Uplink transmission and reception method and apparatus in radio communication system

Abstract

To disclose an uplink transmission and reception method and an apparatus in a radio communication system.SOLUTION: A method for performing uplink transmission by a terminal in a radio communications system includes: a step of receiving, from a base station, first information on a satellite orbit, second information on a common timing advance (TA), and third information on a TA update period; a step of calculating a first TA based on the first information and the second information; a step of performing first uplink transmission based on the first TA; a step of updating the first TA to a second TA at a specific time point based on the third information; and a step of performing second uplink transmission based on the second TA. The TA update period may be set based on a value of 2^n, and n may be a positive integer including 0.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for applying a standard for time applied to uplink transmission and reception in a wireless communication system.

Background Art

[0002] Mobile communication systems were developed to provide voice services while ensuring user mobility. However, mobile communication systems have expanded their scope to include data services as well as voice, and currently, due to the explosive increase in traffic, there is a shortage of resources, and users are also demanding faster services. Therefore, a more advanced mobile communication system is desired.

[0003] Requirements for next-generation mobile communication systems include, among other things, the acceptance of explosive data traffic, a revolutionary increase in transmission rate per user, the acceptance of a significantly increased number of connected devices, very low end-to-end latency, and support for high energy efficiency. To this end, various technologies such as dual connectivity, massive multiple input multiple output (Massive MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking are being studied.

Summary of the Invention

Problems to be Solved by the Invention

[0004] A technical problem of the present disclosure is to provide an uplink transmission and reception method and apparatus in a wireless communication system.

[0005] A further technical problem of the present disclosure is to provide a method and an apparatus for applying a time reference applied to uplink transmission in a wireless communication system including a non-terrestrial network (non-terrestrial network, NTN).

[0006] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present disclosure pertains from the following description.

Means for Solving the Problems

[0007] An uplink transmission method and apparatus in a wireless communication system according to an aspect of the present disclosure are disclosed. A method for performing uplink transmission by a terminal in a wireless communication system according to an embodiment of the present disclosure includes receiving, from a base station, first information regarding a satellite orbit, second information regarding a common timing advance (TA), and third information regarding a TA update period; calculating a first TA based on the first information and the second information; performing a first uplink transmission based on the first TA; updating the first TA to a second TA at a specific time point based on the third information; and performing a second uplink transmission based on the second TA, wherein the TA update period is set based on a 2^n value, and the n may be a positive integer including 0.

[0008] In a wireless communication system according to a further aspect of the present disclosure, a method for a base station to receive uplink transmission includes transmitting, to a terminal, first information regarding a satellite orbit, second information regarding a common timing advance (TA), and third information regarding a TA update period; receiving, from the terminal, a first uplink transmission to which a first TA applied based on the first information and the second information is applied; and receiving, from the terminal, a second uplink transmission to which a second TA updated at a specific time based on the third information is applied. The TA update period is set based on a value of 2^n, and the n may be a positive integer including 0.

Advantages of the Invention

[0009] According to the present disclosure, an uplink transmission / reception method and apparatus in a wireless communication system can be provided.

[0010] According to the present disclosure, in a wireless communication system including a non-terrestrial network (NTN), a method and apparatus for applying a time reference applied to uplink transmission / reception can be provided.

[0011] The effects obtained from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present disclosure pertains from the following description.

Brief Description of the Drawings

[0012] The accompanying drawings, which are included as a part of the detailed description to assist in understanding the present disclosure, provide examples of embodiments of the present disclosure and explain the technical features of the present disclosure together with the detailed description.

[0013]

Figure 1

Figure 2

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Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Mode for Carrying Out the Invention

[0014] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below together with the accompanying drawings is for explaining exemplary embodiments of the present disclosure, and is not for showing the only embodiments in which the present disclosure can be implemented. The following detailed description includes specific details in order to provide a complete understanding of the present disclosure. However, it is understood by those skilled in the art that the present disclosure can be implemented without such specific details.

[0015] In some cases, to avoid obscuring the concept of the present disclosure, well-known structures and devices may be omitted, and may be shown in the form of a block diagram centered on the core functions of each structure and device.

[0016] In the present disclosure, when a certain component is "connected", "coupled" or "connected" to another component, this can include not only a direct connection relationship, but also an indirect connection relationship in which there are further other components between them. Also, in the present disclosure, the terms "comprising" or "having" identify the presence of the recited features, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and / or groups thereof.

[0017] In the present disclosure, terms such as "first" and "second" are used only for the purpose of distinguishing one component from another, and are not used to limit the components. Unless otherwise specifically mentioned, they do not limit the order or importance between components. Therefore, within the scope of the present disclosure, the first component in one embodiment can also be referred to as the second component in another embodiment, and similarly, the second component in one embodiment can be referred to as the first component in another embodiment.

[0018] The terms used in this disclosure are for the purpose of describing particular embodiments and are not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms are also intended to include the plural forms unless the context clearly dictates otherwise. The term "and / or" as used in this disclosure may refer to one of the related listed items or include any and all possible combinations of two or more of them. Also, in this disclosure, " / " between words has the same meaning as "and / or" unless otherwise specified.

[0019] This disclosure is described with respect to a wireless communication network or a wireless communication system, and the operations performed in the wireless communication network may be performed in the process where a device (e.g., a base station) that governs the wireless communication network controls the network and transmits or receives signals, or may be performed in the process where a terminal coupled to the wireless network transmits or receives signals to / from the network or between terminals.

[0020] In this disclosure, transmitting or receiving a channel includes the meaning of transmitting or receiving information or a signal on the channel. For example, transmitting a control channel means transmitting control information or a signal on the control channel. Similarly, transmitting a data channel means transmitting data information or a signal on the data channel.

[0021] Hereinafter, the downlink (DL) means communication from the base station to the terminal, and the uplink (UL) means communication from the terminal to the base station. In the downlink, the transmitter may be part of the base station and the receiver may be part of the terminal. In the uplink, the transmitter may be part of the terminal and the receiver may be part of the base station. The base station may be represented as the first communication device, and the terminal may be represented as the second communication device. The base station (BS: Base Station) may be replaced by terms such as fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP: Access Point), network (5G network), AI (Artificial Intelligence) system / module, RSU (road side unit), robot, drone (UAV: Unmanned Aerial Vehicle), AR (Augmented Reality) device, VR (Virtual Reality) device, terrestrial satellite base station, VAST (very-small-aperture terminal), gateway communicating with satellites, IAB (Integrated Access and Backhaul), etc.Also, the terminal may be fixed or have mobility and may be replaced by terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, RSU (road side unit), robot, AI (Artificial Intelligence) module, drone (UAV: Unmanned Aerial Vehicle), AR (Augmented Reality) device, VR (Virtual Reality) device, terrestrial satellite base station, VAST, gateway communicating with satellites, IAB, etc.

[0022] The following techniques may be used in various wireless connection systems such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may be implemented by wireless technologies such as UTRA (Universal Terrestrial Radio Access) and CDMA2000. TDMA may be implemented by wireless technologies such as GSM (Global System for Mobile communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA may be implemented by wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA), etc. UTRA is part of UMTS (Universal Mobile Telecommunications System). 3GPP (registered trademark) (3rd Generation Partnership Project) LTE (Long Term Evolution) is part of E-UMTS (Evolved UMTS) using E-UTRA, and LTE-A (Advanced) / LTE-A pro is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A / LTE-A pro.

[0023] For clarity of description, the description is based on the 3GPP communication system (e.g., LTE-A, NR), but the technical idea of the present disclosure is not limited thereto. LTE means the technology after 3GPP TS (Technical Specification) 36.xxx Release 8. Specifically, the LTE technology after 3GPP TS 36.xxx Release 10 is called LTE-A, and the LTE technology after 3GPP TS 36.xxx Release 13 is called LTE-A pro. 3GPP NR means the technology after TS 38.xxx Release 15. LTE / NR may be called the 3GPP system. "xxx" means the detailed number of the standard document. LTE / NR may be called the 3GPP system. Regarding the background technology, terms, abbreviations, etc. used in the description of the present disclosure, reference can be made to the matters described in the standard documents published before the present disclosure. For example, the following documents can be referred to.

[0024] In 3GPP LTE, reference can be made to TS 36.211 (Physical Channels and Modulation), TS 36.212 (Multiplexing and Channel Coding), TS 36.213 (Physical Layer Procedures), TS 36.300 (General Description), TS 36.331 (Radio Resource Control).

[0025] In 3GPP NR, reference can be made to TS 38.211 (Physical Channels and Modulation), TS 38.212 (Multiplexing and Channel Coding), TS 38.213 (Physical Layer Procedures for Control), TS 38.214 (Physical Layer Procedures for Data), TS 38.300 (General Description of NR and NG-RAN (New Generation - Radio Access Network)), TS 38.331 (Radio Resource Control Protocol Specification).

[0026] The abbreviations of the terms that can be used in the present disclosure are defined as follows.

[0027] - BM: Beam Management

[0028] - CQI: Channel Quality Indicator

[0029] - CRI: Channel State Information - Reference Signal Resource Indicator

[0030] - CSI: Channel State Information

[0031] - CSI-IM: Channel State Information - Interference Measurement

[0032] - CSI-RS: Channel State Information - Reference Signal

[0033] - DMRS: Demodulation Reference Signal

[0034] - FDM: Frequency Division Multiplexing

[0035] - FFT: Fast Fourier Transform

[0036] - IFDMA: Interleaved Frequency Division Multiple Access

[0037] - IFFT: Inverse Fast Fourier Transform

[0038] - L1-RSRP: Layer 1 reference signal received power

[0039] - L1-RSRQ: Layer 1 reference signal received quality

[0040] - MAC: medium access control

[0041] - NZP: non-zero power

[0042] - OFDM: orthogonal frequency division multiplexing

[0043] - PDCCH: physical downlink control channel

[0044] - PDSCH: physical downlink shared channel

[0045] - PMI: precoding matrix indicator

[0046] - RE: resource element

[0047] - RI: Rank indicator

[0048] - RRC: radio resource control

[0049] - RSSI: received signal strength indicator

[0050] - Rx: Reception

[0051] - QCL: Quasi co-location

[0052] - SINR: Signal to interference and noise ratio

[0053] - SSB (or, SS / PBCH block): Synchronization signal block (including primary synchronization signal (PSS), secondary synchronization signal (SSS) and physical broadcast channel (PBCH))

[0054] - TDM: Time division multiplexing

[0055] - TRP: Transmission and reception point

[0056] - TRS: Tracking reference signal

[0057] - Tx: Transmission

[0058] - UE: User equipment

[0059] - ZP: Zero power

[0060] System Overview

[0061] As more communication devices demand larger communication capacities, there is a growing need for mobile broadband communication that offers improvements over existing radio access technologies (RATs). Additionally, massive Machine Type Communications (MTC), which involves connecting a large number of devices and things to provide various services anytime and anywhere, is also one of the major issues to be considered in next-generation communications. In addition to this, the design of communication systems that take into account services / terminals sensitive to reliability and latency is also being discussed. Thus, the introduction of next-generation RATs that consider enhanced mobile broadband communication (eMBB), massive MTC (mMTC), Ultra-Reliable and Low Latency Communication (URLLC), etc., is being discussed. For the sake of convenience in this disclosure, this technology is referred to as NR. NR is an expression representing an example of 5G RAT.

[0062] The new RAT system including NR uses an OFDM transmission method or a transmission method similar thereto. The new RAT system may follow OFDM parameters different from those of LTE's OFDM parameters. Or, the new RAT system may directly follow the numerology of existing LTE / LTE-A but can support a larger system bandwidth (e.g., 100 MHz). Or, one cell can also support multiple numerologies. That is, terminals operating with different numerologies may coexist within one cell.

[0063] Numerology corresponds to one subcarrier spacing in the frequency domain. By scaling the reference subcarrier spacing by an integer N, different numerologies can be defined.

[0064] FIG. 1 illustrates the structure of a wireless communication system to which the present disclosure is applicable.

[0065] Referring to FIG. 1, the NG-RAN is composed of gNBs that provide NG-RA (NG-Radio Access) user plane (i.e., new AS (access stratum) sublayer / PDCP (Packet Data Convergence Protocol) / RLC (Radio Link Control) / MAC / PHY) and control plane (RRC) protocol terminations for UEs. The gNBs are interconnected via the Xn interface. The gNBs are also connected to the NGC (New Generation Core) via the NG interface. More specifically, the gNBs are connected to the AMF (Access and Mobility Management Function) via the N2 interface and to the UPF (User Plane Function) via the N3 interface.

[0066] FIG. 2 illustrates the frame structure in a wireless communication system to which the present disclosure is applicable.

[0067] The NR system can support a number of numerologies. Here, the numerology may be defined by the subcarrier spacing and the cyclic prefix (CP: Cyclic Prefix) overhead. At this time, a number of subcarrier spacings may be derived by scaling the basic (reference) subcarrier spacing by an integer N (or μ). Also, even assuming that a very low subcarrier spacing is not used at a very high carrier frequency, the numerology used may be selected independently of the frequency band. Also, in the NR system, various frame structures based on a number of numerologies may be supported.

[0068] The OFDM numerologies and frame structures that can be considered in the NR system will be described below. A number of OFDM numerologies supported in the NR system may be defined as shown in Table 1 below.

[0069]

Table 1

[0070] NR supports a number of numerologies (or subcarrier spacings (SCS)) to support various 5G services. For example, when the SCS is 15 kHz, it supports a wide area in traditional cellular bands. When the SCS is 30 kHz / 60 kHz, it supports dense-urban areas, lower latency, and wider carrier bandwidths. When the SCS is 60 kHz or higher, it supports bandwidths greater than 24.25 GHz to overcome phase noise. The NR frequency band is defined as two types (FR1, FR2) of frequency ranges. FR1 and FR2 may be configured as shown in Table 2 below. Also, FR2 can mean millimeter wave (mmW).

[0071]

Table 2

[0072] Regarding the frame structure in the NR system, the sizes of various fields in the time domain are T c = 1 / (Δf max ·N f ) expressed as multiples of time units. Here, Δf max = 480·10 3 Hz, and N f= 4096. Downlink and uplink transmissions are at T f = 1 / (Δf max N f / 100)·T c = A radio frame having an interval of 10 ms is organized. Here, each radio frame has T sf =(Δf max N f / 1000)·T c = It is composed of 10 subframes each having an interval of 1 ms. In this case, there may be one set of frames for the uplink and one set of frames for the downlink. Also, the transmission at the uplink frame number i from the terminal must start T TA =(N TA +N TA,offset )T c before the start of the corresponding downlink frame at the terminal. For the subcarrier spacing configuration μ, a slot is numbered in ascending order of n s μ ∈{0,...,N slot subframe,μ -1} within a subframe and in ascending order of n s,f μ ∈{0,...,N slot frame,μ -1} within a radio frame. One slot is composed of N symb slot consecutive OFDM symbols, and N symb slot is determined by the CP. In a subframe, the start of slot n s μ is the OFDM symbol n s μ N symb slotis aligned in time with the start. Not all terminals can transmit and receive simultaneously, which means that not all OFDM symbols in a downlink slot or an uplink slot can be used. Table 3 shows the number of OFDM symbols per slot (N symb slot ), the number of slots per radio frame (N slot frame,μ ), and the number of slots per subframe (N slot subframe,μ ) for normal CP, and Table 4 shows the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe for extended CP.

[0073] [Table 3]

[0074] [Table 4]

[0075] Figure 2 is an example when μ = 2 (SCS is 60 kHz). Referring to Table 3, one subframe can include 4 slots. The 1 subframe = {1, 2, 4} slots shown in Figure 2 is an example, and the number of slots that can be included in one subframe is defined as in Table 3 or Table 4. Also, a mini-slot can include 2, 4, or 7 symbols, or more or fewer symbols. In relation to the physical resources in the NR system, antenna ports, resource grids, resource elements (resource elements), resource blocks, carrier parts, etc. may be considered. Hereinafter, the physical resources that can be considered in the NR system will be specifically described. First, in relation to antenna ports, an antenna port is defined such that the channel carried by the symbols on the antenna port can be inferred from the channels carried by other symbols on the same antenna port. When the large-scale properties of the channels carried by the symbols on one antenna port can be inferred from the channels carried by the symbols on other antenna ports, it can be said that the two antenna ports are in a QC / QCL (quasi co-located or quasi co-location) relationship. Here, the large-scale properties include any one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing. Figure 3 illustrates a resource grid in a wireless communication system to which the present disclosure is applicable. Referring to Figure 3, the resource grid is composed of N RB μ N sc RB sub-carriers, and one subframe is 14·2μ Although it is exemplarily described as being composed of OFDM symbols, it is not limited thereto. In the NR system, the transmitted signal is N RB μ N sc RB one or more resource grids composed of subcarriers and 2 μ N symb (μ) described by OFDM symbols of. Here, N RB μ ≤ N RB max,μ is. The N RB max,μ represents the maximum transmission bandwidth, which may vary not only in numerology but also between the uplink and the downlink. In this case, one resource grid may be set for each of μ and antenna port p. JPEG2025109754000006.jpg73163

[0076] Point A serves as a common reference point for the resource block grid and is obtained as follows.

[0077] - offsetToPointA for the primary cell (PCell) downlink indicates the frequency offset between the lowest subcarrier of the lowest resource block that overlaps with the SS / PBCH block used by the terminal for initial cell selection and point A. It is expressed in resource block units assuming a 15 kHz subcarrier spacing for FR1 and a 60 kHz subcarrier spacing for FR2.

[0078] - absoluteFrequencyPointA indicates the frequency-position of point A expressed as in the absolute radio-frequency channel number (ARFCN).

[0079] The common resource block is numbered upward from 0 in the frequency domain with respect to the subcarrier spacing setting μ. The center of subcarrier 0 of common resource block 0 with respect to the subcarrier spacing setting μ coincides with 'point A'. In the frequency domain, the relationship between the common resource block number n CRB μ and the resource element (k, l) with respect to the subcarrier spacing setting μ is given by Equation 1 below.

[0080]

Equation

[0081] In Equation 1, k is defined relative to point A such that k = 0 corresponds to the subcarrier centered at point A. The physical resource block is numbered from 0 to N BWP,i size,μ -1 within the bandwidth part (BWP: bandwidth part), and i is the number of the BWP. In BWP i, the relationship between the physical resource block n PRB and the common resource block n CRB is given by Equation 2 below.

[0082]

Equation

[0083] N BWP,i start,μ is the common resource block where the BWP starts relative to common resource block 0.

[0084] Figure 4 illustrates the physical resource block in a wireless communication system to which the present disclosure is applicable. And Figure 5 illustrates the slot structure in a wireless communication system to which the present disclosure is applicable.

[0085] Referring to FIGS. 4 and 5, a slot contains a plurality of symbols in the time domain. For example, in the case of normal CP, one slot contains 7 symbols, while in the case of extended CP, one slot contains 6 symbols.

[0086] A carrier wave contains a plurality of subcarriers in the frequency domain. An RB (Resource Block) is defined as a plurality (e.g., 12) of consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) is defined as a plurality of consecutive (physical) resource blocks in the frequency domain and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier wave can contain up to N (e.g., 5) BWPs at most. Data communication is performed on the activated BWP, and only one BWP may be activated for one terminal. Each element in the resource grid is called a resource element (RE), and one complex symbol may be mapped.

[0087] The NR system may support up to 400 MHz per component carrier (CC). If a terminal operating in such a wideband CC always operates with the radio frequency (RF) chip for the entire CC turned on, the terminal battery consumption may increase. Alternatively, considering various use cases (e.g., eMBB, URLLC, Mmtc, V2X, etc.) operating within one wideband CC, different numerologies (e.g., subcarrier spacing, etc.) may be supported for different frequency bands within the CC. Alternatively, the capabilities of terminals may differ with respect to the maximum bandwidth. Considering this, the base station may instruct the terminal to operate only on a partial bandwidth rather than the entire bandwidth of the wideband CC, and this partial bandwidth is defined as the bandwidth part (BWP) for convenience. The BWP may be composed of consecutive RBs on the frequency axis and can correspond to one numerology (e.g., subcarrier spacing, CP length, slot / minislot interval).

[0088] On the other hand, the base station can set multiple BWPs even within one CC configured for the terminal. For example, in the PDCCH monitoring slot, a BWP that occupies a relatively small frequency region can be set, and the PDSCH indicated by the PDCCH may be scheduled on a larger BWP than that. Alternatively, when UEs concentrate on a specific BWP, other BWPs may be set for some terminals for load balancing. Alternatively, considering frequency domain inter-cell interference cancellation between adjacent cells, etc., a part of the spectrum of the entire bandwidth can be excluded, and both BWPs can be set even within the same slot. That is, the base station can set at least one DL / UL BWP for the terminal associated with the wideband CC. The base station can activate at least one of the DL / UL BWPs configured at a specific time (by means of L1 signaling or MAC CE (Control Element) or RRC signaling, etc.). Also, the base station can instruct switching to other configured DL / UL BWPs (by means of L1 signaling or MAC CE or RRC signaling, etc.). Alternatively, when the timer value expires based on the timer, it may switch to the defined DL / UL BWP. At this time, the activated DL / UL BWP is defined as the active DL / UL BWP. However, in situations such as when the terminal is in the initial connection (initial access) process or before the RRC connection is set up, the terminal may not be able to receive the configuration for the DL / UL BWP. Therefore, the DL / UL BWP assumed by the terminal in such a situation is defined as the initial active DL / UL BWP.

[0089] FIG. 6 illustrates physical channels used in a wireless communication system to which the present disclosure is applicable and a general signal transmission / reception method using them.

[0090] In a wireless communication system, a terminal receives information from a base station on the downlink, and the terminal transmits information to the base station on the uplink. The information transmitted and received between the base station and the terminal includes data and various control information, and there are various physical channels according to the types / uses of the information they transmit and receive.

[0091] When the terminal is powered on or newly enters a cell, it performs initial cell search (Initial cell search) operations such as synchronizing with the base station (S601). For this purpose, the terminal receives the primary synchronization signal (PSS) and the secondary synchronization signal (SSS) from the base station to synchronize with the base station and can obtain information such as the cell identifier (ID: Identifier). After that, the terminal can receive the physical broadcast channel (PBCH) from the base station to obtain in-cell broadcast information. On the other hand, the terminal can receive the downlink reference signal (DL RS) in the initial cell search stage to check the downlink channel state.

[0092] After completing the initial cell search, the terminal receives the physical downlink shared channel (PDSCH) based on the physical downlink control channel (PDCCH) and the information carried on the PDCCH, and can obtain more specific system information (S602).

[0093] On one hand, when the terminal first connects to the base station or there is no radio resource for signal transmission, the terminal can perform a random access procedure (RACH: Random Access Procedure) with respect to the base station (steps S603 to S606). For this purpose, the terminal transmits a specific sequence as a preamble on a physical random access channel (physical random access channel, PRACH: Physical Random Access Channel) (S603 and S605), and can receive a response message for the preamble on the PDCCH and the corresponding PDSCH (S604 and S606). In the case of contention-based RACH, furthermore, a contention resolution procedure can be performed.

[0094] After performing the above-described procedure, the terminal can then perform PDCCH / PDSCH reception (S607) and physical uplink shared channel (PUSCH: Physical Uplink Shared Channel) / physical uplink control channel (PUCCH: Physical Uplink Control Channel) transmission (S608) as a general uplink / downlink signal transmission procedure. In particular, the terminal receives downlink control information (DCI: Downlink Control Information) on the PDCCH. Here, the DCI includes control information such as resource allocation information for the terminal, and the formats are different from each other depending on the purpose of use.

[0095] On the other hand, the control information that the terminal transmits to the base station on the uplink or that the terminal receives from the base station includes downlink / uplink ACK / NACK (Acknowledgement / Non-Acknowledgement) signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indicator), etc. In the 3GPP LTE system, the terminal can transmit control information such as the above-described CQI / PMI / RI on the PUSCH and / or PUCCH.

[0096] Table 5 shows an example of DCI format in the NR system.

[0097] [Table 5]

[0098] Referring to Table 5, DCI formats 0_0, 0_1, and 0_2 can include resource information related to PUSCH scheduling (e.g., UL / SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), transport block (TB) related information (e.g., MCS (Modulation Coding and Scheme), NDI (New Data Indicator), RV (Redundancy Version), etc.), HARQ (Hybrid-Automatic Repeat and request) related information (e.g., process number, DAI (Downlink Assignment Index), PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information (e.g., PUSCH power control, etc.), and the control information included in each DCI format may be predefined. DCI format 0_0 is used for PUSCH scheduling in one cell. The information included in DCI format 0_0 is transmitted after being CRC (cyclic redundancy check) scrambled by C-RNTI (Cell RNTI:Cell Radio Network Temporary Identifier) or CS-RNTI (Configured Scheduling RNTI) or MCS-C-RNTI (Modulation Coding Scheme Cell RNTI). DCI format 0_1 is used to indicate one or more PUSCH scheduling or configured grant (CG) downlink feedback information to the terminal in one cell. The information included in DCI format 0_1 is transmitted after being CRC scrambled by C-RNTI or CS-RNTI or SP-CSI-RNTI (Semi-Persistent CSI RNTI) or MCS-C-RNTI. DCI format 0_2 is used for PUSCH scheduling in one cell.The information included in DCI format 0_2 is transmitted after being CRC scrambled by C-RNTI or CS-RNTI or SP-CSI-RNTI or MCS-C-RNTI.

[0099] Next, DCI formats 1_0, 1_1, and 1_2 can include resource information related to PDSCH scheduling (e.g., frequency resource allocation, time resource allocation, VRB (virtual resource block)-PRB (physical resource block) mapping, etc.), transmission block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), multiple antenna related information (e.g., antenna port, TCI (transmission configuration indicator), SRS (sounding reference signal) request, etc.), and PUCCH related information (e.g., PUCCH power control, PUCCH resource indicator, etc.). The control information included in each DCI format may be predefined.

[0100] DCI format 1_0 is used for PDSCH scheduling in one DL cell. The information included in DCI format 1_0 is transmitted after being CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.

[0101] DCI format 1_1 is used for PDSCH scheduling in one cell. The information included in DCI format 1_1 is transmitted after being CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.

[0102] DCI format 1_2 is used for scheduling the PDSCH in one cell. The information included in DCI format 1_2 is transmitted after being CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.

[0103] Wireless communication system supporting non-terrestrial network (NTN)

[0104] NTN means a network or a segment of a network configured to use radio frequency (RF) resources in a satellite or an unmanned aircraft system (UAS) platform. The use of NTN services is considered to ensure a wider coverage or to provide wireless communication services in locations where it is difficult to install a wireless communication base station.

[0105] Here, the NTN service refers to installing a base station on an artificial satellite (such as a geostationary-orbit, low-orbit, medium-orbit satellite, etc.), an airplane, an unmanned airship, a drone, etc. instead of on the ground to provide wireless communication services to terminals. In the following description, the NTN service may include NR NTN services and / or LTE NTN services. The terrestrial network (TN) service refers to installing a base station on the ground to provide wireless communication services to terminals.

[0106] The frequency bands considered for NTN services are mainly the 2 GHz band (S-band: 2 - 4 GHz) in the first frequency range (frequency range1, FR1) (e.g., 410 MHz - 7.125 GHz), and the downlink 20 GHz and uplink 30 GHz bands (Ka-Band: 26.5 - 40 GHz) in the second frequency range (FR2) (e.g., 24.25 GHz - 52.6 GHz). Furthermore, NTN services may also be supported in the frequency band between 7.125 GHz and 24.25 GHz, or in the frequency band above 52.6 GHz.

[0107] FIG. 7 is a diagram for explaining NTN supported by a wireless communication system to which the present disclosure is applicable.

[0108] FIG. 7(a) illustrates an NTN scenario based on a transparent payload, and FIG. 7(b) illustrates an NTN scenario based on a regenerative payload.

[0109] Here, the NTN scenario based on the transparent payload is a scenario in which a satellite that has received a payload from a terrestrial base station transmits the payload to a terminal, and the NTN scenario based on the regenerative payload means a scenario in which a satellite is embodied as a base station (gNB).

[0110] NTN is generally characterized by the following elements.

[0111] - One or more satellite-gateways for connecting NTN to a shared data network:

[0112] Geostationary earth orbiting (GEO) satellites are provided by one or more satellite-gateways arranged in the coverage targeted by the satellites (e.g., regional or continental coverage). It may be assumed that terminals within a cell are served by a single satellite-gateway.

[0113] Non-GEO satellites may be successively served by one or more satellite-gateways. At this time, the wireless communication system guarantees service and feeder link continuity between serving satellite-gateways in a time interval sufficient to perform mobility anchoring and handover.

[0114] - A feeder link or radio link between a satellite-gateway and a satellite (or, UAS platform)

[0115] - A service link or radio link between a terminal and a satellite (or, UAS platform)

[0116] - A satellite (or, UAS platform) capable of embodying one of a transparent or regenerative (including on-board processing) payload.

[0117] Satellite (or, UAS platform) generated beams generally generate multiple beams in a service area bounded by the field of view of the satellite (or, UAS platform). The footprint of the beam is generally elliptical. The field of view of the satellite (or, UAS platform) is determined by the mounted antenna diagram and the minimum elevation angle.

[0118] Transparent payload: Radio frequency filtering, frequency conversion and amplification. Thereby, the waveform signal repeated by the payload is not changed.

[0119] Regenerative payload: In addition to radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, coding / modulation. This is substantially the same as having all or part of a base station function (e.g., gNB) in a satellite (or, UAS platform).

[0120] - For satellite constellations, ISL (Inter-satellite links). For this purpose, regenerative payloads are required on the satellites. ISL can operate at RF frequencies or in broadband.

[0121] - Terminals are served by satellites (or UAS platforms) within the target service area.

[0122] Table 6 exemplifies the types of satellites (or UAS platforms).

[0123]

Table 6

[0124] Generally, GEO satellites and UASs are used to provide continental, regional, or local services. And LEO (low earth orbiting) and MEO (medium earth orbiting) constellations are used to provide services in both the Northern and Southern Hemispheres. Or, the constellation can provide global coverage including polar regions. Later, appropriate orbital inclinations, sufficient generated beams, and inter-satellite links may be required. And HEO (Highly Elliptical Orbiting) satellite systems may also be considered.

[0125] The following describes a wireless communication system in NTN including the following six reference scenarios.

[0126] - Circular orbit and notational station keeping up platform

[0127] - The highest RTD (Round Trip Delay) constraint

[0128] - The highest Doppler constraint

[0129] - Transparent or regenerative payload

[0130] - One ISL case and one case without ISL. In the case of inter-satellite links, regenerative payload

[0131] The six reference scenarios are considered in Tables 7 and 8.

[0132]

Table 7

[0133]

Table 8-1

Table 8-2

[0134] Reference 1: Each satellite can steer a beam to a fixed point on the Earth using beamforming technology. This is applied at the time corresponding to the satellite's visibility time. Reference 2: The maximum delay variation within a beam (for a terminal fixed to the Earth (or ground)) is calculated based on the minimum elevation angle for both the gateway and the terminal.

[0135] Reference 3: The maximum differential delay within a beam is calculated based on the diameter of the maximum beam reception range at nadir.

[0136] Reference 4: The speed of light used for delay calculation is 299792458 m / s.

[0137] Reference 5: The size of the maximum beam reception range of GEO is determined based on the current state of GEO high-throughput system technology, assuming that there is a spot beam at the coverage edge (low altitude).

[0138] Reference 6: The maximum differential delay at the cell level is calculated considering the beam-level delay for the maximum beam size. When the beam size is small or of medium size, a cell may include two or more beams. However, the cumulative differential delay of all beams within a cell does not exceed the maximum differential delay at the cell level in Table 8.

[0139] Also, in the following, a wireless communication system in IoT NTN including the following five reference scenarios will be described.

[0140] - GEO and LEO orbit scenarios

[0141] - No inter-satellite link

[0142] - Transparent payload

[0143] - Beam footprints used on the ground by fixed or adjustable beams respectively

[0144] - Band of interest below 6 GHz

[0145] The above five reference scenarios are considered in Table 9.

[0146]

Table 9

[0147] The NTN-related descriptions in this disclosure may be applicable to NTN GEO scenarios and all NGSO (non-geostationary orbit) scenarios with circular orbits at an altitude of 600 km or more.

[0148] Furthermore, the above-described content (NR frame structure, NTN, etc.) may be applied in combination with the methods described below and may supplement to clarify the technical features of the methods described in the present disclosure.

[0149] TA (timing advance) value setting method in NTN

[0150] In TN, since the terminal moves within the cell, even if the distance between the base station and the terminal changes, the PRACH preamble transmitted by the terminal can be transmitted to the base station within the time duration of a specific RO (RACH occasion).

[0151] And the TA value for the terminal to transmit the uplink signal / channel may be composed of an initial TA value and a TA offset value. Here, the initial TA value and the TA offset value are TA values that can be expressed within the cell coverage range of the base station and may be indicated by the base station.

[0152] As yet another example, when the base station indicates a PDCCH order by DCI, the terminal can transmit a PRACH preamble to the base station. The terminal can transmit an uplink signal / channel to the base station using the TA value (i.e., the initial TA value) indicated by the response message (random access response, RAR) for the preamble received from the base station.

[0153] In NTN, the distance between the satellite and the terminal may change due to the movement of the satellite regardless of the movement of the terminal. To overcome this, the terminal can use GNSS (global navigation satellite system) to determine the position of the terminal and calculate the UE-specific TA, which is the round trip delay (RTD) between the terminal and the satellite, based on the orbit information of the satellite indicated by the base station.

[0154] Here, the terminal-specific TA may be set such that when a PRACH preamble is transmitted in the RO selected by the terminal, the satellite (or, base station (gNB)) can receive the PRACH preamble within the time interval of the RO.

[0155] And when only the terminal-specific TA is applied when a PRACH preamble is transmitted in the RO selected by the terminal, the PRACH preamble may be transmitted to the satellite (or, gNB) after being delayed from the reference time of the RO. At this time, the initial TA value indicated by the RAR received from the base station can indicate the delayed value.

[0156] Furthermore, the common TA can mean the RTD between the gNB (or, reference point) on the ground and the satellite. Here, the reference point can mean a place where the downlink and uplink frame boundaries coincide. And the common TA may be defined as what the base station indicates to the terminal. If the reference point is at the satellite, the common TA may not be indicated. If the reference point is at the gNB on the ground, the common TA may be used for the purpose of compensating for the RTD between the gNB and the satellite.

[0157] Furthermore, in NTN, the TA value before transmitting a message (Msg) 1 (e.g., PRACH preamble) / Msg A (e.g., PRACH preamble and PUSCH) can be set as the terminal-specific TA and the common TA (when provided). Here, the terminal-specific TA may be the RTD between the terminal and the satellite calculated by the terminal alone as described above.

[0158] As an example of the present disclosure, FIG. 8 illustrates a method of calculating a TA value in a wireless communication system supporting NTN.

[0159] Figure 8(a) illustrates a regenerative payload-based NTN scenario. The common TA (Tcom) (common to all terminals) is calculated as 2D0 (distance between the satellite and the reference signal) / c, and the terminal-specific differential TA (TUEx) for the x-th terminal (UEx) may be calculated as 2(D1x - D0) / c. The total TA (Tfull) may be calculated as "Tcom + TUEx". Here, D1x may represent the distance between the satellite and UEx. Here, c represents the speed of light.

[0160] Figure 8(b) illustrates a transparent payload-based NTN scenario. The common TA (Tcom) (common to all terminals) is calculated as 2(D01 + D02) / c, and the terminal-specific differential TA (TUEx) for the x-th terminal (UEx) may be calculated as 2(D1x - D0) / c. The total TA (Tfull) may be calculated as "Tcom + TUEx". Here, D01 represents the distance between the satellite and the reference point, and D02 may represent the distance between the satellite and the base station located on the ground.

[0161] Time reference applied to NTN uplink transmission and reception

[0162] In the present disclosure, an example regarding the time reference related to the uplink transmission of the NTN terminal and the uplink reception of the base station will be described.

[0163] In the present disclosure, the time reference parameter may include a TA (timing advance) parameter. The TA parameter may include a TA command (TAC). Additionally or alternatively, the TA parameter may include one or more of a common TA parameter or a UE-specific TA parameter. That is, unless otherwise specified, in the following description, the TA parameter may include one or more of TAC, the common TA parameter, or the UE-specific TA parameter.

[0164] The terminal can calculate the TA based on one or more of the TAC, common TA parameters, or terminal-specific TA parameters. The terminal can determine the uplink transmission timing based on the calculated TA.

[0165] FIG. 9 is a flowchart for explaining uplink transmission of a terminal according to an embodiment of the present disclosure.

[0166] In step S910, the terminal can receive from the base station the first information regarding the satellite orbit, the second information regarding the common TA, and the third information regarding the TA update period.

[0167] For example, in step S910, the first information, the second information, and the third information can be received by upper layer signaling (e.g., SIB (system information block), RRC signaling, etc.).

[0168] Here, the TA update period can mean the period in which the terminal estimates and calculates the TA value applied to uplink transmission to adjust or update the uplink transmission timing. The TA update period can be determined by various detailed examples of the present disclosure.

[0169] Together with or separately from step S910, the terminal can receive from the base station the setting / indication information for a certain time interval related to the TA update execution. Here, the setting / indication information can include the size of the certain time interval, whether to apply, etc. The setting / indication information can be received by at least one of upper layer signaling (e.g., RRC signaling, MAC CE, etc.) or DCI.

[0170] Matters related to the certain time interval can be determined by various detailed examples of the present disclosure for satisfying the timing error limit related to uplink transmission.

[0171] In step S920, the terminal can calculate a first TA based on the first information and the second information.

[0172] The calculated first TA may be applied to the uplink transmission timing. Applying TA to the uplink transmission timing may include performing adjustment / update on the uplink transmission timing.

[0173] For example, in step S920, the terminal can calculate a terminal-specific TA based on the satellite orbit included in the first information, and calculate the first TA based on the common TA included in the second information and the calculated terminal-specific TA.

[0174] In step S930, the terminal can perform a first uplink transmission based on the calculated first TA.

[0175] For example, according to various detailed examples of the present disclosure, the first uplink transmission is a narrowband-based PRACH preamble transmission, and the PRACH preamble transmission may be repeatedly performed by a preset number.

[0176] In step S940, the terminal can adjust / update the first TA to a second TA at a specific time based on the third information.

[0177] For example, the terminal can check the time point according to the TA update period set by the base station, and apply new TA information (i.e., the second TA) at that time point to adjust / update the uplink transmission timing.

[0178] For example, the update of the first TA to the second TA may be that at least one of the common TA or the terminal-specific TA is updated, and the update period of the common TA may be set shorter than the update period of the terminal-specific TA.

[0179] Matters related to the TA adjustment / update may be determined by various detailed examples of the present disclosure.

[0180] For example, the TA update period is set based on a 2^n value, where n may be a positive integer including 0. Also, when the uplink transmission corresponds to NPRACH preamble transmission, the TA update period is determined by the product of the 2^n value and the PRACH preamble length, and the lengths of the PRACH preambles may be set to be different from each other according to the PRACH preamble format. Further, the TA update period may be set based on the type of satellite orbit.

[0181] In step S950, the terminal can perform a second uplink transmission based on the adjusted / updated second TA.

[0182] Furthermore, the terminal can report to the base station the time reference information adjusted / updated based on the received / acquired time reference parameter. Alternatively, the terminal can also report to the base station a TA parameter determined by the terminal alone (for example, a terminal-specific TA parameter).

[0183] FIG. 10 is a flowchart for explaining uplink reception of a base station according to an embodiment of the present disclosure.

[0184] In step S1010, the base station can transmit to the terminal first information regarding the satellite orbit, second information regarding the common TA, and third information regarding the TA update period.

[0185] In step S1020, the base station can receive from the terminal a first uplink transmission to which a first TA applied based on the first information and the second information is applied.

[0186] In step S1030, the base station can receive from the terminal a second uplink transmission to which a second TA updated at a specific time based on the third information is applied.

[0187] Detailed examples regarding steps S1010 to S1030 are the same as steps S910 to S950 in FIG. 9, and overlapping descriptions thereof are omitted.

[0188] The base station can receive uplink transmissions from the terminal based on the uplink transmission timing based on the TA parameters provided by the base station to the terminal (e.g., TAC and / or common TA parameters) and the TA parameters determined by the terminal alone (e.g., terminal-specific TA parameters).

[0189] In addition, the base station can also receive from the terminal the provision / reporting of information regarding the terminal-specific TA parameters, and can also receive the provision / reporting of information regarding the overall time reference (e.g., TA) to which the terminal-specific TA parameters are applied.

[0190] Hereinafter, detailed examples according to the present disclosure will be described.

[0191] As described above, the NTN service method may also be applied in a radio communication system for LTE NB-IoT and / or LTE eMTC. In the LTE NB-IoT and / or LTE eMTC systems, in uplink transmission, low-cost terminals may be designed to perform retransmission. At this time, when the NTN service is applied, when the terminal performs a large number of retransmissions for uplink transmission, an error with respect to the initially set TA value may accumulate over time.

[0192] FIG. 11 is a diagram for explaining an NPRACH preamble supported by a radio communication system to which the present disclosure is applicable.

[0193] Referring to FIG. 11(a), in the NPRACH format 0 / 1, the NPRACH preamble may be composed of 4 symbol groups. Although not shown in FIG. 11, in the NPRACH format 2, the NPRACH preamble may be composed of 6 symbol groups.

[0194] Referring to FIG. 11(b), the symbol group of NPRACH format 0 / 1 may be composed of one CP (cyclic prefix) and five symbols, and the symbol group of NPRACH format 2 may be composed of one CP and three symbols. Here, NPRACH format 0 / 1 supports an SCS (subcarrier spacing) of 3.75 kHz, and NPRACH format 2 can support an SCS of 1.25 kHz.

[0195] Here, the length of the CP may be expressed as T_CP, and the length of the sequence composed of symbols (i.e., the five symbols of NPRACH format 0 / 1 and the three symbols of NPRACH format 2) may be expressed as T_SEQ. That is, the symbol group constituting the NPRACH preamble may be expressed as the sum of T_CP and T_SEQ, and the NPRACH preamble may be expressed as a multiple of the sum of T_CP and T_SEQ.

[0196] As shown in FIG. 11, in LTE NB-IoT PRACH (i.e., NPRACH), in the FDD situation, the terminal may be set to repeatedly transmit the NPRACH preamble (e.g., 5.6 ms or 6.4 ms depending on the NPRACH preamble format) up to 128 times (i.e., 716.8 ms to 819.2 ms). For example, in relation to LTE NB-IoT PRACH transmission, after transmitting the NPRACH preamble 64 times, a certain time interval (hereinafter referred to as a timing gap) (e.g., 40 ms) may be set / defined, and the frequency / timing drift may be corrected. In this case, at this timing gap, the terminal can receive at least one of DL RS or PSS / SSS to correct the frequency / timing drift.

[0197] However, even if the existing timing gap is utilized, if the typical timing drift rate of LEO considered in the NTN service is 93 us / s, an error of 33.33 us ((64 * 5.6 ms) * 93 us / s) or 38.09 us ((64 * 6.4 ms) * 93 us / s) may occur during the 64 - time repeated transmission of the NPRACH preamble. In this case, there will be a problem that the said error cannot meet the existing required timing error limit (for example, 80 * Ts = 2.6 us).

[0198] Therefore, in order to solve such a problem, an example of introducing a new (i.e., uplink timing gap) timing gap (hereinafter, Example 1), an example of solving it by other methods instead of introducing a new timing gap (hereinafter, Example 2), and a specific setting example when changing the TA for the uplink transmission of the terminal during transmission based on the proposed content (hereinafter, Example 3) will be described below.

[0199] The method related to the RACH procedure described below is related to uplink transmission and may be equally applicable to the downlink signal transmission method in the above - mentioned NR system or LTE system. Also, it goes without saying that it can be deformed or replaced according to the terms, expressions, structures, etc. defined in each system so that the technical idea proposed in this specification can also be implemented in the said system.

[0200] Also, the method proposed in the present invention is described by taking the NPRACH of the LTE NB - IoT system as an example, but it may be similarly applicable to other uplink channels (for example, NPUSCH, NPUCCH, etc.), and may also be applicable to the uplink channels (for example, PRACH, PUSCH, PUCCH, etc.) of the LTE eMTC system.

[0201] Example 1

[0202] A method of introducing a new timing gap separate from the existing one is proposed to meet the timing error limit required for the support of NTN services.

[0203] In this case, the setting / indication method for the period and / or size of the new timing gap, the setting / indication method when the existing timing gap and the new timing gap coexist, the setting / indication method for the presence or absence of the application of the new timing gap, and the setting / indication method for the uplink signal and / or channel for which the introduction of the new timing gap is possible may be considered.

[0204] Example 1-1

[0205] This embodiment relates to a scheme for setting / indicating the period and / or size of a new timing gap in relation to uplink transmission.

[0206] When a new timing gap is introduced, it is necessary to set an appropriate period and / or size for the new timing gap.

[0207] Here, the timing gap can mean a certain time interval during which the terminal can adjust / update the timing for uplink transmission by adjusting / updating the time reference for the uplink (i.e., the TA value). Also, the period of the timing gap can mean the period during which the terminal adjusts / updates the timing for uplink transmission by adjusting the adjustment of the time reference for the uplink (i.e., the TA value).

[0208] At this time, the period of the new timing gap needs to be defined so as to satisfy the timing error limit described above. That is, considering the maximum time that does not exceed the timing error limit and the minimum repetition unit for each signal and / or channel, a repetition number that is smaller than or equal to the maximum time and is the largest is determined, and the new timing gap may be defined as existing after the transmission of the uplink signal and / or channel for the determined number of repetitions is completed.

[0209] In particular, when the determined number of repetitions is larger than the total number of repetitions of the uplink signal and / or channel set / instructed by the base station, the terminal can expect that there is no new timing gap. Or, when the determined number of repetitions is smaller than the total number of repetitions of the uplink signal and / or channel set / instructed by the base station, the terminal can expect that a new timing gap exists after the transmission of the uplink signal and / or channel for the number of repetitions is completed each time. At this time, in NPRACH, it may be set so that a new timing gap exists separately for each preamble repetition number, and in NPUSCH and / or NPUCCH, it may be set so that a new timing gap exists separately by absolute time (for example, the number of subframes, the number of slots, etc.).

[0210] As a specific example, as described above, the typical timing drift ratio of the fastest moving LED among the satellites considered in the NTN service is 93 us / s, and the existing required timing error limit is 2.6 us (that is, 80*Ts). Therefore, the new timing gap may be required to exist at a period smaller than or equal to 27.95 ms (that is, 2.6 us / (93 us / s)).

[0211] However, since it is not necessary to adjust / update the time reference for the uplink (i.e., TA value) too frequently, the period of the timing gap may be as small as or equal to the calculated value and determined in the form of the largest integer value or the largest power of 2, etc. In other words, the period of the timing gap may be expressed in the form of the product of 2^k (k is a positive integer including 0) and a unit of time.

[0212] For example, the period of the timing gap may be expressed in at least one of the forms of 2^k slots, 2^k subframes, 2^k preamble lengths, 2^k RU (Resource Unit) lengths, 2^k (NPRACH) symbol lengths, 2^k (NPRACH) symbol group lengths, where k may be a positive integer including 0.

[0213] Also, in NPRACH, since the preamble is set as the basic unit of repetition, considering the NPRACH preamble size (i.e., preamble length), a new timing gap may be set to exist after the NPRACH preamble is transmitted N times. For example, for NPRACH format 0 / 1, the new timing gap may be set to exist after transmitting the preamble by N * 4 * (T_CP + T_SEQ). Or, for NPRACH format 2, the new timing gap may be set to exist after transmitting the preamble by N * 6 * (T_CP + T_SEQ). That is, since it corresponds to a length of 5.6 ms or 6.4 ms for different NPRACH formats, according to specific calculations (i.e., 27.95 ms / 5.6 ms = 4.9910, 27.95 ms / 6.4 ms = 4.3671), the N may be set to 4.

[0214] Also, in NPUSCH, a single RU is set as the basic unit of repetition. For NPUSCH format 1, in the case of 15 kHz single-tone transmission, a single RU is 8 sub-frames (i.e., 8 ms), and in the case of 15 kHz 12-tone transmission, a single RU is 1 sub-frame (i.e., 1 ms). Therefore, for each case, it may be set such that there is a new timing gap after the single RU of NPUSCH is repeatedly transmitted N times. For example, in the case of 15 kHz single-tone transmission, the new timing gap may be set to exist after the single RU is repeatedly transmitted 3 times (i.e., 27.95 ms / 8 ms = 3.4936, N = 3). In the case of 15 kHz 12-tone transmission, the new timing gap may be set to exist after the single RU is repeatedly transmitted 27 times (i.e., 27.95 ms / 1 ms = 27.95, N = 27).

[0215] Alternatively, since the RU unit of NPUSCH is composed of one or more sub-frames and / or slots, the new timing gap may be defined to exist after an absolute time from the start time of the first transmission. For example, the new timing gap may be defined to exist every 27 ms (i.e., 27 sub-frames or 27 * 30720 Ts) from the time when NPUSCH transmission starts. Characteristically, for the counting from the time when NPUSCH transmission starts to a specific time point, the actually transmitted NPUSCH can be set to be included, and the NPUSCH postponed by NPRACH etc. can also be included.

[0216] In the above example, the typical time drift ratio of LEO is 93 us / s, and it is necessary to consider that this value is applied to each of the feeder link and the service link. Therefore, it is necessary to set the time drift ratio to 196 us / s, which is twice that of 93 us / s, and consider the period of the new timing gap. Thus, the new timing gap may be set to exist at a period smaller than or equal to 13.97 ms (2.6 us / (186 us / s)). Also, the above proposed method can be similarly applied based on this value (i.e., 13.97 ms).

[0217] The size of the new timing gap may be set smaller than the existing timing gap (i.e., the legacy UL timing gap, 40 ms). From the new timing gap, the terminal can estimate and calculate a new TA (i.e., UL TA), and then transmit subsequent uplink signals and / or channels while adjusting the actually applied TA. Or, the terminal can calculate the new TA value in advance before the first transmission and perform an operation to adjust the actual TA applied to the transmission of the uplink signal and / or channel by the new timing gap. Since this operation is different from the PSS / SSS reception operation performed using the existing timing gap, it does not need to be set as large as the existing timing gap. Here, the new timing gap may be set in units of slots, subframes, or absolute time (e.g., ms).

[0218] The above-mentioned period and / or size of the new timing gap may be predefined in a standard specification, and a method of operating assuming that the terminal and the base station have pre-recognized such information with each other may be considered. Alternatively, a method in which the base station sets / indicates information regarding the above-mentioned period and / or size of the new timing gap to the terminal by upper layer signaling (for example, system information block (SIB), RRC signaling, etc.) may also be considered. In this case, the base station can set / indicate such information by a cell-specific method.

[0219] Also, the period and / or size of the new timing gap, etc. may be defined by the orbit type of the satellite. When the orbit type of the serving cell and the orbit type of the neighbor cell are the same or similar, the period and / or size of the new timing gap indicated by the serving cell may be set to be maintained the same in the neighbor cell. That is, when the base station does not set / indicate information regarding the new timing gap for the neighbor cell to the terminal, the terminal can expect that the information regarding the new timing gap for the serving cell is also applied the same in the neighbor cell.

[0220] When the terminal is configured / instructed by the base station to use a new timing gap, the terminal may be configured to adjust / update the TA for each timing gap and apply the TA to the subsequent uplink signal and / or channel transmission. When the terminal is not configured / instructed by the base station to use a new timing gap, or the size of the new timing gap is set / instructed to be 0 (or an invalid value), or the period of the new timing gap is set / instructed to be infinite (or an invalid value), the terminal may be configured to perform the existing LTE NB-IoT / eMTC operation (i.e., the operation of not adjusting / updating the TA during the repeated transmission of the uplink signal and / or channel). Or, in these cases, the terminal may be configured to adjust / update the TA using only the existing timing gap.

[0221] Also, the size of the new timing gap may be set to vary depending on the size of the TA. That is, if the TA value is large, the size of the new timing gap may also be set large, and if the TA value is small, the size of the new timing gap may also be set small. Here, the size of the TA can mean the size of the overall TA calculated by summing the terminal-specific TA and the common TA, etc., or the size of each TA (i.e., the terminal-specific TA, the common TA).

[0222] Or, the size of the new timing gap may be set to vary over time. For example, in addition to the size of the new timing gap, the base station can set / instruct information regarding the reduction rate and / or the increase rate that can vary over time. Here, the reduction rate and / or the increase rate may be configured as a linear function and / or a polynomial function of degree two or higher. The terminal may be configured to determine the size of the new timing gap that varies over time based on the configured / instructed information and adjust / update the TA using the new timing gap during the transmission of the uplink signal and / or channel.

[0223] Example 1-2

[0224] This embodiment relates to the coexistence or non - coexistence of an existing timing gap and a new timing gap in relation to uplink transmission.

[0225] In an existing LTE NB - IoT system, a timing gap (i.e., the existing timing gap) is defined for a terminal to receive DL RS or PSS / SSS, etc. during the transmission of an uplink signal and / or channel to correct frequency drift and / or time drift. For example, the existing timing gap (e.g., a 40 - ms uplink timing gap) is set to exist after the preamble is transmitted 64 times for NPRACH format 0 / 1, and for NPRACH format 2, it is set to exist after the preamble is transmitted 16 times. That is, in NPRACH format 0, the existing timing gap exists every 358.4 ms (5.6 ms * 64) after preamble transmission, and in NPRACH format 1, it is set to exist every 409.6 ms (6.4 ms * 64) after preamble transmission. Also, in NPUSCH, the existing timing gap is set to exist every 256 ms regardless of the NPUSCH format.

[0226] Basically, even if a new timing gap is introduced, the existing timing gap may need to be maintained. That is, two timing gaps with different purposes can coexist.

[0227] When two timing gaps coexist, as described above, the two timing gaps may be defined to be used for different purposes from each other. In this case, even when the terminal performs uplink transmission after the existing timing gap, it is preferable that the TA be adjusted / updated. That is, the terminal performs an operation newly introduced with the new timing gap (i.e., an operation of adjusting / updating the TA and applying it to uplink transmission), and is set to perform the existing operation (i.e., an operation of receiving DL RS or PSS / SSS, etc. to correct frequency / time drift) and the newly introduced operation (i.e., an operation of adjusting / updating the TA and applying it to uplink transmission) with the existing timing gap simultaneously or sequentially. In the event that the size of the existing timing gap is insufficient to perform the newly introduced operation after performing the existing operation, at least one of before, after, or in the middle of the existing timing gap may be added with the new timing gap, and the terminal may be set to also perform the newly introduced operation.

[0228] Also, in a special case (for example, when the network supports services only for NTN-capable terminals), the base station may be set to set / indicate information regarding the use or non-use of the existing timing gap to the terminal. That is, when the terminal operation performed with the existing timing gap can be replaced by the terminal operation performed with the new timing gap, the existing timing gap may be set not to be used in the cell.

[0229] Example 1-3

[0230] This embodiment relates to a scheme for adaptively setting / indicating the use or non-use of a new timing gap in relation to uplink transmission.

[0231] Even when the base station sets / indicates to the terminal to use the new timing gap, it can be further set / indicated to the terminal whether the timing gap always exists.

[0232] If the base station uses upper layer signaling (e.g., SIB, RRC signaling, etc.) to instruct the terminal about the period, size, or presence / absence of use of a new timing gap, etc., a new timing gap of the corresponding size may be set / defined to always exist according to the period.

[0233] On the other hand, even when the base station uses upper layer signaling (e.g., SIB, RRC signaling, etc.) to instruct the terminal about the period, size, or presence / absence of use of a new timing gap, etc., the base station can also instruct the terminal to continue uplink transmission without applying a new timing gap (i.e., without adjusting / updating the TA) for a specific reason before the actual existence of the timing gap. That is, the base station can instruct the terminal to skip the new timing gap. Here, the specific reason may include cases where, when the base station receives an uplink signal and / or channel, the delay caused by the timing gap is more than expected, and the base station determines that it can receive the uplink transmission without changing the TA value applied by the terminal for the uplink transmission.

[0234] As one method of dynamically scheduling so as not to apply a new timing gap, a method of transmitting a PDCCH (i.e., DCI) or a WUS (Wake Up Signal) etc. before a point in time when a new timing gap may exist to indicate the presence or absence (or skip) of application of the new timing gap may be considered. Here, considering DCI, the DCI may correspond to a UE group specific DCI such as a paging DCI. Also, since DCI monitoring during the transmission of an uplink signal and / or channel may or may not be possible depending on the capabilities of the terminal (e.g., FDD (frequency division duplex), HD (half duplex)-FDD, etc.), the operation may be indicated specific to the UE capability (or specific to the terminal).

[0235] Also, a method of dynamically changing the size of the new timing gap according to the needs of the base station may be considered. That is, the base station has instructed to use a new timing gap so that the terminal can transmit an uplink signal and / or channel by applying an accurate TA. However, if this causes the reception of the uplink signal and / or channel to be not smooth for the base station, the base station can reset the period, size, etc. of the new timing gap.

[0236] For example, the base station can reset the period, size, etc. of the timing gap used at the time of subsequent uplink signal and / or channel transmission using upper layer signaling and / or MAC CE. In the case of the RACH procedure, the base station can indicate the above reset parameters in msg.2 / 4 or msg.B, and can also indicate the above reset parameters using a retransmission DCI format etc. In the case of PUSCH, the base station can also indicate the above reset parameters using a DCI format for scheduling the uplink etc.

[0237] In the proposed method described above, since the terminal may miss the DCI transmitted from the base station, ambiguity may occur regarding the presence or absence of a new timing gap due to this. Therefore, when dynamically indicating the presence or absence of the operation of a new timing gap using the above-described DCI or the like, the terminal may be set to receive the DCI and transmit a HARQ-ACK for the reception of the DCI to the base station. Alternatively, although the base station dynamically instructs the terminal to use a new timing gap using DCI or the like, in case the terminal misses the DCI, the base station may be set to detect whether the terminal is transmitting an uplink signal and / or channel in the new timing gap. In the unlikely event that the base station determines that the terminal continues to transmit an uplink signal and / or channel even in the new timing gap, the base station can be set to instruct to interrupt the transmission of the uplink signal and / or channel in advance.

[0238] Alternatively, when the terminal misses the DCI (or when there is no separate instruction in the DCI), the terminal can assume that it uses the new timing gap as the default. At this time, the base station may be set to retransmit the DCI in the new timing gap in case the terminal may miss the DCI. In addition to this, the terminal may be set to further monitor a specific search space or a specific DCI in the new timing gap.

[0239] In NPRACH repeated transmission, it may be necessary to distinguish and set CFRA (contention free random access) and CBRA (contention based random access).

[0240] For example, in CFRA (e.g., NPDCCH order RACH procedure, etc.), when combined, the base station adds a specific field for the presence or absence of a new timing gap using a DCI format, and can dynamically set / indicate the presence or absence of such a setting to the terminal. That is, even when the presence or absence of a new timing gap is semi-statically set for the terminal by upper layer signaling (e.g., SIB, RRC signaling, etc.), the base station can dynamically newly set / indicate the presence or absence of a new timing gap to the terminal using the DCI format that indicates the NPDCCH order. Even when there is no field indicating the presence or absence of a new timing gap in the DCI format, the terminal can be set to follow the content set using existing upper layer signaling (e.g., SIB, RRC signaling, etc.).

[0241] As another example, in CBRA (e.g., initial connection RACH procedure, etc.), the base station can semi-statically set the presence or absence of a new timing gap using upper layer signaling (e.g., SIB, RRC signaling, etc.).

[0242] Also, when NPRACH preamble retransmission is applied, the base station can dynamically set the presence or absence of a new timing gap using the DCI format.

[0243] Example 1-4

[0244] This embodiment relates to the presence or absence of support for a specific uplink signal and / or channel format in relation to a new timing gap for uplink transmission.

[0245] Among the uplink signals and / or channels described above (e.g., NPRACH, NPUSCH, NPUCCH, etc.), the case of NPUSCH will be described.

[0246] For example, in the case of 3.75 kHz single-tone transmission in NPUSCH format 1, a single RU corresponds to 16 slots. Since the length of a single slot of 3.75 kHz is 2 ms (0.5 ms * 4), which is 4 times longer than the length of a single slot of 15 kHz, the length of a single RU is 32 ms. In this case, since the total time for transmitting a single RU is greater than the maximum time (e.g., 27.95 ms) that does not exceed the timing error limit calculated previously, the new timing gap may be set to exist in the middle of (or be introduced during) the single RU transmission.

[0247] For example, it may be set such that a new timing gap exists every 8 slots (i.e., 16 ms) of 3.75 kHz. That is, not only may a new timing gap exist for each repetition transmission, but it may also be set such that a new timing gap exists after a specific position of the RU for each repetition transmission (e.g., the position where half a slot has been transmitted). As another example, it may be set such that a new timing gap exists every 13 slots (i.e., 26 ms) of 3.75 kHz. In this case, regardless of the number of repetition transmissions, it may be set such that a new timing gap exists after transmitting only a specific number of slots (e.g., a total of 13 slots).

[0248] For uplink signals and / or channels, etc., uplink signals and / or channels (e.g., NPRACH / NPUSCH / NPUCCH formats, etc.) that are longer than the maximum time (e.g., 27.95 ms) that a single transmission unit does not exceed the timing error limit calculated previously can be set not to be supported in IoT NTN. In other words, it can be set that only uplink signals and / or channels (e.g., NPRACH / NPUSCH / NPUCCH formats, etc.) for which a new timing gap may exist after transmitting at least one single transmission unit are serviced by IoT NTN. Or, the base station can configure / indicate to the terminal using upper layer signaling (e.g., SIB, RRC signaling, etc.) information regarding whether the network serving NTN supports the formats of the specific uplink signals and / or channels described above.

[0249] Example 2

[0250] Different from the method described above, without introducing a new timing gap, the time during which the terminal can adjust / update the TA (i.e., UL TA) by other methods described below may be guaranteed.

[0251] Example 2-1

[0252] This embodiment relates to a scheme of dropping, puncturing, postponing, and / or rate-matching a part of the uplink signal and / or channel for TA adjustment / update of the terminal.

[0253] In case, in a situation where no explicit uplink timing gap is introduced, the operation of the terminal adjusting / updating the TA without applying methods such as dropping, puncturing, or postponing a part of the uplink signal and / or channel is applied, problems such as those in FIG. 12 may occur.

[0254] FIG. 12 is a diagram for explaining uplink transmission supported by a wireless communication system to which the present disclosure is applicable. In FIG. 12, it is assumed that a terminal repeatedly transmits an NRPACH preamble.

[0255] FIG. 12(a) shows an example of an existing terminal repeatedly transmitting an NPRACH preamble. FIG. 12(b) shows an example of a case where a terminal is set to adjust / update the TA during the transmission of an uplink signal and / or channel without an uplink timing gap.

[0256] Referring to FIG. 12(b), in the case of a terminal performing single tone transmission (e.g., NPRACH, NPUSCH, NPUCCH, etc.), if the terminal is set to adjust / update the TA at the (N + 1)-th repeated transmission (i.e., the N-th repeated transmission) after N repeated transmissions (i.e., the (N - 1)-th repeated transmission) without a timing gap, the terminal may have to perform multi tone transmission at a specific time. In NB-IoT, single tone transmission is a mandatory feature for the uplink transmission of a terminal, and multi tone transmission is an optional feature. Therefore, a terminal that cannot perform multi tone transmission cannot perform the operation as shown in FIG. 12(b). In particular, for uplink signals and / or channels (e.g., NPRACH, NPUSCH, NPUCCH, etc.) required in the initial access process, since all terminals need to be set to operate normally, a solution to this problem needs to be considered.

[0257] Therefore, a part of the uplink signal and / or channel may be dropped, punctured, delayed, and / or rate-matched so that the terminal adjusts / updates the TA (i.e., UL TA) at that time, or the TA is recalculated and adjusted / updated.

[0258] In NPRACH, the NPRACH preamble is composed of multiple symbol groups, and each symbol group is composed of a CP and multiple symbols. Therefore, when the terminal is set to adjust / update the TA when transmitting an NPRACH preamble corresponding to a specific number of repetitions (e.g., N) according to a preset / indicated period, the following methods of dropping, puncturing, delaying, and / or rate matching specific parts may be considered as shown in FIG. 13 below.

[0259] FIG. 13 is a diagram for explaining the processing for a certain part of the uplink transmission supported by a wireless communication system to which the present disclosure is applicable.

[0260] FIG. 13(a) shows an example of the processing at the NPRACH preamble level in relation to uplink transmission. Referring to FIG. 13(a), in order to prevent the terminal from transmitting multiple tones, the NPRACH preamble may be set / defined to be dropped, punctured, delayed, and / or rate matched.

[0261] For example, the above-mentioned specific part may be the (N - 1)-th NPRACH preamble or M NPRACH preambles prior to the (N - 1)-th NPRACH preamble including the (N - 1)-th NPRACH preamble. In this case, since there is a time during which the terminal can adjust / update the TA by one or more NPRACH preamble lengths, the terminal may receive GNSS signaling, etc. during this time, newly calculate the TA, and be set to newly apply the TA for the transmission of subsequent preambles.

[0262] FIG. 13(b) shows an example of the processing at the symbol group level of the NPRACH preamble in relation to uplink transmission. Referring to FIG. 13(b), in order to prevent the terminal from transmitting multiple tones, the NPRACH symbol group may be set / defined to be dropped, punctured, delayed, and / or rate matched.

[0263] For example, the above-mentioned specific part may be the last NPRACH symbol group among the N-1th NPRACH preambles, or M NPRACH symbol groups prior to that including the last NPRACH symbol group. In this case, there is a time period of one or more NRPACH symbol lengths during which the terminal can adjust / update the TA. Thus, the terminal can newly calculate the TA using information such as GNSS signaling it has already received during this time period, and may be set to newly apply the TA for subsequent preamble transmissions.

[0264] FIG. 13(c) shows an illustration of symbol-level processing of symbol groups constituting an NPRACH preamble in relation to uplink transmission. Referring to FIG. 13(c), the NPRACH symbols may be set / defined to be dropped, punctured, delayed, and / or rate-matched to prevent multi-tone transmission by the terminal.

[0265] For example, the above-mentioned specific part may be the last NPRACH symbol in the last NPRACH symbol group of the N-1th NPRACH preamble, or M NPRACH symbols prior to that including the last NPRACH symbol. In this case, there is a time period of one or more NRPACH symbol lengths during which the terminal can adjust / update the TA. Thus, the terminal can pre-calculate the TA to be changed in advance during this time period, and may be set to newly apply the TA for subsequent preamble transmissions. That is, the terminal may receive a setting / indication of the number of iterations for changing the TA from the base station, pre-calculate the TA value to be changed before the first transmission, and then be set to adjust / update the TA at the above-mentioned specific time.

[0266] As another example, the above-mentioned specific part may be set in units of absolute time, subframe, slot, or OFDM symbol. That is, it may be set to X ms, Y subframes, Z slots, or K OFDM symbols immediately before the Nth NPRACH preamble, and the terminal may be set to adjust / update TA at the time.

[0267] The above-mentioned N value, M value, and / or X, Y, Z, K, etc. can be set to those defined and recognized in advance between the terminal and the base station, and the base station may be set to appropriately set / instruct the terminal with the information as needed. In this case, the information may be transmitted by at least one of upper layer signaling (e.g., SIB, RRC signaling, etc.) and / or dynamic signaling (e.g., DCI, MAC CE, etc.).

[0268] Also, in the case of (N)PUSCH and / or (N)PUCCH, etc., similar to the above-mentioned method, methods such as dropping, puncturing, delaying, or rate matching at the subframe level, slot level, or OFDM symbol level may be considered. However, in this case, since the terminal can recognize in advance which part needs to adjust / update TA based on the base station setting / instructions or pre-defined information, etc., it may be a suitable method for the terminal to perform rate matching on the part and perform uplink transmission. For example, when it is pre-set / instructed to empty only K OFDM symbols immediately before the Nth (N)PUSCH and / or (N)PUCCH transmission, the terminal may be set to perform rate matching except for the K OFDM symbols and transmit (N)PUSCH and / or (N)PUCCH, etc.

[0269] Example 2-2

[0270] This embodiment relates to a solution for setting / instructing to support different operations according to the UE capability in relation to the TA adjustment / update of the terminal.

[0271] The method proposed in the above-described Embodiment 2-1 can be set for terminals that do not support multi-tone transmission and can be set to be applicable regardless of terminal capabilities. However, for terminals that support multi-tone transmission, when operating in the above-described method, although all can be transmitted, some of the specific uplink signals and / or channels cannot be transmitted.

[0272] Therefore, a method of setting so that the above-described method can be performed according to terminal capability information may be considered. That is, a terminal capable of only single-tone transmission may be set to drop, puncture, delay, or rate-match some of the specific uplink signals and / or channels as described above. On the other hand, a terminal capable of multi-tone transmission may be set not to apply the above-described method and to adjust / update the TA during uplink transmission to perform multi-tone transmission in some sections. At this time, considering the section in which multi-tone transmission is performed, adjustment of the transmission power of the terminal may be necessary. That is, it is necessary to divide and apply the transmission power that was applied to all single tones to multi-tones.

[0273] In the NPRACH where only single-tone transmission is performed, as described above, a method of classifying operations according to terminal capabilities may be applied. However, for (N)PUSCH and / or (N)PUCCH etc. where single-tone transmission and / or multi-tone transmission may be performed separately for each terminal, based on at least one of the type of the scheduled uplink channel, the number of frequency resources of the currently scheduled uplink resource (for example, the number of subcarriers), or terminal capabilities, the base station can set / indicate to the terminal whether to use the above-described proposed method (for example, drop, puncture, delay, or rate-match for a certain part).

[0274] Example 3

[0275] The following describes a detailed setting / indication method for adjusting / updating TA during the transmission of an uplink signal and / or channel.

[0276] Example 3-1

[0277] This embodiment relates to the type of TA that can be adjusted / updated during the transmission of an uplink signal and / or channel.

[0278] Among the TA values considered in NTN, at least one of the UE-specific TA or common TA may be set to be adjusted / updated during uplink transmission. Here, the UE-specific TA may be a TA for compensating the RTT (Round Trip Time) between the UE and the satellite. The common TA may be a TA for compensating the RTT between a reference point and the satellite.

[0279] A scheme where only the UE-specific TA that the terminal can measure and adjust / update is adjusted / updated during uplink transmission may also be considered. However, since the base station can track the common TA and can indicate common TA parameters (e.g., common TA series, common TA drift ratio, etc.), the common TA can also be set to be adjusted / updated together.

[0280] Also, the N_TA that is adjusted / updated as indicated by the TAC (TA command) of the Random Access Response (RAR) message and / or MAC CE used in the existing NR can also be set to be adjusted / updated during uplink transmission. For example, when the terminal attempts to adjust / update the TA during the transmission of an uplink signal and / or channel, the base station can be set to pre-indicate the TAC of the RAR message and / or MAC CE to adjust / upate the N_TA.

[0281] The terminal may be set to adjust / update the TA using the following method.

[0282] First, based on the TA adjustment / update related parameter values set / indicated by the base station, the terminal may be set to adjust / update each TA. For example, the common TA may be adjusted / updated based on the common TA drift ratio set / indicated by the base station, etc., and the terminal-specific TA may be adjusted / updated based on the terminal-specific TA drift ratio set / indicated by the base station, etc. Here, the terminal-specific TA drift ratio can be a parameter that the base station calculates in advance how the terminal-specific TA changes and transmits to the terminal in consideration of the satellite orbit information based on the terminal-specific TA value reported by the terminal (or based on a specific position of the cell (e.g., cell center)) under the assumption that the IoT terminal does not move significantly.

[0283] Next, based on the TA adjustment / update related parameter values set / indicated by the base station and / or the values obtained by the terminal alone, the terminal may be set to adjust / update each TA. For example, the common TA may be adjusted / updated based on the common TA drift ratio set / indicated by the base station, etc., and the terminal-specific TA may be adjusted / updated based on GNSS signaling and the satellite orbit information set / indicated by the base station.

[0284] For example, when the base station indicates the terminal-specific TA drift ratio, it can be set to operate as in the first method described above, while when the base station does not indicate the terminal-specific TA drift ratio, it can be set to operate as in the second method described above.

[0285] Also, when adjusting / updating the TA during repeated transmission of the uplink signal and / or channel, a method of setting the periods for adjusting / updating each TA to be different from each other may also be considered.

[0286] For example, the common TA may be set to be adjusted / updated at a relatively shorter period. That is, the common TA may be set to be adjusted / updated at the above-described new timing gap (or at the time created by puncturing a specific signal and / or channel) (and / or even at the existing timing gap). For example, the UE-specific TA may be set to be adjusted / updated at a relatively longer period. That is, the UE-specific TA may be set to be adjusted / updated only at the existing timing gap. In other words, the update period of the common TA may be set shorter than the update period of the UE-specific TA.

[0287] Example 3-2

[0288] This embodiment relates to a solution for setting / indicating whether TA adjustment / update is performed during the transmission of uplink signals and / or channels according to the type of satellite.

[0289] The types of satellites considered in NTN may include at least one of a satellite type that changes rapidly over time (e.g., LEO, MEO, etc.) or a satellite type that appears to be fixed even as time changes (e.g., GEO, etc.). Therefore, the base station needs to transmit information to the UE regarding whether to perform TA adjustment / update during the transmission of uplink signals and / or channels depending on which satellite is used to provide NTN services.

[0290] Therefore, whether to perform TA adjustment / update during the transmission of the uplink signal and / or channel can be set to be broadcast in a cell-specific manner. Specifically, as an explicit method, an indication parameter may be introduced into the upper layer signaling (e.g., SIB, RRC signaling, etc.) to adjust / update the TA during the transmission of the uplink signal and / or channel. As an implicit method, the base station can indicate whether to indicate a new timing gap, or to drop, puncture, delay, or rate-match a specific part of the uplink signal and / or channel, so as to instruct the terminal to adjust / update the TA during the transmission of the uplink signal and / or channel.

[0291] In the present disclosure, the above-described method has been described mainly with respect to LTE NB-IoT, but it may be similarly set / applied in LTE eMTC and / or NR REDCAP (reduced capability), etc.

[0292] An example of the above-described method can also be included as one of the implementation methods of the present disclosure, so it is obvious that it can be regarded as a kind of proposed method. Also, the above-described method may be implemented independently, or may be implemented in the form of a combination (or merger) of some methods. The information on whether to apply the above-described method (or the information on the rules of the above-described method) may be defined such that the base station notifies the terminal by pre-defined signaling (e.g., physical layer signaling and / or upper layer signaling). For example, the upper layer may include one or more of the functional layers such as MAC, RLC, PDCP, RRC, and SDAP.

[0293] Also, the method proposed in this specification may be extended and applied to the technology for estimating the exact position of the terminal.

[0294] FIG. 14 is a diagram for explaining a signaling process according to an embodiment of the present disclosure.

[0295] FIG. 14 shows an example of signaling between the network side (or base station) and the terminal (UE) in the NTN transmission situation of one or more physical channels / signals to which the examples of the present disclosure described above (for example, Examples 1, 2, 3, and one or more combinations of the examples described in the detailed examples thereof) can be applied.

[0296] Here, the UE / network side is exemplary, and as described with reference to FIG. 15, it can also be applied by replacing it with various devices. FIG. 14 is for convenience of explanation and does not limit the scope of the present disclosure. Also, some steps shown in FIG. 14 may be omitted depending on the situation and / or settings, etc. Also, in the operation of the network side / UE in FIG. 14, the uplink transmission / reception operation described above may be referred to or utilized.

[0297] In the following description, the network side may be one base station including a plurality of TRPs, or may be one cell including a plurality of TRPs. Alternatively, the network side may include a plurality of RRHs (remote radio heads) / RRUs (remote radio units). For example, an ideal / non-ideal backhaul may be set between TRP1 and TRP2 constituting the network side. Also, although the following description is made based on a plurality of TRPs, this may be equally extended and applied to transmission using a plurality of panels / cells, and may also be extended and applied to transmission using a plurality of RRHs / RRUs, etc.

[0298] Also, in the following description, it is described based on "TRP". However, as described above, "TRP" may be rephrased as expressions such as panel, antenna array, cell (e.g., macro cell / small cell / pico cell, etc.), TP (transmission point), base station (gNB, etc.). As described above, TRP may be classified by information regarding the CORESET group (or CORESET pool) (e.g., CORESET index, ID). For example, when one terminal is set to perform transmission and reception with a plurality of TRPs (or cells), this may mean that a plurality of CORESET groups (or CORESET pools) are set for one terminal. The setting for such a CORESET group (or CORESET pool) may be performed by upper layer signaling (e.g., RRC signaling, etc.).

[0299] Also, the base station may be a general term for an object that performs data transmission and reception with a terminal. For example, the base station may be a concept including one or more TPs (Transmission Points), one or more TRPs (Transmission and Reception Points), etc. Also, the TP and / or TRP may include a panel of the base station, a transmission and reception unit, etc.

[0300] The terminal can receive configuration information from the base station (S105). For example, the configuration information may include the NTN-related configuration information / configuration information for uplink transmission and reception (e.g., PUCCH-config / PUSCH-config) / HARQ process-related configuration (e.g., HARQ feedback enable / disable / number of HARQ processes, etc.) / CSI report-related configuration (e.g., CSI report setting / config / CSI report quantity / CSI-RS resource config, etc.) described in the above embodiments (e.g., one or more combinations of the examples described in Embodiments 1, 2, 3, and their detailed embodiments). For example, the configuration information may include information related to the satellite's orbital information, setting / indication of parameters with respect to the terminal's time reference, setting / indication of the adjustment / update period according to the terminal's time reference, setting information related to the terminal's parameter application and uplink transmission according to the time reference, reporting with respect to the adjusted / updated time reference value, etc. For example, the configuration information may be transmitted by upper layer (e.g., SIB, RRC, or MAC CE) signaling.

[0301] For example, the operation of the terminal (100 or 200 in FIG. 15) receiving the configuration information from the base station (200 or 100 in FIG. 15) in the above-described S105 step may be implemented by the apparatus in FIG. 15 described below. For example, referring to FIG. 15, one or more processors 102 can control one or more transceivers 106 and / or one or more memories 104 to receive the configuration information, and one or more transceivers 106 can receive the configuration information from the network side.

[0302] The terminal can receive control information from the base station (S110). For example, the control information may include information related to settings / instructions regarding the update / reporting / application of the time reference adjustment value of the terminal. For example, the control information may include settings / instructions related to the reception of common TA parameters or the acquisition of terminal-specific TA parameters, the application of TA parameters, BWP change, scheduling information for uplink transmission, etc.

[0303] For example, the operation of the UE (100 or 200 in FIG. 15) receiving the control information from the base station (200 or 100 in FIG. 15) in the above-described S110 step may be implemented by the device in FIG. 15 described below. For example, referring to FIG. 15, one or more processors 102 can control one or more transceivers 106 and / or one or more memories 104 to receive the control information, and one or more transceivers 106 can receive the control information from the base station.

[0304] The terminal can transmit uplink data / channel to the base station (S115). For example, the terminal can transmit uplink data / channel to the base station based on the above-described embodiments (e.g., one or more combinations of the examples described in Embodiments 1, 2, 3, and their detailed embodiments). For example, the terminal can determine the uplink transmission timing based on one or more of the common TA parameters or the terminal-specific TA parameters, and transmit the uplink signal / channel to the base station according to the determined uplink transmission timing.

[0305] For example, the operation of the terminal (100 or 200 in FIG. 15) transmitting the uplink data / channel in the above-described S115 step may be implemented by the device in FIG. 15 described below. For example, referring to FIG. 15, one or more processors 102 can control one or more memories 104 to transmit the uplink data / channel.

[0306] As mentioned above, the signaling and examples of the base station / terminal described above (for example, one or more combinations of the exemplifications described in Examples 1, 2, 3, and their detailed examples) may be implemented by the apparatus described with reference to FIG. 15. For example, the base station may correspond to the first device 100, and the terminal may correspond to the second device 200, and vice versa may also be considered in some cases.

[0307] For example, the signaling and operations of the base station / terminal described above (for example, one or more combinations of the exemplifications described in Examples 1, 2, 3, and their detailed examples) may be processed by one or more processors (for example, 102, 202) in FIG. 15, and the signaling and operations of the base station / terminal described above (for example, one or more combinations of the exemplifications described in Examples 1, 2, 3, and their detailed examples) may be stored in a memory (for example, one or more memories (for example, 104, 204) in FIG. 15) in the form of instruction words / programs (for example, instruction, executable code) for driving at least one processor (for example, 102, 202) in FIG. 15.

[0308] General devices applicable to the present disclosure

[0309] FIG. 15 is a block configuration diagram illustrating a wireless communication apparatus according to an embodiment of the present disclosure.

[0310] Referring to FIG. 15, the first device 100 and the second device 200 can transmit and receive wireless signals using various wireless connection technologies (for example, LTE, NR).

[0311] The first device 100 includes one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 controls the memory 104 and / or the transceiver 106 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this disclosure. For example, after the processor 102 processes the information in the memory 104 to generate a first information / signal, it may transmit a wireless signal including the first information / signal from the transceiver 106. Also, after the processor 102 receives a wireless signal including a second information / signal from the transceiver 106, it can store the information obtained from the signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and can store various information related to the operation of the processor 102. For example, the memory 104 can store software code including instructions to perform part or all of the processes controlled by the processor 102 or to execute the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless communication technologies (e.g., LTE, NR). The transceiver 106 may be connected to the processor 102 and can transmit and / or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be alternatively referred to as an RF (Radio Frequency) unit. In this disclosure, the device may mean a communication modem / circuit / chip.

[0312] The second device 200 includes one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 controls the memory 204 and / or the transceiver 206, and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure. For example, after processing the information in the memory 204 to generate third information / signals, the processor 202 may transmit a wireless signal including the third information / signals from the transceiver 206. Also, after receiving a wireless signal including fourth information / signals from the transceiver 206, the processor 202 can store the information obtained from the signal processing of the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202 and can store various information related to the operation of the processor 202. For example, the memory 204 can store software code including instructions for performing part or all of the processes controlled by the processor 202 or for executing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless communication technologies (e.g., LTE, NR). The transceiver 206 may be connected to the processor 202 and can transmit and / or receive wireless signals via one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be alternatively referred to as an RF unit. In the present disclosure, the device may mean a communication modem / circuit / chip.

[0313] Hereinafter, the hardware elements of devices 100 and 200 will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors 102 and 202. For example, one or more processors 102 and 202 can implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors 102 and 202 can generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) according to the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure. One or more processors 102 and 202 can generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure. One or more processors 102 and 202 can generate a signal (e.g., a baseband signal) including a PDU, an SDU, a message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in the present disclosure, and provide it to one or more transceivers 106 and 206. One or more processors 102 and 202 can receive a signal (e.g., a baseband signal) from one or more transceivers 106 and 206, and obtain a PDU, an SDU, a message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure.

[0314] One or more processors 102, 202 can be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors 102, 202 may be embodied by hardware, firmware, software, or a combination thereof. As an example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102, 202. The descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this disclosure may be embodied using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. The firmware or software configured to execute the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this disclosure may be included in one or more processors 102, 202, stored in one or more memories 104, 204, and driven by one or more processors 102, 202. The descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this disclosure may be embodied by firmware or software in the form of code, instruction words, and / or a set of instruction words.

[0315] One or more memories 104, 204 may be coupled to one or more processors 102, 202 and can store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories 104, 204 may be constituted by a ROM, a RAM, an EPROM, a flash memory, a hard drive, a register, a cache memory, a computer-readable storage medium, and / or a combination thereof. The one or more memories 104, 204 may be located inside and / or outside the one or more processors 102, 202. Also, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 by various techniques such as wired or wireless connections.

[0316] One or more transceivers 106, 206 can transmit user data, control information, radio signals / channels, etc. mentioned in the methods and / or operation sequence diagrams of the present disclosure to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, radio signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and can transmit and receive radio signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or radio signals to one or more other devices. Also, one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information, or radio signals from one or more other devices. Also, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, radio signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in the present disclosure via one or more antennas 108, 208. In the present disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received radio signals / channels, etc. from RF band signals to baseband signals in order to process received user data, control information, radio signals / channels, etc. using one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, radio signals / channels, etc. processed using one or more processors 102, 202 from baseband signals to RF band signals. For this purpose, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0317] The embodiments described above are those in which the components and features of the present disclosure are combined in a predetermined form. Each component or feature should be considered as optional unless otherwise explicitly stated. Each component or feature may be implemented in a form that does not combine with other components or features. It is also possible to combine some components and / or features to form embodiments of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in other embodiments, or may be replaced by corresponding components or features of other embodiments. It is obvious that claims without an explicit citation relationship in the claims can be combined to form embodiments, or can be included as new claims by amendment after filing.

[0318] It is obvious to those skilled in the art that the present disclosure can be embodied in other specific forms without departing from the essential features of the present disclosure. Therefore, the above detailed description should not be construed in any way as restrictive, but should be considered as exemplary. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and any changes within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0319] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that cause the operations of various example methods to be executed on a device or computer, and non-transitory computer-readable media on which such software or instructions are stored and executable on a device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure may be stored on or in a storage medium or computer-readable storage medium, and the features described in the present disclosure may be implemented using a computer program product including such a storage medium. The storage medium can include, but is not limited to, high-speed random access memory such as DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, and may include non-volatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory may optionally include one or more storage devices located remotely from the processor. The memory or, alternatively, the non-volatile memory device within the memory includes a non-transitory computer-readable storage medium. The features described in the present disclosure may be stored on any one of the machine-readable media, control the hardware of the processing system, and be integrated with software and / or firmware that enables the processing system to interact with other mechanisms that utilize the results according to the embodiments of the present disclosure. Such software or firmware can include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0320] Here, the wireless communication technology implemented in the devices 100 and 200 of the present disclosure may include, in addition to LTE, NR, and 6G, Narrowband Internet of Things (NB-IoT) for low-power communication. At this time, for example, the NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-mentioned names. Additionally or alternatively, the wireless communication technology implemented in the devices 100 and 200 of the present disclosure can communicate based on LTE-M technology. At this time, as an example, the LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, the LTE-M technology may be implemented by at least any one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-mentioned names. Additionally or alternatively, the wireless communication technology implemented in the devices 100 and 200 of the present disclosure may include at least any one of ZigBee (registered trademark), Bluetooth (registered trademark), and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-mentioned names. As an example, the ZigBee technology can generate PAN (personal area networks) related to small / low-power digital communication based on various standards such as IEEE 802.15.4 and may be called by various names.

Industrial Applicability

[0321] The method proposed in this disclosure has been mainly described with examples applied to 3GPP LTE / LTE-A and 5G systems, but it is also applicable to various wireless communication systems other than 3GPP LTE / LTE-A and 5G systems.

Claims

1. Receiving first information for a satellite orbit, second information for a common Timing Advance (TA) value, and third information related to a specific unit for TA adjustment; Performing uplink transmission including a narrowband physical random access channel by applying a TA value based on the first information for the satellite orbit and the second information for the common TA value; Adjustment related to the TA value is performed based on the specific unit; The specific unit is the product of a 2^n value and the length of a random access preamble, where n is a positive integer including 0. A method.

2. The method according to claim 1, wherein the third information is received by a system information block.

3. The method according to claim 1, wherein the specific unit is set based on the type of the satellite orbit.

4. The method according to claim 1, wherein the TA value is calculated based on the common TA value and a UE-specific TA value calculated by a user equipment (UE) based on the satellite orbit.

5. The adjustment is set to be performed within a preset time interval based on the specific unit; The preset time interval is set based on at least one of the common TA value and the UE-specific TA value. The method according to claim 4.

6. At least one of applying the preset time interval or applying the size of the preset time interval is indicated by at least one of upper layer signaling or downlink control information. The method according to claim 5.

7. When the adjustment is performed, at least one of the common TA value or the UE-specific TA value is adjusted. The method according to claim 4.

8. The adjustment interval of the common TA value is set to be shorter than the adjustment interval of the UE-specific TA value. The method according to claim 7.

9. The length of the random access preamble is an interval of a preamble repetition unit. The method according to claim 1.

10. The length of the random access preamble is set to be different based on the format of the random access preamble. The method according to claim 1.

11. The uplink transmission is based on a non-terrestrial network (NTN). The method according to claim 1.

12. At least one transceiver, At least one processor coupled to the at least one transceiver, and comprising: The at least one processor is Receives first information for a satellite orbit, second information for a common TA (Timing Advance) value, and third information related to a specific unit for TA adjustment, Is configured to perform uplink transmission including a narrowband physical random access channel by applying a TA value based on the first information for the satellite orbit and the second information for the common TA value, Adjustment related to the TA value is performed based on the specific unit, The specific unit is a product of a 2^n value and the length of a random access preamble, where n is a positive integer including 0, a user device.

13. At least one transceiver, At least one processor coupled to the at least one transceiver, and comprising: The at least one processor is Transmits first information for a satellite orbit, second information for a common TA (Timing Advance) value, and third information related to a specific unit for TA adjustment, Is configured to receive uplink transmission including a narrowband physical random access channel to which a TA value based on the first information for the satellite orbit and the second information for the common TA value is applied, Adjustment related to the TA value is performed based on the specific unit, The specific unit is a product of a 2^n value and the length of a random access preamble, where n is a positive integer including 0, a base station.

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