam pattern configuration information to the UE through a cell-specific or UE-specific signal via an RRC message or broadcast message such as a System Information Block (SIB). In one example, the network node can map beam pattern information to a reference signal and transmit it. In this case, according to one example, the beam index can be replaced with an SSB index. In this case, the UE can identify the pattern information it should receive based on the above information and perform DRx.

[0187] For example, in cell-specific cases, the aforementioned empty pattern information can be mapped and transmitted via SSB / PBCH. In terminal-specific cases, the aforementioned pattern information can be transmitted via reference signals such as CSI-RS.

[0188] At this time, beam or beam group pattern information may change depending on traffic volume or traffic priority. In such cases, the network node may transmit the changed or newly configured beam or beam group pattern information to the terminal via signals such as SSB / PBCH or CSI-RS.

[0189] Additionally, if beam or beam group pattern information is required based on traffic volume or traffic priority, the terminal can request an update to the beam or beam group pattern via an uplink such as a Sounding Reference Signal (SRS). In this case, the network node can configure a pattern that allocates a longer period or a larger EIRP to the beam or beam group to be received by the terminal. The network node can then transmit the changed beam pattern information to the terminal via SSB / PBCH, CSI-RS, or other signals.

[0190] Referring again to FIG. 8, the terminal receives activation instruction information for a discontinuous reception operation according to discontinuous beam pattern configuration information from a network node (S820), and when the discontinuous reception operation is activated, the terminal can receive a downlink signal from the network node (S830).

[0191] Before starting DTx according to the non-continuous beam pattern configuration information, the network node can transmit a message, i.e., activation indication information, to the terminal to activate or deactivate DRx reception. The network node can transmit the NTN DTx / DRx activation indication information to the terminal through the physical layer or the MAC layer.

[0192] When using the physical layer, the network node can transmit the Activation / Deactivation Indication message using the PDCCH DCI format. For example, DCI Format 1_0 / 1_1 is for scheduling information on the PDSCH of a terminal within a cell, and the network node can transmit Activation / Deactivation information by adding it to the format. Alternatively, the network node can transmit Activation / Deactivation by adding it to the PDCCH-configcommon and ServingCellConfig IE.

[0193] When using the MAC layer, the network node can transmit Activation / Deactivation to the terminal by adding it to the existing MAC CE. For example, NTN DTx / DRx Activation / Deactivation can be added to the index and LCDI values ​​of the LCID (Logical Channel Discontinuity Indicator) table for DL-SCH. In addition, activation / deactivation attributes for each beam or beam group can be added in bitmap form and transmitted to the terminal, such as TCI (Transmission Configuration Indicator) State Activation / Deactivation for terminal-specific PDSCH MAC CE.

[0194] When the terminal receives an activation instruction, the terminal can receive an NTN downlink signal according to the received non-continuous beam pattern configuration information.

[0195] Accordingly, a method and device for performing wireless communication in a non-terrestrial network can be provided, which can improve downlink coverage and provide efficient satellite-terminal communication with low power from a system perspective.

[0196] FIG. 9 is a diagram illustrating a procedure (900) for a network node to perform wireless communication in a non-terrestrial network according to one embodiment. The description given above in FIG. 14 may be omitted to avoid redundant description. In this case, the omitted content may be substantially equally applied to carrier wave nodes, as long as it does not conflict with the technical spirit of the invention.

[0197] Referring to FIG. 9, a network node can transmit non-continuous beam pattern configuration information to a terminal (S910).

[0198] Satellites have a footprint radius of several hundred kilometers, and they must transmit across dozens of beams based on their limited EIRP values. Therefore, network nodes can configure transmission patterns for each beam or beam group to ensure efficient NTN downlink transmission. Network nodes can transmit information about the non-continuous beam pattern configuration for each configured beam or beam group to the terminal.

[0199] For example, the discontinuous beam pattern configuration information may include ON / OFF status and period information for each beam or beam group, or may include Equivalent Isotropically Radiated Power (EIRP) and period information.

[0200] The discontinuous beam pattern configuration information can be configured to have different ON / OFF states and periods for each beam or beam group, i.e., to have different patterns. Considering the limited power of the satellite payload, the discontinuous beam pattern configuration information can be configured to have different ON / OFF states for different time intervals for each beam or beam group, and the periods can also be set to be different.

[0201] In this case, for example, when the network node configures different patterns for each beam or beam group, the total amount of time intervals for each beam or beam group may be set to be equally allocated. For example, in the case of three beams, Beam #1, Beam #2, and Beam #3 may be set to different ON / OFF states and cycles, but the total amount of time intervals for the ON states may be set to be the same. Alternatively, the ON / OFF states may be configured regardless of the total amount of time intervals.

[0202] Alternatively, the discontinuous beam pattern configuration information may be configured such that EIRP and period are set for each beam or beam group. In this case, the value of EIRP may be set to a fixed value or may be set flexibly. However, even in this case, the pattern may be configured such that the sum of the EIRPs for each beam or beam group has the same value. For example, Beam #1, Beam #2, and Beam #3 may be configured with different fixed or flexible EIRP values ​​and periods, but the total EIRPs of the transmitted states may be set to be the same. Alternatively, the pattern may be configured regardless of the total amount of EIRP.

[0203] In one example, the non-continuous beam pattern configuration information may be set based on at least one of the traffic amount of each beam or beam group, the traffic priority, or the power of the network node.

[0204] That is, when configuring different ON / OFF patterns for each beam or beam group, the network node can dynamically change or configure the ON / OFF state and cycle by considering the amount of traffic to be transmitted per beam or beam group or the traffic priority. For example, if the traffic volume of Beam #1 is the largest, it can be changed or configured to have the longest ON state cycle in the Beam #1 area.

[0205] Similarly, network nodes can be configured based on traffic volume or traffic priority per beam or beam group, even when configured with different EIRP values ​​and periods for each beam or beam group. For example, the EIRP can be dynamically changed or configured to increase or allocate longer time intervals for beams or beam groups with the highest traffic volume.

[0206] For example, the discontinuous beam pattern configuration information may be set to correspond to a beam index or a synchronization signal block index, respectively. In this case, for example, the discontinuous beam pattern configuration information may be received via a cell-specific or terminal-specific signal.

[0207] For example, a terminal in an area where a specific beam, Beam #1, is transmitted must know in advance the discontinuous beam pattern configuration information of beam #1 to be received, so that it can perform DRx operation and receive data in synchronization with the DTx operation. Accordingly, a network node can provide mapping information to the terminal to identify the beam pattern to be received by the terminal and perform DRx. In one example, the mapping information may also be included in the discontinuous beam pattern configuration information. Alternatively, the mapping information may be configured separately.

[0208] Accordingly, the network node can transmit non-continuous beam pattern configuration information to the UE through a cell-specific or UE-specific signal via an RRC message or broadcast message such as a System Information Block (SIB). In one example, the network node can map beam pattern information to a reference signal and transmit it. In this case, according to one example, the beam index can be replaced with an SSB index. In this case, the UE can identify the pattern information it should receive based on the above information and perform DRx.

[0209] For example, a network node may transmit the aforementioned empty pattern information by mapping it through SSB / PBCH in cell-specific cases. A network node may transmit the aforementioned pattern information through a reference signal such as CSI-RS in terminal-specific cases.

[0210] At this time, beam or beam group pattern information may change depending on traffic volume or traffic priority. In such cases, the network node may transmit the changed or newly configured beam or beam group pattern information to the terminal via signals such as SSB / PBCH or CSI-RS.

[0211] Additionally, if beam or beam group pattern information is required based on traffic volume or traffic priority, the terminal can request an update to the beam or beam group pattern via an uplink such as a Sounding Reference Signal (SRS). In this case, the network node can configure a pattern that allocates a longer period or a larger EIRP to the beam or beam group to be received by the terminal. The network node can then transmit the changed beam pattern information to the terminal via SSB / PBCH, CSI-RS, or other signals.

[0212] Referring again to FIG. 9, the network node transmits activation instruction information for a discontinuous reception operation according to discontinuous beam pattern configuration information to the terminal (S920), and when the discontinuous reception operation is activated, a downlink signal can be transmitted to the terminal (S930).

[0213] Before starting DTx according to the non-continuous beam pattern configuration information, the network node can transmit a message, i.e., activation indication information, to the terminal to activate or deactivate DRx reception. The network node can transmit the NTN DTx / DRx activation indication information to the terminal through the physical layer or the MAC layer.

[0214] When using the physical layer, the network node can transmit the Activation / Deactivation Indication message using the PDCCH DCI format. For example, DCI Format 1_0 / 1_1 is for scheduling information on the PDSCH of a terminal within a cell, and the network node can transmit Activation / Deactivation information by adding it to the format. Alternatively, the network node can transmit Activation / Deactivation by adding it to the PDCCH-configcommon and ServingCellConfig IE.

[0215] When using the MAC layer, the network node can transmit Activation / Deactivation to the terminal by adding it to the existing MAC CE. For example, NTN DTx / DRx Activation / Deactivation can be added to the index and LCDI values ​​of the LCID (Logical Channel Discontinuity Indicator) table for DL-SCH. In addition, activation / deactivation attributes for each beam or beam group can be added in bitmap form and transmitted to the terminal, such as TCI (Transmission Configuration Indicator) State Activation / Deactivation for terminal-specific PDSCH MAC CE.

[0216] When the terminal receives an activation instruction, the terminal can receive an NTN downlink signal according to the received non-continuous beam pattern configuration information.

[0217] Accordingly, a method and device for performing wireless communication in a non-terrestrial network can be provided, which can improve downlink coverage and provide efficient satellite-terminal communication with low power from a system perspective.

[0218]

[0219] Below, each embodiment of performing wireless communication in a non-terrestrial network will be described in detail with reference to related drawings.

[0220] The purpose of this disclosure is to improve system level performance in 3GPP NR-NTN networks due to limited power of GSO / NGSO satellites (payload), limited feeder link bandwidth and limited downlink EIRP density per beam resulting from these limitations, and to provide maximum throughput to all users while minimizing power consumption of the satellite.

[0221] Accordingly, in order to achieve the aforementioned purpose, the present disclosure proposes a method of applying and optimizing the ON / OFF function of cells or beams based on Cell DTx (Discontinuous Transmission) / DRx (Discontinuous Reception) of NES (Network Energy Saving) as part of downlink coverage enhancements, thereby maximizing the number of simultaneous activations of NTN cells / beams and improving efficient downlink data transmission and coverage.

[0222] The present disclosure can be applied to the architecture proposed by 3GPP NTN, as illustrated in FIG. 10. For transparent or regenerative satellite payloads, the satellite transmits and receives DL / UL signals with a ground terminal, referred to as a service link. The satellite communicates with a ground gateway, and this interface is defined as a feeder link.

[0223] In the present disclosure, as shown in FIGS. 11 and 12, in an NR-NTN network supporting NTN, a method is proposed to map one or more different pattern information to a cell, beam, or beam group by considering a beam pattern / size for a satellite (satellite payload) that transmits a downlink signal composed of one or more cells (PCI (Physical Cell ID)) and beams, and to transmit the information to a terminal. Here, the pattern information may correspond to at least a DTx interval or time for the satellite to discontinuously transmit a signal to the terminal for each cell or beam.

[0224] When a terminal capable of receiving an NTN signal receives the above information, the terminal can perform a DTx operation to receive an NTN downlink signal in a set section in synchronization with the received cell / beam / beam group pattern information. Therefore, in the present disclosure, arbitrary signal / channel / area information is defined and proposed for determining a discontinuous pattern associated with a satellite beam or a satellite beam group for a plurality of satellite beams included in one cell.

[0225] Figures 11 and 12 illustrate options according to the mapping rules of PCI (Physical Cell ID) and Beam index, which represent Cells, as follows. Figure 11 illustrates a case where PCI and Beam are mapped 1:1, and satellite beams have the same PCI. Figure 12 illustrates a case where PCI and Beam are mapped 1:N, and each Beam has one PCI. Although the mapping options between the PCI and Beam of a satellite have been mentioned above, they have not yet been defined. However, the method proposed in the present invention can be applied regardless of the above options.

[0226] (a) Option 1. PCI (Cell): Beam = 1:1

[0227] (b) Option 2. PCI(Cell): Beam = 1:N

[0228]

[0229] The technology proposed in this disclosure can be carried out in the following three ways.

[0230] 1. How to configure patterns for each cell, beam, and beam group

[0231] 1) Set ON / OFF state periodicity for each beam

[0232] 2) Different EIRP and periodicity settings for each beam

[0233] 2. DTx / DRx mapping by cell, beam, and beam group and signaling method for transmission to terminals

[0234] 3. NTN DTx / DRx Activation / Deactivation Transmission Method

[0235]

[0236] Example 1. Method for configuring patterns by cell, beam, and beam group

[0237] The satellite footprint radius (diameter) reaches several hundred kilometers, and currently, 3GPP has not defined the configuration method, such as the satellite cell plan, the number of beams per cell, and the beam shape. Furthermore, the EIRP limit value, which is the radiated power per unit frequency (dBW / MHz), has not been defined for each satellite in each orbit. However, in NTN, satellites must transmit by covering dozens of beams based on the limited EIRP value. Therefore, for efficient NTN downlink transmission, we propose a method to configure the transmission pattern for each beam or beam group. In this example, we propose a method to configure different patterns for each satellite beam or beam group, as follows.

[0238] 1) Set ON / OFF state periodicity for each beam

[0239] 2) Different EIRP and periodicity settings for each beam

[0240]

[0241] 1) Set ON / OFF state periodicity for each beam

[0242] As illustrated in Figures 13 to 15, this step proposes a pattern for discontinuously transmitting signals transmitted by satellites by beam or beam group. Figure 13 shows that each beam or beam group has different ON / OFF states and cycles. Considering the limited power of the satellite payload, the satellite transmits based on the ON / OFF state and DTx pattern during different time intervals, and the terminal performs DRx by receiving the corresponding information in advance.

[0243] Here, when configuring different patterns for each beam / beam group, the same total amount of time can be allocated per beam or beam group. For example, Beam #1, Beam #2, and Beam #3 can each be configured to set frames / subframes / slots in a total of four time domains. Conversely, the ON / OFF state can be configured regardless of the total amount of time (interval).

[0244] Additionally, when configuring different ON / OFF patterns for each beam / beam group, the ON / OFF state periodicity can be configured by considering the amount of traffic to be transmitted per beam or beam group or the traffic priority. For example, if Beam #1 has the largest traffic volume, the longest ON state period can be configured to be set for the Beam #1 area.

[0245] Figure 14 shows an example of EIRP instead of ON / OFF states, allowing for the same pattern configuration for each beam / beam group. The pattern can be configured to have an equal amount of EIRP values ​​for each beam / beam group. Furthermore, similar to the ON / OFF state, each beam / beam group can be configured to have different periodicities in the time domain, taking into account traffic volume or traffic priority.

[0246] 2) Different EIRP and periodicity settings for each beam

[0247] Figure 15 shows that the satellite performs DTx and transmits by setting a discontinuous pattern based on different EIRP values ​​and time interval information for each beam / beam group. When configuring the beam pattern in this way, the NTN network and satellite can flexibly / dynamically allocate EIRP and frame / subframe / slot and time interval to beam / beam groups requiring high DL throughput based on the traffic volume or traffic priority per beam / beam group.

[0248]

[0249] Example 2. DTx / DRx mapping by cell, beam, and beam group and signaling method for transmitting to terminals

[0250] Here, when an NR-NTN satellite performs DTx to a terminal on the ground in the above area based on a beam pattern after configuring an NTN Cell or a Beam / Beam group included in the NTN Cell, a method is proposed in which the terminal receives new configuration information including beam / beam group pattern information and performs DRx based on the same.

[0251] As illustrated in FIGS. 16 and 17, NTN cells and beam / beam groups can be configured as illustrated. FIG. 16 is an example of setting up a beam group based on FIG. 11. In addition, FIG. 17 is an example of setting up a beam group based on FIG. 12. Each beam group is composed of beam index information.

[0252] For example, FIG. 16 is an example of beam grouping, which may be grouped as Beam group 1 {beam index {1, 2, 3}}, Beam group 2 {beam index {4, 5, 6, 7}}. In addition, FIG. 17 is another example of beam grouping, which may be grouped as Beam group 1 {beam index {1, 2}}, Beam group 2 {beam index {3, 6}}, Beam group 3 {beam index {4, 5, 7}}.

[0253] Here, the terminal in Beam #1 must know in advance the DTx / DRx pattern information of beam #1 that it is to receive, so that it can perform the DRx operation and receive data in synchronization with the DTx operation. Accordingly, the satellite can provide the terminal with mapping information for performing DRx by identifying the beam pattern information that the terminal is to receive. Here, the pattern information may include at least the pattern information of FIGS. 13 to 15, and may include ON / OFF state periodicity and / or flexible EIRP setting information.

[0254] Therefore, the satellite can map beam / beam group pattern information to cell-specific or UE-specific reference signals to the terminal through RRC messages and broadcast messages such as SIB (System Information Block) in the form of an example in Table 5. In the example below, the beam index can be replaced with the SSB index, and the terminal can identify the pattern information it should receive based on the above information and perform DRx.

[0255] [Table 5]

[0256]

[0257] In cell-specific cases, the beam / beam group pattern information described above can be mapped and transmitted via SSB (Synchronization Signal Block) / PBCH (Physical Broadcast Channel). In UE-specific cases, the pattern information described above can be transmitted via a reference signal such as CSI-RS.

[0258] At this time, beam / beam group pattern information may change depending on traffic volume or traffic priority. In such cases, the satellite can transmit the changed or newly configured beam / beam group pattern information to the terminal through signals such as UE-specific / cell-specific reference signals, such as SSB / PBCH / CSI-RS.

[0259] Additionally, if pattern information is required based on traffic volume or traffic priority, the terminal can request a beam pattern update via uplink, such as a Sounding Reference Signal (SRS). The satellite that receives this information can configure a beam pattern that allocates more transmission cycles or EIRP to the corresponding beam based on the information. The satellite can then transmit the changed beam pattern information to the terminal via UE-specific / cell-specific reference signals, such as SSB / PBCH / CSI-RS.

[0260] The terminal receiving this can obtain the beam / beam group pattern information that it must receive, and perform DRx operation and receive data based on this.

[0261]

[0262] Example 3. NTN DTx / DRx Activation / Deactivation Transmission Method

[0263] We propose a method for transmitting an Activation / Deactivation indication message to initiate or terminate discontinuous transmission / reception DTx / DRx between an NTN satellite and a terminal. As described above, the satellite can transmit a message to the terminal to activate or deactivate DRx reception before initiating DTx according to a beam / beam group pattern. The NTN satellite transmits an NTN DTx / DRx Activation or Deactivation message to the terminal through the physical layer (PHY layer) or the MAC layer.

[0264] When using the PHY layer, the satellite can transmit Activation / Deactivation Indication messages using the PDCCH DCI format. For example, DCI Format 1_0 / 1_1 is for scheduling information on the PDSCH of a terminal within a single cell, and the Activation / Deactivation information can be added to the corresponding format for transmission. Additionally, Activation / Deactivation can be transmitted by adding it to the PDCCH-configcommon and ServingCellConfig IE.

[0265] When using the MAC layer, the network and NTN satellite can transmit Activation / Deactivation to the UE by adding it to the existing MAC CE. For example, NTN DTx / DRx Activation / Deactivation can be added to the index and LCDI values ​​of the Logical Channel Discontinuity Indicator (LCID) table for DL-SCH. In addition, activation / deactivation attributes for each beam / beam group can be added in bitmap form and transmitted to the UE, such as TCI (Transmission Configuration Indicator) State Activation / Deactivation for UE-specific PDSCH MAC CE.

[0266] That is, the DTx / DRx operation flow of the satellite and terminal considering the discontinuous beam pattern in the NR-NTN network proposed in the present disclosure is as follows. The network and the satellite can configure the NTN DTx / DRx beam pattern. In this case, the ON / OFF state period and the flexible EIRP and period can also be set. The network and the satellite can perform beam / beam group-by-beam mapping of beam pattern information and transmit the beam pattern information to the terminal through an RRC message (terminal-specific or cell-specific). The network and the satellite can transmit an NTN DTx / DRx activation / deactivation instruction to the terminal. When the terminal receives the activation instruction, the terminal can receive the NTN signal according to the beam pattern.

[0267] The present disclosure relates to a device for performing communication through a service link between a satellite and a terminal in an NR-NTN network, wherein a discontinuous pattern linked to a satellite beam / beam group is configured for a plurality of satellite beams included in one cell, and the satellite performs DTx based on this, thereby improving downlink coverage and providing efficient satellite-terminal communication with low power from a system perspective.

[0268] The embodiments described above may be implemented independently of each other, or at least two embodiments may be implemented in combination.

[0269]

[0270] Hereinafter, the configuration of a terminal and a network node capable of performing some or all of the embodiments described with reference to FIGS. 1 to 17 will be described with reference to the drawings. The above description may be omitted to avoid redundant description, and in this case, the omitted content may be substantially equally applied to the following description, as long as it does not contradict the technical spirit of the invention.

[0271] Fig. 18 is a drawing showing the configuration of a terminal (1800) according to another embodiment.

[0272] Referring to FIG. 18, a terminal (1800) according to another embodiment includes a transmitter (1820), a receiver (1830), and a control unit (1810) that controls the operations of the transmitter and receiver.

[0273] The control unit (1810) controls the overall operation of the terminal (1800) according to the method of performing energy harvesting required to perform the present invention described above.

[0274] The control unit (1810) can receive discontinuous beam pattern configuration information from a network node. The control unit (1810) can configure a transmission pattern for each beam or beam group for efficient NTN downlink transmission. The control unit (1810) can receive discontinuous beam pattern configuration information for each beam or beam group set in the network node from the network node.

[0275] For example, the discontinuous beam pattern configuration information may include ON / OFF status and period information for each beam or beam group, or may include Equivalent Isotropically Radiated Power (EIRP) and period information.

[0276] The discontinuous beam pattern configuration information can be configured to have different ON / OFF states and periods for each beam or beam group, i.e., to have different patterns. Considering the limited power of the satellite payload, the discontinuous beam pattern configuration information can be configured to have different ON / OFF states for different time intervals for each beam or beam group, and the periods can also be set to be different.

[0277] In this case, for example, when the network node configures different patterns for each beam or beam group, the total amount of time intervals for each beam or beam group may be set to be equally allocated. For example, in the case of three beams, Beam #1, Beam #2, and Beam #3 may be set to different ON / OFF states and cycles, but the total amount of time intervals for the ON states may be set to be the same. Alternatively, the ON / OFF states may be configured regardless of the total amount of time intervals.

[0278] Alternatively, the discontinuous beam pattern configuration information may be configured such that EIRP and period are set for each beam or beam group. In this case, the value of EIRP may be set to a fixed value or may be set flexibly. However, even in this case, the pattern may be configured such that the sum of the EIRPs for each beam or beam group has the same value. For example, Beam #1, Beam #2, and Beam #3 may be configured with different fixed or flexible EIRP values ​​and periods, but the total EIRPs of the transmitted states may be set to be the same. Alternatively, the pattern may be configured regardless of the total amount of EIRP.

[0279] In one example, the non-continuous beam pattern configuration information may be set based on at least one of the traffic amount of each beam or beam group, the traffic priority, or the power of the network node.

[0280] That is, when configuring different ON / OFF patterns for each beam or beam group, the network node can dynamically change or configure the ON / OFF state and cycle by considering the amount of traffic to be transmitted per beam or beam group or the traffic priority. For example, if the traffic volume of Beam #1 is the largest, it can be changed or configured to have the longest ON state cycle in the Beam #1 area.

[0281] Similarly, network nodes can be configured based on traffic volume or traffic priority per beam or beam group, even when configured with different EIRP values ​​and periods for each beam or beam group. For example, the EIRP can be dynamically changed or configured to increase or allocate longer time intervals for beams or beam groups with the highest traffic volume.

[0282] For example, the discontinuous beam pattern configuration information may be set to correspond to a beam index or a synchronization signal block index, respectively. In this case, for example, the discontinuous beam pattern configuration information may be received via a cell-specific or terminal-specific signal.

[0283] For example, a control unit (1810) in an area where a specific beam, Beam #1, is transmitted must know in advance the discontinuous beam pattern configuration information (i.e., discontinuous transmission (DTx) / discontinuous reception (DRx) pattern information) of beam #1 to be received, so as to perform a DRx operation in synchronization with the DTx operation and receive data. Accordingly, a network node can provide mapping information to a terminal for identifying a beam pattern to be received by the terminal and performing DRx. According to an example, the mapping information may also be included in the discontinuous beam pattern configuration information. Alternatively, the mapping information may be configured separately.

[0284] Accordingly, the network node can transmit non-continuous beam pattern configuration information to the UE through a cell-specific or UE-specific signal via an RRC message or broadcast message such as a System Information Block (SIB). In one example, the network node can map beam pattern information to a reference signal and transmit it. In this case, according to one example, the beam index can be replaced with an SSB index. In this case, the UE can identify the pattern information it should receive based on the above information and perform DRx.

[0285] For example, in cell-specific cases, the aforementioned empty pattern information can be mapped and transmitted via SSB / PBCH. In terminal-specific cases, the aforementioned pattern information can be transmitted via reference signals such as CSI-RS.

[0286] At this time, beam or beam group pattern information may change depending on traffic volume or traffic priority. In such cases, the network node may transmit the changed or newly configured beam or beam group pattern information to the terminal via signals such as SSB / PBCH or CSI-RS.

[0287] Additionally, if beam or beam group pattern information is required based on traffic volume or traffic priority, the control unit (1810) may request an update to the beam or beam group pattern via an uplink such as a Sounding Reference Signal (SRS). In this case, the network node may configure a pattern that allocates a longer period or a larger EIRP to the beam or beam group to be received by the corresponding terminal. Thereafter, the network node may transmit the changed beam pattern information to the terminal via SSB / PBCH, CSI-RS, or other signals.

[0288] The control unit (1810) may receive activation instruction information for a discontinuous reception operation based on discontinuous beam pattern configuration information from a network node. In this case, the control unit (1810) may receive a downlink signal from the network node when the discontinuous reception operation is activated.

[0289] Before starting DTx according to the non-continuous beam pattern configuration information, the network node can transmit a message, i.e., activation indication information, to the terminal to activate or deactivate DRx reception. The network node can transmit the NTN DTx / DRx activation indication information to the terminal through the physical layer or the MAC layer.

[0290] When using the physical layer, the network node can transmit the Activation / Deactivation Indication message using the PDCCH DCI format. For example, DCI Format 1_0 / 1_1 is for scheduling information on the PDSCH of a terminal within a cell, and the network node can transmit Activation / Deactivation information by adding it to the format. Alternatively, the network node can transmit Activation / Deactivation by adding it to the PDCCH-configcommon and ServingCellConfig IE.

[0291] When using the MAC layer, the network node can transmit Activation / Deactivation to the terminal by adding it to the existing MAC CE. For example, NTN DTx / DRx Activation / Deactivation can be added to the index and LCDI values ​​of the LCID (Logical Channel Discontinuity Indicator) table for DL-SCH. In addition, activation / deactivation attributes for each beam or beam group can be added in bitmap form and transmitted to the terminal, such as TCI (Transmission Configuration Indicator) State Activation / Deactivation for terminal-specific PDSCH MAC CE.

[0292] When the control unit (1810) receives an activation instruction, it can receive an NTN downlink signal according to the received non-continuous beam pattern configuration information.

[0293] Accordingly, a method and device for performing wireless communication in a non-terrestrial network can be provided, which can improve downlink coverage and provide efficient satellite-terminal communication with low power from a system perspective.

[0294] Fig. 19 is a diagram showing the configuration of a network node (1900) according to another embodiment.

[0295] Referring to FIG. 19, a network node (1900) according to another embodiment includes a transmitter (1920), a receiver (1930), and a control unit (1910) that controls the operations of the transmitter and receiver.

[0296] The control unit (1910) controls the overall operation of the network node (1900) according to the method for performing wireless communication in a non-terrestrial network required to carry out the present invention described above. The transmitter (1920) transmits downlink control information, data, and messages to the terminal through the corresponding channel. The receiver (1930) receives uplink control information, data, and messages from the terminal through the corresponding channel.

[0297] The control unit (1910) can transmit discontinuous beam pattern configuration information to the terminal. The control unit (1910) can configure transmission patterns for each beam or beam group for efficient NTN downlink transmission. The control unit (1910) can transmit discontinuous beam pattern configuration information for each configured beam or beam group to the terminal.

[0298] For example, the discontinuous beam pattern configuration information may include ON / OFF status and period information for each beam or beam group, or may include Equivalent Isotropically Radiated Power (EIRP) and period information.

[0299] The discontinuous beam pattern configuration information can be configured to have different ON / OFF states and periods for each beam or beam group, i.e., to have different patterns. Considering the limited power of the satellite payload, the discontinuous beam pattern configuration information can be configured to have different ON / OFF states for different time intervals for each beam or beam group, and the periods can also be set to be different.

[0300] In this case, according to an example, the control unit (1910) may set the total amount of time intervals to be equally allocated to each beam or beam group when configuring different patterns for each beam or beam group. For example, in the case of three beams, Beam #1, Beam #2, and Beam #3 are each set to different ON / OFF states and cycles, but the total time intervals of the ON states may be set to be equally set. Alternatively, the ON / OFF states may be configured regardless of the total amount of time intervals.

[0301] Alternatively, the discontinuous beam pattern configuration information may be configured such that EIRP and period are set for each beam or beam group. In this case, the value of EIRP may be set to a fixed value or may be set flexibly. However, even in this case, the pattern may be configured such that the sum of the EIRPs for each beam or beam group has the same value. For example, Beam #1, Beam #2, and Beam #3 may be configured with different fixed or flexible EIRP values ​​and periods, but the total EIRPs of the transmitted states may be set to be the same. Alternatively, the pattern may be configured regardless of the total amount of EIRP.

[0302] In one example, the non-continuous beam pattern configuration information may be set based on at least one of the traffic amount of each beam or beam group, the traffic priority, or the power of the network node.

[0303] That is, when configuring different ON / OFF patterns for each beam or beam group, the control unit (1910) can dynamically change or configure the ON / OFF state and cycle by considering the amount of traffic to be transmitted per beam or beam group or the traffic priority. For example, when the amount of traffic for Beam #1 is the largest, the Beam #1 area can be changed or configured to have the longest ON state cycle.

[0304] Similarly, the control unit (1910) can be configured based on the traffic volume or traffic priority per beam or beam group, even when configuring different EIRP values ​​and periods for each beam or beam group. For example, the control unit can be dynamically changed or configured to increase the EIRP or allocate a longer time interval for the beam or beam group with the highest traffic volume.

[0305] For example, the discontinuous beam pattern configuration information may be set to correspond to a beam index or a synchronization signal block index, respectively. In this case, for example, the discontinuous beam pattern configuration information may be received via a cell-specific or terminal-specific signal.

[0306] For example, a terminal in an area where a specific beam, Beam #1, is transmitted must know in advance the discontinuous beam pattern configuration information of beam #1 to be received, so that it can perform a DRx operation and receive data in synchronization with the DTx operation. Accordingly, the control unit (1910) can provide mapping information to the terminal to identify the beam pattern to be received by the terminal and perform DRx. According to an example, the mapping information may also be included in the discontinuous beam pattern configuration information. Alternatively, the mapping information may be configured separately.

[0307] Accordingly, the control unit (1910) can transmit non-continuous beam pattern configuration information to the terminal through a cell-specific or UE-specific signal via an RRC message or broadcast message such as a System Information Block (SIB). In one example, the control unit (1910) can map beam pattern information to a reference signal and transmit it. In this case, in one example, the beam index can be replaced with an SSB index. In this case, the terminal can identify the pattern information that it should receive based on the above information and perform DRx.

[0308] For example, the control unit (1910) may map and transmit the aforementioned empty pattern information via SSB / PBCH in a cell-specific case. The control unit (1910) may transmit the aforementioned pattern information via a reference signal such as CSI-RS in a terminal-specific case.

[0309] At this time, beam or beam group pattern information may be changed depending on traffic volume or traffic priority. In this case, the control unit (1910) may transmit the changed or newly configured beam or beam group pattern information to the terminal via a signal such as SSB / PBCH or CSI-RS.

[0310] Additionally, if beam or beam group pattern information is required based on traffic volume or traffic priority, the terminal may request an update to the beam or beam group pattern via an uplink such as a Sounding Reference Signal (SRS). In this case, the control unit (1910) may configure a pattern that allocates a longer period or a larger EIRP to the beam or beam group to be received by the terminal. Thereafter, the control unit (1910) may transmit the changed beam pattern information to the terminal via SSB / PBCH, CSI-RS, or another signal.

[0311] Referring again to FIG. 9, the control unit (1910) transmits activation instruction information for a discontinuous reception operation according to discontinuous beam pattern configuration information to the terminal (S920), and when the discontinuous reception operation is activated, a downlink signal can be transmitted to the terminal (S930).

[0312] Before starting DTx according to the non-continuous beam pattern configuration information, the control unit (1910) may transmit a message, i.e., activation instruction information, to the terminal to activate or deactivate DRx reception. The control unit (1910) may transmit NTN DTx / DRx activation instruction information to the terminal via the physical layer or MAC layer.

[0313] When using a physical layer, the control unit (1910) can transmit an Activation / Deactivation Indication message using the PDCCH DCI format. For example, DCI Format 1_0 / 1_1 is for scheduling information of the PDSCH of a terminal within a cell, and the control unit (1910) can transmit Activation / Deactivation information by adding it to the corresponding format. Alternatively, the control unit (1910) can transmit Activation / Deactivation by adding it to PDCCH-configcommon and ServingCellConfig IE.

[0314] When using the MAC layer, the control unit (1910) can add Activation / Deactivation to the existing MAC CE and transmit it to the terminal. For example, NTN DTx / DRx Activation / Deactivation can be added to the index and LCDI values ​​of the LCID (Logical Channel Discontinuity Indicator) table for DL-SCH. In addition, activation / deactivation attributes for each beam or beam group can be added in the form of a bitmap and transmitted to the terminal, such as TCI (Transmission Configuration Indicator) State Activation / Deactivation for a terminal-specific PDSCH MAC CE.

[0315] When the control unit (1910) receives an activation instruction, it can transmit an NTN downlink signal to the terminal according to the received non-continuous beam pattern configuration information.

[0316] Accordingly, a method and device for performing wireless communication in a non-terrestrial network can be provided, which can improve downlink coverage and provide efficient satellite-terminal communication with low power from a system perspective.

[0317] The above-described embodiments may be supported by standard documents disclosed in at least one of the wireless access systems, IEEE 802, 3GPP, and 3GPP2. That is, steps, components, and parts not described in the present embodiments to clearly illustrate the technical concepts herein may be supported by the above-described standard documents. Furthermore, all terms disclosed in this specification may be explained by the above-described standard documents.

[0318] The embodiments described above may be implemented through various means. For example, the embodiments may be implemented through hardware, firmware, software, or a combination thereof.

[0319] In the case of hardware implementation, the method according to the present embodiments may be implemented by one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers, or microprocessors.

[0320] When implemented using firmware or software, the methods according to the present embodiments may be implemented in the form of devices, procedures, or functions that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor using various known means.

[0321] Additionally, terms such as "system," "processor," "controller," "component," "module," "interface," "model," or "unit" as described above may generally refer to a computer-related entity, such as hardware, a combination of hardware and software, software, or software in execution. For example, the aforementioned components may be, but are not limited to, a process driven by a processor, a processor, a controller, a control processor, an object, a thread of execution, a program, and / or a computer. For example, both an application running on a controller or a processor and the controller or the processor may be components. One or more components may be within a process and / or thread of execution, and the components may be located on a single device (e.g., a system, a computing device, etc.) or distributed across two or more devices.

[0322] The above description is merely an illustrative example of the technical idea of ​​the present disclosure, and those skilled in the art to which the present disclosure pertains will appreciate that various modifications and variations can be made without departing from the essential characteristics of the technical idea of ​​the present disclosure. In addition, the present embodiments are not intended to limit the technical idea of ​​the present disclosure but rather to explain it, and therefore the scope of the technical idea of ​​the present disclosure is not limited by these embodiments. The scope of protection of the present disclosure should be interpreted by the claims below, and all technical ideas within a scope equivalent thereto should be interpreted as being included within the scope of the rights of the present disclosure.

[0323]

[0324] CROSS-REFERENCE TO RELATED APPLICATION

[0325] This patent application claims priority under 35 USC §119(a) to Korean Patent Application No. 10-2024-0107127, filed in Korea on August 9, 2024, and Korean Patent Application No. 10-2025-0110070, filed in Korea on August 8, 2025, the entire contents of which are incorporated herein by reference. In addition, this patent application claims priority in countries other than the United States for the same reasons, the entire contents of which are incorporated herein by reference.

Claims

1. In a method for a terminal to perform wireless communication in a non-terrestrial network (NTN), A step of receiving discontinuous beam pattern configuration information from a network node; A step of receiving activation instruction information for a discontinuous reception operation according to the discontinuous beam pattern configuration information from the network node; and A method comprising the step of receiving a downlink signal from the network node when the discontinuous reception operation is activated.

2. In paragraph 1, The above discontinuous beam pattern configuration information is, A method comprising, for each beam or beam group, ON / OFF status and period information, or including EIRP (Equivalent Isotropically Radiated Power) and period information.

3. In paragraph 2, The above discontinuous beam pattern configuration information is, A method of setting based on at least one of the traffic volume of each beam or beam group, the traffic priority, or the power of the network node.

4. In paragraph 1, The above discontinuous beam pattern configuration information is, A method set to correspond to each beam index or synchronization signal block index.

5. In paragraph 4, The above discontinuous beam pattern configuration information is, A method of receiving via cell-specific or terminal-specific signals.

6. A method for performing wireless communication by a network node in a non-terrestrial network (NTN), A step of transmitting non-continuous beam pattern configuration information to a terminal; A step of transmitting activation instruction information for a discontinuous reception operation according to the discontinuous beam pattern configuration information to the terminal; and A method comprising the step of transmitting a downlink signal to the terminal when the discontinuous reception operation is activated.

7. In paragraph 6, The above discontinuous beam pattern configuration information is, A method comprising, for each beam or beam group, ON / OFF status and period information, or including EIRP (Equivalent Isotropically Radiated Power) and period information.

8. In paragraph 7, The above discontinuous beam pattern configuration information is, A method of setting based on at least one of the traffic volume of each beam or beam group, the traffic priority, or the power of the network node.

9. In paragraph 6, The above discontinuous beam pattern configuration information is, A method set to correspond to each beam index or synchronization signal block index.

10. In paragraph 9, The above discontinuous beam pattern configuration information is, A method of receiving via cell-specific or terminal-specific signals.

11. In a terminal performing wireless communication in a non-terrestrial network (NTN), Transmitter; Receiver; and Includes a control unit that controls the operation of the transmitter and receiver, The above control unit, A terminal that receives discontinuous beam pattern configuration information from a network node, receives activation instruction information for discontinuous reception operation according to the discontinuous beam pattern configuration information from the network node, and receives a downlink signal from the network node when the discontinuous reception operation is activated.

12. In paragraph 11, The above discontinuous beam pattern configuration information is, A terminal including ON / OFF status and period information for each beam or beam group, or including EIRP (Equivalent Isotropically Radiated Power) and period information.

13. In paragraph 12, The above discontinuous beam pattern configuration information is, A terminal configured based on at least one of the traffic volume of each beam or beam group, the traffic priority, or the power of the network node.

14. In paragraph 11, The above discontinuous beam pattern configuration information is, A terminal configured to correspond to each beam index or synchronization signal block index.

15. In paragraph 14, The above discontinuous beam pattern configuration information is, A terminal that receives via cell-specific or terminal-specific signals.

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