Method and apparatus for transmitting and receiving periodic data without GNSS information in satellite communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure may provide a method performed by a user equipment (UE) in a wireless communication system, the method comprising the steps of: receiving, from a base station, a first SIB including at least a portion of information related to a reference position of a beam, a location of the base station, a threshold value of an elevation angle at which uplink transmission is restricted, a location range of the base station at which uplink transmission is restricted, and a time at which uplink transmission is restricted; determining, on the basis of the first SIB, that uplink transmission is restricted; and transmitting an allowed uplink signal to the base station.

Description

Method and device for transmitting and receiving periodic data without GNSS information in a satellite communication system

[0001] The present disclosure relates to a satellite communication system, and more particularly, to a method for transmitting and receiving data in a satellite communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] As a result of the development of mobile communication systems and the aforementioned advancements in the provision of diverse services, there is a growing demand for methods to effectively provide these services, and in particular, for methods to optimize non-public networks.

[0009] Meanwhile, with the dramatic decline in satellite launch costs in the late 2010s and into the 2020s, a growing number of operators are seeking to provide satellite-based communication services. Consequently, satellite networks are emerging as a next-generation network system, complementing existing terrestrial networks (TNs). While satellite networks cannot yet provide a user experience comparable to terrestrial networks, their advantage lies in their ability to provide communication services in areas where terrestrial network construction is difficult or in disaster situations. As previously mentioned, the recent rapid decline in satellite launch costs has also secured economic viability. Furthermore, several companies and the 3GPP standards body are pursuing direct smartphone-satellite communication.

[0010] The disclosed embodiment seeks to provide a device and method capable of effectively providing a service in a wireless communication system such as a satellite communication system.

[0011] A method performed by a terminal in a wireless communication system according to one embodiment of the present disclosure may include: receiving time offset information from a base station; calculating a timing advance (TA) value based on the received time offset information; applying the calculated TA value; transmitting information about the applied TA value to the base station; and receiving information for correcting the TA value from the base station.

[0012] The present disclosure provides a device and method capable of effectively providing a service in a wireless communication system such as a satellite communication system.

[0013] FIG. 1 is a diagram showing the basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a downlink or uplink, in a wireless communication system according to one embodiment.

[0014] FIG. 2 is a diagram illustrating a mapping of a synchronization signal (SS) and a physical broadcast channel (PBCH) of a wireless communication system in the frequency and time domains according to one embodiment.

[0015] FIG. 3 is a diagram illustrating symbols in which an SS / PBCH block can be transmitted according to a subcarrier spacing in a wireless communication system according to one embodiment.

[0016] FIG. 4 is a diagram illustrating an example of a control region (control resource set, CORESET) in which a downlink control channel is transmitted in a wireless communication system according to one embodiment.

[0017] FIG. 5 is a diagram schematically illustrating an example of a message transmitted from a MAC layer to a physical layer in a downlink in a wireless communication system according to one embodiment.

[0018] FIG. 6 is a diagram schematically illustrating an example of a message transmitted from a MAC layer to a physical layer in an uplink in a wireless communication system according to one embodiment.

[0019] FIG. 7 is a diagram illustrating an example of a process in which one transport block (TB) is divided into multiple code blocks (CB) and a CRC is added in a wireless communication system according to one embodiment.

[0020] FIG. 8 is a diagram illustrating a processing time of a terminal according to timing advance when the terminal receives a first signal and transmits a second signal in response to the first signal in a wireless communication system according to one embodiment.

[0021] FIG. 9 is a diagram illustrating an example of scheduling and transmitting data (e.g., TB) according to slots in a wireless communication system according to one embodiment, receiving HARQ-ACK feedback for the data, and performing retransmission according to the feedback.

[0022] FIG. 10 is a diagram illustrating an example of a communication system using a satellite according to one embodiment.

[0023] FIG. 11 is a diagram illustrating the Earth orbital period of a communication satellite according to the altitude or height of the satellite according to one embodiment.

[0024] Figure 12 is a diagram illustrating a concept of satellite-terminal direct communication according to one embodiment.

[0025] FIG. 13 is a diagram illustrating a utilization scenario of satellite-terminal direct communication according to one embodiment.

[0026] FIG. 14 is a diagram illustrating an example of calculating an expected data transmission rate (throughput) in an uplink when a LEO satellite at an altitude of 1200 km and a terminal on the ground perform direct communication according to one embodiment.

[0027] FIG. 15 is a diagram illustrating an example of calculating an expected data transmission rate (throughput) in an uplink when a GEO satellite at an altitude of 35,786 km and a terminal on the ground perform direct communication according to one embodiment.

[0028] FIG. 16 is a diagram illustrating a path loss value according to a path loss model between a terminal and a satellite according to one embodiment, and a path loss according to a path loss model between a terminal and a terrestrial network communication base station.

[0029] FIG. 17 is a diagram illustrating a formula and result for calculating the amount of Doppler shift experienced by a signal transmitted from a satellite when received by a ground user according to the altitude and position of the satellite and the position of a terminal user on the ground according to one embodiment.

[0030] FIG. 18 is a diagram illustrating the satellite velocity calculated at the satellite altitude according to one embodiment.

[0031] FIG. 19 is a diagram illustrating the Doppler shift experienced by different terminals within a single beam transmitted to the ground by a satellite according to one embodiment.

[0032] FIG. 20 is a diagram illustrating the difference in Doppler shift occurring within a beam depending on the position of a satellite determined based on an elevation angle according to one embodiment.

[0033] FIG. 21 is a diagram illustrating the delay time from a terminal to a satellite and the round-trip delay time between a terminal, a satellite, and a base station according to the position of the satellite determined based on the elevation angle according to one embodiment.

[0034] FIG. 22 is a diagram illustrating a maximum difference value of round-trip delay time that varies depending on the user's position within one beam according to one embodiment.

[0035] FIG. 23 is a diagram illustrating an example of an information structure of a random access response (RAR) according to one embodiment.

[0036] FIG. 24 is a diagram illustrating an example of a relationship between a PRACH preamble setting resource and an RAR reception time of an LTE system according to one embodiment.

[0037] FIG. 25 is a diagram illustrating an example of a relationship between a PRACH preamble setting resource and an RAR reception time of a 5G NR system according to one embodiment.

[0038] FIG. 26 is a diagram illustrating an example of downlink frame and uplink frame timing in a terminal according to one embodiment.

[0039] FIG. 27 is a diagram illustrating an example of the continuous motion of a satellite relative to a terminal located on the ground or on the Earth as the satellite orbits the Earth according to one embodiment.

[0040] Fig. 28 is a drawing showing an example of the structure of an artificial satellite according to one embodiment.

[0041] Figure 29 shows the initial connection procedure of a terminal according to one embodiment and the terminal is N TA This is a flowchart illustrating the procedure for determining .

[0042] Figure 30 shows the initial connection procedure of a terminal according to one embodiment and the terminal is N TA , N TA,UE-specific , N TA,common This is a flowchart illustrating the procedure for determining .

[0043] Fig. 31 is a diagram illustrating the operation of a terminal in a wireless communication system according to one embodiment.

[0044] Fig. 32 is a diagram illustrating the operation of a terminal in a wireless communication system according to one embodiment.

[0045] Figure 33 illustrates the operation of a base station for reporting a TA value of a terminal according to one embodiment.

[0046] Figure 34 illustrates the operation of a terminal for reporting a TA value of the terminal according to one embodiment.

[0047] Figure 35 illustrates the difference in propagation delay time between a terrestrial network and a satellite network according to one embodiment.

[0048] FIG. 36 illustrates the change in distance between terminals belonging to the same coverage (or beam) within a satellite and a satellite according to one embodiment of the present disclosure.

[0049] FIG. 37 is a conceptual diagram showing a method for a terminal to transmit by applying TA according to one embodiment of the present disclosure.

[0050] FIG. 38 is a conceptual diagram showing a method for a terminal to transmit by applying TA according to one embodiment of the present disclosure.

[0051] FIG. 39 is a diagram that distinguishes between a range of elevation angles in which uplink transmission is possible (or not limited) and a range of elevation angles in which uplink transmission is limited by a terminal that is not equipped with a GNSS (navigation satellite system) function according to one embodiment of the present disclosure.

[0052] Fig. 40 is a flowchart illustrating an operation for determining whether a terminal performs uplink transmission based on a satellite elevation angle according to one embodiment of the present disclosure.

[0053] FIG. 41 is a diagram illustrating a process for determining a frequency resource area for uplink transmission of a terminal equipped with a GNSS function and a terminal not equipped with a GNSS function according to one embodiment of the present disclosure.

[0054] FIG. 42 is a flowchart illustrating an initial connection procedure considering the presence or absence of GNSS support according to one embodiment of the present disclosure.

[0055] FIG. 43 is a diagram illustrating a process for determining a time resource region for uplink transmission of a terminal equipped with a GNSS function and a terminal not equipped with a GNSS function according to one embodiment of the present disclosure.

[0056] FIG. 44 is a block diagram illustrating the internal structure of a terminal according to one embodiment of the present disclosure.

[0057] FIG. 45 is a block diagram illustrating the internal structure of a satellite according to one embodiment of the present disclosure.

[0058] FIG. 46 is a block diagram illustrating the internal structure of a base station according to one embodiment of the present disclosure.

[0059] NR (New Radio Access Technology), the new 5G communication system, is designed to allow various services to be freely multiplexed across time and frequency resources. Accordingly, waveforms, numerology, and reference signals can be dynamically and freely allocated based on the needs of each service. In wireless communication, optimized data transmission through measurement of channel quality and interference is crucial for providing optimal services to terminals. Therefore, accurate channel status measurement is essential. However, unlike 4G communication, where channel and interference characteristics do not significantly vary depending on frequency resources, 5G channel and interference characteristics vary significantly depending on the service. Therefore, support for subsets at the Frequency Resource Group (FRG) level is required to enable separate measurement. Meanwhile, the types of services supported in NR systems can be categorized into eMBB (Enhanced mobile broadband), mMTC (massive Machine Type Communications) (mMTC), and URLLC (Ultra-Reliable and low-latency Communications). eMBB can be viewed as a service aimed at high-speed transmission of high-capacity data, mMTC aims at minimizing terminal power consumption and supporting multiple terminals, and URLLC aims at high reliability and low latency. Different requirements may apply depending on the type of service applied to the terminal.

[0060] In this way, multiple services can be provided to users in a communication system, and in order to provide such multiple services to users, a method and a device using the same are required that can provide each service within the same time period according to its characteristics.

[0061] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0062] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to avoid obscuring the gist of the present invention by omitting unnecessary explanations and to convey the gist more clearly.

[0063] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0064] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0065] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0066] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0067] Here, the term '~ unit' used in the present embodiment means a software or hardware component such as an FPGA or ASIC, and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to regenerate one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in the embodiment, '~bu' may include one or more processors.

[0068] Wireless communication systems are evolving from their initial voice-centric services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as 3GPP's HSPA (high speed Packet Access), LTE (long term evolution or E-UTRA (evolved universal terrestrial radio access)), LTE-Advanced (LTE-A), 3GPP2's HRPD (high rate packet data), UMB (ultra mobile broadband), and IEEE's 802.16e. In addition, communication standards for 5G or NR (new radio) are being developed as the 5th generation wireless communication system.

[0069] As a representative example of the above broadband wireless communication system, the NR system adopts the orthogonal frequency division multiplexing (OFDM) method in the downlink (DL) and uplink. More specifically, the CP-OFDM (cyclic-prefix OFDM) method is adopted in the downlink, and both the CP-OFDM and the DFT-S-OFDM (discrete Fourier transform spreading OFDM) method are adopted in the uplink. The uplink refers to a wireless link in which a user equipment (UE) or mobile station (MS) transmits data or control signals to a base station (gNode B or base station (BS)), and the downlink refers to a wireless link in which a base station transmits data or control signals to a UE. The above multiple access method typically distinguishes the data or control information of each user by allocating and operating the time-frequency resources to be transmitted for each user so that they do not overlap, that is, so as to achieve orthogonality.

[0070] The NR system employs a hybrid automatic repeat request (HARQ) scheme, which retransmits the data at the physical layer if a decoding failure occurs during the initial transmission. HARQ means that if the receiver fails to correctly decode data, the receiver transmits information (negative acknowledgment: NACK) to the transmitter, notifying the receiver of the decoding failure, so that the transmitter can retransmit the data at the physical layer. The receiver combines the retransmitted data with previously failed decoding data to improve data reception performance. Furthermore, if the receiver correctly decodes the data, it can transmit information (acknowledgement: ACK) to the transmitter, notifying the transmitter of the successful decoding, so that the transmitter can transmit new data.

[0071] When a terminal attempts to connect to a base station via satellite, the long distances between the terminal and the satellite, and between the satellite and the terrestrial base station, hundreds, thousands, or even more, cause significant delays in radio transmission. This significant delay is significantly greater than when the terminal and base station communicate directly over a terrestrial network. Furthermore, this delay varies over time due to the satellite's constant movement. All terminals experience varying delays with respect to the satellite or base station.

[0072] The present disclosure provides a method and device for a base station to indicate a time offset, and for a terminal to compensate for the time-varying delay time that occurs due to the long distance to the satellite and the movement of the satellite when a terminal transmits and receives signals with a base station via a satellite, and for the base station to compensate based on this information. Furthermore, the present disclosure provides a method and device for the terminal to calculate a portion of the time offset based on satellite and its own location and time information, apply the calculated portion, and report the calculated portion to the base station.

[0073] When a terminal transmits and receives signals to and from a base station via satellite, compensation for time offset may be necessary due to the long distance between the terminal and the satellite. Accordingly, the present disclosure provides a method and device in which a base station indicates time offset information to a terminal, the terminal calculates and applies a portion of a timing advance, the terminal reports the timing advance information to the base station, and the terminal uses the indicated information to compensate for the time offset.

[0074] As described above, by using the present disclosure, a terminal can connect to a base station via a satellite, the base station can indicate a time offset to the terminal, and the terminal can calculate and correct the time offset, thereby enabling effective exchange of signals between the base station and the terminal.

[0075] FIG. 1 is a diagram showing the basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a downlink or uplink, in a wireless communication system according to one embodiment.

[0076] In Figure 1, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol, N symb (102) OFDM symbols are grouped to form one slot (106). The length of a subframe is defined as 1.0 ms, and a radio frame (114) is defined as 10 ms. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is a total of N BW It consists of (104) subcarriers. 1 frame can be defined as 10ms. 1 subframe can be defined as 1ms, and therefore 1 frame can be composed of a total of 10 subframes. 1 slot can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( ))=14). 1 subframe may be composed of one or more slots, and the number of slots per subframe may vary depending on the setting value μ for the subcarrier spacing. In an example of Fig. 2, cases where μ=0 and μ=1 are illustrated as the subcarrier spacing setting value. When μ=0, 1 subframe may be composed of 1 slot, and when μ=1, 1 subframe may be composed of 2 slots. That is, the number of slots per subframe ( ) may vary, and accordingly the number of slots per frame ( ) may vary. Depending on the subcarrier spacing setting μ and can be defined as shown in Table 1 below.

[0077]

[0078] Before RRC (radio resource control) connection, a terminal can receive an initial bandwidth part (initial BWP) for initial access from a base station through a master information block (MIB). More specifically, during the initial access phase, the terminal can receive configuration information about a control resource set (CORESET) and a search space, through which a physical downlink control channel (PDCCH) can be transmitted to receive system information required for initial access (remaining system information; which may correspond to RMSI or system information block 1; SIB1) through the MIB. The control region and search space configured through the MIB may each be regarded as identifier (Identity, ID) 0. The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for control region #0 through the MIB. Additionally, the base station can notify the terminal of the monitoring cycle and occasion settings for control area #0, i.e., search space #0, via the MIB. The terminal can consider the frequency range designated as control area #0, obtained from the MIB, as the initial bandwidth portion for initial access. At this time, the identifier (ID) of the initial bandwidth portion can be considered as 0.

[0079] The MIB may include information such as those shown in Table 2 below. Of course, it is not limited to the examples below.

[0080]

[0081] The description of MIBfield is as follows:

[0082] - cellBarred

[0083] Value barred means that the cell is barred, as defined in TS 38.304

[0020] .

[0084] - dmrs-TypeA-Position

[0085] Position of (first) DM-RS for downlink (see TS 38.211

[0016] , clause 7.4.1.1.2) and uplink (see TS 38.211

[0016] , clause 6.4.1.1.3).

[0086] - intraFreqReselection

[0087] Controls cell selection / reselection to intra-frequency cells when the highest ranked cell is barred, or treated as barred by the UE, as specified in TS 38.304

[0020] .

[0088] - pdcch-ConfigSIB1

[0089] Determines a common ControlResourceSet (CORESET), a common search space and necessary PDCCH parameters. If the field ssb-SubcarrierOffset indicates that SIB1 is absent, the field pdcch-ConfigSIB1 indicates the frequency positions where the UE may find SS / PBCH block with SIB1 or the frequency range where the network does not provide SS / PBCH block with SIB1 (see TS 38.213

[0013] , clause 13).

[0090] - ssb-SubcarrierOffset

[0091] Corresponds to kSSB (see TS 38.213

[0013] ), which is the frequency domain offset between SSB and the overall resource block grid in number of subcarriers. (See TS 38.211

[0016] , clause 7.4.3.1).

[0092] The value range of this field may be extended by an additional most significant bit encoded within PBCH as specified in TS 38.213

[0013] .

[0093] This field may indicate that this cell does not provide SIB1 and that there is hence no CORESET#0 configured in MIB (see TS 38.213

[0013] , clause 13). In this case, the field pdcch-ConfigSIB1 may indicate the frequency positions where the UE may (not) find a SS / PBCH with a control resource set and search space for SIB1 (see TS 38.213

[0013] , clause 13).

[0094] - subCarrierSpacingCommon

[0095] Subcarrier spacing for SIB1, Msg.2 / 4 for initial access, paging and broadcast SI-messages. If the UE acquires this MIB on an FR1 carrier frequency, the value scs15or60 corresponds to 15 kHz and the value scs30or120 corresponds to 30 kHz. If the UE acquires this MIB on an FR2 carrier frequency, the value scs15or60 corresponds to 60 kHz and the value scs30or120 corresponds to 120 kHz.

[0096] - systemFrameNumber

[0097] The 6 most significant bits (MSB) of the 10-bit System Frame Number (SFN). The 4 LSB of the SFN are conveyed in the PBCH transport block as part of channel coding (i.e. outside the MIB encoding), as defined in clause 7.1 in TS 38.212

[0017] .

[0098] In the method of configuring the bandwidth portion, terminals prior to RRC connection can receive configuration information regarding the initial bandwidth portion through the MIB during the initial access phase. More specifically, the terminal can receive a control region for a downlink control channel on which downlink control information (DCI) for scheduling SIB can be transmitted from the MIB of the PBCH (physical broadcast channel). At this time, the bandwidth of the control region configured through the MIB can be regarded as the initial bandwidth portion, and the terminal can receive the PDSCH (physical downlink shared channel) on which the SIB is transmitted through the configured initial bandwidth portion. In addition to receiving the SIB, the initial bandwidth portion can also be utilized for other system information (OSI), paging, and random access.

[0099] When one or more bandwidth parts are set for a terminal, the base station can instruct the terminal to change the bandwidth part using the bandwidth part indicator field in the DCI.

[0100] The basic unit of resources in the time-frequency domain is a resource element (RE), which can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB or physical resource block; PRB) is a N-bit resource block in the frequency domain. RB It is defined as (110) consecutive subcarriers. In general, the minimum transmission unit of data is the RB unit. In NR systems, the N symb = 14, N RB =12, and N BWis proportional to the bandwidth of the system transmission band. The data rate can be increased in proportion to the number of RBs scheduled to the terminal.

[0101] In the case of an FDD system that operates the downlink and uplink by frequency division, the downlink transmission bandwidth and the uplink transmission bandwidth may be different. The channel bandwidth represents the RF bandwidth corresponding to the system transmission bandwidth. Tables 3 and 4 show part of the correspondence between the system transmission bandwidth, subcarrier spacing, and channel bandwidth defined in the NR system in the frequency band lower than 6 GHz (frequency range 1 (FR 1)) and the frequency band higher than 6 GHz (FR 2), respectively. For example, an NR system with a 100 MHz channel bandwidth with a 30 kHz subcarrier width has a transmission bandwidth composed of 273 RBs. In the following, N / A may be a bandwidth-subcarrier combination that is not supported by the NR system.

[0102]

[0103]

[0104] In the NR system, the frequency range can be divided into FR1 and FR2 and defined as shown in Table 5 below.

[0105]

[0106] The ranges of FR1 and FR2 can be varied and applied differently. For example, the frequency range of FR1 can be varied and applied from 450 MHz to 6000 MHz.

[0107] Next, we will explain the SS (synchronization signal) / PBCH block in 5G.

[0108] An SS / PBCH block may refer to a physical layer channel block composed of a PSS (primary SS, primary synchronization signal), SSS (secondary SS, secondary synchronization signal), and PBCH. Specifically, it is as follows.

[0109] - PSS: A signal that serves as a reference for downlink time / frequency synchronization and provides some information about the cell ID.

[0110] - SSS: It serves as a reference for downlink time / frequency synchronization and provides remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for PBCH demodulation.

[0111] - PBCH: Provides essential system information required for transmission and reception of data and control channels of a terminal. Essential system information may include search space-related control information indicating radio resource mapping information for the control channel, and scheduling control information for a separate data channel that transmits system information.

[0112] - SS / PBCH Block: An SS / PBCH block can be composed of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be transmitted within a 5ms period, and each transmitted SS / PBCH block can be distinguished by an index.

[0113] The terminal can detect PSS and SSS in the initial access stage, and decode PBCH. The terminal can obtain MIB from PBCH and configure control region #0 (which may correspond to a control region with a control region index of 0) therefrom. The terminal can monitor control region #0, assuming that the selected SS / PBCH block and the DMRS (demodulation reference signal) transmitted in control region #0 are quasi-co-located (QCL). The terminal can receive system information through downlink control information transmitted in control region #0. The terminal can obtain RACH (random access channel)-related configuration information required for initial access from the received system information. The terminal can transmit a PRACH (physical RACH) to the base station considering the selected SS / PBCH index, and the base station receiving the PRACH can obtain information on the SS / PBCH block index selected by the terminal. Through this process, the base station can know which block among each SS / PBCH block the terminal has selected and monitor the control region #0 associated with it.

[0114] FIG. 2 is a diagram illustrating a mapping of a synchronization signal (SS) and a physical broadcast channel (PBCH) of a wireless communication system in the frequency and time domains according to one embodiment.

[0115] A primary synchronization signal (PSS, 201), a secondary synchronization signal (SSS, 203), and a PBCH are mapped across 4 OFDM symbols, and the PSS and SSS are mapped to 12 RBs, and the PBCH is mapped to 20 RBs. Table 2 shows how the frequency bands of the 20 RBs change according to the subcarrier spacing (SCS). The resource region where the PSS, SSS, and PBCH are transmitted may be called an SS / PBCH block (SS / PBCH block). In addition, the SS / PBCH block may be called an SSB (synchronization signal block).

[0116] FIG. 3 is a diagram illustrating symbols in which an SS / PBCH block can be transmitted according to a subcarrier spacing in a wireless communication system according to one embodiment.

[0117] Referring to Fig. 3, the subcarrier spacing can be set to 15 kHz, 30 kHz, 120 kHz, 240 kHz, etc., and the position of the symbol where the SS / PBCH block (or SSB) can be located can be determined according to each subcarrier spacing. Fig. 3 illustrates the position of the symbol where the SSB can be transmitted according to the subcarrier spacing in symbols within 1 ms, and the SSB does not always have to be transmitted in the area indicated in Fig. 3. The position where the SSB is transmitted can be set to the terminal through system information or dedicated signaling.

[0118] Below, the downlink control channel in a 5G communication system will be described in more detail with reference to drawings.

[0119] FIG. 4 is a diagram illustrating an example of a control region (control resource set, CORESET) in which a downlink control channel is transmitted in a wireless communication system according to one embodiment. FIG. 4 illustrates an example in which two control regions (control region #1 (401), control region #2 (402)) are set within a UE bandwidth part (410) in the frequency axis and within one slot (420) in the time axis. The control regions (401, 402) may be set to specific frequency resources (403) within the entire UE bandwidth part (410) in the frequency axis. The time axis may be set to one or more OFDM symbols, which may be defined as the control region length (Control Resource Set Duration, 404). Referring to the example illustrated in FIG. 4, control region #1 (401) is set to a control region length of two symbols, and control region #2 (402) is set to a control region length of one symbol.

[0120] In the aforementioned 5G system, the control region can be established by the base station to the terminal via higher-layer signaling (e.g., system information, MIB, RRC signaling). Establishing a control region for the terminal means providing information such as the control region identifier (Identity), the frequency location of the control region, and the symbol length of the control region. For example, the higher-layer signaling may include the information in Table 6 below. However, the present disclosure is not limited to the following examples.

[0121]

[0122] In Table 6, the tci-StatesPDCCH (simply named TCI (transmission configuration indication) state) configuration information may include information on one or more SS / PBCH block indices or CSI-RS (channel state information reference signal) indices that are in a QCL relationship with the DMRS transmitted in the corresponding control region.

[0123] Next, we will specifically explain downlink control information (DCI) in 5G systems.

[0124] In a 5G system, scheduling information for uplink data (or physical uplink shared channel, PUSCH) or downlink data (or physical downlink shared channel, PDSCH) is transmitted from a base station to a terminal via DCI. The terminal can monitor a fallback DCI format and a non-fallback DCI format for the PUSCH or PDSCH. The fallback DCI format can be composed of fixed fields defined between the base station and the terminal, and the non-fallback DCI format can include configurable fields. In addition, there are various formats for DCI, and each format can indicate whether it is DCI for power control or DCI for notifying a slot format indicator (SFI).

[0125] DCI can be transmitted through the physical downlink control channel (PDCCH) after going through the channel coding and modulation process. A cyclic redundancy check (CRC) is attached to the DCI message payload, and the CRC can be scrambled with a radio network temporary identifier (RNTI) corresponding to the identity of the UE. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response. That is, the RNTI is not transmitted explicitly, but is included in the CRC calculation process. When the UE receives a DCI message transmitted on the PDCCH, the UE verifies the CRC using the assigned RNTI. If the CRC verification result is correct, the UE can know that the received DCI message has been transmitted to the UE. The PDCCH can be mapped and transmitted in a control resource set (CORESET) set for the UE.

[0126] For example, a DCI scheduling a PDSCH for system information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a random access response (RAR) message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a paging message may be scrambled with P-RNTI. A DCI notifying a slot format indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a transmit power control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI). However, the type of RNTI is not limited to the above examples.

[0127] DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI can include, for example, the following information, but is not limited to the following examples.

[0128]

[0129] DCI format 0_1 ​​can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI can include, for example, the following information, but is not limited to the following examples.

[0130]

[0131]

[0132] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI can include, for example, the following information, but is not limited to the following examples.

[0133]

[0134] DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI can include, for example, the following information, but is not limited to the following examples.

[0135]

[0136]

[0137] For example, each control information included in DCI format 1_1, which is scheduling control information (DL grant) for downlink data, may include the following information. However, the present invention is not limited to the following examples.

[0138] - Carrier indicator: Indicates on which carrier the data scheduled by DCI is transmitted - 0 or 3 bits

[0139] - Identifier for DCI formats: This indicates the DCI format, and specifically, it is an indicator that distinguishes whether the DCI is for downlink or uplink. - [1] bits

[0140] - Bandwidth part indicator: Indicates if there is a change in the bandwidth part - 0, 1, or 2 bits

[0141] - Frequency domain resource assignment: Resource allocation information that indicates frequency domain resource allocation. The resource expressed varies depending on whether the resource allocation type is 0 or 1.

[0142] - Time domain resource assignment: Resource allocation information indicating time domain resource allocation, which can indicate the day setting of upper layer signaling or a predefined PDSCH time domain resource allocation list - 1, 2, 3, or 4 bits

[0143] - VRB-to-PRB mapping: Indicates the mapping relationship between virtual resource blocks (VRBs) and physical resource blocks (PRBs) - 0 or 1 bit

[0144] - PRB bundling size indicator: Indicates the physical resource block bundling size assuming the same precoding is applied - 0 or 1 bit

[0145] - Rate matching indicator: Indicates which rate match group among the rate match groups set by the upper layer applied to the PDSCH is applied - 0, 1, or 2 bits

[0146] - ZP CSI-RS trigger: Triggers the zero power channel state information reference signal - 0, 1, or 2 bits

[0147] - Transport block (TB) related configuration information: Indicates MCS (Modulation and coding scheme), NDI (New data indicator), and RV (Redundancy version) for one or two TBs.

[0148] - Modulation and coding scheme (MCS): Indicates the modulation method and coding rate used for data transmission. That is, it can indicate a coding rate value that can provide TBS and channel coding information, along with information such as whether it is QPSK, 16QAM, 64QAM, or 256QAM.

[0149] - New data indicator: Indicates whether this is a HARQ initial transmission or a retransmission.

[0150] - Redundancy version: Indicates the redundancy version of HARQ.

[0151] - HARQ process number: Indicates the HARQ process number applied to PDSCH - 4 bits

[0152] - Downlink assignment index: This is an index for generating a dynamic HARQ-ACK codebook when reporting HARQ-ACK for PDSCH - 0 or 2 or 4 bits

[0153] - TPC command for scheduled PUCCH: Power control information applied to PUCCH for HARQ-ACK reporting on PDSCH - 2 bits

[0154] - PUCCH resource indicator: Information indicating PUCCH resources for HARQ-ACK reporting on PDSCH - 3 bits

[0155] - PDSCH-to-HARQ_feedback timing indicator: Configuration information on which slot the PUCCH for HARQ-ACK reporting on the PDSCH is transmitted - 3 bits

[0156] - Antenna ports: Information indicating the antenna ports of the PDSCH DMRS and the DMRS CDM group where the PDSCH is not transmitted - 4, 5, or 6 bits

[0157] - Transmission configuration indication: Information indicating beam-related information of PDSCH - 0 or 3 bits

[0158] - SRS request: Information requesting SRS transmission - 2 bits

[0159] - CBG transmission information: When code block group-based retransmission is set, information indicating which code block group (CBG) data is transmitted through the PDSCH - 0, 2, 4, 6, or 8 bits

[0160] - CBG flushing out information: Information indicating whether the code block group previously received by the terminal can be used for HARQ combining - 0 or 1 bit

[0161] - DMRS sequence initialization: Indicates DMRS sequence initialization parameters - 1 bit

[0162] Below, a time domain resource allocation method for a data channel in a 5G communication system is described.

[0163] Downlink data can be transmitted on the PDSCH, a physical channel for downlink data transmission. Uplink data can be transmitted on the PUSCH, a physical channel for uplink data transmission. The PDSCH can be transmitted after the control channel transmission period, and scheduling information such as specific mapping locations and modulation methods in the frequency domain are determined based on the DCI transmitted via the PDCCH.

[0164] The base station can set up a table for time-domain resource allocation information for the downlink data channel (PDSCH) and the uplink data channel (PUSCH) to the terminal through higher-layer signaling (e.g., RRC signaling). For the PDSCH, a table consisting of up to maxNrofDL-Allocations=16 entries can be set up, and for the PUSCH, a table consisting of up to maxNrofUL-Allocations=16 entries can be set up. The time domain resource allocation information may include, for example, PDCCH-to-PDSCH slot timing (the time interval in slot units between the time point at which a PDCCH is received and the time point at which a PDSCH scheduled by the received PDCCH is transmitted, denoted as K0) or PDCCH-to-PUSCH slot timing (the time interval in slot units between the time point at which a PDCCH is received and the time point at which a PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information about the position and length of the start symbol for which a PDSCH or PUSCH is scheduled within a slot, the mapping type of the PDSCH or PUSCH, etc. For example, information such as those in Tables 11 and 12 below may be notified from the base station to the terminal. However, the present invention is not limited to the following examples.

[0165]

[0166]

[0167] The base station can notify the terminal of one of the entries in the table for the above time domain resource allocation information via L1 signaling (e.g., DCI) (e.g., by indicating it with the 'Time Domain Resource Allocation' field in the DCI). The terminal can obtain time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0168] Time domain resource assignment can be conveyed by information about the slot in which the PDSCH / PUSCH is transmitted, the starting symbol position S in the slot, and the number of symbols L to which the PDSCH / PUSCH is mapped. S can be a relative position from the start of the slot, L can be a number of consecutive symbols, and S and L can be determined from a start and length indicator value (SLIV) defined as in Equation 1 below.

[0169] [Mathematical Formula 1]

[0170]

[0171] In the NR system, PDSCH mapping types are defined as type A and type B. In PDSCH mapping type A, the first DMRS symbol is located in the second or third OFDM symbol of a slot. In PDSCH mapping type B, the first DMRS symbol is located in the first OFDM symbol of the time-domain resource allocated for PUSCH transmission.

[0172] Among the control information constituting the above DCI, the base station notifies the terminal of the modulation method applied to the PDSCH to be transmitted and the size of the data to be transmitted (transport block size, TBS) through the MCS (modulation coding scheme). In an embodiment, the MCS may be composed of 5 bits or more or fewer bits. The TBS corresponds to the size of the data (transport block, TB) to be transmitted by the base station before channel coding for error correction is applied.

[0173] In the present disclosure, a transport block (TB) may include a MAC (medium access control) header, a MAC control element, one or more MAC SDUs (service data units), and padding bits. Alternatively, a TB may refer to a unit of data delivered from a MAC layer to a physical layer or a MAC PDU (protocol data unit).

[0174] The modulation methods supported in the NR system are QPSK (quadrature phase shift keying), 16QAM (quadrature amplitude modulation), 64QAM, and 256QAM, and each modulation order (Q m ) correspond to 2, 4, 6, and 8. That is, 2 bits per symbol can be transmitted for QPSK modulation, 4 bits per symbol for 16QAM modulation, 6 bits per symbol for 64QAM modulation, and 8 bits per symbol for 256QAM modulation.

[0175] The terms "physical channel" and "signal" in an NR system may be used to describe the method and device proposed in one embodiment of the present disclosure. However, the contents of the present disclosure may be applied to wireless communication systems other than NR systems.

[0176] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in describing the present disclosure, detailed descriptions of related functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0177] In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station.

[0178] While the embodiments of the present disclosure are described below using the NR system as an example, the embodiments of the present disclosure may also be applied to other communication systems with similar technical backgrounds or channel types. Furthermore, the embodiments of the present disclosure may be applied to other communication systems with some modifications, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure.

[0179] In this disclosure, the conventional terms "physical channel" and "signal" may be used interchangeably with "data" or "control signal." For example, while PDSCH is a physical channel through which data is transmitted, in this disclosure, PDSCH may be referred to as "data."

[0180] In the present disclosure below, upper signaling is a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer, and may also be referred to as RRC signaling or a MAC control element (MAC CE).

[0181] In various embodiments of the present disclosure, the timing advance (TA) may be transmitted via a MAC Control Element (CE), for example, a Timing Advance Command MAC CE or an Absolute Timing Advance Command MAC CE.

[0182] Meanwhile, a message from the MAC layer transmitted to the physical layer, for example, a MAC PDU, may include one or more MAC sub-PDUs. Each MAC sub-PDU may include one of the following, but is not limited to the following examples.

[0183] - MAC subheader only (including padding)

[0184] - MAC subheader and MAC SDU

[0185] - MAC subheader and MAC CE

[0186] - MAC subheader and padding

[0187] MAC SDUs can have variable sizes, and each MAC subheader can correspond to a MAC SDU, a MAC CE, or padding.

[0188] Meanwhile, a message from the MAC layer transmitted to the physical layer, for example, a MAC PDU, can be configured as shown in FIGS. 5 and 6 for downlink and uplink, respectively.

[0189] First, referring to FIG. 5, an example of a message transmitted from a MAC layer to a physical layer in a downlink in a communication system according to various embodiments of the present disclosure will be described.

[0190] FIG. 5 is a diagram schematically illustrating an example of a message transmitted from a MAC layer to a physical layer in a downlink in a wireless communication system according to one embodiment.

[0191] Referring to FIG. 5, an example of a message transmitted from the MAC layer to the physical layer in the downlink may be a downlink MAC PDU (DL MAC PDU). In FIG. 5, a MAC sub-PDU (500) including MAC CE 1 may include an R / LCID subheader (502) and a fixed-sized MAC CE (504), and a MAC sub-PDU (510) including MAC CE 2 may include an R / F / LCID / L subheader (512) and a variable-sized MAC CE (514). In addition, a MAC sub-PDU (520) including a MAC SDU may include an R / F / LCID / L subheader (522) and a MAC SDU (524).

[0192] In FIG. 5, LCID represents a logical channel ID field, and the LCID field indicates an instance of a corresponding MAC SDU or a type or padding of a corresponding MAC CE, which are described in detail in Tables 13 and 14 below. Here, Table 13 below represents the values ​​of LCID for DL-SCH, and Table 14 represents the values ​​of LCID for UL-SCH.

[0193]

[0194]

[0195] There is one LCID field per MAC subheader, and the size of the LCID field is 6 bits. When the LCID field is set to, for example, "34", there is one additional octet in the MAC subheader including the eLCID field, and it follows the octet including the LCID field. When the LCID field is set to, for example, "33", there are two additional octets in the MAC subheader including the eLCID field, and these two octets follow the octet including the LCID field.

[0196] Additionally, eLCID represents the extended logical channel ID field and indicates the logical channel instance of the corresponding MAC SDU or the type of the corresponding MAC CE. The size of the eLCID field is 8 or 16 bits.

[0197] Additionally, L represents a length field, which indicates the length of the corresponding MAC SDU or variable-size MAC CE. There is one length field for each MAC subheader, excluding subheaders corresponding to the fixed-size MAC CEs, padding, or MAC SDUs containing the UL common control channel (CCCH). The size of the length field is indicated by the F field.

[0198] Additionally, F represents the format field and indicates the size of the length field. There is one F field for each MAC subheader, excluding MAC SDUs containing fixed MAC CEs, padding, and UL CCCH. The size of the F field is 1 bit, and for example, a value of 0 indicates 8 bits of the length field, and for another example, a value of 1 indicates 16 bits of the length field.

[0199] Additionally, R is a reserved bit, which is set to "0" for example.

[0200] As illustrated in FIG. 5, MAC CEs, for example, MAC CE 1 and MAC CE 2, are placed together, and MAC sub-PDU(s) containing MAC CE(s) are placed before MAC sub-PDU(s) containing MAC SDU(s) and MAC sub-PDU(s) containing padding. Here, the size of the padding can be zero.

[0201] Next, with reference to FIG. 6, an example of a message transmitted from the MAC layer to the physical layer in the uplink in a communication system according to various embodiments of the present disclosure will be described.

[0202] FIG. 6 is a diagram schematically illustrating an example of a message transmitted from a MAC layer to a physical layer in an uplink in a wireless communication system according to one embodiment.

[0203] Referring to FIG. 6, an example of a message transmitted from the MAC layer to the physical layer in the uplink may be an uplink MAC PDU (UL MAC PDU). In FIG. 6, a MAC sub-PDU (610) including MAC CE 1 includes an R / LCID subheader (612) and a fixed-size MAC CE (614), and a MAC sub-PDU (620) including MAC CE 2 includes an R / F / LCID / L subheader (622) and a variable-size MAC CE (624). In addition, a MAC sub-PDU (600) including a MAC SDU includes an R / F / LCID / L subheader (602) and a MAC SDU (604).

[0204] As illustrated in FIG. 6, MAC CEs, for example, MAC CE 1 and MAC CE 2, are placed together, and MAC sub-PDU(s) containing MAC CE(s) are placed after MAC sub-PDUs containing MAC SDUs and before MAC sub-PDUs containing padding. Here, the size of the padding can be zero.

[0205] In FIGS. 5 and 6, the LCID included in the subheader of the MAC layer, i.e., the logical channel ID or the extended logical channel ID (eLCID), can indicate the type of transmitted MAC SDU or MAC CE, etc. The mapping between the index of the LCID and the type of MAC SDU or MAC CE, etc. can be represented, for example, as in Table 13, and the mapping between the index of the eLCID and the type of MAC SDU or MAC CE, etc. can be represented, for example, as in Table 14. In various embodiments of the present disclosure, the LCID can indicate an instance of a logical channel of a MAC SDU, a type of a MAC CE, or padding information of a downlink shared channel (DL-SCH) and an uplink shared channel (UL-SCH). One LCID is mapped per MAC subheader, and the LCID can be implemented with, for example, 6 bits.

[0206] FIG. 7 is a diagram illustrating an example of a process in which one transport block (TB) is divided into multiple code blocks (CB) and a CRC is added in a wireless communication system according to one embodiment.

[0207] Referring to FIG. 7, a CRC (703) may be added to the last or first part of a transport block (TB, 701) to be transmitted in uplink or downlink. The CRC (703) may have 16 bits or 25 bits, a fixed number of bits, or a variable number of bits depending on channel conditions, and may be used to determine whether channel coding is successful. A block to which the CRC (703) is added to the TB (701) may be divided into multiple code blocks (codeblocks, CB) (707, 709, 711, 713) (705). Here, the code blocks may be divided with a predetermined maximum size, and in this case, the last code block (713) may be smaller than the other code blocks (707, 709, 711). However, the present invention is not limited to the above example. For example, by inserting 0, a random value, or 1 into the last code block (713), the lengths of the last code block (713) and other code blocks (707, 709, 711) can be made identical.

[0208] Additionally, CRCs (717, 719, 721, 723) may be added to each of the code blocks (707, 709, 711, 713) (715). The CRC may have 16 bits, 24 bits, or a predetermined number of bits, and may be used to determine whether channel coding is successful.

[0209] TB(701) and a cyclic generator polynomial can be used to generate CRC(703), and the cyclic generator polynomial can be defined in various ways. For example, the cyclic generator polynomial gCRC24A(D) = D for a 24-bit CRC. 24 + D 23 + D 18 + D 17 + D 14 + D 11 + D10 + D 7 + D 6 + D 5 + D 4 + D 3 Assuming + D + 1 and L = 24, TB data a0, a1, a2, a3, ..., a A-1 For CRC p0, p1, p2, p3, ..., p L-1 is a0D A+23 + a1D A+22 + ... + a A-1 D 24 + p0D 23 + p1D 22 + ... + p 22 D 1 + p 23 The values ​​that divide by gCRC24A(D) and have a remainder of 0 are p0, p1, p2, p3, ..., p L-1 can be determined. In the above example, the CRC length L is assumed to be 24, but the CRC length L can be determined to various lengths such as 12, 16, 24, 32, 40, 48, and 64.

[0210] After the CRC is added to the TB through this process, the TB+CRC can be divided into N CBs (707, 709, 711, 713). A CRC (717, 719, 721, 723) can be added to each of the divided CBs (707, 709, 711, 713) (715). The CRC added to the CB may have a different length than that used when generating the CRC added to the TB, or a different cyclic generator polynomial may be used for CRC generation. In addition, the CRC (703) added to the TB and the CRCs (717, 719, 721, 723) added to the code block may be omitted depending on the type of channel code to be applied to the code block. For example, if a LDPC (low density parity check) code rather than a turbo code is applied to the code block, the CRCs (717, 719, 721, 723) to be inserted into each code block may be omitted.

[0211] However, even when LDPC is applied, CRCs (717, 719, 721, 723) can be added to the code block as is. Also, when polar codes are used, CRCs can be added or omitted.

[0212] As described above in FIG. 7, the maximum length of one code block is determined according to the type of channel coding applied to the TB to be transmitted, and the TB and the CRC added to the TB can be divided into code blocks according to the maximum length of the code block.

[0213] In the conventional LTE system, a CRC for CB is added to the divided CB, the data bits and CRC of the CB are encoded with a channel code, coded bits are determined, and the number of bits that are rate-matched is determined as promised in advance for each coded bit.

[0214] In the NR system, the size of TB (TBS) can be calculated through the following steps.

[0215] Step 1: N' is the number of REs allocated for PDSCH mapping in one PRB within the allocated resources. RE Calculate N' RE Is can be calculated as follows: Here, is 12, can indicate the number of OFDM symbols allocated to the PDSCH. is the number of REs in a PRB (physical resource block) occupied by DMRSs of the same CDM (code division multiplexing) group. is the number of REs occupied by overhead within a PRB set by upper signaling, and can be set to one of 0, 6, 12, and 18. After this, the total number of REs allocated to the PDSCH, N RE can be calculated. N RE is min(156, N' RE )·n PRB is calculated as , n PRB Indicates the number of PRBs allocated to the terminal.

[0216] Step 2: Number of temporary information bits N info is N RE * R * Q m * can be calculated as v. Here, R is the code rate, and Q m is the modulation order, and the information of this value can be transmitted using the MCS bit field of DCI and a pre-arranged table. Also, v is the number of allocated layers. If N info If it is 3824, TBS can be calculated through step 3 below. Otherwise, TBS can be calculated through step 4.

[0217] Step 3: and N' through the formula info can be calculated. TBS is N' in Table 15 below. infoN' among values ​​not less than info can be determined as the closest value.

[0218]

[0219] Step 4: and N' through the formula info can be calculated. TBS is N' info The value can be determined through [pseudo-code 1] below. Below, C corresponds to the number of code blocks contained in one TB.

[0220] [Pseudo-code 1 begins]

[0221]

[0222] [End of Pseudo-code 1]

[0223] In the NR system, when one CB is input to the LDPC encoder, parity bits can be added and output. At this time, the amount of parity bits can vary depending on the LDPC base graph. The method of sending all parity bits generated by LDPC coding for a specific input can be called FBRM (full buffer rate matching), and the method of limiting the number of transmittable parity bits can be called LBRM (limited buffer rate matching). When resources are allocated for data transmission, the LDPC encoder output is made into a circular buffer, and the bits of the created buffer are repeatedly transmitted as many times as the allocated resources, and the length of the circular buffer is N. cb It can be said that.

[0224] If the number of all parity bits generated by LDPC coding is N, then in the FBRM method, N cb = N. In the LBRM method, N cb is min(N,Nref ) and N ref Is is given as R LBRM can be decided by 2 / 3. TBS LBRM In order to obtain , the method for obtaining TBS described above is used, but the maximum number of layers and maximum modulation order supported by the terminal in the cell are assumed, and the maximum modulation order Q m is assumed to be 8 if the cell is set to use an MCS table that supports 256QAM for at least one BWP, otherwise it is assumed to be 6 (64QAM), the code rate is assumed to be the maximum code rate of 948 / 1024, and N RE is 156·n PRB is assumed to be n PRB is n PRB,LBRM It is calculated assuming n PRB,LBRM can be given as Table 16 below.

[0225]

[0226] The maximum data rate supported by a terminal in an NR system can be determined using the following mathematical expression 2.

[0227] [Equation 2]

[0228]

[0229] In the above mathematical expression 2, J is the number of carriers bound by frequency aggregation, and Rmax = 948 / 1024. is the maximum number of layers, is the maximum modulation order, may represent a scaling factor, and μ may represent a subcarrier spacing. The terminal can report one of the values ​​1, 0.8, 0.75, and 0.4, and μ can be given as Table 17 below.

[0230]

[0231] also, is the average OFDM symbol length, Is can be calculated as, is the maximum number of RBs in BW(j). OH (j) is an overhead value, which can be given as 0.14 in downlink and 0.18 in uplink of FR1 (band below 6 GHz), and as 0.08 in downlink and 0.10 in uplink of FR2 (band above 6 GHz). Through mathematical expression 2, the maximum data rate in downlink in a cell with 100 MHz frequency bandwidth at 30 kHz subcarrier spacing can be calculated as shown in Table 18 below.

[0232]

[0233] On the other hand, the actual data rate that a terminal can measure in actual data transmission may be the data amount divided by the data transmission time. This may be the TBS for 1 TB transmission or the sum of TBS for 2 TB transmission divided by the TTI length. For example, assuming Table 15, the maximum actual data rate in downlink in a cell with a 100 MHz frequency bandwidth at a 30 kHz subcarrier spacing may be determined as shown in Table 19 below depending on the number of allocated PDSCH symbols.

[0234]

[0235] Table 18 shows the maximum data rate supported by the terminal, and Table 16 shows the actual data rate based on the allocated TBS. Depending on scheduling information, the actual data rate may be higher than the maximum data rate.

[0236] In wireless communication systems, particularly New Radio (NR) systems, the data rate that a terminal can support can be mutually agreed upon between the base station and the terminal. This can be calculated using the maximum frequency band, maximum modulation order, and maximum number of layers supported by the terminal. However, the calculated data rate may differ from the value calculated from the transport block size (TBS) and transmission time interval (TTI) length used for actual data transmission.

[0237] Accordingly, a terminal may be allocated a TBS that is greater than the data rate it supports. To prevent this, there may be restrictions on the schedulable TBS depending on the data rate supported by the terminal.

[0238] Since terminals are typically located far from the base station, signals transmitted from the terminal are received at the base station after a propagation delay. Propagation delay is the distance a radio wave travels from the terminal to the base station divided by the speed of light, and is typically the distance from the terminal to the base station divided by the speed of light. In one embodiment, for a terminal located 100 km away from the base station, a signal transmitted from the terminal is received at the base station approximately 0.34 msec later. Conversely, a signal transmitted from the base station is also received at the terminal approximately 0.34 msec later. As described above, the time it takes for a signal transmitted from a terminal to arrive at the base station may vary depending on the distance between the terminal and the base station. Therefore, if multiple terminals located in different locations transmit signals simultaneously, the arrival times at the base station may all be different. To address this issue and ensure that signals transmitted from multiple terminals arrive at the base station simultaneously, the time at which the uplink signal is transmitted can be varied for each terminal depending on its location. In 5G, NR, and LTE systems, this is called timing advance (TA).

[0239] FIG. 8 is a diagram illustrating a processing time of a terminal according to timing advance when the terminal receives a first signal and transmits a second signal in response to the first signal in a wireless communication system according to one embodiment.

[0240] When the base station transmits the first signal (uplink scheduling grant (UL grant) or downlink control signal and data (DL grant and DL data)) to the terminal in slot n (802), the terminal can receive the first signal in slot n (804). At this time, the terminal can receive the first signal at a transmission delay time (T) longer than the time at which the base station transmitted the signal. p, 810) can receive a signal as late as possible. In one embodiment, when the terminal receives the first signal in slot n (804), the terminal transmits the corresponding second signal (HARQ-ACK / NACK for uplink data or downlink data) in slot n+4 (806). Even when the terminal transmits a signal to the base station, in order to arrive at the base station at a specific time, the terminal can transmit the second signal at a timing (806) that is earlier than slot n+4 by a timing advance (TA, 812) based on the signal received by the terminal. Therefore, in one embodiment, the time that the terminal can receive uplink scheduling approval and transmit uplink data or receive downlink data and prepare to transmit HARQ ACK or NACK may be the time corresponding to three slots minus the TA (814).

[0241] To determine the timing described above, the base station can calculate the absolute value of the TA of the corresponding terminal. The base station can calculate the absolute value of the TA by adding or subtracting the amount of change in the TA value transmitted through upper signaling thereafter to the TA value initially transmitted to the terminal during the random access phase when the terminal initially accesses. In the present disclosure, the absolute value of the TA can be a value obtained by subtracting the start time of the nth TTI received by the terminal from the start time of the nth TTI transmitted by the terminal.

[0242] Meanwhile, one of the key performance criteria of cellular wireless communication systems is packet data latency. To achieve this, LTE systems transmit and receive signals in subframe units with a 1ms transmission time interval (TTI). As described above, an LTE system can support short-TTI UEs (UEs) with a transmission time interval shorter than 1ms. Meanwhile, in 5G or NR systems, the transmission time interval can be shorter than 1ms. Short-TTI UEs are suitable for latency-critical services such as Voice over LTE (VoLTE) and remote control. Furthermore, short-TTI UEs can serve as a means to realize the mission-critical Internet of Things (IoT) on a cellular basis.

[0243] In a 5G or NR system, when a base station transmits a PDSCH including downlink data, the DCI that schedules the PDSCH indicates a K1 value corresponding to timing information for transmitting HARQ-ACK information of the PDSCH by the terminal. The HARQ-ACK information may be transmitted by the terminal to the base station unless it is instructed to be transmitted before symbol L1, including a timing advance. That is, the HARQ-ACK information may be transmitted from the terminal to the base station at a time equal to or later than symbol L1, including a timing advance. If the HARQ-ACK information is instructed to be transmitted before symbol L1, including a timing advance, the HARQ-ACK information may not be valid HARQ-ACK information in HARQ-ACK transmission from the terminal to the base station.

[0244] Symbol L1 is T from the last point of PDSCH. proc,1It may be the first symbol after which a cyclic prefix (CP) begins. T proc,1 can be calculated as shown in mathematical formula 3 below.

[0245] [Equation 3]

[0246]

[0247] In the above mathematical expression 3, N1, d 1,1 , d 1,2 , , μ, T C can be defined as follows.

[0248] - When HARQ-ACK information is transmitted on PUCCH (uplink control channel), d 1,1 =0, and if transmitted on PUSCH (uplink shared channel, data channel), d 1,1 =1.

[0249] - When a terminal is configured with multiple activated configuration carriers or carriers, the maximum timing difference between carriers may be reflected in the second signal transmission.

[0250] - For PDSCH mapping type A, i.e., when the first DMRS symbol position is the 3rd or 4th symbol of the slot, if the position index i of the last symbol of the PDSCH is less than 7, d 1,2 It is defined as =7-i.

[0251] - For PDSCH mapping type B, i.e., when the first DMRS symbol position is the first symbol of the PDSCH, if the length of the PDSCH is 4 symbols, d 1,2 =3, and if the length of PDSCH is 2 symbols, d 1,2 =3+d, where d is the number of symbols overlapping the PDSCH and the PDCCH including the control signal scheduling the PDSCH.

[0252] - N1 is defined according to μ as shown in Table 20 below. μ=0, 1, 2, 3 mean subcarrier spacing of 15 kHz, 30 kHz, 60 kHz, 120 kHz, respectively.

[0253]

[0254] - The N1 value provided in Table 20 described above may have different values ​​depending on the UE capability.

[0255] - are defined respectively.

[0256] Additionally, in a 5G or NR system, when a base station transmits control information including uplink scheduling approval, the terminal may indicate a K2 value corresponding to timing information for transmitting uplink data or PUSCH.

[0257] A PUSCH may be transmitted from a UE to a base station unless it is instructed to be transmitted before symbol L2, including a timing advance. That is, a PUSCH may be transmitted from a UE to a base station at a time equal to or later than symbol L2, including a timing advance. If a PUSCH is instructed to be transmitted before symbol L2, including a timing advance, the UE may ignore uplink scheduling grant control information from the base station.

[0258] Symbol L2 is T from the last point of PDCCH containing scheduling grant. proc,2 The CP of the PUSCH symbol to be transmitted later may be the first symbol starting with T proc,2 can be calculated as shown in mathematical formula 4 below.

[0259] [Equation 4]

[0260]

[0261] In the above mathematical expression 4, N2, d2,1 , , μ, T C can be defined as follows.

[0262] - If the first symbol among the PUSCH allocated symbols contains only DMRS, then d 2,1 =0, otherwise d 2,1 =1.

[0263] - If the terminal is configured with multiple activated configuration carriers or carriers, the maximum timing difference between carriers may be reflected in the second signal transmission.

[0264] - N2 is defined as shown in Table 21 below according to μ. μ=0, 1, 2, 3 mean subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, and 120 kHz, respectively.

[0265]

[0266] - The N2 value provided in Table 21 described above may have different values ​​depending on the UE capability.

[0267] - are defined respectively.

[0268] Meanwhile, 5G or NR systems can configure frequency band portions (BWPs) within a single carrier, allowing specific terminals to transmit and receive within the configured BWP. This can be used to reduce terminal power consumption. Base stations can configure multiple BWPs and change the activated BWP in control information. The time available to a terminal while a BWP is being changed can be defined as shown in Table 22 below.

[0269]

[0270] In Table 22, the frequency range FR1 refers to a frequency band below 6 GHz, and the frequency range FR2 refers to a frequency band above 6 GHz, and they can be distinguished as shown in Table 4. Typically, FR2 refers to a high-frequency band close to the mmWave band, and FR1 refers to a relatively low-frequency band compared to FR2. In the above-described embodiment, Type 1 and Type 2 can be determined according to UE capability. In the above-described embodiment, Scenarios 1, 2, 3, and 4 are given as shown in Table 23 below.

[0271]

[0272] Figure 9 illustrates an example in which TB1 through TB8 are sequentially scheduled and transmitted starting from slot 0. This may be, for example, where TB1 through TB8 are each assigned HARQ process IDs 0 through 7 and transmitted. If the number of HARQ process IDs available to the base station and terminal is only 4, transmission for 8 different TBs may not be possible consecutively.

[0273] FIG. 10 is a diagram illustrating an example of a communication system using a satellite according to one embodiment. For example, when a terminal (1001) transmits a signal to a satellite (1003) through a service link, the satellite (1003) transmits the signal to a base station (1005) through a feeder link, and the base station (1005) processes the received signal and transmits a signal including a request for a subsequent action to the terminal (1001), which may be transmitted again through the satellite (1003). Since the distance between the terminal (1001) and the satellite (1003) and the distance between the satellite (1003) and the base station (1005) are both long, the time required for data transmission and reception from the terminal (1001) to the base station (1005) ultimately becomes longer.

[0274] FIG. 11 is a diagram illustrating the Earth orbital period of a communication satellite according to the altitude or height of the satellite according to one embodiment. Satellites for communication can be classified into low Earth Orbit (LEO), middle Earth Orbit (MEO), geostationary Earth Orbit (GEO), etc., depending on the satellite's orbit. Generally, GEO (1100) refers to a satellite at an altitude of approximately 36,000 km, MEO (1110) refers to a satellite at an altitude of 5,000 to 15,000 km, and LEO refers to a satellite at an altitude of 500 to 1,000 km. However, the present invention is not limited thereto.

[0275] The Earth's orbital period varies depending on each altitude. For GEO (1100), the Earth's orbital period is approximately 24 hours, for MEO (1110), approximately 6 hours, and for LEO (1130), approximately 90 to 120 minutes. Low Earth Orbit (~2,000 km) satellites have an advantage over geostationary orbit (36,000 km) satellites in terms of propagation delay (which can be understood as the time it takes for a signal transmitted from a transmitter to reach a receiver) and loss due to their relatively low altitude.

[0276] Figure 12 is a conceptual diagram illustrating direct satellite-to-terminal communication according to one embodiment. A satellite (1200) positioned at an altitude of 100 km or higher via a rocket transmits and receives signals with a ground terminal (1210), and also transmits and receives signals with a ground station (1220) connected to a ground base station (DU farm) (1230).

[0277] FIG. 13 is a diagram illustrating a utilization scenario of satellite-terminal direct communication according to one embodiment. Satellite-terminal direct communication can support specialized communication services by complementing the coverage limitations of terrestrial networks. For example, by implementing a satellite-terminal direct communication function in a user terminal, transmission and reception of emergency rescue and / or disaster signals for users outside of terrestrial network communication coverage are possible (1300), mobile communication services can be provided to users in areas where terrestrial network communication is not possible, such as ships and / or aircraft (1310), real-time tracking and control of the locations of ships, trucks and / or drones, etc., without border restrictions (1320), and by supporting a satellite communication function in a base station, it is possible to utilize satellite communication to function as a backhaul of the base station and perform the backhaul function when physically distant (1330).

[0278] FIG. 14 is a diagram illustrating an example of calculating an expected data transmission rate (throughput) in the uplink when a LEO satellite at an altitude of 1200 km and a ground terminal directly communicate with each other according to one embodiment. When the effective isotropic radiated power (EIRP) of the ground terminal in the uplink is 23 dBm, the path loss of the wireless channel to the satellite is 169.8 dB, and the satellite receiving antenna gain is 30 dBi, the achievable signal-to-noise ratio (SNR) is estimated to be -2.63 dB. In this case, the path loss may include path loss in space, loss in the atmosphere, etc. Assuming that the signal-to-interference ratio (SIR) is 2 dB, the signal-to-interference and noise ratio (SINR) is calculated to be -3.92 dB, and when using a 30 kHz subcarrier spacing and 1 PRB frequency resource, a transmission rate of 112 kbps can be achieved.

[0279] FIG. 15 is a diagram illustrating an example of calculating the expected data transmission rate (throughput) in the uplink when a GEO satellite at an altitude of 35,786 km and a ground terminal perform direct communication according to one embodiment. When the transmission power EIRP of the ground terminal in the uplink is 23 dBm, the path loss of the wireless channel to the satellite is 195.9 dB, and the satellite receiving antenna gain is 51 dBi, the achievable SNR is estimated to be -10.8 dB. In this case, the path loss may include the path loss in space and the loss in the atmosphere. Assuming the SIR is 2 dB, the SINR is calculated to be -11 dB, and in this case, when using a 30 kHz subcarrier spacing and a frequency resource of 1 PRB, a transmission rate of 21 kbps may be achieved, which may be the result of performing three repeated transmissions.

[0280] Figure 16 is a diagram illustrating path loss values ​​according to a path loss model between a terminal and a satellite according to one embodiment, and path loss according to a path loss model between a terminal and a terrestrial network communication base station. In Figure 16, d corresponds to distance, and f c is the frequency of the signal. In free space where communication between a terminal and a satellite is performed, the path loss (FSPL, 1600) is inversely proportional to the square of the distance, but on the ground where air exists, where communication between a terminal and a terrestrial gNB is performed, the path loss (PL2, PL') is inversely proportional to the square of the distance. Uma-NLOS , 1610, 1620) is inversely proportional to almost the fourth power of the distance. d 3D means the straight-line distance between the terminal and the base station, and h BS is the height of the base station, h UT is the height of the terminal. d' BP = 4 xh BS xh UT xf c / c is calculated, where fc is the center frequency in Hz and c is the speed of light in m / s.

[0281] In satellite communications (or Non-Terrestrial Networks, NTN), the Doppler shift, or frequency shift (offset) of the transmitted signal occurs as the satellite continuously moves rapidly.

[0282] Figure 17 is a diagram illustrating a formula and result for calculating the amount of Doppler shift experienced by a signal transmitted from a satellite when received by a ground user according to the altitude and position of the satellite and the position of the terminal user on the ground according to one embodiment. The radius of the Earth is R, h is the altitude of the satellite, v is the speed at which the satellite orbits the Earth, and f c is the frequency of the signal. The speed of the satellite can be calculated from the altitude of the satellite, which is the speed at which the gravitational force, which is the force that pulls the satellite towards the Earth, and the centripetal force generated as the satellite orbits become equal, and this can be calculated as shown in Fig. 18.

[0283] Fig. 18 is a diagram illustrating the velocity of a satellite calculated at the altitude of the satellite according to one embodiment. As can be seen in Fig. 17, each α is determined by the elevation angle θ, and therefore the value of the Doppler shift is determined according to the elevation angle θ.

[0284] FIG. 19 is a diagram illustrating the Doppler shift experienced by different terminals within a single beam transmitted from a satellite to the ground according to one embodiment. In FIG. 19, the Doppler shift experienced by terminal 1 (1900) and terminal 2 (1910) according to the elevation angle θ are each calculated. The results are assuming a center frequency of 2 GHz, a satellite altitude of 700 km, a beam diameter of 50 km from the ground, and a terminal speed of 0. In addition, the Doppler shift calculated in this disclosure ignores the effect of the Earth's rotation speed, because the effect is considered to be small because the Earth's rotation speed is slow compared to the satellite's speed.

[0285] Figure 20 is a diagram illustrating the difference in Doppler shift occurring within a beam depending on the position of the satellite determined based on the elevation angle according to one embodiment. It can be seen that the difference in Doppler shift within the beam (or cell) is largest when the satellite is located directly above the beam, i.e., when the elevation angle is 90 degrees. This may be because when the satellite is located above the center, the Doppler shift values ​​at one end of the beam and the other end have positive and negative values, respectively.

[0286] Meanwhile, satellite communication has a large delay time compared to terrestrial network communication because the satellite is far from the user on the ground.

[0287] FIG. 21 is a diagram illustrating the delay time from a terminal to a satellite and the round-trip delay time between a terminal, a satellite, and a base station, based on the satellite's position determined based on an elevation angle according to one embodiment. The first graph (2100) illustrates the delay time from a terminal to a satellite, and the second graph (2110) illustrates the round-trip delay time between a terminal, a satellite, and a base station. In this case, the delay time between the satellite and the base station is assumed to be equal to the delay time between the terminal and the satellite.

[0288] Figure 22 is a diagram illustrating the maximum difference in round-trip delay time that varies depending on the user's location within a beam, according to one embodiment. For example, when the beam radius (or cell radius) is 20 km, the difference in round-trip delay time to the satellite experienced by terminals at different locations within the beam, depending on the satellite's location, can be considered to be approximately 0.28 ms or less.

[0289] In satellite communications, when a terminal transmits and receives signals with a base station, it can mean that the signals are transmitted via a satellite. In other words, in the downlink, the base station transmits a signal to the satellite, which then receives and transmits it to the terminal. In the uplink, the satellite receives a signal transmitted by the terminal and then transmits it to the base station. The satellite can either perform a frequency shift after receiving the signal and then transmit it, or it can perform signal processing, such as decoding and re-encoding, based on the received signal before transmitting it.

[0290] For LTE or NR, the terminal can connect to the base station through the following procedure.

[0291] - Step 1: The terminal receives a synchronization signal (or a synchronization signal block (SSB), which may include a broadcast signal) from the base station. The synchronization signal may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The synchronization signal may include information such as slot boundaries, frame numbers, downlink, and uplink settings of a signal transmitted by the base station. In addition, through the synchronization signal, the terminal can obtain subcarrier offsets, scheduling information for transmitting system information, etc.

[0292] - Step 2: The terminal receives system information (System Information Block: SIB) from the base station. The SIB may include information for initial access and random access. The information for performing random access may include resource information for transmitting a random access preamble.

[0293] - Step 3: A random access preamble (or message 1, msg1) is transmitted to the random access resource set in Step 2. The preamble may be a signal determined based on the information set in Step 2 using a predetermined sequence. The base station receives the preamble transmitted by the terminal. The base station attempts to receive the preamble set in the resource set by the base station itself without knowing which terminal transmitted the preamble, and if the reception is successful, it can know that at least one terminal transmitted the preamble.

[0294] - Step 4: When the preamble is received in Step 3, the base station transmits a random access response (RAR, or message 2, msg2) in response thereto. The terminal that transmitted the random access preamble in Step 3 can attempt to receive the RAR transmitted by the base station in this step. The RAR is transmitted on the PDSCH, and the PDCCH that schedules the PDSCH is transmitted together with or in advance. A CRC scrambled with an RA-RNTI value is added to the DCI that schedules the RAR, and the DCI (and CRC) are channel-coded and then mapped to the PDCCH and transmitted. The RA-RNTI can be determined based on the time and frequency resources on which the preamble in Step 3 is transmitted.

[0295] The maximum time limit until the terminal that transmitted the random access preamble in step 3 receives the RAR in this step can be set in the SIB transmitted in step 2. The maximum time limit can be set to a maximum of 10 ms or 40 ms, for example. That is, if the terminal that transmitted the preamble in step 3 does not receive the RAR within a time determined based on the maximum time set, for example, 10 ms, the preamble can be transmitted again. The RAR can include scheduling information that allocates resources for a signal to be transmitted by the terminal in the next step, step 5.

[0296] Fig. 23 is a diagram illustrating an example of an information structure (MAC payload) of a random access response (RAR) according to one embodiment. This may be the MAC payload format (fallback RAR) of Msg B. The RAR (2300) may be, for example, a MAC PDU, and may also include information (2310) about a timing advance (TA) to be applied by the terminal and a temporary C-RNTI value (2320) to be used from the next step.

[0297] * R field: A reserved bit, which can be set to "0", for example.

[0298] * Timing Advanced Command field (2310): The Timing Advanced Command field is an index value T used to control the amount of timing adjustment that the MAC entity should apply. A . The size of the above timing advance command field may be, for example, 12 bits.

[0299] * UL Grant field: The UL Grant field indicates the resources to be used in the uplink, and the size of the UL Grant field is, for example, 27 bits.

[0300] * Temporary C-RNTI field (2320): The temporary C-RNTI field indicates a temporary identifier used by the MAC entity during random access, and the size of the temporary C-RNTI field can be, for example, 16 bits.

[0301] - Step 5: The terminal that received the RAR in Step 4 transmits Message 3 (msg3) to the base station according to the scheduling information included in the RAR. The terminal may include its own unique ID value in msg3 and transmit it. The base station may attempt to receive msg3 according to the scheduling information it transmitted in Step 4.

[0302] - Step 6: The base station receives msg3, verifies the ID information of the terminal, and then generates message 4 (msg4) including the ID information of the terminal and transmits it to the terminal. The terminal that transmitted msg3 in step 5 can then attempt to receive msg4 to be transmitted in step 6. The terminal that receives msg4 can compare the ID value included in msg4 after decoding it with the ID value transmitted by the terminal in step 5 to determine whether the msg3 transmitted by the terminal was received by the base station. There may also be a limit to the time between the terminal transmitting msg3 in step 5 and receiving msg4 in this step, and this maximum time may also be set from the SIB in step 2.

[0303] When applying the initial access procedure using the aforementioned steps to satellite communications, the propagation delay time required in satellite communications can become a problem. For example, in step 3, the terminal transmits a random access preamble (or PRACH preamble), and in step 4, the period (random access window) during which the RAR can be received, i.e., the maximum time required for reception, can be set via ra-ResponseWindow. In conventional LTE or 5G NR systems, this maximum time can be set to a maximum of 10 ms.

[0304] FIG. 24 is a diagram illustrating an example of the relationship between a PRACH preamble configuration resource and a RAR reception time in an LTE system according to an embodiment, and FIG. 25 is a diagram illustrating an example of the relationship between a PRACH preamble configuration resource and a RAR reception time in a 5G NR system according to an embodiment. Referring to FIG. 24, in the case of LTE, a random access window (2410) starts 3 ms after transmitting (2400) a PRACH (random access preamble), and when a terminal receives (2420) a RAR within the random access window, it can determine that the transmission of the PRACH preamble is successful. Referring to FIG. 25, in the case of NR, a random access window (2510) starts from a control information area for RAR scheduling that first appears after transmitting (2500) a PRACH (random access preamble). If the terminal receives RAR (2520) within the above random access window, it can be determined that the transmission of the PRACH preamble was successful.

[0305] For example, the TA for uplink transmission timing in a 5G NR system can be determined as follows. First, Tc = 1 / (Δf max ·N f ) is determined, where Δf max =480·10 3 Hz and N f =4096. Also, k=T s / T c =64, Ts=1 / (Δf ref ·N f,ref ), Δf ref =15·10 3 Hz, N f,ref =2048 can be defined respectively.

[0306] Fig. 26 is a diagram illustrating an example of downlink frame and uplink frame timing in a terminal according to one embodiment. The terminal transmits an uplink frame based on the downlink frame timing. TA =(N TA +NTA,offset )T C Uplink transmission can be performed as early as N TA The value of can be passed through RAR or determined based on MAC CE, and N TA,offset may be a value set to the terminal or determined based on a predetermined value.

[0307] In RAR of 5G NR system, T A You can indicate the value, and in this case, T A may indicate one of the values ​​0, 1, 2, ..., 3846. In this case, the subcarrier spacing (SCS) of RAR If kHz, N TA is N TA =T A ·16·64 / 2 μ is determined. After the terminal completes the random access process, it can receive a change value of TA from the base station, which can be indicated through MAC CE, etc. T indicated through MAC CE A The information can indicate one of the values ​​0, 1, 2, ..., 63, which is added to or subtracted from the existing TA value to calculate a new TA value, and the resulting TA value is N TA_new =T A_old +(T A -31)·16·64 / 2 μ It can be newly calculated as follows. The TA value indicated in this way can be applied to uplink transmission by the terminal after a certain period of time.

[0308] Figure 27 is a diagram illustrating an example of the continuous movement of a satellite relative to a terminal located on or above the Earth's surface as the satellite orbits the Earth according to one embodiment. Since the distance between the terminal and the satellite varies depending on the elevation angle at which the terminal views the satellite, the propagation delay between the terminal, the satellite, and the base station varies.

[0309] FIG. 28 is a diagram illustrating an example of the structure of a satellite according to one embodiment. The satellite may be configured with a solar panel or solar array (2800) for solar or solar thermal power generation, a main mission antenna (2810) for communication with a terminal, a feeder link antenna (2820) for communication with a ground station, an inter-satellite link (2830) for communication between satellites, and a processor for controlling transmission and reception and performing signal processing, etc. However, the present disclosure is not limited thereto, and the satellite in the present disclosure may include more or fewer components than those illustrated in FIG. 28. In addition, according to one embodiment, if the satellite does not support inter-satellite communication, an antenna for transmitting and receiving signals between satellites may not be arranged. Although FIG. 28 illustrates the use of the L band of 1 to 2 GHz for communication with the terminal, it may also be possible to use high-frequency bands such as the K band (18 to 26.5 GHz), Ka band (26.5 to 40 GHz), and Ku band (12 to 18 GHz).

[0310] Additionally, in various embodiments of the present disclosure, the term "base station (BS)" may refer to any component (or set of components) configured to provide wireless access, such as a transmit point (TP), a transmit-receive point (TRP), an enhanced node B (eNodeB or eNB), a 5G base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wireless enabled devices, based on the type of wireless communication system. The base stations may provide wireless access according to one or more wireless protocols, such as 5G 3GPP new radio interface / access (NR), long term evolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc.

[0311] Additionally, in various embodiments of the present disclosure, the term "terminal" may represent any component such as "user equipment (UE), "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receive point," or "user device." For convenience, the term "terminal" is used in various embodiments of the present disclosure to represent a device that accesses a base station, regardless of whether the terminal is considered a mobile device (such as a mobile phone or a smart phone) or a stationary device (such as a desktop computer or a vending machine).

[0312] Additionally, in various embodiments of the present disclosure, the term “TA” may be used interchangeably with “TA information,” “TA value,” or “TA index.”

[0313] In various embodiments of the present disclosure, data or control information transmitted by a base station to a terminal may be referred to as a first signal, and an uplink signal associated with the first signal may be referred to as a second signal. For example, the first signal may include DCI, UL grant, PDCCH, PDSCH, RAR, etc., and the second signal associated with the first signal may include PUCCH, PUSCH, msg 3, etc.

[0314] In addition, there may be an association between the first signal and the second signal. For example, if the first signal is a PDCCH including a UL grant for uplink data scheduling, the second signal corresponding to the first signal may be a PUSCH including uplink data. Meanwhile, the gap between the times at which the first signal and the second signal are transmitted and received may be a value pre-determined between the terminal and the base station. Alternatively, the gap between the times at which the first signal and the second signal are transmitted and received may be determined by an instruction from the base station or by a value transmitted through upper layer signaling.

[0315] In direct terminal-satellite communication, the distance between the terminal and the satellite and the satellite and the base station is long, and the satellite is constantly moving, so that when a signal transmitted by the base station or terminal is received by the terminal or the base station, a time offset due to delay time, etc. occurs. Therefore, the present disclosure provides a method and device in which the base station indicates time offset information so that the terminal can correct the time offset. Although the embodiments below are described assuming communication between the terminal and the satellite and the ground station, the case in which the satellite base station and the terminal communicate is not excluded. In the present disclosure, the time offset may be used interchangeably with timing advance. The methods and devices provided in various embodiments of the present disclosure can be applied not only to satellite communication systems but also to terrestrial communication systems. In addition, the embodiments below may be operated in combination with each other.

[0316] [First embodiment]

[0317] In a first embodiment of the present disclosure, when a terminal transmits an uplink signal to a satellite or a base station, a method and device for directly determining (for example, calculating) a TA value by the terminal itself and applying the determined TA value are described. In addition, in the first embodiment of the present disclosure, a method and device for allowing the base station or satellite to indicate to the terminal a TA value to be applied when the terminal transmits an uplink signal to the satellite or base station, and thus the terminal transmits the uplink signal by applying the indicated TA value is described. In addition, in the first embodiment of the present disclosure, a method and device for adaptively determining a TA value to be applied when the terminal transmits an uplink signal to the satellite or base station are described. More specifically, in the first embodiment of the present disclosure, a method and device for adaptively selecting one of a method in which the terminal determines a TA value by itself and a method in which the base station or satellite indicates a TA value to the terminal as described in the present disclosure and the terminal applies the indicated TA value are described.

[0318] First, the terminal compares the uplink transmission time with the downlink reception time for uplink synchronization, and based on the comparison result, sets the uplink transmission time to T later than the downlink reception time. TA It can be brought forward as much as T calculated for TA for satellite communication TA can be expressed as in the following mathematical formula 5.

[0319] [Equation 5]

[0320] T TA = (N TA + N TA,UE-specific + N TA,common + N TA,offset ) T C

[0321] In the above mathematical expression 5, T c is T c = 1 / (Δfmax ·N f ) can be given as Δf max =480·10 3 Hz and N f =4096. In mathematical expression 5, N TA T included in RAR or MAC CE received from base station A It is a value determined based on values, etc., and N TA,offset can be a fixed or promised value in advance. In Equation 5, N TA,UE-specific is the TA correction value measured by the terminal based on the position (or reference position) of the terminal itself and the satellite, and N TA,common may be a TA correction value set or indicated by the base station using upper signaling or physical layer signals.

[0322] Mathematical expression 5 is compared with the conventional TA application method, Mathematical expression 6 below, in terms of N TA,UE-specific Wow N TA,common It may be a formula with added parameters.

[0323] [Equation 6]

[0324] T TA = (N TA + N TA,offset ) T c

[0325] Figure 29 shows the initial connection procedure of a terminal according to one embodiment and the terminal is N TA is a flowchart illustrating a procedure for determining a terminal. Fig. 30 illustrates an initial connection procedure of a terminal according to one embodiment and a terminal N TA , N TA,UE-specific , N TA,common This is a flowchart illustrating the procedure for determining .

[0326] Referring to Figure 29, the terminal is N TA =0 is applied to transmit the PRACH preamble to the base station, and the base station transmits N TA The RAR that instructs the terminal is transmitted. After that, the terminal sends N TA =A is applied to transmit PUSCH, and the base station transmits ΔNTA transmits a MAC CE indicating N to the terminal. After that, the terminal sends N TA =A+ΔN TA PUSCH is transmitted by applying .

[0327] Referring to Figure 30, the base station provides satellite information and N TA,common and transmits setting information including drift rate to the terminal. After that, the terminal N TA Assuming =0, N measured by yourself TA,UE-specific and set N TA,common The PRACH preamble is transmitted to the base station by applying N . After that, the base station transmits the PRACH preamble to the base station. TA Send RAR to the terminal, indicating N TA,UE-specific and N TA,common can be updated. After that, the terminal will be N TA Assuming =A, T is calculated according to mathematical formula 5 TA The base station transmits PUSCH according to ΔN TA MAC CE indicating the destination can be transmitted to the terminal. After that, N TA,UE-specific and N TA,common can be updated, and the terminal is N TA =A+ΔN TA Updated N by applying TA,UE-specific and N TA,common T calculated according to mathematical formula 5 by applying TA PUSCH can be transmitted according to the following.

[0328] T TA is transmitted in RAR or msg B A = Based on 0, 1, 2, ..., 3846, N TA =T A ·16·64 / 2 μ can be determined as . Also, T as MAC CE A = 0, 1, 2,..., 63 are transmitted, N TA_new =N TA_old +(T A -31)·16·64 / 2 μ can be updated. Also, Δfmax· N f , T transmitted in RAR or msg B A or T transmitted from MAC CE A The values ​​may change depending on the communication system. And the T transmitted from the MAC CE A Based on N TA_new =N TA_old +(T A -M)·16·64 / 2 μ When the terminal performs a TA update as follows, if T A If the maximum value for is greater than 63, the value of M may be greater than or equal to 31, and T A If the maximum value for is less than 63, the terminal updates N based on the value of M less than or equal to 31. TA Value N TA_new can decide.

[0329] Fig. 31 is a diagram illustrating the operation of a terminal in a wireless communication system according to one embodiment.

[0330] Referring to FIG. 31, the terminal may perform an initial connection procedure according to the process described in FIG. 31, and may determine a TA after performing the initial connection procedure, which is described in detail as follows.

[0331] First, in operation 3111, the terminal detects a synchronization signal and PBCH block (SSB) received from the base station. In operation 3113, the terminal decodes system information blocks (SIBs) based on the detected SSBs. Here, the terminal can detect information about random access channel (RACH) resources by decoding the SIBs.

[0332] In operation 3115, the terminal obtains (or decodes) satellite information by decoding SIBs. Here, the satellite information may include at least one of various parameters such as satellite position information. In operation 3115, the terminal obtains a UE-specific TA correction value, for example, N, based on the position (or reference position) of the terminal itself and the satellite based on the obtained satellite information. TA,UE-specific can be obtained. In operation 3117, the terminal decodes the SIBs to obtain a common TA offset, e.g., N TA,common Obtain (or decode) .

[0333] At action 3119, the terminal is N TA,UE-specific Wow N TA,common TAs can be calculated based on the calculated TAs, and a PRACH is transmitted to the base station by applying the calculated TAs. In operation 3121, the terminal receives an RAR including a TA value as a response to the PRACH transmission. In operation 3123, the terminal adjusts the TA based on the received RAR.

[0334] In operation 3125, the terminal transmits msg3 to the base station by applying TA. Here, msg3 represents a message transmitted on the uplink shared channel (UL-SCH) including a C-RNTI MAC CE or a common control channel (CCCH) SDU as part of a random access procedure, and may be the first scheduled transmission of the random access procedure. In operation 3127, the terminal receives a MAC CE including a TA adjustment value from the base station. In operation 3129, the terminal transmits a PUSCH or / and a PUCCH by applying TA based on the TA adjustment value included in the MAC CE.

[0335] The operation process of the terminal as described in FIG. 31, that is, the process of performing the initial connection procedure and determining the TA after performing the initial connection procedure, can be summarized as shown in Table 24 below when compared with the operation process of the terminal in other embodiments of the present disclosure.

[0336]

[0337] Additionally, the order of some operations in the terminal operation process described in FIG. 31 may be changed, and for example, the order of the operation of decoding satellite information and the operation of decoding common TA offset may be changed.

[0338] Meanwhile, while the operation process of a terminal in a communication system according to various embodiments of the present disclosure is illustrated with reference to FIG. 31, the present disclosure may include various embodiments that are modifications of FIG. 31. For example, although FIG. 31 illustrates sequential steps, it is to be understood that the steps described in FIG. 31 may overlap, occur in parallel, occur in a different order, or one or more steps may occur multiple times.

[0339] Fig. 32 is a diagram illustrating the operation of a terminal in a wireless communication system according to one embodiment.

[0340] The terminal may perform an initial connection procedure according to the process described in FIG. 32, and may determine a TA after performing the initial connection procedure, which is described in detail as follows. In particular, FIG. 31 illustrates an operation process of a terminal based on a random access procedure for a 4-step random access (RA) type, and the operation process of the terminal illustrated in FIG. 32 may be an operation process of a terminal based on a random access procedure for a 2-step RA type.

[0341] First, in operation 3211, the terminal detects an SSB received from the base station. In operation 3213, the terminal decodes SIBs based on the detected SSBs. Here, the terminal can obtain information about RACH resources by decoding the SIBs.

[0342] In operation 3215, the terminal obtains (or decodes) satellite information by decoding SIBs. The satellite information may include at least one of various parameters, such as satellite position information. In operation 3215, the terminal obtains a UE-specific TA correction value, for example, N, based on the position (or reference position) of the terminal and the satellite based on the decoded satellite information. TA,UE-specific can be obtained. In operation 3217, the terminal decodes the SIBs to obtain a common TA offset, for example, N TA,common can be obtained (or decoded). In operation 3219, the terminal receives N TA,UE-specific Wow N TA,common Based on the TAs, the UE calculates TAs and transmits msgA to the base station by applying the calculated TAs. Here, msgA may be preamble and payload transmissions of a random access procedure for a 2-step random access (RA) type. In operation 3221, the UE receives msgB including a TA value from the base station. Here, msgB may include response(s) for contention resolution, fallback indication(s), and backoff indication as a response to msgA in the random access procedure for the 2-step RA type. In operation 3223, the UE adjusts the TA based on the TA adjustment value included in msgB. In operation 3225, the UE transmits a PUSCH or / and a PUCCH by applying the adjusted TA.

[0343] The operation process of the terminal as described in FIG. 32, that is, the process of performing the initial connection procedure and determining the TA after performing the initial connection procedure, can be summarized as shown in Table 25 below when compared with the operation process of the terminal in other embodiments of the present disclosure.

[0344]

[0345] Additionally, the order of some operations in the terminal operation process described in FIG. 32 may be changed, and for example, the order of the operation of decoding satellite information and the operation of decoding common TA offset may be changed.

[0346] Meanwhile, while the operation process of a terminal in a communication system according to various embodiments of the present disclosure has been disclosed with reference to FIG. 32, the present disclosure may include various embodiments that are modifications of FIG. 32. For example, although FIG. 32 illustrates sequential steps, it should be understood that the steps described in FIG. 32 may overlap, occur in parallel, occur in a different order, or one or more steps may occur multiple times.

[0347] Meanwhile, N used in the embodiments of the present disclosure TA,UE-specific is the value calculated and applied by the terminal. Therefore, the base station calculates N calculated by the terminal. TA,UE-specific The value may not be known. Also, N calculated by the terminal in this way TA,UE-specific Values ​​may change over time due to movement of the satellite or terminal.

[0348] Therefore, in embodiments of the present disclosure, the base station may have N that can change over time. TA,UE-specific It may be necessary to control the TA of the terminal considering the value, and thus the terminal may be N TA,UE-specificIt may be necessary to set the point in time at which the value is updated. Therefore, the terminal may set N based on one of the following methods, for example, one of Methods 1-1 to 1-6, or a method combining at least two of Methods 1-1 to 1-6. TA,UE-specific You can update the value.

[0349] - Method 1-1: The terminal always receives N whenever an SIB containing satellite information (e.g., including satellite information, etc.) is received. TA,UE-specific Method 1-1 can be applied when the terminal determines that SIB is received from the base station or when a paging signal instructing SIB update is received from the base station.

[0350] - Method 1-2: Base station is TA, for example N TA,UE-specific The rate of change of TA can be separately instructed, and also the cycle and offset for updating the TA value, for example, recalculating the TA value according to the rate of change of TA, can be set. In this case, the terminal updates the TA, for example, N, at a time determined by the update cycle and offset. TA,UE-specific The amount of TA updated by the terminal may be determined based on the rate of change of the TA. In various embodiments of the present disclosure, the base station may indicate the rate of change of the TA based on an explicit or implicit method.

[0351] - Method 1-3: The base station determines whether the terminal is N based on the satellite's location and the terminal's location. TA,UE-specific The update cycle and offset for updating the TA can be set. In this case, the terminal can update the TA at the corresponding time determined according to the update cycle and offset set by the base station. In various embodiments of the present disclosure, the base station can indicate the update cycle and offset based on an explicit or implicit method.

[0352] - Method 1-4: The terminal performs uplink transmission (e.g., PUCCH / PUSCH, PRACH, SRS transmission, etc.) at least in some cases (performed every time, or at regular intervals, or at irregular times), for example, N at the slot time. TA,UE-specific You can always update and apply it.

[0353] - Method 1-5: The terminal determines N based on the time when the TA command transmitted by the base station through MAC CE expires. TA,UE-specific updates. For example, when the TA expires, the terminal TA,UE-specific . At this time, the expiration of the TA command may mean that the timer value for the TA command has reached a certain point in time based on the timer for the TA command. The timer for the TA command may be set to timeAlignmentTimer, which may be a parameter regarding how long the uplink time synchronization lasts. When a new TA command is received, the terminal may start or restart timeAlignmentTimer. When timeAlignmentTimer expires, the terminal may empty the HARQ buffer and reconfigure RRC settings, etc.

[0354] - Method 1-6: N TA,UE-specific A new timer timeAlignmentTimer_UEspecific is introduced, and the terminal can use N based on the new timer timeAlignmentTimer_UEspecific. TA,UE-specific can be updated. timeAlignmentTimer_UEspecific is when the terminal is N TA,UE-specific Recalculate or N TA,UE-specific When transmitting information about the UE to the base station, it can be started or restarted. When timeAlignmentTimer_UEspecific expires, the UE is N TA,UE-specificUpdate by recalculating or N TA,UE-specific can be set to 0, or PRACH transmission can be performed.

[0355] [Second Embodiment]

[0356] A second embodiment provides a method and device for a terminal to transmit (report) a timing advance (TA) value that it is applying or has applied to a base station or satellite. In the present disclosure, a "satellite" may be an object located high above the ground, and may include aircraft, airships, and the like.

[0357] A terminal may perform an operation to transmit the TA value it is applying to the base station. This may be to inform the base station of the applied TA value when the terminal applies the TA value without a separate instruction from the base station, or to confirm or determine how the terminal is applying the TA value indicated by the base station. For example, this operation may be performed when the satellite to which the terminal is connected changes so that the newly connected satellite can check the terminal's TA value. For example, the terminal may independently apply a TA calculated based on the positions of the terminal and the satellite.

[0358] A terminal may use one or a combination of two or more of the following methods to report a TA value to a base station.

[0359] - Method 2-1: The base station can trigger the TA value reporting of the terminal through DCI. The base station can trigger the TA value reporting through some bit field values ​​of the DCI or a combination of bit field values. If a field indicating the TA value reporting trigger is included in the DCI and in this case, if the above-mentioned field of the received DCI is set to a specific value, the terminal can understand that the TA value reporting is triggered. Alternatively, if the value of one or more fields (for example, for other purposes) included in the DCI is set to a predetermined value, the terminal can understand that the TA value reporting is triggered. The terminal can transmit the TA value at a specific point in time based on the point in time when the DCI is received to the base station.

[0360] - Method 2-2: The base station can trigger the terminal's TA value reporting through the MAC CE. The base station can trigger the TA value reporting using some bit values ​​or bit field values ​​of the MAC CE, and the terminal can transmit the TA value at the time of receiving the MAC CE or at a certain time after the time of receiving the MAC CE to the base station.

[0361] - Method 2-3: The base station can instruct the terminal which TA value to report through RRC configuration. For example, the base station can determine the time point at which the terminal reports the TA value by setting the period and offset value for TA reporting and / or specific conditions for the terminal to report the TA value through upper signaling. In this case, the base station can also specify the reference TA value application time (i.e., the time at which the TA value to be reported is applied, which can be referred to as the TA value reference time point). The specific conditions for the terminal to report the TA value may be, for example, when the TA value is greater than or equal to a predetermined value, or when the distance between the terminal and the satellite is greater than or equal to a predetermined value. The predetermined values ​​may be set by upper signaling, may be information transmitted in SIB, etc., or may be fixed values.

[0362] - Method 2-4: The terminal can report the TA value without a separate trigger from the base station. For example, Method 4 may be that the terminal transmits information indicating the TA value to the base station according to a specific condition, and the specific condition may be a condition that is predetermined, such as a time for performing TA value reporting (without signaling such as DCI, MAC CE, RRC, etc. for triggering from the base station) or a condition regarding the result of comparing the TA value applied by the terminal with a specific threshold value, etc.

[0363] When transmitting TA values ​​as described above, the terminal may transmit the TA value information to the base station using a physical channel such as PUCCH or PUSCH, or via higher-level signaling. When the terminal transmits the TA value information using a physical channel, the resources to be used for reporting the TA value information may be configured via higher-level signaling.

[0364] Reporting the TA value means that T in the above mathematical formula TA value or N TA,UE-specific It may be that the value is reported. Or, T TA Wow N TA,UE-specific The base station can configure which of these to report to the terminal through SIB or higher-level signaling.

[0365] The reference time for determining the TA value reported by the terminal and the time for reporting the TA value can be determined based on the time at which the terminal performs the TA value report, the time at which the TA value report is triggered, etc. For example, if the TA value report is triggered by DCI in slot n, the terminal can report the TA value applied or calculated in slot nK, and the terminal can report the TA value to the base station in slot n+N. K and N can be values ​​determined according to the subcarrier spacing, UE capability, DL / UL configuration of the slot, PUCCH resource configuration, etc., respectively.

[0366] K can be 0. K=0 can mean that the terminal reports the TA value based on the time point when the TA value reporting triggering signal is received. In addition, K can be a value less than 0, and K less than 0 can mean that, for example, the terminal pre-calculates the TA value at the time point when the TA value is reported and generates and reports the report information. In addition, K can be an integer value greater than 0. This can mean that the terminal reports the TA value earlier than the time point when the terminal reports the TA value (for example, slot n+N). This can be because the terminal needs time to encode the information to be reported and prepare for transmission, so it may report the TA value earlier.

[0367] Fig. 33 illustrates the operation of a base station for reporting a TA value of a terminal according to one embodiment. Fig. 34 illustrates the operation of a terminal for reporting a TA value of a terminal according to one embodiment. When reporting a TA value of the present disclosure, the TA value applied by the terminal may be indicated in units of ms, slots, or symbols, or may be provided as information including a decimal point value rather than an integer. The report of a TA value of the present disclosure may include an absolute value of the TA, but may also include a TA value indicated from a previous base station, a relative TA value excluding a predetermined TA value, or a change in the TA value (which may be, for example, a change in TA over a certain period of time).

[0368] Figure 33 is a diagram illustrating the operation of a base station. The base station transmits configuration information related to TA reporting through upper layer signaling (3300). The configuration information related to TA reporting may include at least one of information for configuring TA reporting, such as a period and offset at which TA reporting is to be performed, a TA reporting trigger condition, information on a TA value reference point in time, the type of TA information to be reported, and resource configuration information for which TA reporting is to be performed. The base station triggers a TA report to a terminal (operation 3310). This trigger may be performed, for example, through upper layer signaling or DCI of the specific content described above, but may also be omitted. The base station receives the TA report transmitted by the terminal according to the transmitted configuration information (operation 3320).

[0369] Figure 34 is a diagram illustrating the operation of a terminal. The terminal receives configuration information related to a TA report transmitted by a base station through upper layer signaling (operation 3430). This configuration information may include at least one of information for configuring a TA report, such as a period and offset at which the TA report is to be performed, a TA report trigger condition, information on a TA value reference point in time, the type of TA information to be reported, and resource configuration information for which the TA report is to be performed. The terminal receives a signal that triggers a TA report transmitted by the base station (operation 3440). This trigger may be performed, for example, through upper layer signaling or DCI of the specific content described above, but may also be omitted. The terminal transmits a TA report according to the received configuration information (operation 3420). For example, if the terminal receives TA report resource information, it transmits a TA report on the configured resource. Each step disclosed in Figures 33 and 34 may be applied with the order changed, and other steps may be added or omitted.

[0370] [Third Embodiment]

[0371] In the third embodiment, N described through the first and second embodiments TA,UE-specific It provides a method for the terminal to calculate, decide and report N TA,UE-specific The value may be calculated based on the terminal's distance from itself and a non-terrestrial network (NTN) satellite. The terminal may calculate its own position by receiving signals from navigation satellites in a satellite navigation system, and the navigation satellites may be different from the NTN satellites. However, the above method is merely an example of a method for the terminal to calculate its own position and does not limit the present disclosure. For example, the terminal may also receive its position from another entity.

[0372] The terminal can estimate the delay time between the satellite and the terminal based on its own position and the satellite's position, and can perform uplink transmission by correcting the estimated delay time value on its own. For example, a satellite transmits information about its own position through broadcast information, and the terminal can receive the information about the satellite's position transmitted by the satellite and compare it with its own position. The terminal's own position can be determined independently or in combination using information from one of several types of Global Positioning System (GPS) systems or base stations. Through the comparison, the terminal can estimate the time it takes for a radio wave to propagate to the satellite and calculate the uplink transmission time.

[0373] For example, if a terminal receives a signal in slot n in downlink at a specific point in time and needs to perform uplink transmission corresponding to the signal in slot n+k, the uplink transmission can be transmitted 2*Td earlier than slot n+k. The delay time Td may be the delay time from the terminal to the satellite calculated using the position information of the satellite and the terminal, or a corresponding value thereof. The delay time Td may be the distance from the terminal to the satellite or a corresponding value thereof divided by the speed of light, or a corresponding value thereof. The position of the satellite may be a value calculated based on slot n+k in which the terminal performs uplink transmission, for example. This is because the position of the satellite in slot n and the position of the satellite in slot n+k may differ depending on the movement of the satellite.

[0374] In terrestrial networks, propagation delay times of less than 1 ms occur considering the distance to the base station of up to about 100 km, but in satellite networks, the distance to the satellite can be thousands of km, and the distance from the satellite to the base station can also be thousands of km, so the delay time can be much greater than in the case of terrestrial networks.

[0375] Figure 35 illustrates the difference in propagation delay times between a terrestrial network and a satellite network according to one embodiment. In satellite network communication, the delay time varies depending on the altitude and orbital angle of the satellite. Figure 35 illustrates the terminal-satellite distance and the round-trip time of radio waves according to the altitude angle when the satellite altitude is 700 km. In the case of the satellite network, a low-orbit satellite is assumed, and when the altitude angle is 0 to 180°, it is illustrated that the radio round trip time (radio RTT, which may include the round-trip time for a signal to be transmitted between a transmitter and receiver and the processing time at the other node) may range from 40.9 ms to 9.3 ms. The above delay time is merely an example and may vary depending on the altitude and orbit of the satellite. For example, the average delay time may increase at high altitudes.

[0376] In terrestrial networks, since the maximum delay time is within 1 or 2 ms, the timing advance provided by LTE and 5G NR systems can be used to match the slot timing for transmitting the downlink from the base station's perspective with the slot timing for receiving the uplink (i.e., the indices of the DL slot and the UL slot can match). In other words, if the terminal performs uplink transmission ahead of the downlink timing by the timing advance value indicated by the base station, the uplink signal transmitted by the terminal will match the downlink timing of the base station when received by the base station. On the other hand, in satellite networks, it may be difficult to match the slot timing for transmitting the downlink from the base station's perspective with the slot timing for receiving the uplink using the timing advance provided by the existing LTE and 5G NR systems. This is because the propagation delay time in the satellite network is on the order of tens of ms, which is larger than the maximum value of the timing advance provided by the existing LTE and 5G NR systems.

[0377] A satellite navigation system may also be referred to as a Global Navigation Satellite System (GNSS), and the GNSS may include, for example, the GPS of the United States, the GLONASS of Russia, the Galileo of the EU, and the BeiDou of China, but is not limited thereto. The GNSS may include a Regional Navigation Satellite System (RNSS), and the RNSS may include, for example, the IRNSS of India, the QZSS of Japan, and the KPS of Korea. Meanwhile, a signal transmitted from the GNSS may include at least one of auxiliary navigation information, normal operation status of a satellite, satellite time, satellite ephemeris, satellite altitude, reference time, and information on various correction data.

[0378] Meanwhile, in various embodiments of the present disclosure, an NTN satellite may be a communication satellite that transmits a signal for a terminal to connect to a base station. In addition, in various embodiments of the present disclosure, a GNSS satellite may be a satellite that transmits a signal of a satellite navigation system. Meanwhile, the terminal may receive a signal from each of one or more GNSS satellites, calculate its own location based on the signals received from each of the one or more GNSS satellites, and also identify a reference time for each of the one or more GNSS satellites. If the terminal may calculate multiple locations as its own location based on signals received from multiple GNSS satellites, the terminal may determine a single location based on an average of the multiple locations, a location corresponding to a received signal with the strongest intensity among the multiple locations, or an average of the multiple locations based on signal intensity (for example, a method of applying a weight to a location corresponding to a signal with a strong signal intensity), and may determine the determined single location as the terminal's actual location. Here, the method by which the terminal calculates its own location based on signals received from the multiple GNSS satellites can be implemented in various forms, and a detailed description thereof will be omitted.

[0379] In various embodiments of the present disclosure, the time acquired from the GNSS or the time of the base station transmitted by the base station may be based on, for example, Coordinated Universal Time (UTC) time, which may be based on the time from 00:00:00 on January 1, 1900 in the Gregorian calendar. This may vary depending on the type of GNSS system, and a reference time zone as shown in Table 26 below may be used.

[0380]

[0381] In Table 26 above, NavIC may mean NAVigation with Indian Constellation, QZS may mean Quasi Zenith Satellite, QZSS may mean Quasi-Zenith Satellite System, QZST may mean Quasi-Zenith System Time, SBAS may mean Space Based Augmentation System, and BDS may mean BeiDou Navigation Satellite System.

[0382] Additionally, the base station can indicate, via satellite, the type of GNSS system that serves as the basis for the location or time information used by the base station itself, and can use an indicator as shown in Table 27 below, for example.

[0383]

[0384] As described above, the terminal can calculate the time required for a signal to be transmitted from an NTN satellite to the terminal based on its own location calculated by the terminal and the location of the NTN satellite received from the NTN satellite, and can determine a TA value based on this. When determining the TA value, the terminal can also consider the distance from the NTN satellite to a ground base station, or, if the signal is transmitted to the ground base station via another NTN satellite, the distance from the NTN satellite to another NTN satellite.

[0385] In contrast, the terminal can obtain reference time information from information transmitted by a GNSS satellite, compare the time information transmitted by the NTN satellite with the reference time information obtained from the GNSS satellite, and calculate the time required from the NTN satellite to the terminal (propagation delay) based on the comparison result.

[0386] The location and time information of NTN satellites can be transmitted from the base station to the terminal via SIB. This may be transmitted directly by the NTN satellite.

[0387] The distance between the terminal and the satellite or its corresponding value is d UE,sat (unit km) and the speed of light is v c When (unit km / sec), N TA,UE-specific is d UE,sat / v c (unit: sec) can be determined. For example, It can be determined and applied as (d UE,sat / v c )·(1 / T c ) integerize the value to N TA,UE-specific is a method that can be determined by. Or / and additionally, the terminal is N in a method such as a combination of at least one of the following three methods. TA,UE-specific Decide on N TA,UE-specific It will be able to report information to the base station.

[0388] - Method 3-1: Terminal is N TA,UE-specific =(D+a) / T C can be determined by . D is an integer, and a is a prime number greater than or equal to 0 and less than 1. Here, And, That is, Method 3-1 can be a method of dividing the propagation delay between the terminal and the satellite into integer and decimal parts, and reporting only the integer or its corresponding value, or reporting the integer and decimal or its corresponding values, respectively. By using this method, the number of bits used to report the propagation delay can be reduced. Here, the decimal part is T in the above. c It was explained to be an integer multiple of 16·64·T c / 2 μ may be determined to be a multiple of . μ may mean the subcarrier spacing of the current carrier or BWP, or the related CORESET. Or it may be a value used for transmit / receive signals such as PDSCH or PUSCH. Here, μ=0, 1, 2, 3, 4, 5 may be values ​​corresponding to the subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, and 480 kHz, respectively. Or μ may be N TA,UE-specific It can be set via upper signaling from the base station for determination. Alternatively, μ can be used as a fixed value, and for example, it can be used as one of the values ​​0, 1, 2, 3, 4, 5, such as μ=5.

[0389] - Method 3-2: Terminal is N TA,UE-specific Ga 16·64 / 2 μ It can be determined to be a multiple of N. This is TA,UE-specific = ·16·64 / 2 μ It can be determined as follows. In this disclosure can mean the largest integer not greater than x, which can be rounded down to the integer unit, that is, discarding the decimal value. However, it is not limited to this. For example, Instead of rounding down using μ, rounding up or down from a decimal place can be used instead. μ can mean the subcarrier spacing of the current carrier or BWP, SIB, or related CORESET. Or it can be a value used in a transmit / receive signal such as a PDSCH or PUSCH being transmitted / received. Here, μ=0, 1, 2, 3, 4, 5 can be values ​​corresponding to the subcarrier spacing of 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, 480 kHz, respectively. Alternatively, μ can be N TA,UE-specific can be set via upper signaling from the base station for the decision. Or μ can be used as a fixed value, for example, μ=5 can be used. Or N TA,UE-specific The μ to be used in the calculation can be set separately by the base station through SIB or higher-level signaling.

[0390] - Method 3-3: Terminal is N TA,UE-specific = T A,UE-specific ·16·64 / 2 μ Decided on T A,UE-specific is N TA,UE-specific go It can be determined by the integer that makes it closest to . Or, N TA,UE-specific can be determined as the minimum integer that satisfies N, or TA,UE-specific It can be determined as the maximum integer that satisfies .

[0391] - Method 3-4: Depending on the base station settings, the terminal is N TA,UE-specific =0 can be determined. This is because the propagation delay occurring in the link between the terminal and the satellite (which can be called a service link) is almost the same as that of the conventional TA mechanism and N because the terminals within the coverage area of ​​a specific beam of the satellite have little difference. TA,common This may be because uplink time synchronization can be achieved with the terminal NTA,UE-specific Value N TA,UE-specific =0 or N calculated based on the position of the satellite and terminal and the speed of light according to the GNSS signal. TA,UE-specific The base station can set whether to use the value through SIB. As another example, the base station calculates N based on the time when the terminal transmits the PRACH preamble based on the position of the satellite and the terminal and the speed of light according to the GNSS signal. TA,UE-specific Whether to continue to use the value until further instructions or settings are made, or to recalculate N for each uplink transmission. TA,UE-specific The value to be used can be set by SIB or separate RRC signaling. That is, in the above mathematical expression 5, as follows: N TA,UE-specific It may be determining the value.

[0392] N TA,UE-specific If set, it may include the UE's own estimated TA to pre-compensate for service link delay, and if not set, N TA,UE-specific The value can be 0. (N TA,UE-specific is UE self-estimated TA to pre-compensate for the service link delay if configured, and N TA,UE-specific is 0 otherwise.)

[0393] In the above methods 3-1 to 3-4, N is determined based on the distance between the terminal and the satellite (or its corresponding value) and the speed of light. TA,UE-specific The methods for determining are only examples and there may be more diverse methods. For example, in general, N TA,UE-specific When defining a value as an integer or defining an expression based on an integer value, to represent it as a multiple of a specific integer or rational number value K. or It can also be expressed as, where K can be a predetermined value or a value determined by signaling parameters. Method 2 is K = 16·64 / 2. μ This means that if K is μ or T c It may be determined by at least one of the same system parameters. In this way, N TA,UE-specific Instead of having a somewhat sparse granularity for values, it has the advantage of being able to express more diverse values ​​with the same bit signaling. In addition, in each of the above methods, Instead of using the floor operation like this, we round up to the decimal place ( ) or rounding ( ) and can also determine the values ​​based on operations, etc.

[0394] [Example 4]

[0395] In the fourth embodiment, N described through the first and second embodiments TA,common It provides a method for a base station to transmit data to a terminal and for the terminal to calculate and apply the data.

[0396] Below, the base station sets and instructs the terminal to N TA,common This is a method for a base station to transmit information to a terminal, and at least one or more of these methods can be applied in combination.

[0397] - Method 4-1: The base station can set an offset value to the terminal through RRC signaling. The value set through RRC signaling is T A,common and based on this, N TA,common can be decided.

[0398] - Method 4-2: The base station can instruct the terminal to provide an offset value through MAC CE. The value set through MAC CE is T A,common and based on this, N TA,commoncan be determined. This method is different from the case of using the above method 4-1 in that the base station and the terminal are N TA,common There is an advantage in that the base station and the terminal can clearly determine the point in time when applying the MAC CE. For example, N can be applied after a certain period of time from the point in time when the MAC CE is received or the point in time when an ACK for the reception of the MAC CE is transmitted. TA,common This can be applied. For example, the base station can transmit T in msec units through MAC CE 8 bits. A,common By passing N, you can indicate from 0ms to 255ms. At this time, N TA,common is N TA,common = T A,common / (1000·T c ) is determined as follows.

[0399] - Method 4-3: The base station can set one or more offset values ​​to the terminal through upper layer signaling. Alternatively, these values ​​can be preset. These preset values ​​are T A,common These are candidate values, and the base station can indicate one of them through MAC CE.

[0400] - Method 4-4: The base station can set an offset value to the terminal through SIB. The value set through SIB is T A,common and based on this, N TA,common can be decided. N TA,common Using the value, the terminal calculates and applies TA when transmitting the PRACH preamble during the initial connection process. Afterwards, ΔT is calculated through MAC CE. A,common is directed to the terminal, and the terminal uses this to N TA,common The amount of change can be calculated, N TA,common(new) = N TA,common(old) +(ΔT A,common- x)·y can be calculated as x and y are ΔT A,common can be determined based on the number of bits and units for transmission. For example, NTA,common(new) = N TA,common(old) +(ΔT A,common -M)·16·64 / 2 μ can be determined as follows. Here, the M value can be 31, and ΔT can be indicated through MAC CE. A,common If the maximum value of the value is greater than 63, it may be greater than or equal to 31, and ΔT A,common If the maximum value of the value is less than 63, it may be less than or equal to 31.

[0401] - Method 4-5: The base station can instruct the terminal to have one offset value through MAC CE. This set value is T A,common and based on this, N TA,common can be determined. This method is better than the above method 4-1 in that N between the base station and the terminal TA,common There is an advantage in that the application time can be clarified. For example, N can be applied after a certain period of time from the time of receiving the MAC CE or the time of transmitting an ACK for receiving the MAC CE. TA,common This can be applied. For example, the base station can transmit 16·64·T through MAC CE about 19 bits or 24 bits. c / 2 μ T in sec A,common will be able to convey. At this time N TA,common is N TA,common =T A,common ·16·64 / 2 μ It is determined as follows. The number of bits of MAC CE may be a different number than the above example.

[0402] - Method 4-6: The base station can instruct the terminal to have one offset value through MAC CE. This set value is T A,common and, along with this, based on the altitude of the satellite, N TA,commoncan be determined. This method has the advantage of reducing the number of bits to be transmitted compared to the case of using the above method 4-5. For example, the base station can transmit 16·64·T through MAC CE about 16 bits. c / 2 μ T in sec A,common will be able to convey. At this time N TA,common Is It is determined as follows: h sat can mean the altitude of the satellite. This means that when the satellite is at a certain altitude, the minimum distance between the terminal and the satellite becomes the above-mentioned certain altitude, so the base station can only calculate the remaining additional distance T A,common It may mean signaling through. The number of bits of MAC CE may be a different number than the above example.

[0403] In the above formula The values ​​can also be defined by integerization or rationalization in a similar manner to the third embodiment. For example, or or In addition to integerization or rationalization using a rounding operation such as d in the third embodiment, UE,sat h instead of value sat Various integerization or rationalization methods can be applied based on the value. Of course, A similar integerization or rationalization as described above can also be applied to the entire value. For example, It can also be defined as, in this case, In K=16·64 / 2 μ It may be the same way as what was considered. In addition, the operation used for the above integerization or rationalization may apply various other operations such as rounding up, rounding down, and not just rounding down.

[0404] - Method 4-7: The base station receives N at the time of transmission through SIB. TA,common Value and N TA,commonIt can convey information on the rate of change of N TA,common Value and N TA,common The change rate information may be transmitted to a specific terminal through RRC signaling rather than SIB, and the transmission method may vary depending on the status of the terminal (RRC_idle, RRC_inactive, RRC_connected).

[0405] N TA,common The rate of change information can be transmitted through SIB via one, two, or three parameters. For example, if the rate of change information is transmitted through one parameter A, then N can be transmitted through SIB. TA,common Let t1 be the time point at which the data is transmitted, and t2 be the time point at which uplink transmission is performed. Then, at t2, the terminal will apply N TA,common InN TA,common(t2) is N TA,common(t2) = N TA,common(t1) It can be calculated as +(t2-t1)·A. In this case, the units of t1 and t2 are msec and the unit of A can be Tc / msec. That is, what A means is how many Tc per 1 msec N TA,common It can indicate whether the value has changed. As another example, if the change rate information is transmitted through two parameters A and B, N is transmitted through SIB. TA,common Let t1 be the time point at which uplink transmission is performed and t2 be the time point at which uplink transmission is performed, then N to be applied by the terminal at t2 TA,common In N TA,common(t2) is N TA,common(t2) = N TA,common(t1) +(t2-t1) 2 ·B+(t2-t1)·A can be calculated as follows. (If the change rate information is transmitted through n parameters, it is also possible to express it in the form of an nth-order polynomial for the difference (t2-t1) between two points in time.) At this time, the units of t1 and t2 are msec, the unit of A is Tc / msec, and the unit of B can be Tc / msec^2. In other words, what A means is how many Tc per 1 msec is N.TA,common What does B mean, if the value has changed, how many Tc per 1 msec is N TA,common It can indicate whether the rate of change of a value has changed.

[0406] [Example 5]

[0407] The fifth embodiment is a parameter K for determining the timing at which a terminal transmits a second signal in response to a first signal transmitted by a base station. offset Provides a method and device for transmitting a signal from a base station to a terminal.

[0408] When a base station transmits a first signal, it indicates the timing at which a terminal transmits a corresponding second signal using upper signaling and DCI. For example, when transmitting a PDSCH, HARQ-ACK feedback for it can be indicated by an HARQ-ACK timing-related indicator in the bit field of the DCI that scheduled the PDSCH. However, in satellite communication, the delay time between the terminal and the base station is very large, so the offset value indicated in the conventional DCI may not be able to indicate the correct timing. Therefore, the base station may indicate an additional timing offset, the K, through SIB. offset The value is transmitted to the terminal, and the terminal receives the offset K offset In addition, the transmission timing of the second signal (uplink transmission) can be determined.

[0409] When the terminal is in the RRC_connected state after the initial connection, the base station provides K to the terminal. offset The value can be updated through RRC signaling. However, if the update is performed only through RRC signaling, the base station and the terminal may have different K values ​​during the time period in which RRC reconfiguration is performed. offset In this case, the correct transmission and reception of the second signal may not be performed. To eliminate this ambiguity time interval, the base station may provide the terminal with multiple K offsetSet the value and K set above as MAC CE offset It may indicate one of the values. Therefore, the terminal will receive the updated K from a predetermined point in time after receiving the MAC CE. offset You can apply values.

[0410] For example, through RRC signaling, K is assigned according to the index as shown in Table 28 below. offset You can set candidate values ​​for the value.

[0411]

[0412] Table 28 shows K through 8 indices. offset This is an example of setting at regular intervals, and various other settings are also possible. If the values ​​of index i are 0, 1, 2, ..., 2 M 2 like -1 M (M is an integer such as 2, 3, 4, ...) and K for index i offset Value K offset (i), for i > 0, K offset (i) = K offset It can also be defined to have evenly spaced values, such as (0) + (i - 1)*A (where A is a positive constant). Of course, the value of M can be variable depending on the system settings, and the value of A can also be set variably depending on the value of M. In addition, some of the indices can be defined as reserved fields. K excluding reserved fields offset The maximum value of K offset (i max ), when A = (K offset (i max ) - K offset (0)) / i max There may be a relationship.

[0413] Of course, this is just an example of values ​​set to uniform differences, and in general, it may not be composed of values ​​with uniform differences overall. For example, depending on the range of the index, it may be set to different values ​​with different differences as follows: (i m The value is simply 2 M-1 ) may be set to , and may generally be set to another integer value.)

[0414]

[0415] A1, A2 are different positive constants, and A1 = (K offset (i m ) - K offset (0)) / i m , A2 = (K offset (i max ) - K offset (i m )) / (i max - i m ), may be.

[0416] After this, the base station transmits the index to the terminal through MAC CE in slot n, and the terminal transmits the index to the terminal in slot n+k. offset The transmission of the second signal can be performed by applying the k value. The k value can be set or determined according to the subcarrier spacing.

[0417] In the preceding examples, the terminal can calculate the distance between the terminal and the satellite based on its own location information determined based on GNSS information and satellite location information acquired through a separate upper level signal or L1 signal, thereby determining the delay time between the terminal and the satellite. Therefore, this can be utilized when applying TA. If the terminal is not equipped with GNSS functionality, it may be difficult for the terminal to compensate for the delay between the terminal and the satellite through the above-mentioned operation.

[0418] Figure 36 illustrates the change in distance between terminals belonging to the same coverage (or beam) within a satellite and a satellite according to one embodiment.

[0419] In Fig. 36, the position of the satellite can be determined based on the elevation angle of the satellite. Fig. 36(a) shows a case where the elevation angle of the satellite measured with respect to the center of the satellite beam is 90 degrees, and Fig. 36(b) shows a case where the elevation angle of the satellite measured with respect to the center of the satellite beam is 30 degrees. Terminal 1 may be located at the center of the beam, and terminal 2 may be located at the beam boundary. The distance between terminal 1 and terminal 2 may represent the radius of the beam. In this case, when the altitude of the satellite is 600 km, the distance between terminal 1 and the satellite in Fig. 36(a) may be 600 km. And, the distance between terminal 1 and the satellite in Fig. 36(b) may be approximately 1075.5 km. Typically, as the distance between terminal 1 and terminal 2 increases, the difference between (the distance between the satellite and terminal 1) and (the distance between the satellite and terminal 2) increases. [Table 29] is a diagram showing the difference in distance and delay time from the satellite for each of terminal 1 and terminal 2 within the same coverage area of ​​the satellite in Fig. 36(a).

[0420]

[0421] [Table 30] is a diagram showing the difference in distance and delay time between each of terminal 1 and terminal 2 within the same satellite coverage in Fig. 36(b).

[0422]

[0423] In [Table 29] and [Table 30], the difference between (satellite-terminal 1 delay time) and (satellite-terminal 2 delay time) increases as the distance between terminal 1 and terminal 2 increases (for example, as the beam radius provided by the satellite increases). In addition, the difference between (satellite-terminal 1 delay time) and (satellite-terminal 2 delay time) in [Table 29] and [Table 30] may vary depending on the elevation angle between the satellite and terminal 1. Therefore, if two different terminals existing within the same beam are not in the same location, the distance between the satellite and the terminal may vary, and the difference in the satellite-terminal delay time may also vary depending on the radius of the beam and the elevation angle between the satellite and the terminal. In the case of a terminal equipped with a GNSS function, if only the position information of the satellite can be separately received and confirmed, the delay time according to the different distance differences between the satellite and the terminal can be compensated for by considering the terminal's own position information and the position information of the satellite. However, for terminals that do not have GNSS functionality, it is difficult to properly compensate for this, and there is a possibility that signals transmitted between different terminals from satellite or base station receivers may cause interference.

[0424] FIG. 37 and FIG. 38 are conceptual diagrams showing a method for a terminal to transmit by applying TA according to one embodiment of the present disclosure.

[0425] In Fig. 37, the terminal may be equipped with a GNSS function. As described in Fig. 36, in the scenario (3700) of Fig. 37, the radius of the beam may be 50 km, the altitude of the satellite may be 600 km, and the distance between the terminal at the beam boundary and the satellite may be 602 km. If the GNSS function is equipped, the terminal at the beam boundary may determine the delay time as the value obtained by dividing the distance between the satellite and the terminal by the speed of light. Accordingly, as in the procedure (3710) of Fig. 37, the terminal may transmit (3712) by applying a TA value that takes this into account, and the satellite receiver may receive (3714) the corresponding signal at a desired slot or timing. The satellite receiver may receive signals transmitted by multiple terminals without interference through a common receiver without having to implement a separate receiver for each terminal. That is, within the radius of one beam, multiple terminals can adjust TA by considering different distances between satellites and terminals and different delay times caused by them, and thus, even if the transmission timings of each terminal are different, it is possible to receive the corresponding signals at the same time from the perspective of the satellite receiver.

[0426] In Fig. 38, the terminal may not be equipped with a GNSS function. If the terminal is not equipped with a GNSS function, it may not operate as in Fig. 37. For example, in scenario (3800), the satellite may have difficulty determining whether the terminal is at the center of the beam or at the edge of the beam.

[0427] Instead, since the satellite can know the location where the satellite transmits its beam, it can transmit information about that location (e.g., the reference location (R) in FIG. 38) to the terminal via an upper signal. Based on the information received via the upper signal, the terminal can calculate the distance between the reference location and the satellite (e.g., the terminal can determine that this value is 600 km) and transmit the TA value taking this into account.

[0428] In the procedure (3810) of FIG. 38, if the terminal is equipped with a GNSS function, the terminal can transmit an uplink signal (3812) because it knows the value of 602 km, and the satellite can receive it (3816).

[0429] However, a terminal without a GNSS function can determine the distance between the reference position of the terminal and the satellite (e.g., 600 km in scenario (3800)) based on information about the reference position (R) received through a separate upper signal, and can determine the TA value using the determined distance value. In the procedure (3810) of FIG. 38, the terminal transmits a signal (3814) by applying the corresponding TA value, and the satellite receiver receives the signal (3818) at a time that is delayed from the time intended by the actual satellite receiver because the actual distance is 602 km. Therefore, the satellite receiver needs to perform a blind search for a certain period of time because it does not know from what point in time the signal transmitted by the actual terminal is transmitted. In addition, although the delay time due to the distance difference between the satellite and the terminal can be compensated to some extent by providing information about the reference position (R) to the terminals existing within the radius of the corresponding beam as in the scenario (3800) of FIG. 38, it is difficult to compensate for the exact delay time for each individual terminal. Therefore, a method of indicating the reference position and a method of compensating the TA value more quickly through the L1 signal can be considered.

[0430] For example, in FIG. 38, after the terminal identifies the reference location information through SIB and transmits an uplink signal based on it, the satellite or base station can analyze the received signal and include the TA value of the uplink signal to be transmitted by the terminal in the DCI that schedules the signal and transmit it. The terminal can update the TA value for transmitting the uplink signal by receiving the DCI. For reference, in a terrestrial network, the terminal usually updates the TA value through RAR or MAC CE, but in the case of a satellite network, the TA needs to be updated more quickly because the distance between the satellite and the terminal varies over time. For example, as described in FIG. 26, the terminal transmits the uplink frame based on the downlink frame timing. TA =(N TA +N TA,offset )T C Uplink transmission can be performed as early as N TA The value of can be passed through RAR or determined based on MAC CE, and N TA,offset is set to the terminal, or may be a value determined based on a predetermined value according to the frequency band or duplexing mode such as TDD / FDD. Alternatively, N may be used instead of the above formula. TA =(N TA +N TA,OFFSET +N TA1 +N TA2 )·T C It may be possible to apply Tc, where Tc has the same meaning as applied to other mathematical formulas of the present disclosure.

[0431] For terminals with GNSS function, N TA1 It can refer to a value that compensates for the delay time between the satellite and the terminal. A terminal with GNSS function determines the distance between the terminal and the satellite using the terminal's own location information and the satellite's location information, and uses the calculated distance between the terminal and the satellite to determine N TA1 can be determined (calculated). NTA2 can mean a value that compensates for the delay time between the satellite and the ground station, and can be provided as a constant value or in the form of a linear, quadratic or cubic function with time as a variable.

[0432] For terminals without GNSS function, N TA1 may refer to a value that compensates for the delay time between satellite-terminal or ground station-terminal. N TA1 can be provided as a constant value or as a linear, quadratic or cubic function with time as a variable. Or, N TA1 may refer to a value that compensates for the delay time between the satellite and the terminal, and the terminal does not know its own location information, but determines the distance between the terminal and the satellite using the reference location (R) and the location information of the satellite provided through a separate upper signal, and uses the determined distance to determine N TA1 can be determined (calculated). N TA2 It can refer to a value that compensates for the delay time instantaneously by the terminal through an L1 signal such as DCI.

[0433] In the following description, satellite may be understood as being replaced with base station or ground station.

[0434] [Example 6]

[0435] The following examples describe a method for determining whether a terminal can transmit uplink data based on its elevation angle. Figure 38 illustrates a scenario where the satellite's elevation angle is 90 degrees from the reference position. However, in scenarios where the satellite's elevation angle is less than 90 degrees, as illustrated in Figure 36, the difference in satellite-to-terminal delay time between terminals within the same beam is likely to increase.

[0436] For terminals without GNSS capabilities, even if TA is compensated using only reference position information at low satellite elevations, the actual delay error range can be large. This large error range increases the likelihood that a satellite receiver will receive uplink signals from non-GNSS terminals within a given beam within a given elevation range, resulting in interference because the signals are unlikely to be precisely synchronized in time and frequency.

[0437] When a satellite has a low elevation angle, restrictions may be set to prevent the satellite from receiving uplink signals from terminals that do not support GNSS functions within its beam radius. To this end, the terminal may determine the elevation angle of a satellite that is unable (or restricted) to transmit uplink, and / or the elevation angle of a satellite that is not restricted.

[0438] FIG. 39 is a diagram illustrating a range of elevation angles in which uplink transmission is possible (or not limited) and a range of elevation angles in which uplink transmission is limited by a terminal without a GNSS function according to an embodiment of the present disclosure. Satellites other than geostationary satellites orbit the Earth over time, and as shown in FIG. 39, the satellites can be located at positions (3900), (3902), and (3904). In a range in which the elevation angle is higher than a predetermined value (or in a range equal to or higher than the predetermined value) (3910), the terminal can be configured to be able to perform uplink transmission, and in a range in which the elevation angle is equal to or lower than the predetermined value (or in a range lower than the predetermined value) (3912, 3914), the terminal can be configured not to be able to perform uplink transmission.

[0439] Specifically, the terminal can determine an elevation angle at which uplink transmission is impossible (or limited) through at least one of the following methods or some combination thereof.

[0440] - Method A-1: ​​A satellite can provide reference position information for a beam to which a terminal belongs. The reference position information can include three-dimensional information such as latitude, longitude, and altitude, such as (x, y, z), and can be transmitted by being included in an SIB. The terminal can calculate an elevation angle by using the reference position information and the satellite position information. The satellite position information can be included in the SIB that transmits the reference position information and transmitted together with the reference position information or transmitted separately. When the satellite position information and the reference position information are transmitted separately, the satellite position information can be transmitted and received through the Xth SIB because the terminal needs it regardless of whether the terminal is equipped with a GNSS function. The reference position information can be transmitted and received through the Yth SIB provided for terminals that are not equipped with a GNSS function because it is necessary only for terminals that are not equipped with a GNSS function. Through this method, the terminal can determine an elevation angle based on the satellite position and the reference position information. In addition, information about the elevation angle at which uplink transmission is impossible (or limited) may be transmitted separately through the SIB or other terminal common upper signal. For example, if the value transmitted as the upper signal is 30 degrees, it may be determined that uplink transmission is impossible for a satellite having an elevation angle equal to or less than 30 degrees. For example, in FIG. 39, if the position (3906) is the reference position information provided by the satellite, the satellite may provide a predetermined angle (3920) as a threshold value at which uplink transmission is impossible. Accordingly, when the satellite is located at position (3900), the terminal may determine that uplink transmission is possible because the elevation angle based on position (3906) is higher than angle (3920). On the other hand, when the satellite is located at position (3902) or position (3904), the terminal may determine that uplink transmission is impossible because the elevation angle based on position (3906) is lower than angle (3920).

[0441] - Method A-2: The altitude range where uplink transmission is impossible can be determined based only on the satellite's location information without utilizing separate reference location information. The satellite's location information can be periodically provided in the form of a constant, a linear function, a quadratic function, or a cubic function. When the satellite's location information is provided in the form of a linear, quadratic, or cubic function, the satellite's location information can be transmitted together with a separate reference point in time, a coefficient constituting the function, and a constant value. Through this, the terminal can predict the satellite's location over time. In addition, according to one embodiment, the satellite can provide information on the satellite's location or orbit instead of the altitude information in order to provide the terminal with information on the altitude angle where uplink transmission is impossible. Alternatively, whether uplink transmission is possible can be determined based on information on the satellite's location or orbit, and the satellite can provide the terminal with information on the satellite's location or orbit. For example, referring to FIG. 39, a satellite may provide a terminal with orbit sections in which uplink transmission and reception are possible, such as sections 3930, 3932, and / or 3934. Orbit section 3930 may include sections in which uplink transmission is possible (or not restricted), and sections 3932 and 3934 may be configured as sections in which uplink transmission is not possible (or restricted). In this case, the terminal may determine whether the satellite belongs to a section in which uplink transmission is possible or a section in which transmission is not possible based on the satellite's location information and which of the configured orbit sections the satellite's location belongs to. For example, if the satellite is located at position (3904), the terminal may determine that the satellite is in a state in which uplink transmission is not possible because the satellite is within section 3932. As another example, if a satellite is located at position (3902), the terminal may determine that the satellite is in a state where uplink transmission is not possible because the satellite is within the section (3934).As another example, if a satellite is located at position (3900), the terminal can determine that the satellite is capable of uplink transmission because the satellite is within the section (3930).

[0442] - Method A-3: Uplink transmission possible or impossible section can be determined based on time information. Since satellites periodically orbit a specific orbit, the satellite's location at a specific point in time can be determined. Therefore, instead of considering satellite location information, orbit information, or reference location information as in Method 6-1 or Method 6-2, time information can be considered and transmitted and received. For example, in FIG. 39, the satellite provides the terminal with time information corresponding to the section (3930), and the terminal can determine that uplink transmission is possible only at that time. For example, the time information corresponding to the section (3930) can include information on the time when the satellite begins to orbit above the orbit section (3930) and information on the time when it leaves the orbit section (3930). Alternatively, the time information can be based on actual time information, such as t1 or t2. Alternatively, the time information may indicate a predetermined value or a range of values ​​in units such as milliseconds (msec) or seconds (sec), or in units that the terminal transmits and receives (e.g., units of slots, subframes, or frames). Alternatively, the time information may indicate whether uplink transmission is possible or impossible for a specific period of time after receiving a periodically transmitted NTN-only SIB. The time information may include information about a specific time. The specific time may refer to a specific amount of time that has elapsed since the SIB was received, or the specific time may refer to a specific amount of time that has elapsed since the SIB was received. The information about the specific time may be transmitted and received as time information through the corresponding SIB. Alternatively, the value of the specific time may be implicitly determined in a predefined state.

[0443] When the terminal determines an altitude at which uplink transmission is impossible through the methods described above, the terminal may perform at least one or a combination of some of the following operations.

[0444] - Action B-1: The terminal may not transmit for all uplink signals or channels. That is, the terminal may not perform transmission for all uplink channels, such as PRACH, PUSCH, PUCCH, and SRS.

[0445] - Action B-2: The terminal may not perform transmission only for uplink signals that are periodically configured. For example, if the terminal determines that the elevation angle is such that uplink transmission is impossible, the terminal may not perform transmission for periodically configured resources PUCCH, PUSCH, and SRS. The periodically configured resources may include resources that are periodically configured in advance by a higher-order signal or an L1 signal and / or resources that enable uplink transmission without receiving a separate scheduling DCI. In addition, for PUCCH, PUSCH, or SRS scheduled by DCI, the terminal may transmit an uplink signal even if the terminal determines that the elevation angle is such that uplink transmission is impossible.

[0446] - Action B-3: Similar to Action B-1, the terminal may not transmit on some uplink channels. However, the terminal may transmit PRACH and Msg3 PUSCH. For example, if the terminal wishes to transmit a PRACH to request uplink resources, it may transmit the PRACH even if it determines that the elevation angle is such that uplink transmission is impossible.

[0447] - Action B-4: Similar to Action B-1, the UE may not transmit on some uplink channels. However, the UE may transmit PRACH, Msg3 PUSCH, and SRS. For example, if the base station schedules a DCI to trigger an aperiodic SRS to obtain uplink channel status information from the UE at a specific time, the UE may transmit the SRS even if it determines that the elevation angle is such that uplink transmission is impossible.

[0448] - Action B-5: Similar to Action B-1, the terminal may not perform transmission for some uplink channels. However, the terminal may only transmit for uplink signals scheduled with DCI. If the DCI that schedules the uplink includes information for compensating for delay time or Doppler shift so that the satellite or base station can dynamically adjust the time and frequency synchronization of the scheduled uplink signal, the terminal may transmit for the uplink signals scheduled with the corresponding DCI even if the terminal determines that the elevation angle is not suitable for uplink transmission.

[0449] - Operation B-6: Similar to Method B-1, the terminal may not transmit on some uplink channels. However, the terminal may only transmit on uplink signals that have been periodically configured as upper-level signals in advance. For example, in a situation where PUSCH resources that have been periodically configured as upper-level signals in advance are determined to be at an elevation angle that makes uplink transmission impossible, the terminal may transmit on the periodically configured PUSCH resources.

[0450] - Operation B-7: The base station can individually configure which uplink signals or channels can be transmitted or not using a separate higher-order signal. For example, if the base station determines that the UE cannot transmit on an elevation angle for PUCCH resources that have been periodically configured in advance, and if the base station configures another higher-order signal to not transmit, the UE may not transmit the corresponding PUCCH. As another example, if the base station determines that the UE cannot transmit on an elevation angle for PUCCH resources that have been periodically configured in advance, and if the base station configures another higher-order signal to transmit, the UE may transmit the corresponding PUCCH.

[0451] If the terminal determines that uplink transmission is impossible, the terminal may perform other operations in addition to the operations described above. If the terminal determines that the elevation angle is impossible for uplink transmission and fails to transmit HARQ-ACK information, and then determines that uplink transmission is possible for PUCCHs including the HARQ-ACK information that was not transmitted, the terminal may transmit HARQ-ACK information for each HARQ process at once. This may be referred to as one-shot HARQ-ACK feedback. The one-shot HARQ-ACK feedback may be scheduled through a separate DCI. Alternatively, if the terminal transmits an SR (scheduling request) after determining that the elevation angle is possible for uplink transmission, the terminal may transmit the one-shot HARQ-ACK feedback on a specific PUCCH resource.

[0452] Figure 40 is a flowchart illustrating a procedure for determining whether a terminal performs uplink transmission based on a satellite elevation angle according to one embodiment of the present disclosure. The terminal may perform an initial connection to a satellite network. Thereafter, the terminal may receive relevant upper signal information for methods A-1 to A-3, and determine the satellite elevation angle through the received information. If the terminal determines that the satellite elevation angle is an elevation angle at which uplink transmission is impossible, the terminal may perform at least one of operations B-1 to B-7, or a combination of some of them.

[0453] [Example 7]

[0454] Hereinafter, an embodiment describes a method for supporting coexistence of terminals equipped with and without GNSS capabilities within a single satellite network. For terminals equipped with GNSS capabilities, the terminal can transmit uplink signals while reflecting delay and Doppler shift. Therefore, uplink signals transmitted by multiple terminals equipped with GNSS capabilities are less likely to cause interference from the perspective of a satellite receiver. However, for terminals without GNSS capabilities, although the satellite can indirectly schedule uplink signals by reflecting delay and Doppler shift to some extent, because the satellite does not know the exact location of the terminal, the terminal may have difficulty transmitting uplink signals while appropriately reflecting delay and Doppler shift. Therefore, uplink signals transmitted by multiple terminals without GNSS capabilities are highly likely to cause interference from the perspective of a satellite receiver. Furthermore, interference may also occur when terminals equipped with GNSS capabilities and terminals without GNSS capabilities perform uplink transmissions in adjacent frequency or time domains. Therefore, it may be reasonable to support terminals equipped with GNSS functions and terminals without GNSS functions separately from the uplink frequency resource perspective.

[0455] FIG. 41 is a diagram illustrating a process for determining a frequency resource region for uplink transmission between a terminal equipped with a GNSS function and a terminal without a GNSS function according to an embodiment of the present disclosure. The terminal first receives a synchronization signal (SS) and MIB information included in a PBCH, and then can determine a resource region for initial access through a separate SIB1 (or an NTN-specific SIB). At this time, different frequency bands may be set in the SIB1 (or an NTN-specific SIB) depending on whether the terminal supports GNSS. As an example, FIG. 41 illustrates that when a terminal is equipped with a GNSS function, the terminal performs an initial access (PRACH) in a band (4100), and thereafter, transmission of other uplink signals (e.g., PUCCH, PUSCH) can also be performed in the band (4100). If the terminal is not equipped with a GNSS function, the terminal may perform an initial access (PRACH) in the band (4102) and then transmit other uplink signals (e.g., PUCCH, PUSCH) in the band (4102). Through this, the satellite can distinguish between the uplink band in which terminals equipped with a GNSS function operate and the uplink band in which terminals not equipped with a GNSS function operate.

[0456] Figure 42 is a flowchart illustrating an initial connection procedure considering GNSS support according to one embodiment of the present disclosure. The terminal may receive a synchronization signal and an MIB. Subsequently, the terminal may receive SIB1 or an NTN-specific SIB and determine a frequency band based on whether GNSS functionality is present. Depending on whether GNSS functionality is present, the terminal may perform an initial connection in the configured frequency band and subsequently perform operations related to uplink transmission in the corresponding band.

[0457] As described above, the present disclosure may include an embodiment that distinguishes resource regions for uplink transmission of a terminal equipped with a GNSS function and a terminal without a GNSS function from a frequency resource perspective. The present disclosure is not limited thereto, and may also include an embodiment that distinguishes resource regions from a time resource perspective. For example, in the same frequency resource, a terminal equipped with a GNSS function may perform an uplink transmission operation in an even-numbered subframe or frame, and a terminal without a GNSS function may perform an uplink transmission operation in an odd-numbered subframe or frame. In addition to distinctions such as odd and even numbers, the time at which a terminal equipped with a GNSS function performs an uplink transmission operation and the time at which a terminal without a GNSS function performs an uplink transmission operation may also be determined by distinguishing by a specific time interval.

[0458] FIG. 43 is a diagram illustrating a process for determining a time resource region for uplink transmission of a terminal equipped with a GNSS function and a terminal without a GNSS function according to an embodiment of the present disclosure. The terminal receives a synchronization signal and an SIB, and can distinguish time resource information for uplink transmission of the terminal based on whether or not the terminal is equipped with a GNSS function through the SIB. For each specific PERIOD, a time resource region that can be used by terminals equipped with a GNSS function and a time resource region that can be used by terminals without a GNSS function can be provided. Each time resource region may be continuous without a separate GAP, as shown in FIG. 43, or, unlike FIG. 43, may not be continuous and may include a GAP between each time resource region. In addition, the PERIOD information may be provided as separate upper signal information. Alternatively, the PERIOD information may be determined to be identical to the period at which SS / PBCH is transmitted and received. Alternatively, the resources to be used for uplink transmission by terminals equipped with GNSS and terminals without GNSS may be distinguished using code resources. For example, even if the same time and frequency resources are allocated for uplink transmission by terminals equipped with GNSS and terminals without GNSS, uplink transmission can be performed using the Orthogonal Cover Code (OCC) method (e.g., terminals equipped with GNSS and terminals without GNSS use different OCC codes). Time or code resource information for uplink transmission by terminals equipped with GNSS and terminals without GNSS can be transmitted via SIB information, similar to that described in FIG. 41.

[0459] For convenience, the present disclosure has been described separately as Embodiments 1 through 7 of the present disclosure. However, since each embodiment includes operations related to each other, the present disclosure may also include a combination of at least two embodiments from Embodiments 1 through 7. Furthermore, the methods or operations of each embodiment are not mutually exclusive, and it is also possible for one or more methods or operations to be combined and performed.

[0460] The present disclosure includes operations of a base station, a satellite, and a terminal or a transmitter and receiver for performing embodiments, and to perform the same, a receiving unit, a processing unit, and a transmitting unit of the base station, satellite, or terminal may each operate according to the embodiments.

[0461] FIG. 44 is a block diagram illustrating the internal structure of a terminal according to an embodiment of the present disclosure. As illustrated in FIG. 44, the terminal of the present disclosure may include a terminal receiving unit (4400), a terminal transmitting unit (4420), and a terminal processing unit (4410). The terminal receiving unit (4400) and the terminal transmitting unit (4420) may be collectively referred to as a transceiver unit in the embodiment of the present disclosure. The transceiver unit may transmit and receive signals with a base station. The signals may include control information and data. To this end, the transceiver unit may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. In addition, the transceiver unit may receive a signal through a wireless channel and output it to the terminal processing unit (4410), and transmit a signal output from the terminal processing unit (4410) through the wireless channel. The terminal processing unit (4410) can control a series of processes so that the terminal can operate according to the embodiments of the present disclosure described above. For example, the terminal receiving unit (4400) can receive signals from satellites or terrestrial base stations and signals from GNSS, and the terminal processing unit (4410) can transmit and receive signals to and from the base station according to the methods described in the present disclosure. Thereafter, the terminal transmitting unit (4420) can transmit signals using the determined time point.

[0462] FIG. 45 is a block diagram illustrating the internal structure of a satellite according to an embodiment of the present disclosure. As illustrated in FIG. 45, the satellite of the present disclosure may include a satellite receiver (4500), a satellite transmitter (4520), and a satellite processor (4510). The receiver, transmitter, and processor may be configured in multiple units. That is, the satellite may include a receiver and a transmitter for transmitting and receiving signals from a terminal, a receiver and a transmitter for transmitting and receiving signals from a base station, and a receiver and a transmitter for transmitting and receiving signals with other satellites. The satellite receiver (4500) and the satellite transmitter (4520) may be collectively referred to as a satellite transceiver in the embodiment of the present disclosure. The transceiver may transmit and receive signals with a terminal and a base station. The signals may include control information and data. To this end, the transceiver may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, an RF receiver that low-noise-amplifies the received signal, and down-converts the frequency. In addition, the transceiver may receive a signal through a wireless channel and output it to the satellite processing unit (4510), and transmit the signal output from the satellite processing unit (4510) through the wireless channel. The satellite processing unit (4510) may include a compensator (pre-compensator) for correcting a frequency offset or a Doppler shift, and may include a device capable of tracking a location from a GPS, etc. In addition, the satellite processing unit (4510) may include a frequency shift function capable of shifting the center frequency of the received signal. The satellite processing unit (4510) may control a series of processes so that a satellite, a base station, and a terminal can operate according to the above-described embodiment of the present disclosure. For example, a satellite receiver (4500) may receive a PRACH preamble from a terminal, transmit the corresponding RAR back to the terminal, and decide to transmit TA information to the base station.Thereafter, the satellite transmitter (4520) can transmit the corresponding signals at a determined time.

[0463] FIG. 46 is a block diagram illustrating the internal structure of a base station according to an embodiment of the present disclosure. As illustrated in FIG. 46, the base station of the present disclosure may include a base station reception unit (4600), a base station transmission unit (4620), and a base station processing unit (4610). The base station may be a terrestrial base station or a portion of a satellite. The base station reception unit (4600) and the base station transmission unit (4620) may be collectively referred to as a transceiver unit in the embodiment of the present disclosure. The transceiver unit may transmit and receive signals with a terminal. The signals may include control information and data. To this end, the transceiver unit may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. In addition, the transceiver unit may receive a signal through a wireless channel and output it to the base station processing unit (4610), and transmit the signal output from the base station processing unit (4610) through the wireless channel. The base station processing unit (4610) can control a series of processes so that the base station can operate according to the embodiments of the present disclosure described above. For example, the base station processing unit (4610) can transmit an RAR including TA information.

[0464] Meanwhile, the embodiments of the present invention disclosed in this specification and drawings are merely specific examples to easily explain the technical content of the present invention and help understand the present invention, and are not intended to limit the scope of the present invention. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present invention are possible. In addition, each of the above embodiments can be combined and operated as needed. In addition, other modifications based on the technical idea of ​​the above embodiments can be implemented in LTE systems, 5G systems, etc.

Claims

1. In a method performed by a UE (user equipment) in a wireless communication system, A step of receiving a first SIB including at least some of information related to a reference position of a beam from a base station, a position of the base station, a threshold value of an elevation angle at which uplink transmission is restricted, a position range of the base station at which uplink transmission is restricted, and a time at which uplink transmission is restricted; A step of determining that uplink transmission is restricted based on the first SIB; and A method comprising the step of transmitting an allowed uplink signal to the base station.

2. In claim 1, A method in which the allowed uplink signal includes at least one of a physical uplink control channel (PUCCH) scheduled through downlink control information (DCI), a physical uplink shared channel (PUSCH) scheduled through the DCI, a sounding reference signal (SRS) scheduled through the DCI, a physical random access channel (PRACH), an uplink signal scheduled through the DCI, an uplink signal periodically set through a higher layer signal, and an uplink signal set to be allowed even when uplink transmission is restricted through the higher layer signal.

3. In claim 1, A step of receiving a second SIB from the base station; A step of determining that uplink transmission is not restricted based on the second SIB; and A method further comprising the step of transmitting, to the base station, a single HARQ-ACK (acknowledgment) feedback signal including information on whether reception of multiple HARQ (hybrid automatic repeat request) processes has been successful.

4. In claim 1, The above UE does not support GNSS (global navigation satellite system) function.

5. In a method performed by a base station in a wireless communication system, A step of transmitting a first SIB including at least some of information related to a reference position of a beam, a position of the base station, a threshold value of an elevation angle at which uplink transmission is restricted, a location range of the base station at which uplink transmission is restricted, and a time at which uplink transmission is restricted to the UE (user equipment); and A method comprising the step of receiving an allowed uplink signal from the UE when uplink transmission is restricted.

6. In claim 5, A method in which the allowed uplink signal includes at least one of a physical uplink control channel (PUCCH) scheduled through downlink control information (DCI), a physical uplink shared channel (PUSCH) scheduled through the DCI, a sounding reference signal (SRS) scheduled through the DCI, a physical random access channel (PRACH), an uplink signal scheduled through the DCI, an uplink signal periodically set through a higher layer signal, and an uplink signal set to be allowed even when uplink transmission is restricted through the higher layer signal.

7. In claim 5, A step of transmitting a second SIB to the UE; A step of determining that uplink transmission is not restricted based on the second SIB; and A method further comprising the step of receiving, from the UE, a single HARQ-ACK (acknowledgment) feedback signal including information on whether reception of multiple HARQ (hybrid automatic repeat request) processes was successful.

8. In claim 5, The above UE does not support GNSS (global navigation satellite system) function.

9. In UE (user equipment), At least one transceiver; At least one processor communicatively coupled to said at least one transceiver; and At least one memory communicatively coupled to said at least one processor and storing instructions, The above instructions are executed individually or in any combination by the at least one processor so that the UE: Receive a first SIB including at least some of information related to a reference position of a beam from a base station, a position of the base station, a threshold value of an elevation angle at which uplink transmission is restricted, a position range of the base station at which uplink transmission is restricted, and a time at which uplink transmission is restricted; Based on the above first SIB, it is determined that uplink transmission is restricted, A UE that transmits an allowed uplink signal to the base station.

10. In claim 9, The UE includes at least one of a physical uplink control channel (PUCCH) scheduled through downlink control information (DCI), a physical uplink shared channel (PUSCH) scheduled through the DCI, a sounding reference signal (SRS) scheduled through the DCI, a physical random access channel (PRACH), an uplink signal scheduled through the DCI, an uplink signal periodically set through a higher layer signal, and an uplink signal set to be allowed even when uplink transmission is restricted through the higher layer signal.

11. In claim 9, The above commands cause the UE to: Receive a second SIB from the base station, Based on the above second SIB, it is determined that uplink transmission is not restricted, A UE that transmits to the base station a single HARQ-ACK (acknowledgment) feedback signal including information on whether reception of multiple HARQ (hybrid automatic repeat request) processes has been successful.

12. In claim 9, The above UE does not support GNSS (global navigation satellite system) function.

13. At the base station, At least one transceiver; At least one processor communicatively coupled to said at least one transceiver; and At least one memory communicatively coupled to said at least one processor and storing instructions, The above instructions are executed individually or in any combination by the at least one processor so that the base station: Transmitting a first SIB to a UE (user equipment) that includes at least some of information related to a reference position of a beam, a position of the base station, a threshold value of an elevation angle at which uplink transmission is restricted, a location range of the base station at which uplink transmission is restricted, and a time at which uplink transmission is restricted; A base station that receives an allowed uplink signal from the UE when uplink transmission is restricted.

14. In claim 13, A base station, wherein the above-mentioned allowed uplink signal includes at least one of a physical uplink control channel (PUCCH) scheduled through downlink control information (DCI), a physical uplink shared channel (PUSCH) scheduled through the DCI, a sounding reference signal (SRS) scheduled through the DCI, a physical random access channel (PRACH), an uplink signal scheduled through the DCI, an uplink signal periodically set through a higher layer signal, and an uplink signal set to be allowed even when uplink transmission is restricted through the higher layer signal.

15. In claim 13, The above commands cause the base station to: Transmit a second SIB to the UE, Based on the above second SIB, it is determined that uplink transmission is not restricted, A base station configured to receive, from the UE, a single HARQ-ACK (acknowledgment) feedback signal including information on whether reception of multiple HARQ (hybrid automatic repeat request) processes has been successful.

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