Methods and apparatus for instructions regarding time and frequency offsets in communication systems

Abstract

This disclosure relates to a communication technology for combining a 5G communication system with IoT technology, wherein the 5G communication system is used to support higher data transmission rates than 4G systems. This disclosure also relates to a system for this communication technology. Based on 5G communication technology and IoT-related technologies, this disclosure can be applied to smart services such as smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, and security-related services. The invention can provide a method and apparatus in which a base station provides instructions to a UE regarding time and frequency offset information, so as to correct time and frequency by offsetting the provided time and frequency offset information.

Description

Technical Field

[0001] This disclosure relates to communication systems, specifically, in cases where a UE transmits signals to and receives signals from a base station via a satellite, significant time and frequency shifts may occur, necessitating correction of these time and frequency offsets. Therefore, this disclosure provides a method and apparatus in which a base station indicates time and frequency offset information to a UE, and the UE performs corrections equal to the offset value based on the indicated information. Background Technology

[0002] Since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems to meet the growing demand for wireless data services. Therefore, 5G or pre-5G communication systems are also referred to as "beyond 4G networks" or "post-LTE systems." To achieve higher data rates, the implementation of 5G communication systems in ultra-high frequency (millimeter wave (mmWave)) bands (e.g., the 60GHz band) is being considered. To mitigate path loss of radio waves and increase transmission distance in ultra-high frequency bands, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are being discussed for 5G communication systems. Furthermore, in 5G communication systems, technologies for improving system networks are being developed based on evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, cooperative multipoint (CoMP), and receiver interference cancellation. In addition, hybrid FSK (Frequency Shift Keying) and QAM (Four-way Amplitude Modulation) modulation and sliding window superposition coding (SWSC) have been developed as advanced coding and modulation (ACM) systems, as well as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0003] On the other hand, the internet is evolving from a human-centric network of connections where humans generate and consume information into an Internet of Things (IoT) network that exchanges and processes information between distributed components such as things. The Internet of Everything (IoE), combining IoT technology with big data processing technology through connection to cloud servers, has also emerged. IoT implementation requires technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology; therefore, technologies for connecting things are currently under research, such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC). Such an IoT environment can provide intelligent Internet of Things (IT) services, creating new value for human life by collecting and analyzing data generated between connected things. Through the convergence and integration of existing information technology (IT) and various industrial applications, IoT can be applied to a wide range of fields, including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0004] Correspondingly, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) can be implemented using beamforming, MIMO, and array antenna technologies corresponding to 5G communication technologies. Cloud radio access networks (cloud RAN), as an application of the aforementioned big data processing technologies, can also be considered an example of the convergence between 5G and IoT technologies.

[0005] From the late 2010s to the 2020s, with the significant reduction in satellite launch costs, the number of companies intending to provide communication services via satellite has steadily increased. Therefore, satellite networks have been proposed as a next-generation network system to complement existing terrestrial networks. While satellite networks cannot provide the same user experience as terrestrial networks, they offer the advantage of providing communication services in areas where establishing terrestrial networks is difficult or in disaster situations, and, as mentioned above, can even ensure economic viability due to the recent dramatic reduction in satellite launch costs. Furthermore, some companies and the 3GPP standardization organization are now promoting direct communication between smartphones and satellites. Summary of the Invention

[0006] Technical issues

[0007] When a UE intends to connect to a base station via satellite, a significant delay occurs before the radio waves arrive due to the long distances of hundreds or thousands of kilometers between the UE and the satellite, and between the satellite and the ground base station. This large delay is far greater than that of a UE and base station performing direct communication in a terrestrial network. Furthermore, the delay changes over time due to the continuous movement of the satellite. Each UE has a varying delay relative to the satellite or base station. Additionally, the frequency of the transmitted or received signal shifts as the satellite moves, potentially due to Doppler shift caused by satellite movement.

[0008] This disclosure relates to communication systems, and more specifically, provides a method and apparatus in which a base station indicates time and frequency offsets, and based thereon, when a UE transmits signals to and receives signals from the base station via a satellite, the UE performs corrections to correct time-varying delays and frequency shifts that depend on the long distance to the satellite and the movement of the satellite.

[0009] Technical solution

[0010] According to embodiments of this disclosure, in order to achieve the above-described technical subject matter, a method performed by a UE in a communication system may include: receiving information from a base station regarding the rate of change of timing advance (TA) or frequency offset; determining a timing advance or frequency offset for uplink transmission based on the information regarding the rate of change of timing advance or frequency offset; and sending uplink transmission to the base station by applying the determined timing advance, wherein the information regarding the rate of change of timing advance or frequency offset includes information regarding the period and time to which the rate of change is applied.

[0011] According to one embodiment, the timing advance for uplink transmission can be determined based on the value of the common application to UEs located in the same beam when the timing advance is determined, and the value of the common application can be received from the base station via system information.

[0012] According to one embodiment, the frequency offset for uplink transmission can be determined based on frequency units determined according to the subcarrier spacing.

[0013] According to one embodiment, the frequency offset for uplink transmission can be determined based on the value of the common application to UEs located in the same beam when the frequency offset is determined, and the value of the common application can be received from the base station via system information.

[0014] According to embodiments of this disclosure, a method performed by a base station in a communication system may include: sending information to a UE about the rate of change of timing advance (TA) or frequency offset; and receiving from the UE an uplink transmission sent by applying a timing advance or frequency offset determined based on the information about the rate of change of timing advance or frequency offset, wherein the information about the rate of change of timing advance or frequency offset includes information about the period and time to which the rate of change is applied.

[0015] According to embodiments of this disclosure, a UE in a communication system may include: a transceiver; and a controller configured to: receive information from a base station regarding the rate of change of timing advance (TA) or frequency offset, determine a timing advance or frequency offset for uplink transmission based on the information regarding the rate of change of timing advance or frequency offset, and transmit uplink transmission to the base station by applying the determined timing advance or frequency offset, wherein the information regarding the rate of change of timing advance or frequency offset includes information regarding the period and time to which the rate of change is applied.

[0016] According to embodiments of this disclosure, a base station in a communication system may include: a transceiver; and a controller configured to: send information about the rate of change of timing advance (TA) or frequency offset to a UE, and receive uplink transmissions from the UE that are transmitted by applying a timing advance or frequency offset determined based on the information about the rate of change of timing advance or frequency offset, wherein the information about the rate of change of timing advance or frequency offset includes information about the period and time to which the rate of change is applied.

[0017] Beneficial effects

[0018] As described above, by using this disclosure, the UE can access the base station via satellite and can transmit and receive signals between the base station and the UE in a manner in which the base station instructs the UE on time and frequency offsets and the UE corrects for the offsets. Attached Figure Description

[0019] Figure 1 This is a diagram illustrating the basic structure of the time-frequency domain, which is the radio resource area in an NR system for transmitting data or control channels on the downlink or uplink.

[0020] Figure 2A This is a diagram illustrating an example of a time slot structure used in a 5G wireless communication system according to an embodiment of the present disclosure.

[0021] Figure 2B This is a diagram illustrating an example of a control resource set (CORESET) for transmitting a downlink control channel in a 5G wireless communication system according to an embodiment of the present disclosure.

[0022] Figure 3This is a diagram illustrating an example of how eMBB, URLLC, and mMTC data are allocated across the entire system frequency band.

[0023] Figure 4 This is a diagram illustrating an example of how eMBB, URLLC, and mMTC data are allocated to the divided system frequency bands.

[0024] Figure 5 This is a diagram illustrating an example of the process of dividing one of the transport blocks into several code blocks and adding a CRC to the transport block.

[0025] Figure 6 This is a diagram showing the mapping between the synchronization signal (SS) and the physical broadcast channel (PBCH) in the frequency and time domains of an NR system.

[0026] Figure 7 This is a diagram illustrating the symbols for transmitting SS / PBCH blocks based on subcarrier intervals.

[0027] Figure 8 This is a diagram illustrating the UE's processing time according to a timing advance, when a UE receives a first signal and sends a second signal about the first signal in a 5G or NR system, according to a disclosed embodiment.

[0028] Figure 9 This is a diagram illustrating an example of scheduling and sending data (e.g., TB) according to time slots, receiving HARQ-ACK feedback for the corresponding data, and performing retransmissions based on that feedback.

[0029] Figure 10 This is a diagram illustrating an example of a communication system that uses satellites.

[0030] Figure 11 It is a diagram showing the Earth orbital period of a communication satellite based on its elevation or altitude.

[0031] Figure 12 This is a diagram illustrating the concept of satellite-UE direct communication.

[0032] Figure 13 This diagram illustrates a scenario where satellite-UE direct communication is used.

[0033] Figure 14 This is a diagram illustrating an example of calculating the expected data throughput in the uplink when an LEO satellite with an altitude of 1200 km and a UE on the ground perform direct communication with each other.

[0034] Figure 15 This is a diagram illustrating an example of the expected data throughput calculation in the uplink when a GEO satellite with an altitude of 35,786 km and a UE on the ground perform direct communication with each other.

[0035] Figure 16 This is a graph showing the path loss values ​​based on the path loss model between the UE and the satellite, and the path loss based on the path loss model between the UE and the terrestrial network communication base station.

[0036] Figure 17 This is a graph showing the mathematical expression and results of calculating the Doppler frequency shift experienced by the signal transmitted from the satellite, based on the satellite's elevation and position and the location of the ground UE user, when the signal is received by the ground user.

[0037] Figure 18 This is a graph showing the satellite velocity calculated at the satellite's elevation.

[0038] Figure 19 It is a graph showing the Doppler shift experienced by different UEs within a single beam transmitted from a satellite to the ground.

[0039] Figure 20 This is a diagram showing the Doppler frequency shift that occurs within a beam based on the satellite position determined from the elevation angle.

[0040] Figure 21 This is a graph showing the time delay between the UE and the satellite based on the satellite position determined from the elevation angle, as well as the round-trip time delay between the UE, the satellite, and the base station.

[0041] Figure 22 This is a graph showing the maximum difference in round-trip time delay based on the user's location within a beam.

[0042] Figure 23 This is a diagram illustrating an example of the information structure of a Random Access Response (RAR).

[0043] Figure 24 This is a diagram illustrating an example of the relationship between PRACH preamble configuration resources and RAR reception time in an LTE system.

[0044] Figure 25 This is a diagram illustrating an example of the relationship between PRACH preamble configuration resources and RAR reception time in a 5G NR system.

[0045] Figure 26 This is a diagram illustrating an example of downlink and uplink frame timing in a UE.

[0046] Figure 27 This is a graph showing the maximum Doppler frequency shift experienced by different UEs within a beam, depending on the beam size and center frequency (fc), at a satellite elevation of 700 km.

[0047] Figure 28 It is a graph showing the absolute velocity of a satellite orbiting the Earth, based on its elevation, and the relative velocity between the satellite and stationary objects on the ground.

[0048] Figure 29 The diagram illustrates an example of how a satellite's position changes over time, and therefore, the UE experiences frequency shifts due to delays or the Doppler effect experienced in UE-satellite communications.

[0049] Figure 30 This is a diagram illustrating an example of frequency offset indication information for several UEs included in a single MAC CE when the frequency offset is indicated by using the same MAC CE for a group as a unit.

[0050] Figure 31 This is a graph showing the difference in propagation delay between terrestrial and satellite networks.

[0051] Figure 32 This diagram illustrates examples of applying timing advance in terrestrial and satellite networks.

[0052] Figure 33 This is a graph showing the maximum round-trip propagation delay difference experienced by multiple users located in one of several beams transmitted by the satellite among the UE, satellite, and base station.

[0053] Figure 34 This is a graph showing how the round-trip propagation delay between the UE and the base station changes over time as the satellite moves along its orbit.

[0054] Figure 35 This is a block diagram illustrating the internal structure of a UE according to an embodiment of the present disclosure.

[0055] Figure 36 This is a block diagram illustrating the internal structure of a satellite according to an embodiment of the present disclosure.

[0056] Figure 37 This is a block diagram illustrating the internal structure of a base station according to an embodiment of the present disclosure. Detailed Implementation

[0057] A new radio access technology (NR) has been designed as a new 5G communication technology, enabling various services to be freely multiplexed in terms of time and frequency resources. Therefore, waveform / parameter sets and reference signals can be dynamically or freely allocated when the corresponding service is needed. In wireless communication, it is important to transmit optimal data by measuring channel quality and interference levels to provide optimal service to the UE; therefore, accurate channel state measurement is necessary. However, in the case of 5G channels, unlike 4G communication where channel and interference characteristics do not change significantly based on frequency resources, these characteristics change significantly based on the service. Therefore, it is necessary to support subsets of the frequency resource group (FRG) dimension to classify and measure channel and interference characteristics. Meanwhile, in the NR system, the supported service types can be categorized as Enhanced Mobile Broadband (eMBB), Massive Machine-Type Communication (mMTC), and Ultra-Reliable Low-Latency Communication (URLLC). eMBB can be considered a service aimed at high-speed transmission of high-capacity data, mMTC at minimizing UE power and supporting multiple UE access, and URLLC at high reliability and low latency. Different requirements can be applied depending on the type of service being applied to the UE.

[0058] In such a communication system, multiple services can be provided to a user, and in order to provide multiple services to a user, a method and an apparatus for providing various services in the same time interval to match their characteristics are needed.

[0059] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0060] In describing the embodiments, explanations of technical content known in the art to which this disclosure pertains and not directly related to this disclosure will be omitted. This is to more clearly convey the subject matter of this disclosure without making it obscure due to the omission of unnecessary explanations.

[0061] For the same reason, some components are exaggerated, omitted, or simplified in the accompanying drawings. Furthermore, the dimensions of the individual components do not perfectly reflect their actual dimensions, and the same reference numerals are used for the same or corresponding components in various drawings.

[0062] The aspects and features of this disclosure, as well as methods for implementing these aspects and features, will become apparent from the embodiments described in detail with reference to the accompanying drawings. However, this disclosure is not limited to the embodiments disclosed below and can be implemented in various forms. The definitions in the embodiments of this disclosure are merely provided to assist those skilled in the art in fully understanding the specific details of this disclosure, and this disclosure is defined only within the scope of the appended claims. Throughout the description of this disclosure, the same reference numerals are used for the same elements in different figures.

[0063] In this context, it will be understood that each block of the flowchart illustration, and combinations of boxes within the flowchart illustration, can be executed by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that the instructions, executed by the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart blocks. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium, which can instruct the computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-usable or computer-readable storage medium produce an article of manufacture including instruction means for implementing the functions specified in the flowchart blocks or blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable data processing apparatus, thereby producing a computer-implemented process, such that the instructions, which execute on the computer or other programmable data processing apparatus, provide steps for implementing the functions specified in one or more blocks of the flowchart.

[0064] Furthermore, each block of the flowchart can represent a module, segment, or code section, which includes one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions mentioned in a block may appear out of order. For example, depending on the functions involved, two blocks shown consecutively may actually execute substantially simultaneously, or these blocks may sometimes execute in reverse order.

[0065] In this context, the term "~unit" as used in the embodiments means, but is not limited to, a software or hardware component performing certain tasks, such as an FPGA or ASIC. However, "~unit" is not intended to be limited to software or hardware. The term "~unit" can advantageously be configured to reside on an addressable storage medium and configured to execute on one or more processors. Thus, by way of example, "unit" can include components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided in components and "~units" can be combined into fewer components and "~units," or further divided into additional components and "~units." Furthermore, components and "~units" can be implemented as one or more CPUs in an operating device or secure multimedia card. Additionally, in one embodiment, "~unit" can include one or more processors.

[0066] Wireless communication systems were initially developed to provide voice-oriented services, but have expanded to include broadband wireless communication systems that provide high-speed and high-quality packet data services, such as communication standards like 3GPP High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), 3GPP2 High-Speed ​​Packet Data (HRPD), Ultra Mobile Broadband (UMB), and IEEE 802.16e. Furthermore, as a fifth-generation wireless communication system, 5G, or New Radio (NR), communication standards have been developed.

[0067] In NR systems, a representative example of broadband wireless communication systems, the downlink (DL) and uplink employ Orthogonal Frequency Division Multiplexing (OFDM) schemes. More specifically, the downlink uses Cyclic Prefix OFDM (CP-OFDM), and the uplink (UL) uses two schemes: CP-OFDM and Discrete Fourier Transform Spread Spectrum OFDM (DFT-S-OFDM). The uplink refers to the radio link through which a user equipment (UE) or mobile station (MS) transmits data or control signals to a base station (gNode B or BS), while the downlink refers to the radio link through which the base station transmits data or control signals to the UE. According to these multiple access schemes, typical data or control information for each user is distinguished from each other by performing allocation and operation to prevent time-frequency resources used to carry each user's data or control information from overlapping, i.e., establishing orthogonality.

[0068] The NR system employs a Hybrid Automatic Repeat Request (HARQ) scheme, in which the physical layer retransmits the corresponding data if decoding fails during the initial transmission. According to the HARQ scheme, if the receiver cannot accurately decode the data, it can send a negative acknowledgment (NACK) to notify the transmitter of the decoding failure, and the transmitter can then retransmit the corresponding data. The receiver can combine the retransmitted data with the previously decoded data to improve data reception performance. Furthermore, if the receiver has accurately decoded the data, it can send an acknowledgment (ACK) to notify the transmitter of successful decoding, and the transmitter can then transmit new data.

[0069] Figure 1 This is a diagram illustrating the basic structure of the time-frequency domain, which is the radio resource area in an NR system for transmitting data or control channels on the downlink or uplink.

[0070] exist Figure 1 In the diagram, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The smallest transmission unit in the time domain is an OFDM symbol, and N... symb OFDM symbols (102) are aggregated to form a time slot 106. The subframe length is defined as 1.0 ms, and radio frame 114 is defined as 10 ms. The smallest transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission band is composed of all N... BW It consists of 104 subcarriers. A frame can be defined as 10 ms. A subframe can be defined as 1 ms, therefore, a frame can consist of a total of 10 subframes. A time slot can be defined as 14 OFDM symbols (i.e., the number of symbols in a time slot). A subframe can consist of one or more time slots, and the number of time slots in a subframe can vary depending on the set value μ of a subcarrier interval.

[0071] Figure 2A This is a diagram illustrating an example of a time slot structure used in a 5G wireless communication system according to an embodiment of the present disclosure.

[0072] refer to Figure 2A With μ=0 and μ=1, the time slot structure is shown as the subcarrier spacing setting. With μ=0, a subframe can consist of one time slot, while with μ=1, a subframe can consist of two time slots. That is, the number of time slots in a subframe depends on the subcarrier spacing setting value μ. The number of time slots in a frame may differ. It may differ. It depends on the subcarrier spacing setting μ. and It can be defined in Table 1 below.

[0073] [Table 1]

[0074]

[0075] Prior to Radio Resource Control (RRC) connection, the UE can be configured with an initial bandwidth portion (initial BWP) for initial access from the base station via the Master Information Block (MIB). More specifically, the UE can receive configuration information regarding the control resource set (CORESET) and search space, and can transmit the Physical Downlink Control Channel (PDCCH) for receiving system information required for initial access via the MIB during the initial access phase (corresponding to the Residual System Information (RMSI) or System Information Block 1 (SIBI)). The control resource set and search space configured by the MIB can be considered as ID 0. The base station can notify the UE of the configuration information for control resource set #0 via the MIB, such as frequency allocation information, time allocation information, and parameter sets. Furthermore, the base station can notify the UE of the configuration information regarding the monitoring period and timing of control resource set #0 via the MIB, i.e., the configuration information regarding search space #0. The UE can consider the frequency domain configured as control resource set #0 obtained from the MIB as the frequency domain used for initial access.

[0076]

[0077] Initial bandwidth portion. In this case, the identifier (ID) of the initial bandwidth portion can be considered as 0.

[0078] The MIB can include the following information.

[0079] MIB

[0080]

[0081] In the method for configuring the bandwidth portion, the UE can receive configuration information for the initial bandwidth portion via the MIB during the initial access phase prior to RRC connection. More specifically, the UE can be configured with a control resource set for a downlink control channel on which downlink control information (DCI) for scheduling SIBs from the MIB via the Physical Broadcast Channel (PBCH) can be transmitted. In this case, the bandwidth of the control resource set configured with the MIB can be considered as the initial bandwidth portion, and through the configured initial bandwidth portion, the UE can receive the Physical Downlink Shared Channel (PDSCH) on which SIBs are transmitted. Besides the purpose of receiving SIBs, the initial bandwidth portion can be used for other System Information (OSI), paging, and random access.

[0082] When one or more bandwidth portions are configured for a UE, the base station can instruct the UE to change the bandwidth portion by using the bandwidth portion indicator field in the DCI.

[0083] In the time-frequency domain, the basic resource unit is a resource element (RE) 112, which can be represented as an OFDM symbol index and a subcarrier index. A resource block (RB) or physical resource block (PRB) 108 is defined as N in the frequency domain. RB 110 consecutive subcarriers. Typically, the smallest data transmission unit is the RB unit. In NR systems, typically N... symb and N RB They are 14 and 12 respectively, and N BW The data rate is proportional to the bandwidth of the system's transmission band and the number of RBs scheduled by the UE; the data rate can be increased.

[0084] In NR systems, in the case of FDD systems that operate the downlink and uplink by frequency differentiation, the downlink transmission bandwidth and uplink transmission bandwidth can be different from each other. Channel bandwidth represents the RF bandwidth corresponding to the system transmission bandwidth. Tables 2 and 3 show some correspondences between system transmission bandwidth, subcarrier spacing, and channel bandwidth defined in NR systems in frequency bands below and above 6 GHz. For example, an NR system with a 100 MHz channel bandwidth and a 30 kHz subcarrier spacing consists of a transmission bandwidth composed of 273 RBs. In the following text, N / A can refer to a bandwidth-subcarrier combination that is not supported in the NR system.

[0085] [Table 2]: Configuration of Frequency Range 1 (FR1)

[0086]

[0087] [Table 3]: Configuration of Frequency Range 2 (FR2)

[0088]

[0089] In an NR system, the frequency range can be defined as divided into FR1 and FR2, as shown in Table 4 below.

[0090] [Table 4]

[0091] Frequency range name Corresponding frequency range FR1 450MHz–7125MHz FR2 24250MHz–52600MHz

[0092] As mentioned above, it is possible to vary and apply the ranges of FR1 and FR2 differently. For example, the frequency range of FR1 can be varied and applied from 450MHz to 6000MHz.

[0093] Next, the synchronization signal (SS) / PBCH block in 5G will be described.

[0094] The SS / PBCH block can refer to a physical layer channel block composed of the primary SS (PSS), secondary SS (SSS), and PBCH. Specifically, it may be as follows.

[0095] -PSS: This is the signal that forms the basis for downlink time / frequency synchronization and provides some information about the cell ID.

[0096] -SSS: This forms the basis for downlink time / frequency synchronization and provides residual cell ID information not provided by PSS. Additionally, it can be used as a reference signal for demodulating the PBCH.

[0097] -PBCH: This provides the basic system information necessary for the UE to transmit and receive data and control channels. The basic system information may include search space-related control information representing radio resource mapping information for control channels and scheduling control information for separate data channels used to transmit system information.

[0098] -SS / PBCH Blocks: SS / PBCH blocks are composed of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be sent within 5ms, and each SS / PBCH block being sent can be distinguished by an index.

[0099] The UE can detect the PSS and SSS during the initial access phase and can decode the PBCH. The UE can obtain the MIB from the PBCH and thus be configured with Control Resource Set #0 (corresponding to the Control Resource Set index 0). Assuming the Demodulation Reference Signal (DMRS) transmitted from the selected SS / PBCH block and Control Resource Set #0 are quasi-co-located (QCLed), the UE can monitor Control Resource Set #0. The UE can receive system information via downlink control information transmitted from Control Resource Set #0. The UE can obtain the Random Access Channel (RACH) configuration information necessary for initial access from the received system information. Considering the selected SS / PBCH block index, the UE can transmit the Physical RACH (PRACH) to the base station, and the base station, having received the PRACH, can obtain information about the SS / PBCH block index selected by the UE. Through this process, the base station can know which SS / PBCH block the UE has selected and the fact that the UE is monitoring Control Resource Set #0 associated with the selected block.

[0100] Next, we will describe downlink control information (DCI) in a 5G system in detail.

[0101] In 5G systems, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or Physical Downlink Shared Channel (PDSCH)) is transmitted from the base station to the UE via DCI. The UE can monitor the fallback DCI format and the non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format can consist of fixed fields predefined between the base station and the UE, while the non-fallback DCI format can include configurable fields. Furthermore, several formats exist within the DCI, and each format can indicate whether the DCI is used for power control or for notifying the slot format indicator (SFI).

[0102] DCI messages can be transmitted on the PDCCH, which serves as the physical downlink control channel, through channel coding and modulation processes. Cyclic Redundancy Check (CRC) can be appended to the DCI message payload, and the CRC can be scrambled by a Radio Network Temporary Identifier (RNTI) corresponding to the UE's identifier. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. That is, the RNTI is not explicitly transmitted but is included in the CRC calculation process. If a DCI message transmitted on the PDCCH is received, the UE identifies the CRC using the assigned RNTI, and if the CRC identification is correct, the UE knows that the corresponding message has been sent. The PDCCH is mapped to a control resource set (CORESET) configured for the UE for transmission.

[0103] For example, the DCI of the PDSCH for scheduling System Information (SI) can be scrambled by SI-RNTI. The DCI of the PDSCH for scheduling Random Access Response (RAR) messages can be scrambled by RA-RNTI. The DCI of the PDSCH for scheduling paging messages can be scrambled by P-RNTI. The DCI of the Notification Slot Format Indicator (SFI) can be scrambled by SFI-RNTI. The DCI of the Notification Transmission Power Control (TPC) can be scrambled by TPC-RNTI. The DCI of the scheduling UE-specific PDSCH or PUSCH can be scrambled by Cell RNTI (C-RNTI).

[0104] DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, and in this case, CRC can be scrambled by C-RNTI. DCI format 0_0 with CRC scrambled by C-RNTI can include, for example, the following information.

[0105] [Table 5]

[0106]

[0107]

[0108] DCI format 0_1 ​​can be used as a non-back-off DCI for scheduling PUSCH, and in this case, CRC can be scrambled by C-RNTI. The DCI format 0_1 ​​with CRC scrambled by C-RNTI can include, for example, the following information.

[0109] [Table 6]

[0110]

[0111]

[0112]

[0113] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, and in this case, CRC can be scrambled by C-RNTI. DCI format 1_0 with CRC scrambled by C-RNTI can include, for example, the following information.

[0114] [Table 7]

[0115]

[0116] DCI format 1_1 can be used as a non-back-off DCI for scheduling PDSCH, and in this case, CRC can be scrambled by C-RNTI. The DCI format 1_1 with CRC scrambled by C-RNTI can include, for example, the following information.

[0117] [Table 8]

[0118]

[0119]

[0120] The following section describes a method for allocating time-domain resources for data channels in 5G communication systems.

[0121] The base station can configure tables for the UE using upper-layer signaling (e.g., RRC signaling) to provide time-domain resource allocation information for the downlink data channel (PDSCH) and uplink data channel (PUSCH). Tables with a maximum maxNrofDL-Allocations of 16 entries can be configured for PDSCH, and tables with a maximum maxNrofDL-Allocations of 16 entries can be configured for PUSCH. The time-domain resource allocation information may include, for example, PDCCH-PDSCH time slot timing (corresponding to the time interval of time slot units between the time of receiving the PDCCH and the time of transmitting the PDSCH scheduled by the received PDCCH) (denoted by K0), or PDCCH-PUSCH time slot timing (corresponding to the time interval of time slot units between the time of receiving the PDCCH and the time of transmitting the PUSCH scheduled by the received PDCCH) (denoted by K2), information regarding the position and length of the start symbol for scheduling the PDSCH or PUSCH in the time slot, and the mapping type of the PDSCH or PUSCH. For example, the information in Tables 9 and 10 below can be notified to the UE from the base station.

[0122] [Table 9]

[0123]

[0124] [Table 10]

[0125]

[0126] The base station can notify the UE of one of the entries in the table of time-domain resource allocation information via L1 signaling (e.g., DCI) (e.g., it can be indicated by the "Time-domain Resource Allocation" field in the DCI). The UE can obtain the time-domain resource allocation information of PDSCH or PUSCH based on the DCI received from the base station.

[0127] The downlink control channel in a 5G communication system will be described in more detail below with reference to the accompanying drawings.

[0128] Figure 2B This is a diagram illustrating an example of a control resource set for transmitting a downlink control channel in a 5G wireless communication system according to an embodiment of the present disclosure.

[0129] refer to Figure 2BAn example is shown where the UE bandwidth portion 210 is configured on the frequency axis, and two control resource sets (control resource set #1 201 and control resource set #2 202) are configured in a time slot 220 on the time axis. Control resource sets 201 and 202 can be configured for specific frequency resources 203 within the entire UE bandwidth portion 210 on the frequency axis. On the time axis, one or more OFDM symbols can be configured, and this can be defined as a control resource set duration 204. Referring to the example shown in Figure 2, control resource set #1 201 can be configured for a control resource set duration of two symbols, and control resource set #2 202 can be configured for a control resource set duration of one symbol.

[0130] The control resource set in 5G described above can be configured from the base station to the UE via upper-layer signaling (e.g., system information, MIB, and RRC signaling). Configuring the control resource set for the UE means providing information such as the control resource set identifier, the frequency location of the control resource set, and the symbol duration of the control resource set. For example, upper-layer signaling may include the information in Table 11 below.

[0131] [Table 11]

[0132]

[0133] In Table 11, the tci-statepdcch (referred to as Transmission Configuration Indicator (TCI) status) configuration information may include information on one or more SS / PBCH block indices or Channel State Information Reference Signal (CSI-RS) indices that have a QCL relationship with the DMRS transmitted in the corresponding control resource set.

[0134] As an example, the various control information included in DCI format 1_1, namely the scheduling control information (DL license) for downlink data, can be as follows.

[0135] - Carrier indicator: This indicates on which carrier the DCI-scheduled data is transmitted (0 or 3 bits).

[0136] - Identifier for DCI format: This indicates the DCI format, and specifically, it is an indicator that distinguishes whether the corresponding DCI is used for the downlink or the uplink ([1] bits).

[0137] - Bandwidth portion indicator: This indicates the change (0, 1, or 2 bits) if the bandwidth portion is changed.

[0138] - Frequency domain resource allocation: This is the resource allocation information that indicates the allocation of frequency domain resources, and different resources are represented by whether the resource allocation type is 0 or 1.

[0139] - Time-domain resource allocation: This is resource allocation information that indicates the allocation of time-domain resources, and can be a configuration (1, 2, 3 or 4 bits) that indicates the upper-layer signaling or the pre-defined PDSCH time-domain resource allocation list.

[0140] -VRB to PRB mapping: This indicates the mapping relationship (0 or 1 bit) between Virtual Resource Block (VRB) and Physical Resource Block (PRB).

[0141] -PRB Bundle Size Indicator: This indicates the bundle size (0 or 1 bit) of the physical resource blocks that are assumed to be applied with the same precoding.

[0142] - Rate Matching Indicator: This indicates which rate matching group among the configured rate matching groups is applied to the upper layer of the PDSCH (0, 1, or 2 bits).

[0143] -ZP CSI-RS trigger: This triggers the zero-power channel state information reference signal (0, 1, or 2 bits).

[0144] - Configuration information related to transport blocks (TB): This indicates the modulation and coding scheme (MCS), new data indicator (NDI), and redundancy version (RV) for one or two TBs.

[0145] - Modulation and Coding Scheme (MCS): This indicates the modulation method and coding rate used for data transmission. In other words, it indicates a coding rate value that informs the TBS and channel coding information, as well as information about whether the modulation is QPSK, 16QAM, 64QAM, or 256QAM.

[0146] - New data indicator: This indicates whether the transmission is a HARQ initial transmission or a retransmission.

[0147] - Redundant version: This indicates the HARQ redundant version.

[0148] -HARQ process number: This indicates the HARQ process number (4 bits) applied to PDSCH.

[0149] - Downlink dispatch index: This is an index (0, 2, or 4 bits) used to generate a dynamic HARQ-ACK codebook during the HARQ-ACK reporting of PDSCH.

[0150] - TPC command for PUCCH for scheduling: Power control information (2 bits) applied to the PUCCH for HARQ-ACK reporting used in PDSCH.

[0151] -PUCCH Resource Indicator: Information (3 bits) indicating the PUCCH resource used for HARQ-ACK reporting of PDSCH.

[0152] -PDSCH-to-HARQ_Feedback Timing Indicator: Configuration information (3 bits) about from which time slot the PUCCH for sending HARQ-ACK reports for PDSCH is sent.

[0153] - Antenna Port: Indicates the antenna port of PDSCH DMRS and information (4, 5, or 6 bits) for DMRS CDM groups that do not transmit PDSCH.

[0154] - Transmission configuration indication: Information (0 or 3 bits) indicating beam-related information for the PDSCH.

[0155] -SRS Request: Information (2 bits) used to request SRS transmission.

[0156] -CBG Transmission Information: When block-based retransmission is configured, this information (0, 2, 4, 6, or 8 bits) indicates which block group (CBG) the corresponding data is transmitted to via PDSCH.

[0157] -CBG Clear Information: Information (0 or 1 bit) indicating whether previously received code block groups by the UE can be used for HARQ merging.

[0158] -DMRS sequence initialization: This indicates the DMRS sequence initialization parameters (1 bit).

[0159] As described above, when data transmission occurs on PDSCH or PUSCH, time-domain resource allocation can be transmitted using information about the time slot for transmitting PDSCH / PUSCH, the start symbol position S within the corresponding time slot, and the number of symbols L mapped to the PDSCH / PUSCH. In this case, S can be the relative position from the start of the time slot, L can be the number of consecutive symbols, and S and L can be determined based on the start and length indicator values ​​(SLIV) defined in the mathematical expression 1 below.

[0160] [Mathematical Expression 1]

[0161]

[0162] In an NR system, the UE can be configured with information about the SLIV value, PDSCH / PUSCH mapping type, and the time slots for transmitting PUSCH / PUSCH in a single row via RRC configuration (e.g., this information can be configured in tabular form). Subsequently, in the DCI time-domain resource allocation, the index value in the configured table is indicated, allowing the base station to transmit information about the SLIV value, PDSCH / PUSCH mapping type, and the time slots for transmitting PDSCH / PUSCH to the UE.

[0163] In NR systems, PDSCH mapping types A and B are defined. In PDSCH mapping type A, the first symbol in the DMRS symbol is located in the second or third OFDM symbol of the time slot. In PDSCH mapping type B, the first symbol in the DMRS symbol is located in the first OFDM symbol in the time domain resources allocated via PUSCH transmission.

[0164] Downlink data can be transmitted on the PDSCH, which is the physical channel used to transmit downlink data. The PDSCH can be transmitted after the control channel transmission interval, and the scheduling information in the frequency domain, such as detailed mapping positions and modulation methods, is determined based on the DCI transmitted via the PDCCH.

[0165] By using the MCS (Modulation Control Sequence) in the control information that constitutes the DCI (Distributed Control Information), the base station informs the UE (User Equipment) of the modulation method and data size (Transmission Block Size (TBS)) to be applied to the PDSCH (Programmable Streaming Disk) to be transmitted. In one embodiment, the MCS may consist of 5 bits or more or fewer. The TBS corresponds to the size of the channel coding used for error correction before it is applied to the transmission block (TB).

[0166] In this disclosure, a transport block (TB) may include a media access control (MAC) header, a MAC control element, and one or more MAC service data units (SDUs). Furthermore, the TB may indicate data units or MAC protocol data units (PDUs) delivered from the MAC layer to the physical layer.

[0167] The NR system supports modulation methods including Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (QAM), 64QAM, and 256QAM, with each modulation order (Qm) corresponding to 2, 4, 6, or 8. That is, in QPSK modulation, each symbol can transmit 2 bits, while in 16QAM modulation, each symbol can transmit 4 bits. In 64QAM modulation, each symbol can transmit 6 bits, and in 256QAM modulation, each symbol can transmit 8 bits.

[0168] Figure 3 and Figure 4 This is a diagram illustrating an example of how eMBB, URLLC, and mMTC data are allocated on frequency-time resources as services considered in 5G or NR systems.

[0169] refer to Figure 3 and Figure 4 It can identify the methods by which frequency and time resources are allocated to each system for information transmission.

[0170] Figure 3This is a diagram illustrating an example of how eMBB, URLLC, and mMTC data are allocated across the entire system frequency band. First, Figure 3 The diagram illustrates the allocation of eMBB, URLLC, and mMTC data across the entire system frequency band 300. When URLLC data 303, 305, and 307 are generated and need to be transmitted when eMBB 301 and mMTC 309 are allocated and transmitted in a specific frequency band, URLLC data 303, 305, and 307 can be transmitted without clearing the already allocated portions of eMBB 301 and mMTC 309 or without transmitting eMBB 301 and mMTC 309. Because it is necessary to reduce the latency of URLLC between services, URLLC data (303, 305, and 307) can be allocated to a portion of the allocated resource 301 and then transmitted. However, if URLLC is additionally allocated to and transmitted over a resource already allocated to eMBB, eMBB data may not be transmitted in the same frequency-time resource, thus potentially reducing eMBB data transmission performance. In other words, in the above scenario, eMBB data transmission failure may occur due to URLLC allocation.

[0171] Figure 4 This is a diagram illustrating an example of how eMBB, URLLC, and mMTC data are allocated to the divided system frequency bands. Figure 4 In this system, the entire frequency bandwidth 400 can be divided into subbands 402, 404, and 406 for transmitting services and data. Information related to the subband configuration can be predetermined and transmitted from the base station to the UE via upper-layer signaling. Furthermore, subbands can be optionally allocated by the base station or network nodes and can provide services to the UE without sending separate subband configuration information. Figure 4 Subband 402 is shown for eMBB data transmission, subband 404 for URLLC data transmission, and subband 406 for mMTC data transmission.

[0172] To explain the methods and apparatus presented in the embodiments, the terms "physical channel" and "signal" may be used in NR systems. However, the content of this disclosure will be applicable to wireless communication systems that are not NR systems.

[0173] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in describing the present disclosure, detailed explanations of relevant functions or configurations that would unnecessarily obscure the subject matter will be omitted. Additionally, the terms to be described below have been defined by consideration of their function in the present disclosure and may vary depending on the intent or habits of the user or operator. Therefore, each term should be defined based on the entirety of this specification.

[0174] In this disclosure, downlink (DL) is the radio transmission path of signals sent from the base station to the UE, and uplink (UL) is the radio transmission path of signals sent from the UE to the base station.

[0175] In the following description, although embodiments of the present disclosure will be illustrated using an NR system as an example, the embodiments of the present disclosure can also be applied to other communication systems with similar technical backgrounds or channel types. Furthermore, as judged by those skilled in the art, the embodiments of the present disclosure can also be applied to other communication systems with partial modifications that do not materially depart from the scope of the present disclosure.

[0176] In this disclosure, the terms "physical channel" and "signal" in the related art can be used interchangeably with "data" or "control signal". For example, although PDSCH is a physical channel for transmitting data, in this disclosure, PDSCH can be referred to as data.

[0177] In the following, in this disclosure, upper-layer signaling is a method for transmitting signals from a base station to a UE using a downlink data channel of the physical layer, or for transmitting signals from a UE to a base station using an uplink data channel of the physical layer, and may be referred to as RRC signaling or MAC control unit (MAC CE).

[0178] Figure 5 This is a diagram illustrating an example of the process of dividing a transport block into several code blocks and adding a CRC to them.

[0179] refer to Figure 5 A CRC 503 can be added to the end or header portion of a transport block (TB) 501 intended to be transmitted on the uplink or downlink. The CRC 503 can consist of 16 bits, 25 bits, or a prefix number of bits, or a variable number of bits depending on the channel conditions, and can be used to determine whether channel coding was successful. The block including the added TB 501 and CRC 503 can be divided into several code blocks (CBs) 507, 509, 511, and 513 (505). Here, the code blocks can have a predetermined maximum size; in this case, the final code block 513 can have a smaller size than the other code blocks 507, 509, and 511. However, this is merely exemplary; according to another example, the final code block 513 can be set to have the same length as the other code blocks 507, 509, and 511 by inserting 0, random values, or 1 into it.

[0180] In addition, CRC 517, 519, 521 and 523 can be added to code blocks 507, 509, 511 and 513 (515), respectively. CRC can consist of 16 bits, 24 bits or a prefix number of bits and can be used to determine whether the channel coding was successful.

[0181] To generate CRC 503, TB 501 and a cyclic generator polynomial can be used, and the cyclic generator polynomial can be defined in various ways. For example, if we assume that the cyclic generator polynomial for a 24-bit CRC is gCRC24A(D)=D24+D23+D18+D17+D14+D11+D10+D7+D6+D5+D4+D3+D+1, and L is 24, then for TB data a0, a1, a2, a3, ..., a A-1 ,CRC p0,p1,p2,p3,...,p L-1 It can be determined by a0D A+23 +a1D A+22 +…+a A-1 D 24 +p0D 23 +p1D 22 +...+p 22 D 1 +p 23 The value obtained by dividing by gCRC24A(D) has a remainder of 0. In the example above, although it is assumed that the CRC length L is 24, the CRC length L can be determined to include various lengths, such as 12, 16, 24, 32, 40, 48, 64, etc.

[0182] After adding CRC to TB in the above process, TB+CRC can be divided into N CBs 507, 509, 511, and 513. CRCs 517, 519, 521, and 523 can be added to the divided CBs 507, 509, 511, and 513 respectively (515). The length of the CRC added to CB can be different from the length of the CRC added to TB, or another cyclic generating polynomial can be used to generate the CRC. Furthermore, CRC 503 added to TB and CRCs 517, 519, 521, and 523 added to the code block can be omitted depending on the type of channel code to be applied to the code block. For example, if LDPC codes are applied to the code block instead of turbo codes, CRCs 517, 519, 521, and 523 inserted into the code block can be omitted.

[0183] However, even when applying LDPC, CRC 517, 519, 521, and 523 can be added to the code block as is. Furthermore, even when using polar codes, CRC can be added or omitted.

[0184] As per the above reference Figure 5 The maximum length of a code block can be determined based on the type of channel coding applied in the TB to be transmitted, and based on the maximum length of the code block, the TB and the CRC added to the TB can be divided into code blocks.

[0185] In the LTE system of the related technology, the CRC for the CB is added to the divided CB, and the data bits of the CB and CRC are encoded with the channel code to determine the coded bits, and as a pre-joining of the coded bits, the number of rate matching bits is determined.

[0186] In the NR system, the TB size (TBS) can be calculated through the following operations.

[0187] Operation 1: Within a PRB of allocated resources, calculate, i.e., the number N′ of REs allocated to the PDSCH mapping within a PRB of allocated resources. RE .

[0188] Here, N′ RE It is possible Calculation. Here, It is 12, and It can indicate the number of OFDM symbols assigned to the PDSCH. It is the number of REs in a PRB occupied by DMRS in the same CDM group. This refers to the number of REs used for overhead within a PRB, configured via upper-layer signaling. It can be configured as one of 0, 6, 12, or 18. Subsequently, the total number N of REs allocated to the PDSCH can be calculated. RE Here, N RE By min(156, N′) RW )·n PRB Calculate, and n PRB Indicates the number of PRBs allocated to the UE.

[0189] Operation 2: Number of temporary information bits N info It can be calculated as N RE *R*Q m *v. Here, R is the code rate, Qm is the modulation order, and these values ​​can be transmitted using a table pre-joined with the MCS bit field in the control information. Furthermore, v is the number of layers allocated. If N info If the value is ≤3824, the TBS can be calculated using operation 3 below. Otherwise, the TBS can be calculated using operation 4.

[0190] Operation 3: N′ info It can be done and The formula is used for calculation. In Table 12 below, TBS can be determined to be not less than N′. info The value closest to N′ info The value of .

[0191] [Table 12]

[0192] index TBS index TBS index TBS index TBS 1 24 31 336 61 1288 91 3624 2 32 32 352 62 1320 92 3752 3 10 33 368 63 1352 93 3824 4 48 34 384 64 1416 6 56 35 408 65 1480 6 64 36 432 66 1544 7 72 37 456 67 1608 8 80 38 480 68 1672 9 88 39 504 69 1736 10 96 40 528 70 1800 11 104 41 552 71 1864 12 112 42 576 72 1928 13 120 43 608 73 2024 14 128 44 610 74 2088 15 136 45 672 75 2152 16 144 46 704 76 2216 17 152 47 736 77 2280 18 160 48 768 78 2408 19 168 49 808 79 2472 20 176 50 848 80 2536 21 184 51 888 81 2600 22 192 52 928 82 2664 23 208 53 984 83 2728 24 224 54 1032 84 2792 25 240 55 10064 85 2856 26 256 56 1128 86 2976 27 272 57 1160 87 3104 28 288 58 1192 88 3240 29 304 59 1224 89 3368 30 320 60 1256 90 3496

[0193] Operation 4: N′ info It can be done and The formula can be used to calculate it. It can be done through N′. info The value and [pseudocode 1] below determine the TBS. In the following text, C corresponds to the number of code blocks included in a TB.

[0194] [Starting with pseudocode 1]

[0195]

[0196] [End of Pseudocode 1]

[0197] In an NR system, if a CB is input to an LDPC encoder, parity bits can be added to the CB to be output. In this case, the number of parity bits can vary depending on the LDPC basemap. The method used to send all parity bits generated by LDPC encoding for a specific input is called full buffer rate matching (FBRM), and the method used to limit the number of parity bits that can be sent is called limited buffer rate matching (LBRM). If resources are allocated for data transmission, the LDPC encoder output is generated by a circular buffer, and the bits in the resulting buffer are repeatedly sent within the allocated resource range. In this case, the length of the circular buffer can be N. cb .

[0198] If the number of parity bits generated by LDPC encoding is N, then in the FBRM method, the length of the circular buffer is N. cb It becomes N. In the LBRM method, N cb It becomes min(N, N) ref ), N ref Given as And R LBRM It may be determined to be 2 / 3. In order to obtain TBS LBRMUsing the method described above for obtaining TBS, we can assume that the UE in the corresponding cell supports and is configured with the maximum number of layers and the maximum modulation order. Furthermore, we assume that if configured to use an MCS table supporting 256QAM for at least one BWP, the maximum modulation order Qm is 8; otherwise, the maximum modulation order Qm is 6 (64QAM), and the code rate is 948 / 1024, i.e., the maximum code rate. Furthermore, we assume N... RE It is 156·n PRB And n PRB It needs to be calculated. Here, n PRB，LBRM As shown in Table 13 below.

[0199] [Table 13]

[0200] Maximum number of PRBs for all BWP configurations of the carrier <![CDATA[n PRB.LBRM ]]> Less than 33 32 33 to 66 66 67 to 107 107 108 to 135 135 136 to 162 162 163 to 217 217 Greater than 217 273

[0201] In an NR system, the maximum data rate supported by the UE can be determined by the following mathematical expression 2.

[0202] [Mathematical Expression 2]

[0203]

[0204] In mathematical expression 2, it can mean that J is the number of carriers bound by carrier aggregation, and R max =948 / 1024, It is the maximum number of floors. It is the maximum modulation order, f (j) f is the scaling index, and μ is the subcarrier spacing. Here, f (j) It can be one of the values ​​of 1, 0.8, 0.75 and 0.4 reported by the UE, and μ can be given as shown in Table 14 below.

[0205] [Table 14]

[0206] μ <![CDATA[Δf=2 μ ·15[kHz]]]> Cyclic prefix 0 15 normal 1 30 normal 2 60 Normal, extended 3 120 normal 4 240 normal

[0207] also, It is the average OFDM symbol length. It can be calculated as and It is the maximum number of RBs in BW(j). Furthermore, OH (j)This is the overhead value, which can be given as 0.14 in the downlink of FR1 (not higher than 6GHz band) and 0.18 in the uplink; it can be given as 0.08 in the downlink of FR2 (above 6GHz band) and 0.10 in the uplink. In a cell with a frequency bandwidth of 100MHz at a subcarrier spacing of 30kHz, the maximum data rate in the downlink can be calculated using mathematical expression 2, as shown in Table 15 below.

[0208] [Table 15]

[0209]

[0210] Conversely, the actual data rate that the UE can measure in actual data transmission can be a value obtained by dividing the data volume by the data transmission time. This could be the TBS in a 1TB transmission, or it could be a value obtained by dividing the sum of the TBS in a 2TB transmission by the TTI length. As an example, in the same manner as the assumptions used to obtain Table 15 above, the actual maximum data rate in the downlink of a cell with a frequency bandwidth of 100MHz at a 30kHz subcarrier spacing can be determined based on the number of allocated PDSCH symbols as shown in Table 16 below.

[0211] [Table 16]

[0212]

[0213] Table 15 identifies the maximum data rate supported by the UE, and Table 16 identifies the actual data rate after the allocated TBS. In this case, the actual data rate may be higher than the maximum data rate, depending on the scheduling information.

[0214] In wireless communication systems, particularly New Radio (NR) systems, the data rate that a UE can support can be used between the base station and the UE. This can be calculated using the maximum frequency band, maximum modulation order, and maximum number of layers supported by the UE. However, the calculated data rate may differ from the value calculated based on the transport block size (TBS) and transmission time interval (TTI) used for actual data transmission.

[0215] Therefore, a TBS greater than the data rate supported by the UE can be allocated to the UE, and to prevent this, there may be a limit in the schedulable TBS based on the data rate supported by the UE.

[0216] Figure 6 This is a diagram showing the mapping between the synchronization signal (SS) and the physical broadcast channel (PBCH) in the frequency and time domains of an NR system.

[0217] The primary synchronization signal (PSS) 601, secondary synchronization signal (SSS) 603, and PBCH are mapped onto each other on four OFDM symbols. The PSS and SSS are mapped onto 12 RBs, and the PBCH is mapped onto 20 RBs. Figure 7 The table shows how the frequency bands of the 20 RBs change according to the subcarrier spacing (SCS). The resource area on which PSS, SSS, and PBCH are transmitted can be referred to as the SS / PBCH block. Furthermore, the SS / PBCH block can be referred to as the SSB block.

[0218] Figure 7 This is a diagram illustrating the symbols for transmitting SS / PBCH blocks based on subcarrier intervals.

[0219] Reference Figure 7 The subcarrier spacing can be configured to 15kHz, 30kHz, 120kHz and 240kHz, and the position of the symbol in which the SS / PBCH block (or SSB block) can be located can be determined according to the subcarrier spacing. Figure 7 The symbol positions are shown, where the SSB can be transmitted on each symbol within 1 ms depending on the subcarrier spacing, but the SSB does not always have to be transmitted on each symbol. Figure 7 The SSB block is transmitted within the area shown. Therefore, the location for transmitting the SSB block can be configured in the UE via system information or dedicated signaling.

[0220] Typically, because the UE is far from the base station, signals transmitted from the UE are received at the base station after a propagation delay. The propagation delay is a value obtained by dividing the path of a radio wave from the UE to the base station by the speed of light, and often it can be obtained by dividing the distance between the UE and the base station by the speed of light. In one embodiment, if the UE is located 100 km from the base station, the signal transmitted from the UE is received at the base station after approximately 0.34 milliseconds. Conversely, the signal transmitted from the base station is received at the UE after approximately 0.34 milliseconds. As mentioned above, the arrival time of signals transmitted from the UE at the base station can vary depending on the distance between the UE and the base station. Therefore, in the case of several UEs located in different locations transmitting signals simultaneously, the arrival time of each signal at the base station may differ. To address this issue and ensure that signals transmitted from several UEs arrive at the base station simultaneously, the timing of uplink signal transmission can vary depending on the location of each UE. In 5G, NR, and LTE systems, this is called timing advance.

[0221] Figure 8 This is a diagram illustrating the UE's processing time according to a timing advance, when a UE receives a first signal and sends a second signal about the first signal in a 5G or NR system, according to a disclosed embodiment.

[0222] The processing time of the UE based on the timing advance will be described in detail below. If the base station sends an uplink scheduling grant (UL grant) or downlink control signals and data (DL grant and DL data) to the UE in time slot n 802, the UE can receive the uplink scheduling grant or downlink control signals and data in time slot n 804. In this case, compared with the time the base station sends the signal, the UE can receive the uplink scheduling grant or downlink control signals and data in time slot n 804. p Signals are received after time slot n 804. In one embodiment, if the UE receives the first signal in time slot n+4 806, the UE transmits the second signal in time slot n+4. Even when the UE is transmitting a signal to the base station, in order to ensure that the signal arrives at the base station at a specific time, the UE can, based on the signal received by the UE, advance the timing (T) earlier than time slot n+4. A In timing 806 of 812, the UE transmits HARQ ACK / NACK for uplink or downlink data. Therefore, in this embodiment, after receiving uplink scheduling permission to transmit uplink data or receiving downlink data, the time at which the UE can prepare to transmit HARQ ACK or NACK can be determined by excluding T from the time corresponding to the three time slots. A The time gained was (814).

[0223] To determine the aforementioned timing, the base station can calculate the corresponding UE's T. A The absolute value of . During the initial access of the UE, the base station can transmit the T value to the UE first during the random access phase. A Add to or subtract from the value the T transmitted via subsequent upper-layer signaling A Calculate T by changing the value A The absolute value of T. In this disclosure, T A The absolute value can be obtained by subtracting the start time of the nth TTI received by the UE from the start time of the nth TTI sent by the UE.

[0224] Meanwhile, one of the important performance standards of cellular wireless communication systems is packet data latency. Therefore, in LTE systems, signal transmission / reception is performed in subframes with a transmission time interval (TTI) of 1 ms. In LTE systems operating as described above, UEs with transmission time intervals shorter than 1 ms (short TTI UEs) can be supported. Similarly, in 5G or NR systems, the transmission time interval can be shorter than 1 ms. Short TTI UEs are suitable for LTE voice over LTE (VoLTE) services or remote control services where latency is critical. Furthermore, short TTI UEs can be a means of implementing cellular-based mission-critical Internet of Things (IoT).

[0225] In 5G or NR systems, when a base station transmits a PSDCH containing downlink data, the DCI indicator K1 value used for scheduling the PDSCH corresponds to the timing information of the HARQ-ACK information transmitted by the UE for the PDSCH. The UE can send a HARQ-ACK to the base station without indicating that the HARQ-ACK information includes a timing advance earlier than symbol L1. That is, the HARQ-ACK information can be transmitted from the UE to the base station when or after the timing advance becomes equal to symbol L1. If the HARQ-ACK information includes a timing advance and is indicated to be transmitted earlier than symbol L1, the HARQ-ACK information may not be valid during the HARQ-ACK transmission from the UE to the base station.

[0226] Symbol L1 can be the cyclic prefix (CP) from the last time T of PDSCH. proc，1 The first symbol after. T proc，1 It can be calculated according to the following mathematical expression 3.

[0227] [Mathematical Expression 3]

[0228] T proc，1 =((N1+d) 1，1 +d 1，2 (2048+144)·κ2 -μ )·T C

[0229] In mathematical expression 3 as described above, N1, d 1，1 d 1，2 κ, μ and T C It can be defined as follows.

[0230] - If the HARQ-ACK message is sent to the uplink control channel (PUCCH), then d 1，1 Change to d 1，1 =0, while if the uplink shared channel (PUSCH) (data channel) is transmitted, then d 1，1 Change to d 1，1 =1.

[0231] - In the case where the UE is configured with multiple active configuration (multiple) carriers, the maximum timing difference between the carriers can be reflected in the second signal transmission.

[0232] - In the case of PDSCH mapping type A, i.e., if the first DMRS symbol position is the third or fourth symbol of the slot, then if the position index i of the last symbol in the PDSCH is less than 7, d 1，2 Defined as d 1，2 =7-i.

[0233] - In the case of PDSCH mapping type B, i.e., if the first DMRS symbol position is the first symbol of the PDSCH, then when the length of the PDSCH is 4 symbols, d 1，2 Become d 1，2 =3, and when the length of PDSCH is 2 symbols, d 1，2 Become d 1，2 =3+d. In this case, d is the number of symbols in which the PDSCH and the PDCCH, which includes control signals for scheduling the corresponding PDSCH, overlap each other.

[0234] - According to μ, N1 is defined as shown in Table 17 below. μ = 0, 1, 2 and 3 represent subcarrier spacing of 15 kHz, 30 kHz, 60 kHz and 120 kHz, respectively.

[0235] [Table 17]

[0236]

[0237] Depending on the UE capabilities, different N1 values ​​provided in Table 17 above can be used.

[0238] Defined as

[0239] T c =1 / (Δf) max ·N f ), Δf max =480·10 3 Hz, N f =4096, κ=T s / T c =64,T s =1 / (Δf) ref ·N f，ref )

[0240] -Δf ref =15·10 3 Hz, N f，ref =2048

[0241] Furthermore, in 5G or NR systems, when the base station sends control information including uplink scheduling permission, the UE can indicate a K2 value corresponding to the timing information used to send uplink data or PUSCH.

[0242] If the PUSCH including timing advance is not indicated to be sent before symbol L2, the UE may send the PUSCH to the base station. That is, the PUSCH including timing advance can be sent from the UE to the base station when or after symbol L2. If the PUSCH includes timing advance and is indicated to be sent earlier than symbol L2, the UE may ignore the uplink scheduling permission control information from the base station.

[0243] Symbol L2 can be the first symbol starting with the CP of the PUSCH symbol, which should be at the last time T of the PDSCH including the scheduling permission. proc，2 It was then sent. T proc，2 It can be calculated according to the following mathematical expression 4.

[0244] [Mathematical Expression 4]

[0245] T proc，2 =((N2+d 2，1 (2048+144)·κ2 -μ )·T C

[0246] In mathematical expression 4 as described above, N2, d 2，1 κ, μ and T C It can be defined as follows.

[0247] - If the first symbol in the symbols assigned by PUSCH includes only DMRS, then d 2，1 Change to d 2，1 =0, otherwise d 2，1 Change to d 2，1 =1.

[0248] - In the case where the UE is configured with multiple active configuration (multiple) carriers, the maximum timing difference between the carriers can be reflected in the second signal transmission.

[0249] - According to μ, N2 is defined as shown in Table 18 below. μ = 0, 1, 2 and 3 represent subcarrier spacing of 15 kHz, 30 kHz, 60 kHz and 120 kHz, respectively.

[0250] [Table 18]

[0251] μ <![CDATA[PUSCH preparation time N2 [symbols]]]><![CDATA[ ]]>< 0 10 1 12 2 23 3 36

[0252] - Depending on the UE capabilities, different N2 values ​​provided in Table 18 above can be used.

[0253] Defined as

[0254] T c=1 / (Δf) max ·N f )Δf max =480·10 3 Hz, N f =4096, κ=T s / T c =64,T s =1 / (Δf) ref ·N f，ref ),

[0255] -Δf ref =15·10 3 Hz N f,ref =2048

[0256] Meanwhile, 5G or NR systems can configure a frequency band portion (BWP) within a carrier and can specify a particular UE to perform transmission and reception within the configured BWP. This is likely to reduce UE power consumption. The base station can configure multiple BWPs and can change the active BWP in the control information. The time a UE can use to change a BWP is defined as shown in Table 19 below.

[0257] [Table 19]

[0258]

[0259]

[0260] In Table 19, frequency range 1 represents a frequency band equal to or below 6 GHz, and frequency range 2 represents a frequency band equal to or above 6 GHz. In the above embodiments, type 1 and type 2 can be determined based on UE capabilities. In the above embodiments, scenarios 1, 2, 3, and 4 are given in Table 20 below.

[0261] [Table 20]

[0262] Center frequency change The center frequency remains unchanged. Frequency bandwidth change Scene 3 Scene 2 Frequency bandwidth remains unchanged Scene 1 Scenario 4: When the subcarrier spacing changes

[0263] Figure 9 This is a diagram illustrating an example of scheduling and transmitting data (e.g., TB) according to time slots, receiving HARQ-ACK feedback for the corresponding data, and performing retransmissions based on that feedback. Figure 9In the transmission, TB1 900 is initially transmitted in time slot 0 902, and the ACK / NACK feedback 904 for this transmission is transmitted in time slot 4 906. If the initial transmission of TB1 fails and a NACK is received, a retransmission of TB1 910 can be performed in time slot 8 908. As mentioned above, the timing of sending the ACK / NACK feedback and performing the retransmission can be predetermined, or it can be determined based on the values ​​indicated by control information and / or by upper-layer signaling.

[0264] Figure 9 An example is shown of scheduling and transmitting TB1 through TB8 according to the time slot sequence starting from time slot 0. For example, TB1 through TB8 can be transmitted with HARQ process IDs 0 through 7 assigned to TB1 through TB8 respectively. If the number of HARQ process IDs available to the base station and UE is only 4, the transmission of the 8 different TBs may not be executed consecutively.

[0265] Figure 10 This diagram illustrates an example of a communication system using a satellite. For instance, if UE 1001 sends a signal to satellite 1003, satellite 1003 can transmit that signal to base station 1005. Base station 1005 can process the received signal and can retransmit a signal including a request for subsequent operations back to UE 1001 via satellite 1003. In use... Figure 10 In the satellite communication system, due to the long distance between UE 1001 and satellite 1003, and the long distance between satellite 1003 and base station 1005, the time required for data transmission / reception between UE 1001 and base station 1005 increases.

[0266] Figure 11 This diagram illustrates the Earth orbit period of communication satellites based on their altitude or elevation. According to their orbits, communication satellites can be categorized as Low Earth Orbit (LEO), Medium Earth Orbit (MEO), and Geostationary Orbit (GEO). Generally, GEO 1100 means a satellite with an altitude of approximately 36,000 km, MEO 1110 means a satellite with an altitude of 5,000 to 15,000 km, and LEO 1130 means a satellite with an altitude of 500 to 1,000 km. The Earth orbit period varies depending on the altitude: approximately 24 hours for Geo 1100, approximately 6 hours for MEO 1110, and approximately 90 to 120 minutes for LEO 1130. LEO (~2,000 km) satellites have relatively low altitudes and therefore offer advantages in terms of propagation delay and loss compared to geostationary orbit (36,000 km) satellites.

[0267] Figure 12This is a diagram illustrating the concept of direct satellite-UE communication. A satellite 1200, located at an altitude of 100 km or higher via a rocket, can send signals to and receive signals from a ground UE 1210, and can also send signals to and receive signals from a ground station 1220 connected to a ground base station (DU farms) 1230.

[0268] Figure 13 This diagram illustrates a scenario for utilizing satellite-UE direct communication. Satellite-UE direct communication can support dedicated communication services in a way that supplements the limitations of terrestrial network coverage. For example, by implementing satellite-UE directional communication functionality in a user UE, it is possible to send and receive emergency rescue and / or disaster signals from users in locations not covered by terrestrial network communication (1300), to provide mobile communication services to users in areas where terrestrial network communication is impossible (such as ships and / or aircraft) (1310), to potentially track and control the location of ships, trucks, and / or unmanned aerial vehicles in real time without boundary restrictions (1320), and to potentially utilize satellite communication to perform backhaul functionality (1330) and serve as backhaul when the base station is physically far away and supports satellite communication functionality.

[0269] Figure 14 This diagram illustrates an example of calculating the expected data throughput in the uplink when a LEO satellite at an altitude of 1200 km and a UE on the ground perform direct communication with each other. If, in the uplink, the effective isotropic radiated power (EIRP) of the ground UE is 23 dBm, the path loss of the radio channel to the satellite is 169.8 dB, and the satellite receiver antenna gain is 30 dBi, the achievable signal-to-noise ratio (SNR) can be estimated to be -2.63 dB. In this case, path loss can include path loss in free space and atmospheric loss. If we assume a signal-to-interference ratio (SIR) of 2 dB, the signal-to-interference-noise ratio (SINR) is calculated to be -3.92 dB, and in this case, a transmission speed of 112 kbps can be achieved using a subcarrier spacing of 30 kHz and one PRB frequency resource.

[0270] Figure 15This diagram illustrates an example of calculating the expected data throughput in the uplink when a GEO satellite at an altitude of 35,786 km and a UE on the ground perform direct communication with each other. If, in the uplink, the transmitted EIRP of the ground UE is 23 dBm, the path loss of the radio channel to the satellite is 195.9 dB, and the satellite receive antenna gain is 51 dBi, the achievable SNR can be estimated as -10.8 dB. In this case, the path loss can include path loss in free space and atmospheric loss. If we assume an SIR of 2 dB, the SINR is calculated to be -11 dB, and in this case, a transmission speed of 21 kbps can be achieved using a 30 kHz subcarrier spacing and one PRB frequency resource, which is likely the result of performing three repeated transmissions.

[0271] Figure 16 This is a graph showing the path loss values ​​based on the path loss model between the UE and the satellite, and the path loss based on the path loss model between the UE and the terrestrial network communication base station. Figure 16 In this context, d corresponds to distance, and f c It refers to the signal frequency. In free space during UE-satellite communication, the path loss (FSPL)1600 is inversely proportional to the square of the distance. However, in the air during communication between the UE and the ground gNB, there are ground-based path losses (PL2 and PL'). Uma-NLOS 1610 and 1620 are inversely proportional to approximately the fourth power of the distance. Figure 16 In this equation, d_3D represents the straight-line distance between the UE and the base station, h_BS is the height of the base station, and h_UT is the height of the UE. The calculation method for d'_BP is: d'_BP = 4 x h_BS x h_UT x f c / c,f c is the center frequency, measured in Hz, and c is the speed of light, measured in m / x.

[0272] In satellite communications (or non-terrestrial networks), as satellites continue to move rapidly, Doppler shift may occur, which is a frequency shift of the transmitted signal.

[0273] Figure 17 This is a graph showing the mathematical expression and results of calculating the Doppler frequency shift experienced by the signal transmitted from the satellite, based on the satellite's elevation and position, and the location of the ground UE user, when the signal is received by the ground user. Figure 17 In this context, R is the Earth's radius, h is the satellite's elevation, v is the satellite's orbital speed around the Earth, and f is the satellite's orbital speed around the Earth. cIt refers to the signal frequency. The satellite's speed can be calculated based on its elevation. Specifically, the satellite's speed is the speed at which gravity, the force pulling the satellite along with the Earth, becomes equal to the centripetal force generated by the satellite's orbit around the Earth. This can be achieved as follows: Figure 18 Calculated in that way. Figure 18 This is a graph showing the satellite's velocity calculated at its elevation. From Figure 17 As can be seen from this, since α is determined by the elevation angle θ, the Doppler frequency shift value is determined based on the elevation angle θ.

[0274] Figure 19 This is a graph showing the Doppler shift experienced by different UEs within a single beam transmitted from a satellite to the ground. Figure 19 In this study, the Doppler shift experienced by UE 1 at 1900 and UE 2 at 1910 has been calculated based on the elevation angle. Figure 19 An example is shown assuming a center frequency of 2 GHz, a satellite elevation of 700 km, a beam diameter of 50 km on the ground, and a UE velocity of 0. Furthermore, the Doppler shift calculated in this disclosure does not consider the effect of the Earth's rotation speed, and since the Earth's rotation speed is sufficiently slow compared to the satellite's velocity, it can be considered that a small effect is imposed when calculating the Doppler shift.

[0275] Figure 20 This is a graph showing the Doppler frequency shift within a beam based on the satellite's position determined from the elevation angle. When the satellite is directly above the beam, i.e., at an elevation angle of 90 degrees, the Doppler frequency shift becomes maximum within the beam (or cell). This is likely because when the satellite is centered above the beam, the Doppler frequency shift values ​​at one end are positive and the other negative.

[0276] Meanwhile, in satellite communications, because satellites are far from ground users, there may be significant time delays compared to terrestrial network communications.

[0277] Figure 21 This is a graph showing the time delay between the UE and the satellite based on the satellite position determined from the elevation angle, as well as the round-trip time between the UE, the satellite, and the base station. Figure 21 In the diagram, 2100 shows the latency between the UE and the satellite, and 2110 shows the round-trip latency between the UE, satellite, and base station. In this case, it is assumed that the latency between the satellite and the base station is equal to the latency between the UE and the satellite. Figure 22 This is a graph showing the maximum difference in round-trip time delay based on the user's location within a beam. For example, with a beam radius (or cell radius) of 20 km, the difference in round-trip time delay from the UE to the satellite at different locations within the beam can be equal to or less than approximately 0.28 ms, depending on the satellite's location.

[0278] In satellite communication, signal transmission / reception between the UE and the base station can be achieved through satellite signal transmission. That is, in the downlink case, the satellite can receive signals sent to it by the base station and transmit the received signals to the UE. In the uplink case, the satellite can receive signals sent to it by the UE and transmit the received signals to the base station. As described above, a satellite that has received a signal from the UE or base station can perform frequency shifting on the received signal before transmitting it to the base station or UE, or the satellite can perform signal processing, such as decoding and re-encoding, and then transmit the processed signal to the base station or UE.

[0279] In the case of LTE or NR, the UE can access the base station through the following process.

[0280] - Operation 1: The UE receives a synchronization signal from the base station. The synchronization signal may include the primary synchronization signal (PSS), the secondary synchronization signal (SSS), and the physical broadcast channel (PBCH). The synchronization signal may include information such as the time slot boundaries, frame number, downlink and uplink configuration of the signals transmitted by the base station. In addition, the UE can find subcarrier offset and scheduling information used for system information transmission.

[0281] - Operation 2: The UE receives a System Information Block (SIB) from the base station. The SIB may include information for performing initial access and random access.

[0282] - Operation 3: Transmit a random access preamble on the random access resources configured in Operation 2. The preamble can be a signal determined using a sequence based on the information configured in Operation 2. The base station receives the preamble transmitted by the UE. Without knowing which UE has transmitted the preamble, the base station attempts to receive the preamble configured on the resources configured by the base station itself, and if the reception is successful, the base station knows that at least one UE has transmitted the preamble.

[0283] - Operation 4: If a preamble is received in Operation 3, the base station responds by sending a Random Access Response (RAR) in response to the preamble. In this operation, the UE that has already sent the random access preamble can receive the RAR sent by the base station. The RAR is sent on the PDSCH, and the PDCCH for scheduling the RAR is sent together or pre-sent. The DCI for scheduling the RAR is scrambled with a CRC based on RA-RNTI, channel-coded, and then mapped onto the PDCCH to be sent. The RA-RNTI can be determined based on the time and frequency resources of the preamble sent in Operation 3. In Operation 3, the UE has already sent the random access preamble. In this operation, the maximum time limit until the RAR is received can be configured by the SIB sent in Operation 2. The maximum time limit can be configured to be limited to 10ms or 40ms. For example, if the RAR is not received from the base station within a determined time based on 10ms, the UE that has already sent the preamble in Operation 3 can resend the preamble. The RAR may include scheduling information for allocating resources for the signal sent by the UE in Operation 5, which is the next operation. Figure 23 This is a diagram illustrating an example of the RAR information structure. (See diagram for example.) Figure 23 As shown, the RAR can include information about the timing advance (TA) to be applied by the UE and a temporary C-RNTI value to be used from the next operation.

[0284] - Operation 5: The UE, having received the RAR in Operation 4, sends message 3 (msg3) to the base station based on the scheduling information included in the RAR. As mentioned above, the random access preamble can be referred to as message 1 (msg1), and the RAR can be referred to as message 2 (msg2). The UE can include its own ID value in the msg3 to be sent. In Operation 4, the base station can attempt to receive msg3 based on its own scheduling information.

[0285] - Operation 6: The base station receives msg3, identifies the UE's ID information, and then generates message 4 including the ID information to send message 4 to the UE. Afterwards, the UE that has already sent msg3 in Operation 5 can attempt to receive the msg4 to be sent in Operation 6. In Operation 5, the UE that has already received msg4 can identify whether the msg3 sent by itself was received by the base station by comparing the decoded ID value with the ID value sent by the UE itself. In Operation 2, after the UE sends msg3, the time required for the UE to receive msg4 in this operation can be limited, and the maximum time can be configured based on SIB.

[0286] When applying the initial access procedure using the above operations to satellite communications, the propagation delay consumed by satellite communications may cause problems. For example, the UE can be configured to send the random access preamble (or PRACH preamble) in operation 3 and receive the RAR in operation 4 (the random access window), i.e., the maximum time that can be spent receiving that period. In traditional LTE or 5G NR, the corresponding maximum time can be configured to a maximum of 10ms. Figure 24 This is a diagram illustrating an example of the relationship between PRACH preamble configuration resources and RAR reception time in an LTE system. Figure 25 This is a diagram illustrating an example of the relationship between PRACH preamble configuration resources and RAR reception time in a 5G NR system. (Reference) Figure 24 In the case of LTE, the random access window can begin 3ms after the PRACH (random access preamble) is sent. (See reference...) Figure 25 In the case of NR, the random access window can begin from the control information area used for RAR scheduling, which first appears after the PRACH (random access preamble) is sent.

[0287] As an example, the timing interaction (TA) for uplink transmission in a 5G NR system can be determined as follows. First, the TA is determined as T. C =1 / (Δf) max ·N f ), and here it is determined to be Δf max =480·10 3 Hz and N f =4096. Furthermore, it can be defined as k=T s / T c =64, T s =1 / (Δf) ref ·N f，ref ), Δf ref =15·10 3 Hz and N f，ref =2048.

[0288] Figure 26 This diagram illustrates an example of downlink and uplink frame timing in a UE. The UE can advance the uplink frame timing by T based on the downlink frame timing. TA =(N TA +N TA,offset )T c To perform uplink transmission. As mentioned above, N TA It can be transmitted from RA, or it can be determined based on MAC CE, and N TA，offsetIt can be a value configured for the UE, or it can be determined based on a predetermined value.

[0289] In a 5G NR system, the base station can indicate T to the UE via RAR. A The value, in this case, can be one of 0, 1, 2... and 3846, indicating T. A Value. In this case, if the subcarrier spacing (SCS) of the RAR is 2 μ ·15kHz, then N TA Determined as N TA =T A ·16·64 / 2 μ After the random access procedure is completed, the UE can indicate changes in TA from the base station, and this can be indicated via MAC CE. In this case, T A The value can be indicated as one of 0, 1, 2, ..., and 63, and can be added to an existing T. A The value is either subtracted from the existing TA value to calculate the new T. A Value. T A The value can be recalculated as After a predetermined time, the UE can send the T signal as indicated above. A The value is applied to uplink transmission.

[0290] In UE-satellite direct communication, due to the large distances between the UE and the satellite and the base station, and the continuous movement of the satellite, time and frequency offsets occur when the UE or the base station receives signals transmitted by the base station or the base station. Accordingly, this disclosure provides a method and apparatus in which the base station indicates the time and frequency offsets, and the UE performs corrections accordingly to correct the time and frequency offsets.

[0291] [First Embodiment]

[0292] The first embodiment provides a method and apparatus in which a base station indicates frequency offset information to a UE, and the UE applies the indicated value.

[0293] The base station can indicate frequency offset information to the UE using the following method, and the UE can use the offset information indicated according to the following method to correct the frequency by the same amount as the offset, thereby performing downlink or uplink signal transmission / reception.

[0294] - Method 1: The frequency offset unit can be determined based on the frequency domain or frequency band (or spectrum). Figure 27This graph illustrates the maximum Doppler frequency shift experienced by different UEs within a single beam, depending on the beam size and center frequency (fc), at a satellite altitude of 700 km. For example, if the radius of the satellite-provided beam (or cell) is 100 km, two UEs within the beam may experience a maximum Doppler frequency shift of approximately 15 kHz at a center frequency of 2 GHz. This means the base station should adjust the frequency offset by approximately 15 kHz for different UEs in uplink transmission. If the radius of the satellite-provided beam (or cell) is 100 km, two UEs within the beam may experience a maximum Doppler frequency shift of approximately 5 kHz at a center frequency of 700 MHz (0.7 GHz). This also means the base station should adjust the frequency offset by approximately 5 kHz for different UEs in uplink transmission. For example, in the frequency domain equal to or below 1 GHz, the frequency offset indicator unit could be 5 / (2^12) kHz, or 1.2207 Hz. For example, in a frequency domain exceeding 1 GHz and equal to or below 2 GHz, the frequency offset indicator unit could be 15 / (2^12) kHz, or 3.6621 Hz. This assumes the use of 12 bits to indicate the frequency offset, and can even be applied to cases using different numbers of bits. For example, when using an N-bit size to indicate the frequency offset, the frequency offset indicator unit could be 5 / (2^N) kHz. Figure 28 This is a graph showing the absolute velocity of a satellite orbiting the Earth and the relative velocity between the satellite and a stationary object on the Earth's surface, based on the satellite's elevation. Because the Earth rotates, even stationary objects on the Earth's surface can be considered to be moving; therefore, the satellite's absolute velocity may differ from its relative velocity with the Earth. The satellite's velocity is the velocity at which the effects of centripetal force and gravity become equal in order to maintain the satellite's elevation. Although... Figure 27 The results are shown by using the absolute velocity of the satellite, but the Doppler shift can be based on, for example... Figure 28 The relative velocity of the satellites is shown. The Doppler shift can be calculated based on a combination of one or more of the following: satellite elevation, position, UE position, and elevation angle of the UE and satellite. The relative velocity of the satellites can be calculated as a value obtained by subtracting the angular velocity of the Earth's rotation from the angular velocity of the satellite orbiting the Earth.

[0295] Method 2: The frequency offset indicator may differ depending on the subcarrier spacing used between the UE and the satellite. For example, the impact of a 1kHz frequency offset may differ depending on whether a 15kHz subcarrier spacing or a 60kHz subcarrier spacing is used, and the impact may be much smaller, for example, when using a 60kHz subcarrier spacing. Therefore, the frequency offset indicator can be determined as (subcarrier spacing) / (2^12)kHz or As mentioned above, μ is a value determined based on the subcarrier spacing, and can be expressed as such that the subcarrier spacing is 15×2. μ The value of μ in kHz is such that, with a subcarrier spacing of 15 kHz, μ becomes μ = 0; with a subcarrier spacing of 30 kHz, μ becomes μ = 1; with a subcarrier spacing of 60 kHz, μ becomes μ = 2; with a subcarrier spacing of 120 kHz, μ becomes μ = 3; and with a subcarrier spacing of 240 kHz, μ becomes μ = 4.

[0296] Method 3: The base station can indicate frequency offset changes to the UE. Satellites can move regularly over time, and the frequency offset can change linearly within a specified time interval. Therefore, the base station can instruct the UE how to apply and change the frequency offset in the future by indicating frequency offset changes to the UE. The frequency offset change can be the amount of frequency offset change applied at a specific future time. Using the indication of frequency offset changes, the base station can either indicate or pre-indicate via upper-layer signaling, or configure the time period and time point for applying the frequency offset change as control information to the UE. As mentioned above, the upper-layer signaling can be MAC CE or RRC signaling, which are not physical layer signals.

[0297] Method 4: Frequency offset information can be indicated during the random access procedure. For example, in the random access procedure of Operation 4, it can be indicated by RAR, and in the random access procedure of Operation 2, it can be indicated by msg B. In the random access procedure of Operation 2, the UE sends msgA to the base station, and the base station sends msgB to the UE after receiving msgA. msgB may include frequency offset information.

[0298] Method 5: Frequency offset information can be included in the MAC CE to indicate after UE random access.

[0299] - Method 6: Frequency offset information can be indicated by downlink control information (DCI).

[0300] Method 7: Frequency offset information can be indicated to one or more UEs in a group-common manner using the same DCI or the same MAC. In this method, frequency offset or frequency offset change can be indicated to one or more UEs using the same indication information field. When indicating to each UE using different indication information fields, the UE can pre-configure the bit field position or bit field position offset value to be interpreted by the UE. Figure 29 This is a diagram illustrating an example of how a satellite's position changes over time, and therefore, the UE experiences frequency shifts due to delays or Doppler effects in UE-satellite communications. Figure 29In this scenario, assuming the satellite orbits the Earth counter-clockwise, the satellite starts at position (1) and moves to position (7). When the satellite is at positions (1) and (7), the time delay increases and the Doppler shift value increases as the satellite-UE distance increases. This Doppler shift affects… Figure 17 As shown in the image. Figure 29 As shown, since UEs located within a beam area provided by a satellite send and receive signals from the same satellite, they may have similar time delays and Doppler shift variations. Therefore, Figure 29 The UEs (UE1, UE2, UE3, UE4 and UE5) can perform time and frequency offset corrections for delay and Doppler shift corrections using the same indication information. Figure 30 This diagram illustrates an example of frequency offset indication information for several UEs included in a single MAC CE when frequency offset is indicated by using the same MAC CE for a group. The start position of the frequency offset indicator for each UE can be pre-configured via upper-layer signaling. Although Figure 30 An example of indicating frequency offset in groups via MAC CE is shown, but frequency offset can also be indicated in groups via DCI in a similar manner. That is, Figure 30 The bit field can be sent as part of the DCI.

[0301] Method 8: The base station can indicate the value to be applied to the common beam from the system information via SIB. As an example, the frequency offset f_offset can be calculated as f_offset1 + f_offset2, and as mentioned above, f_offset1 can be a common configuration or a value indicated to the UE belonging to the corresponding beam, and f_offset2 can be a configuration or a value indicated to a specific UE.

[0302] Method 9: The base station can configure frequency offset units for the corresponding UE via RRC configuration. For example, the base station can use RRC configuration to indicate the number of frequency offset units in the MAC CE or DCI, and the UE can calculate the accurate frequency offset value using the aforementioned units and the number of frequency offset units. As another modification, candidate values ​​for the frequency offset units can be indicated via RRC configuration, and one of them can be indicated via MAC CE or DCI.

[0303] Method 10: The base station can configure a frequency offset value for the corresponding UE via RRC configuration. As another example, the base station can transmit the frequency offset value to the UE via a combination of RRC configuration and MAC CE.

[0304] One or more of the above methods can be applied in combination. For example, methods 1 and 5 can be combined with each other, and frequency offset information can be transmitted from the MAC CE based on frequency domain-determined units. Furthermore, as another example, methods 1, 5, and 7 can be combined with each other, and frequency offset information with frequency domain-determined units can be transmitted to multiple UEs through the same MAC CE. For the MAC CE, multiple UEs can receive the same DCI and the same PDSCH, and frequency offset information can be transmitted to the UEs through different bit fields of the MAC CE.

[0305] In the method described above, if the base station transmits frequency offset information to the UE, the UE can perform uplink transmission by shifting the uplink center frequency by the same amount as the transmitted frequency offset value. The frequency offset indicated to the UE can be transmitted via MAC CE, or it can be determined to be applied after a specific time point in the time frame transmitted via DCI.

[0306] [Second Embodiment]

[0307] The second embodiment provides a method and apparatus in which a base station indicates time offset information to a UE, and the UE applies the indicated value.

[0308] Figure 31 This graph illustrates the difference in propagation delay between terrestrial and satellite networks. In terrestrial networks, considering a maximum distance of approximately 100 km to the base station, a propagation delay of 1 ms or less occurs. However, in satellite networks, the distance between the UE and the satellite can be thousands of kilometers, as can the distance between the satellite and the base station. Therefore, the delay can be significantly greater than that of terrestrial networks. In satellite network communication, the delay varies depending on the satellite's elevation angle and altitude. Figure 31 It shows the time required for a round trip based on the UE-satellite distance and radio waves, when the satellite's altitude is 700 km.

[0309] Figure 32This diagram illustrates examples of timing advance in terrestrial and satellite networks. In terrestrial networks, the maximum latency is within 1 or 2 ms, and it is possible for the base station to synchronize the downlink time slot timing with the uplink time slot timing provided by the timing advance in LTE and 5G NR systems. That is, if the UE performs uplink transmission by advancing the downlink time by the same amount as the timing advance value indicated by the base station, the uplink signal transmitted by the UE will coincide with the downlink time point of the base station when the base station receives the uplink signal. In contrast, in satellite networks, it is impossible for the base station to synchronize the downlink time slot timing with the uplink time slot timing provided by the timing advance in conventional LTE and 5G NR systems because the propagation latency in satellite networks is tens of milliseconds, which is greater than the maximum timing advance value provided by conventional LTE and 5G NR systems.

[0310] Figure 33 This is a graph showing the maximum round-trip propagation delay difference experienced by multiple users located in one of several beams transmitted by a satellite, between the UE, the satellite, and the base station. As the beam size decreases, the round-trip propagation delay difference decreases.

[0311] Figure 34 This is a graph showing how the round-trip propagation delay between the UE and the base station changes over time as the satellite moves along its orbit. (Reference) Figure 34 It can be identified that latency varies somewhat in terrestrial networks, while in satellite networks, the amount of latency variation becomes very large over time.

[0312] The base station can indicate time offset information to the UE using the following method, and the UE can use the offset information indicated according to the following method to correct the time by the same amount as the offset, thereby performing the transmission / reception of downlink or uplink signals.

[0313] - Method 1: Based on the frequency domain or frequency band (spectrum), the indication range of the delay, or the size of the bit field for the delay indication or timing advance indication, can be determined. For example, 12 bits can be used at a center frequency equal to or below 1 GHz, and 16 bits can be used at a center frequency above 1 GHz.

[0314] Method 2: The base station can indicate changes in timing advance to the UE. Satellites can move regularly in time, and the delay can vary linearly within a specified time interval. Therefore, the base station can instruct the UE how to apply and change the timing advance in the future by indicating changes in delay or timing advance. A The change in time offset (or timing advance) can be applied to a specific time in the future. AThe amount of change. Using the indication of time offset change, the base station can indicate, either in advance or via upper-layer signaling, the time period and time point for applying the time offset change as control information to the UE. As mentioned above, the upper-layer signaling can be MAC CE or RRC signaling, which are not physical layer signals.

[0315] Method 3: Time offset (or timing advance) information can be indicated to one or more UEs in a group-common manner using the same DCI or the same MAC. In this method, timing advance or timing advance can be indicated to one or more UEs via the same indication information field or via different indication information fields. A Changes. When instructing each UE through different indication information fields, the UE can pre-configure the bit field position or bit field position offset value to be interpreted by the UE. For example... Figure 29 As shown, since UEs located within a beam area provided by a satellite send and receive signals from the same satellite, they may have similar time delays and Doppler shift variations. Therefore, Figure 29 The UEs (UE1, UE2, UE3, UE4 and UE5) can perform time offset correction for time delay and timing advance value correction using the same indication information. Figure 30 This diagram illustrates an example of time offset indication information for several UEs included in a single MAC CE when time offsets are indicated by using the same MAC CE for a group. The start position of the time offset indicator for each UE can be preconfigured via upper-layer signaling. Although Figure 30 An example of indicating time offsets in groups via MAC CE is shown, but time offsets can also be indicated in groups via DCI in a similar manner. That is, Figure 30 The bit field can be sent as part of the DCI.

[0316] Method 4: The base station can indicate the value to be commonly applied to the beam from the system information via SIB. As an example, the time offset TA_offset can be calculated as TA_offset1 + TA_offset2, and as mentioned above, TA_offset1 can be a value commonly configured or indicated to UEs belonging to the corresponding beam, and TA_offset2 can be a value configured or indicated to a specific UE.

[0317] Method 5: The base station can configure time offset units for the corresponding UE via RRC configuration. For example, the base station can use RRC configuration to indicate the number of time offset units in the MAC CE or DCI, and the UE can calculate the accurate time offset value using the aforementioned units and the number of time offset units. As another modification, candidate values ​​for the time offset units can be indicated via RRC configuration, and one of them can be indicated via MAC CE or DCI.

[0318] Method 6: The base station can configure a time offset value for the corresponding UE via RRC configuration. As another example, the base station can transmit the time offset value to the UE via a combination of RRC configuration and MAC CE.

[0319] As described above, for ease of explanation, although the first and second embodiments of this disclosure have been explained separately, each embodiment includes operations related to each other, and at least two embodiments can be combined and configured.

[0320] In order to implement the above embodiments, Figure 35 , 36 Figure 37 illustrates a transmitter, receiver, and processor for a UE, a satellite, and a base station. To perform the operations for determining signal transmission / reception in the first and second embodiments, a base station, a satellite, and a UE, or a transmission and reception method for a transmitter and receiver, may be represented. Furthermore, to perform the same operations, the UE's receiver, processor, and transmitter may operate according to various embodiments.

[0321] Specifically, Figure 35 This is a block diagram illustrating the internal structure of a UE according to an embodiment of the present disclosure. Figure 35As shown, the UE according to this disclosure may include a UE receiver 3500, a UE transmitter 3520, and a UE processor 3510. In embodiments of this disclosure, the UE receiver 3500 and the UE transmitter 3520 may generally be referred to as transceivers. The transceivers can transmit signals to and receive signals from a base station. These signals may include control information and data. For this purpose, the transceiver may consist of an RF transmitter for up-converting and amplifying the transmitted signal frequency and an RF receiver for low-noise amplification and down-converting the received signal frequency. Furthermore, the transceiver can receive signals on a radio channel and can output the received signals to the UE processor 3510. Additionally, the transceiver can transmit signals output from the UE processor 3510 on a radio channel. The UE processor 3510 can control a series of processes that cause the UE to operate according to the above embodiments of this disclosure. For example, the UE receiver 3500 can receive signals from a satellite or terrestrial base station, and the UE processor 3510 can transmit signals to and receive signals from the base station. Subsequently, the UE transmitter 3520 can transmit signals using determined time points.

[0322] Figure 36 This is a block diagram illustrating the internal structure of a satellite according to an embodiment of the present disclosure. Figure 36As shown, the satellite according to this disclosure may include a satellite receiver 3600, a satellite transmitter 3620, and a satellite processor 3610. As described above, multiple receivers, transmitters, and processors can be provided. That is, receivers and transmitters for transmitting / receiving from a UE and for transmitting / receiving from a base station can be provided. The satellite receiver 3600 and satellite transmitter 3620 may generally be referred to as satellite transceivers. The transceiver can transmit signals to and receive signals from the UE and the base station. The signals may include control information and data. For this purpose, the transceiver may consist of an RF transmitter for up-converting and amplifying the transmitted signal frequency and an RF receiver for low-noise amplification and down-converting the received signal frequency. Furthermore, the transceiver can receive signals on a radio channel and can output the received signals to the satellite processor 3610. Additionally, the transceiver can transmit signals output from the satellite processor 3610 on a radio channel. The satellite processor 3610 may include a compensator (pre-compensator) for compensating for frequency offset or Doppler shift, and may include a device capable of tracking location from GPS or similar sources. Furthermore, the satellite processor 3610 may include a frequency shifting function capable of moving the center frequency of the received signal. According to embodiments of this disclosure as described above, the satellite processor 3610 can control a series of processes enabling the satellite, base station, and UE to operate. For example, the satellite receiver 3600 can receive a PRACH preamble from the UE, resend the subsequent RAR to the UE, and determine to send this information to the base station. Subsequently, the satellite transmitter 3620 can transmit the corresponding signal at a predetermined time.

[0323] Figure 37 This is a block diagram illustrating the internal structure of a base station according to an embodiment of the present disclosure. Figure 37 As shown, the base station according to this disclosure may include a base station receiver 3700, a base station transmitter 3720, and a base station processor 3710. The base station may be part of a terrestrial base station or a satellite. In embodiments of this disclosure, the base station receiver 3700 and the base station transmitter 3720 are generally referred to as transceivers. The transceiver can transmit signals to and receive signals from the UE. The signals may include control information and data. For this purpose, the transceiver may consist of an RF transmitter for up-converting and amplifying the transmitted signal frequency and an RF receiver for low-noise amplification and down-converting the received signal frequency. Furthermore, the transceiver can receive signals via a radio channel and can output the received signals to the base station processor 3710. Additionally, the transceiver can transmit signals output from the base station processor 3710 via a radio channel. The base station processor 3710 can control a series of processes that enable the base station to operate according to the above embodiments of this disclosure. For example, the base station processor 3710 may pre-transmit RARs based on its own configured configuration information.

[0324] On the other hand, the embodiments of this disclosure described in the specification and drawings are merely for the purpose of explaining the technical content of this disclosure and providing specific examples to aid understanding, and are not intended to limit the scope of this disclosure. That is, it will be apparent to those skilled in the art that other modifications based on the technical concept of this disclosure can be implemented. Furthermore, the various embodiments can be combined as appropriate. For example, the first embodiment and the fourth embodiment can be used in combination. Moreover, other modifications based on the technical concept of the above embodiments can be implemented in LTE systems and 5G systems.

Claims

1. A method performed by a user equipment (UE) in a communication system, the method comprising: Receive first information about the rate of change of timing advance (TA) and second information about the rate of change of frequency offset from the base station; Based on the first information about the rate of change of timing advance, the timing advance for uplink transmission is determined; Based on the second information regarding the rate of change of frequency offset, the frequency offset used for uplink transmission is determined. as well as Uplink transmissions are sent to the base station using the determined timing advance and frequency offset. The first piece of information regarding the rate of change of timing advance indicates the period and time to which the rate of change of timing advance is applied, and The second piece of information regarding the rate of change of frequency offset indicates the period and time to which the rate of change of frequency offset is applied.

2. The method according to claim 1, wherein, Timing advance for uplink transmission is determined based on values ​​commonly applied to UEs located in the same beam when determining the timing advance, and The values ​​for public applications are received from the base station via system information.

3. The method according to claim 1, wherein, The frequency offset used for uplink transmission is determined based on the frequency units determined according to the subcarrier spacing.

4. The method according to claim 1, wherein, The frequency offset used for uplink transmission is determined based on values ​​commonly applied to UEs located within the same beam when determining the frequency offset, and The values ​​for public applications are received from the base station via system information.

5. A method performed by a base station in a communication system, the method comprising: Send first information about the rate of change of timing advance (TA) and second information about the rate of change of frequency offset to the user equipment (UE); as well as The UE receives uplink transmissions transmitted by applying timing advance determined based on first information about the rate of change of timing advance and frequency offset determined based on second information about the rate of change of frequency offset. The first piece of information regarding the rate of change of timing advance indicates the period and time to which the rate of change of timing advance is applied, and The second piece of information regarding the rate of change of frequency offset indicates the period and time to which the rate of change of frequency offset is applied.

6. The method according to claim 5, wherein, Timing advance for uplink transmission is determined based on values ​​commonly applied to UEs located in the same beam when determining the timing advance, and The values ​​of public applications are sent to the UE via system information.

7. The method according to claim 5, wherein, The frequency offset used for uplink transmission is determined based on the frequency units determined according to the subcarrier spacing.

8. The method according to claim 5, wherein, The frequency offset used for uplink transmission is determined based on values ​​commonly applied to UEs located in the same beam when determining the frequency offset, and The values ​​of public applications are sent to the UE via system information.

9. A user equipment (UE) in a communication system, the UE comprising: transceiver; and The controller is configured as follows: Receive first information about the rate of change of timing advance (TA) and second information about the rate of change of frequency offset from the base station. Based on the first information regarding the rate of change of timing advance, the timing advance used for uplink transmission is determined. Based on the second information regarding the rate of change of frequency offset, the frequency offset used for uplink transmission is determined, and Uplink transmissions are sent to the base station using the determined timing advance and frequency offset. The first piece of information regarding the rate of change of timing advance indicates the period and time to which the rate of change of timing advance is applied, and The second piece of information regarding the rate of change of frequency offset indicates the period and time to which the rate of change of frequency offset is applied.

10. The UE according to claim 9, wherein, Timing advance for uplink transmission is determined based on values ​​commonly applied to UEs located in the same beam when determining the timing advance, and The values ​​for public applications are received from the base station via system information.

11. The UE according to claim 9, wherein, The frequency offset used for uplink transmission is determined based on the frequency units determined according to the subcarrier spacing.

12. The UE according to claim 9, wherein, The frequency offset used for uplink transmission is determined based on values ​​commonly applied to UEs located within the same beam when determining the frequency offset, and The values ​​for public applications are received from the base station via system information.

13. A base station in a communication system, the base station comprising: transceiver; and The controller is configured as follows: Send first information about the rate of change of timing advance (TA) and second information about the rate of change of frequency offset to the user equipment (UE), and The UE receives uplink transmissions transmitted by applying timing advance determined based on first information about the rate of change of timing advance and frequency offset determined based on second information about the rate of change of frequency offset. The first piece of information regarding the rate of change of timing advance indicates the period and time to which the rate of change of timing advance is applied, and The second piece of information regarding the rate of change of frequency offset indicates the period and time to which the rate of change of frequency offset is applied.

14. The base station according to claim 13, wherein, Timing advance for uplink transmission is determined based on values ​​commonly applied to UEs located in the same beam when determining the timing advance, and The values ​​of public applications are sent to the UE via system information.

15. The base station according to claim 13, wherein, The frequency offset used for uplink transmission is determined based on the frequency units determined according to the subcarrier spacing.

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