Method and device for transmitting channel information in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. In addition, the present disclosure provides a method and a device for reducing a delay time to reduce energy consumption of a base station in a mobile communication system. According to the present disclosure, the problem of excessive energy consumption of a base station in a mobile communication system can be resolved and high energy efficiency can be achieved.

Description

Method and apparatus for transmitting channel information in a wireless communication system

[0001] The present disclosure relates to a wireless communication system. Specifically, the present disclosure relates to a method and apparatus for a terminal to transmit channel information to a base station in a wireless communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz band (e.g., the 3 terahertz (3 THz) band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as the operation of multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for the reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.

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

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

[0006] When such 5G mobile communication systems are commercialized, connected devices, which are increasing explosively, will be connected to communication networks. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] Furthermore, the advancement of these 5G mobile communication systems encompasses multi-antenna transmission technologies such as new waveforms, Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas to guarantee coverage in the terahertz band of 6G mobile communication technology; metamaterial-based lenses and antennas; high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM); and Reconfigurable Intelligent Surface (RIS) technology to improve terahertz band signal coverage; as well as full-duplex technology for enhancing frequency efficiency and system networks in 6G mobile communication technology; AI-based communication technologies that realize system optimization by utilizing satellites and Artificial Intelligence (AI) from the design stage and internalizing end-to-end AI support functions; and the realization of services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could serve as a foundation for the development of next-generation distributed computing technologies.

[0008] As a result of the aforementioned developments and advancements in mobile communication systems, it has become possible to provide a variety of services, and thus measures to effectively provide these services are required.

[0009] The present disclosure aims to provide a method and apparatus capable of effectively providing services in a wireless communication system.

[0010] The present disclosure aims to provide a method and apparatus for a terminal to transmit channel information to a base station in a wireless communication system.

[0011] The technical problems to be solved by the present disclosure are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art from the various embodiments of the present disclosure described below.

[0012] The present disclosure may provide a method performed by a user equipment (UE) in a wireless communication system. The method may include: receiving a radio resource control (RRC) message from a base station (BS) that includes setting information for a joint operation of a channel state information-reference signal (CSI-RS) and a sounding reference signal (SRS); receiving downlink control information (DCI) for the joint operation from the base station; receiving the CSI-RS from the base station based on the DCI and the setting information; transmitting the SRS to the base station through a first antenna port based on the DCI and the setting information; and transmitting a CSI report to the base station that includes a per-port precoding matrix indicator (PMI) and a per-port phase difference through a second antenna port different from the first antenna port based on the CSI-RS and the setting information.

[0013] The present disclosure may provide a method performed by a base station (BS) in a wireless communication system. The method may include the steps of: transmitting a radio resource control (RRC) message to a terminal (user equipment, UE) that includes setting information for the joint operation of a channel state information-reference signal (CSI-RS) and a sounding reference signal (SRS); transmitting downlink control information (DCI) to the terminal for the joint operation; transmitting the CSI-RS to the terminal based on the DCI and the setting information; receiving the SRS from the terminal through a first antenna port based on the DCI and the setting information; and receiving a CSI report from the terminal, based on the CSI-RS and the setting information, that includes a per-port precoding matrix indicator (PMI) and a per-port phase difference through a second antenna port different from the first antenna port.

[0014] The present disclosure may provide a terminal (user equipment, UE) in a wireless communication system. The terminal may include at least one transceiver; at least one processor communicatively coupled to the at least one transceiver; and at least one memory communicatively coupled to the at least one processor for storing instructions. The above instructions may be executed individually or in any combination by the at least one processor so that the terminal: receives a radio resource control (RRC) message from a base station (BS) containing setting information for the joint operation of a channel state information-reference signal (CSI-RS) and a sounding reference signal (SRS); receives downlink control information (DCI) for the joint operation from the base station; receives the CSI-RS from the base station based on the DCI and the setting information; transmits the SRS to the base station through a first antenna port based on the DCI and the setting information; and transmits a CSI report to the base station, containing a per-port precoding matrix indicator (PMI) and a per-port phase difference through a second antenna port different from the first antenna port, based on the CSI-RS and the setting information.

[0015] The present disclosure may provide a base station (BS) in a wireless communication system. The base station comprises: at least one transceiver; and at least one processor communicatively coupled to the at least one transceiver; and includes at least one memory that is communicationally coupled to the at least one processor and stores instructions, wherein the instructions are executed by the at least one processor individually or in any combination, so that the base station: transmits downlink control information (DCI) for the joint operation to the terminal, transmits the CSI-RS to the terminal based on the DCI and the configuration information, receives the SRS from the terminal through a first antenna port based on the DCI and the configuration information, and receives a CSI report including a per-port precoding matrix indicator (PMI) and a per-port phase difference from the terminal through a second antenna port different from the first antenna port based on the CSI-RS and the configuration information. Various embodiments of the present disclosure are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of various embodiments of the present disclosure may be derived and understood by those skilled in the art based on the detailed description to be described below.

[0016] According to one embodiment of the present disclosure, by defining a signal transmission method of a base station in a wireless communication system, the base station can obtain a more accurate channel state of a terminal than in the past.

[0017] The present disclosure may provide an apparatus and method capable of effectively providing services in a mobile communication system.

[0018] The effects obtainable from the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art based on the following detailed description.

[0019] FIG. 1 illustrates the basic structure of the time-frequency resource domain of a 5G system according to one embodiment of the present disclosure.

[0020] FIG. 2 illustrates a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0021] FIG. 3 illustrates a random access procedure according to one embodiment of the present disclosure.

[0022] FIG. 4 illustrates a procedure in which a terminal reports terminal capability (UE capability) information to a base station according to one embodiment of the present disclosure.

[0023] FIG. 5 illustrates a Control Resource Set (CORESET) as a time-frequency resource to which a PDCCH is mapped according to one embodiment of the present disclosure.

[0024] FIG. 6 illustrates the mapping of DCI and DMRS in a REG, which is the basic unit of a downlink control channel according to one embodiment of the present disclosure.

[0025] FIG. 7 illustrates base station beam allocation according to TCI state setting according to one embodiment of the present disclosure.

[0026] FIG. 8 illustrates a hierarchical signaling method for dynamic allocation of a PDCCH beam of NR according to one embodiment of the present disclosure.

[0027] FIG. 9 illustrates a TCI indication MAC CE signaling structure for a PDCCH DMRS according to one embodiment of the present disclosure.

[0028] FIG. 10 is a diagram illustrating a method for transmitting and receiving data by a base station and a terminal in consideration of a downlink data channel and rate matching resources according to one embodiment of the present disclosure.

[0029] FIG. 11 illustrates a non-periodic CSI reporting method when the CSI-RS offset is 0 according to one embodiment of the present disclosure.

[0030] FIG. 12 illustrates a non-periodic CSI reporting method when the CSI-RS offset is 1 according to one embodiment of the present disclosure.

[0031] FIG. 13 illustrates the configuration of a bandwidth part in a 5G communication system according to one embodiment of the present disclosure.

[0032] FIG. 14 illustrates Discontinuous Reception (DRX) in a 5G communication system according to one embodiment of the present disclosure.

[0033] Figure 15 is a diagram showing the timeline for the joint framework for CSI-RS and SRS.

[0034] Figure 16 is a diagram of an RRC message for operating a joint framework that shares an existing resource set for CSI-RS and SRS.

[0035] Figure 17 is a diagram of an RRC message for operating a joint framework that shares an existing resource set for non-periodic CSI-RS and SRS.

[0036] Figure 18 is a diagram of an RRC message for a new integrated resource set to operate a joint framework for CSI-RS and SRS.

[0037] Figure 19 is a diagram illustrating the operation of a base station requesting a non-periodic SRS port through a joint framework trigger.

[0038] FIG. 20 illustrates a terminal transceiver device according to one embodiment of the present disclosure.

[0039] FIG. 21 is a block diagram of a terminal according to one embodiment of the present disclosure.

[0040] FIG. 22 is a block diagram of a base station according to one embodiment of the present disclosure.

[0041] FIG. 23 is a drawing illustrating a hybrid transmission method and system architecture according to one embodiment of the present disclosure.

[0042] FIG. 24 is a diagram comparing the performance of various DL CSI acquisition methods in one embodiment of the present disclosure.

[0043] For convenience of explanation, devices not directly related to the present disclosure may be omitted from illustration and description.

[0044] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in describing the present disclosure, if it is determined that a detailed description of related known functions or configurations might unnecessarily obscure the essence of the present disclosure, such detailed description will be omitted. Additionally, the terms described below are defined considering their functions in the present disclosure, and these may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0045] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the size of each component does not entirely reflect its actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference numbers.

[0046] The advantages and features of the present disclosure and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the disclosure is defined only by the scope of the claims. Throughout the specification, like reference numerals refer to like components.

[0047] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing instruction means to perform the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that perform a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer can also provide steps for executing the functions described in the flowchart block(s).

[0048] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order according to their corresponding functions.

[0049] In this embodiment, the term "part" refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or configured to run one or more processors. Thus, as an example, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, in the embodiments, 'parts' may include one or more processors.

[0050] In describing the present disclosure below, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the present disclosure. Embodiments of the present disclosure will be described below with reference to the attached drawings.

[0051] Terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc., are examples provided for the convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0052] In the following description, the terms "physical channel" and "signal" may be used interchangeably with "data" or "control signal." For example, PDSCH (physical downlink shared channel) is a term referring to a physical channel through which data is transmitted, but PDSCH may also be used to refer to data. That is, in this disclosure, the expression "transmits a physical channel" may be interpreted as equivalent to the expression "transmits data or a signal through a physical channel."

[0053] In the present disclosure, upper layer signaling refers to a signal transmission method transmitted from a base station to a terminal using a physical layer downlink data channel, or from a terminal to a base station using a physical layer uplink data channel. Upper layer signaling may be understood as radio resource control (RRC) signaling or a media access control (MAC) control element (CE).

[0054] For convenience of explanation, the present disclosure uses terms and names defined in the 3GPP NR (New Radio: 5th generation mobile communication standard) specifications. However, the present disclosure is not limited by the above terms and names and may be applied equally to systems conforming to other standards. Additionally, the term "terminal" may refer to mobile phones, smartphones, IoT devices, sensors, as well as other wireless communication devices.

[0055] Hereinafter, the base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, gNB, eNode B, eNB, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. The terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. Of course, it is not limited to the above examples.

[0056] 5G (5 thInitial standards for the Generation) system or New Radio access technology (NR) have been completed. While existing mobile communication systems focused on conventional voice / data communication, 5G systems aim to satisfy various services and requirements, such as enhanced Mobile BroadBand (eMBB) services to improve existing voice / data communication, Ultra-Reliable and Low Latency Communication (URLLC) services, and massive Machine Type Communication (MTC) services to support mass communication of the Internet of Things.

[0057] While the transmission bandwidth per carrier in existing LTE and LTE-A is limited to a maximum of 20 MHz, 5G systems aim to provide ultra-high-speed data services reaching several Gbps by utilizing significantly wider ultra-wide bandwidths. Accordingly, 5G systems are considering ultra-high frequency bands ranging from several GHz to up to 100 GHz as candidate frequencies, where securing ultra-wide bandwidth frequencies is relatively easy. Additionally, it is possible to secure wide bandwidth frequencies for 5G systems through frequency reallocation or allocation from frequency bands ranging from hundreds of MHz to several GHz currently used by existing mobile communication systems.

[0058] The above-mentioned radio waves in the ultra-high frequency band have wavelengths of several millimeters and are also called millimeter waves (mmWave). However, in the ultra-high frequency band, path loss of radio waves increases in proportion to the frequency band, and the coverage of mobile communication systems becomes smaller.

[0059] To overcome the disadvantage of reduced coverage in the aforementioned ultra-high frequency band, beamforming technology can be applied by using multiple antennas to concentrate the radiated energy of radio waves toward a predetermined target point, thereby increasing the reach of the radio waves. That is, a signal to which the beamforming technology is applied has a relatively narrowed beam width, and as radiated energy is concentrated within this narrowed beam width, the reach of the radio waves is increased. The beamforming technology can be applied to both the transmitting and receiving ends. In addition to the effect of increasing coverage, beamforming technology has the effect of reducing interference in areas outside the beamforming direction. For the beamforming technology to operate properly, accurate measurement and feedback methods for the transmit and receive beams are required. The beamforming technology can be applied to a control channel or data channel that corresponds one-to-one between a predetermined terminal and a base station. In addition, beamforming technology may be applied to common signals transmitted by a base station to multiple terminals within the system, such as synchronization signals, physical broadcast channels (PBCH), control channels for transmitting system information, and data channels, to increase coverage. When beamforming technology is applied to common signals, beam sweeping technology, which changes the beam direction to transmit the signal, is additionally applied to ensure that the common signal reaches terminals located at any position within the cell.

[0060] Another requirement for 5G systems is ultra-low latency services, where the transmission delay between the transmitter and receiver is approximately 1ms. As a measure to reduce transmission delay, it is necessary to design a frame structure based on a short TTI (Transmission Time Interval) that is shorter than that of LTE and LTE-A. TTI is the basic time unit for performing scheduling, and the TTI of existing LTE and LTE-A systems is 1ms, which corresponds to the length of one subframe. For example, to satisfy the requirements for ultra-low latency services in the aforementioned 5G systems, short TTIs such as 0.5ms, 0.25ms, and 0.125ms, which are shorter than those of existing LTE and LTE-A systems, are possible.

[0061] FIG. 1 illustrates the basic structure of a time-frequency resource domain of a 5G system according to one embodiment of the present disclosure. FIG. 1 may be a diagram showing the basic structure of a time-frequency resource domain, which is a wireless resource domain where data or control channels of a 5G system are transmitted.

[0062] Referring to FIG. 1, the horizontal axis in FIG. 1 may represent the time domain, and the vertical axis may represent the frequency domain. The minimum transmission unit in the time domain of a 5G system is an OFDM (Orthogonal Frequency Division Multiplexing) symbol, (102) symbols are combined to form one slot (106), and A number of slots can be combined to form a single subframe (105). The length of the subframe is 1.0 ms, and 10 subframes can be combined to form a 10 ms frame (114). The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the total system transmission bandwidth is a total It can be composed of (104) subcarriers.

[0063] In the time-frequency domain, the basic unit of a resource is a resource element (RE) (112), which can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB or Physical Resource Block, PRB) is in the frequency domain. It can be defined as (110) consecutive subcarriers. In a 5G system And, the data rate can increase in proportion to the number of RBs scheduled to the terminal.

[0064] In a 5G system, base stations map data in RB units, and generally, scheduling can be performed on RBs that constitute one slot for a given terminal. That is, in a 5G system, the basic time unit for which scheduling is performed is a slot, and the basic frequency unit for which scheduling is performed can be an RB.

[0065] OFDM symbol count It is determined by the length of the cyclic prefix (CP) added to each symbol to prevent interference between symbols; for example, if a normal CP is applied , when Extended CP is applied Extended CP can be applied to systems with relatively longer transmission distances than standard CP, allowing orthogonality between symbols to be maintained. In the case of standard CP, the ratio of CP length to symbol length is maintained at a constant value, so the overhead caused by CP can remain constant regardless of the subcarrier spacing. That is, if the subcarrier spacing is small, the symbol length increases, and consequently, the CP length can also increase. Conversely, if the subcarrier spacing is large, the symbol length decreases, and consequently, the CP length can be reduced. The symbol length and CP length can be inversely proportional to the subcarrier spacing.

[0066] In 5G systems, various frame structures can be supported by adjusting the subcarrier spacing to satisfy diverse services and requirements. For example,

[0067] From the perspective of the operating frequency band, a larger subcarrier spacing may be advantageous for recovering phase noise in the high-frequency band.

[0068] - From the perspective of transmission time, a large subcarrier spacing shortens the symbol length in the time domain, and consequently shortens the slot length, which can be advantageous for supporting ultra-low latency services such as URLLC.

[0069] - From the perspective of cell size, a longer CP length allows for the support of larger cells, so a smaller subcarrier spacing allows for the support of relatively larger cells. In mobile communication, a cell can represent an area covered by a single base station.

[0070] The aforementioned subcarrier spacing, CP length, etc., are essential information for OFDM transmission and reception; therefore, the base station and the terminal must recognize the subcarrier spacing, CP length, etc., as common values ​​to enable smooth transmission and reception. [Table 1] below shows the subcarrier spacing configuration (μ) and subcarrier spacing ( It can represent the relationship between the lengths of ), and CP.

[0071] [Table 1]

[0072]

[0073] [Table 2] below shows the number of symbols per slot for each subcarrier spacing setting (μ) for the general type CP ( ), number of slots per frame ( ), number of slots per subframe ( It can represent ).

[0074] [Table 2]

[0075]

[0076] [Table 3] below shows the number of symbols per slot for each subcarrier spacing setting (μ) for extended CP ( ), number of slots per frame ( ), number of slots per subframe ( It can represent ).

[0077] [Table 3]

[0078]

[0079] In the early stages of introducing 5G systems, coexistence or dual-mode operation with at least existing LTE or / and LTE-A (hereinafter LTE / LTE-A) systems may be expected. This allows existing LTE / LTE-A to provide stable system operation to terminals, while the 5G system can perform the role of providing enhanced services to said terminals. Therefore, the frame structure of the 5G system may need to include at least the frame structure or essential parameter set of LTE / LTE-A (subcarrier spacing = 15 kHz).

[0080] For example, when comparing a frame structure with a subcarrier spacing setting μ=0 (hereinafter frame structure A) and a frame structure with a subcarrier spacing setting μ=1 (hereinafter frame structure B), compared to frame structure A, frame structure B may have a subcarrier spacing and RB size that are twice as large, and a slot length and symbol length that are twice as small. In the case of frame structure B, two slots may be configured into one subframe, and 20 subframes may be configured into one frame.

[0081] Generalizing the frame structure of the above 5G system, high scalability can be provided by ensuring that the essential parameter sets, such as subcarrier spacing, CP length, and slot length, have an integer multiple relationship with each other for each frame structure. A subframe of a fixed length of 1ms can be defined to represent a reference time unit independent of the frame structure.

[0082] The above frame structure can be applied in response to various scenarios. From the perspective of cell size, since a longer CP length allows for the support of larger cells, the above frame structure A can support relatively larger cells compared to the above frame structure B. From the perspective of operating frequency band, since a larger subcarrier spacing is advantageous for recovering phase noise in the high-frequency band, the above frame structure B can support relatively higher operating frequencies compared to the above frame structure A. From the perspective of service, since a shorter slot length, which is the basic time unit of scheduling, is advantageous for supporting ultra-low latency services such as URLLC, the above frame structure B can be relatively more suitable for URLLC services compared to the above frame structure A.

[0083] In the following description of the present disclosure, an uplink (UL) refers to a wireless link through which a terminal transmits data or control signals to a base station, and a downlink (DL) may refer to a wireless link through which a base station transmits data or control signals to a terminal.

[0084] In the initial access phase, when the terminal first connects to the system, the terminal can synchronize downlink time and frequency using the synchronization signal transmitted by the base station through a cell search and obtain a cell ID. Then, the terminal can use the obtained cell ID to receive a Physical Broadcast Channel (PBCH) and obtain a Master Information Block (MIB), which contains essential system information, from the PBCH. Additionally, the terminal can receive a System Information Block (SIB) transmitted by the base station to obtain cell-common control information related to transmission and reception. This cell-common control information related to transmission and reception may include control information related to random access, control information related to paging, and common control information for various physical channels.

[0085] The synchronization signal serves as a reference for cell search, and subcarrier spacing can be applied for each frequency band to suit channel environments such as phase noise. In the case of data channels or control channels, as described above, subcarrier spacing may be applied differently depending on the service type to support various services.

[0086] FIG. 2 illustrates a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0087] For the purpose of explanation in the present disclosure, the following components may be defined.

[0088] - PSS (Primary Synchronization Signal): A signal that serves as the reference for DL ​​time / frequency synchronization and provides some cell ID information.

[0089] - SSS (Secondary Synchronization Signal): Serves as a reference for DL ​​time / frequency synchronization and provides some of the remaining information, including the cell ID. Additionally, it can serve as a reference signal for PBCH demodulation.

[0090] - PBCH (Physical Broadcast Channel): Can provide MIB (Master Information Block), which is essential system information required for the transmission and reception of the terminal's data channel and control channel. The said essential system information may include control information related to the search space representing wireless resource mapping information of the control channel, scheduling control information for a separate data channel transmitting system information, and information such as SFN (System Frame Number), which is a frame-unit index serving as a timing reference.

[0091] - SS / PBCH Block (Synchronization Signal / PBCH Block or SSB): An SS / PBCH block consists of N OFDM symbols and can be composed of combinations such as PSS, SSS, and PBCH. In systems where beam sweeping technology is applied, the SS / PBCH block may be the minimum unit to which beam sweeping is applied. For example, in a 5G system, N may be 4. A base station can transmit up to L SS / PBCH blocks, and said L SS / PBCH blocks can be mapped within a half frame (0.5ms). And said L SS / PBCH blocks may be repeated periodically in units of a predetermined period P. said period P may be announced to the terminal by the base station through signaling. If there is no separate signaling for said period P, the terminal may apply a pre-agreed default value.

[0092] FIG. 2 illustrates an embodiment in which beam sweeping is applied in units of SS / PBCH blocks over time. Referring to FIG. 2, terminal 1 (205) can receive an SS / PBCH block using a beam radiated in the direction of #d0 (203) by beamforming applied to SS / PBCH block #0 at time t1 (201). Terminal 2 (206) can receive an SS / PBCH block using a beam radiated in the direction of #d4 (204) by beamforming applied to SS / PBCH block #4 at time t2 (202). The terminal can obtain an optimal synchronization signal through a beam radiated from the base station toward the direction where the terminal is located. For example, it may be difficult for terminal 1 (205) to obtain time / frequency synchronization and essential system information from an SS / PBCH block through a beam radiated in the direction of #d4, which is far from the location of terminal 1.

[0093] According to one embodiment, in addition to the initial connection procedure, the terminal may also receive an SS / PBCH block to determine whether the radio link quality of the current cell is maintained above a certain level. According to one embodiment, in a handover procedure in which the terminal moves the connection from the current cell to an adjacent cell, the terminal may receive an SS / PBCH block of an adjacent cell to determine the radio link quality of the adjacent cell and to obtain time / frequency synchronization of the adjacent cell.

[0094] According to one embodiment, after the terminal obtains MIB and system information from the base station through an initial access procedure, the terminal may perform a random access procedure to transition the link with the base station to a connected state (connected state or RRC_CONNECTED state). Upon completion of the random access procedure, the terminal transitions to a connected state, and one-to-one communication between the base station and the terminal may become possible. The random access procedure will be described in detail below with reference to FIG. 3.

[0095] FIG. 3 illustrates a random access procedure according to one embodiment of the present disclosure. FIG. 3 illustrates one embodiment of a random access procedure, but the present disclosure is not limited thereto. Furthermore, the present disclosure is not limited to the 4-step random access procedure illustrated in FIG. 3 and may also be applied to a 2-step random access procedure (transmission and reception of message A (e.g., a message containing information corresponding to message 1 and message 3 in FIG. 3) and transmission and reception of message B (e.g., a message containing information corresponding to message 2 and message 4 in FIG. 3).

[0096] Referring to FIG. 3, according to one embodiment, in the first step (310) of the random access procedure, the terminal (UE) can transmit a random access preamble to the base station (Gnb). The random access preamble, which is the initial transmission message of the terminal in the random access procedure, may be referred to as message 1. The base station can measure the transmission delay value between the terminal and the base station from the random access preamble and synchronize the uplink. The terminal may arbitrarily select a random access preamble to use from a set of random access preambles given in advance by system information. The initial transmission power of the random access preamble may be determined according to the path loss between the base station and the terminal measured by the terminal. Additionally, the terminal may determine the transmission beam direction of the random access preamble from the synchronization signal received from the base station and transmit the random access preamble.

[0097] According to one embodiment, in the second step (320), the base station (gNB) may transmit an uplink transmission timing control command to the terminal (UE) based on the transmission delay value measured from the random access preamble received in the first step (310). The base station may transmit uplink resource and power control commands to be used by the terminal as scheduling information. The scheduling information may include control information for the terminal's uplink transmission beam.

[0098] According to one embodiment, if the terminal does not receive a Random Access Response (RAR) (or message 2), which is scheduling information for message 3, from the base station within a predetermined time in the second step (320), the terminal may proceed to the first step (310) again. When the terminal proceeds to the first step (310) again, the terminal may increase the probability of the base station receiving the Random Access Preamble by increasing the transmission power of the Random Access Preamble by a predetermined step (power ramping).

[0099] In one embodiment, in the third step (330), the terminal (UE) may transmit uplink data (message 3) including its terminal ID to the base station (gNB) via the uplink data channel (Physical Uplink Shared Channel, PUSCH) using the uplink resources allocated in the second step (320). The transmission timing of the uplink data channel for transmitting Message 3 may follow the timing control command received from the base station in the second step (320). The transmission power of the uplink data channel for transmitting Message 3 may be determined by considering the power control command received from the base station in the second step (320) and the power ramping value of the random access preamble. The uplink data channel for transmitting Message 3 may refer to the first uplink data signal transmitted by the terminal to the base station after the terminal transmits the random access preamble.

[0100] According to one embodiment, in step 4 (340), if the base station (gNB) determines that the terminal (UE) has performed random access without collision with other terminals, it may transmit data (message 4) containing the ID of the terminal that transmitted uplink data in step 3 (330) to the terminal. When the terminal receives the signal transmitted by the base station in step 4 (340) from the base station, it may determine that the random access was successful. Then, the terminal may transmit HARQ-ACK information indicating whether the message 4 was successfully received to the base station through the uplink control channel (Physical Uplink Control Channel, PUCCH).

[0101] According to one embodiment, if the data transmitted by the terminal in the third step (330) and the data of another terminal collide with each other and the base station fails to receive the data signal from the terminal, the base station may not transmit any further data to the terminal. Accordingly, if the terminal fails to receive the data transmitted from the base station in the fourth step (340) within a certain period of time, it determines that the random access procedure has failed and may start again from the first step (310).

[0102] According to one embodiment, upon successful completion of the random access procedure, the terminal transitions to a connected state, enabling one-to-one communication between the base station and the terminal. The base station receives UE capability information from the terminal in the connected state and can adjust scheduling by referring to the terminal's UE capability information. Through the UE capability information, the terminal can inform the base station of whether it supports a specific function, the maximum allowable value of the function supported by the terminal, etc. Accordingly, the UE capability information reported by each terminal to the base station may be different values ​​for each terminal.

[0103] According to one embodiment, the terminal may report UE capability information to the base station, which includes at least a portion of the following control information as the UE capability information.

[0104] - Control information related to frequency bands supported by the terminal

[0105] - Control information related to channel bandwidth supported by the terminal

[0106] - Control information regarding the maximum modulation scheme supported by the terminal

[0107] - Control information regarding the maximum number of beams supported by the terminal

[0108] - Control information regarding the maximum number of layers supported by the terminal

[0109] - Control information related to CSI reporting supported by the terminal

[0110] - Control information on whether the terminal supports frequency hopping

[0111] - Bandwidth-related control information when Carrier Aggregation (CA) is supported

[0112] - Control information on whether cross-carrier scheduling is supported when carrier bundling is supported

[0113] FIG. 4 illustrates a procedure in which a terminal reports terminal capability (UE capability) information to a base station according to one embodiment of the present disclosure.

[0114] Referring to FIG. 4, according to one embodiment, in step 410, the base station (402) may transmit a UE capability information request message to the terminal (401). In response to the base station's UE capability information request, the terminal may transmit UE capability information to the base station in step 420.

[0115] According to one embodiment, a terminal connected to a base station through the process described above is a terminal in the RRC_CONNECTED state, and the terminal connected to the base station can perform one-to-one communication. Conversely, a terminal not connected to a base station is a terminal in the RRC_IDLE state, and the operation of a terminal in the RRC_IDLE state can be distinguished as follows.

[0116] - Operates terminal-specific DRX (Discontinuous Reception) cycles set by the upper layer

[0117] - Operation of receiving paging messages from the core network

[0118] - Obtain system information

[0119] - Measurement operation and cell reselection related to surrounding cells

[0120] In 5G systems, a new terminal state called RRC_INACTIVE has been defined to reduce the energy and time consumed for the initial access of terminals. A terminal in the RRC_INACTIVE state can perform the following operations in addition to the operations performed by a terminal in the RRC_IDLE state.

[0121] - Stores AS (Access stratum) information required for cell access

[0122] - Terminal-specific DRX cycle operation set by the RRC layer

[0123] - Configure RNA (RAN-based notification area) that can be utilized during handover by the RRC layer and perform periodic updates

[0124] - Monitoring RAN-based paging messages transmitted via I-RNTI

[0125] The following describes a scheduling method in which a base station transmits downlink data to a terminal or instructs the terminal to transmit uplink data.

[0126] Downlink Control Information (DCI) is control information transmitted by a base station to a terminal via a downlink, and may include downlink data scheduling information or uplink data scheduling information for a specific terminal. In one embodiment, the base station may channel-code the DCI independently for each terminal and then transmit it to each terminal via a Physical Downlink Control Channel (PDCCH), which is a downlink physical control channel.

[0127] According to one embodiment, a base station may operate by applying a predetermined DCI format to a terminal to be scheduled, depending on the purpose, such as whether it is scheduling information for downlink data (Downlink assignment), whether it is scheduling information for uplink data (Uplink grant), or whether it is a DCI for power control.

[0128] According to one embodiment, a base station can transmit downlink data to a terminal via a Physical Downlink Shared Channel (PDSCH), which is a physical channel for transmitting downlink data. Scheduling information, such as specific mapping locations in the time and frequency domains of the PDSCH, modulation schemes, HARQ-related control information, and power control information, can be provided by the base station to the terminal through a DCI related to downlink data scheduling information among the DCIs transmitted via the PDSCH.

[0129] According to one embodiment, a terminal can transmit uplink data to a base station via a PUSCH (Physical Uplink Shared Channel), which is a physical channel for transmitting uplink data. Scheduling information, such as specific mapping locations in the time and frequency domains of the PUSCH, modulation schemes, HARQ-related control information, and power control information, can be provided by the base station to the terminal through a DCI related to uplink data scheduling information among the DCIs transmitted via the PDCCH.

[0130] FIG. 5 illustrates a Control Resource Set (CORESET) as a time-frequency resource to which a PDCCH is mapped according to one embodiment of the present disclosure.

[0131] Referring to FIG. 5, two control resource sets (control resource set #1 (501), control resource set #2 (502)) can be set within the terminal bandwidth part (UE bandwidth part) (510) on the frequency axis and one slot (520) on the time axis. The control resource sets (501, 502) can be set to a specific frequency resource (503) within the entire terminal bandwidth part (510) on the frequency axis. On the time axis, they can be set to one or more OFDM symbols, which can be defined as the control resource set duration (504).

[0132] According to one embodiment, with reference to FIG. 5, control resource set #1 (501) can be set to a control resource set length of 2 symbols, and control resource set #2 (502) can be set to a control resource set length of 1 symbol.

[0133] According to one embodiment, a base station may set one or more CORESETs to a terminal through upper layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Setting a CORESET to a terminal may mean providing information such as a CORESET identifier, the frequency location of the CORESET, and the symbol length of the CORESET. The information provided by the base station to the terminal to set a CORESET may include at least some of the information included in [Table 4] below.

[0134] [Table 4]

[0135]

[0136] According to one embodiment, CORESET is in the frequency domain It can be composed of RBs, and in the time domain It can be composed of symbols. An NR PDCCH can be composed of one or more CCEs (Control Channel Elements). One CCE can be composed of six REGs (Resource Element Groups), and a REG can be defined as one RB during one OFDM symbol. Within a CORESET, REGs can be indexed in time-first order starting with REG index 0, beginning with the first OFDM symbol of the CORESET, the lowest RB.

[0137] According to one embodiment, interleaved and non-interleaved methods may be supported as transmission methods for PDCCH. The base station may set whether to perform interleaved or non-interleaved transmission for each CORESET to the terminal through upper-layer signaling. Interleaving may be performed in units of REG bundles. A REG bundle may be defined as a set of one or more REGs. Based on whether to perform interleaved or non-interleaved transmission set by the base station, the terminal may determine the CCE-to-REG mapping method in the corresponding CORESET in the manner shown in [Table 5] below.

[0138] [Table 5]

[0139]

[0140] The base station can inform the terminal of configuration information, such as which symbol the PDCCH is mapped to within the slot and the transmission period, through signaling.

[0141] FIG. 6 illustrates the mapping of DCI and DMRS in a REG, which is the basic unit of a downlink control channel according to one embodiment of the present disclosure.

[0142] Referring to FIG. 6, the REG (603), which is the basic unit of the downlink control channel, may include both the REs to which the DCI is mapped and the DMRS (605), which is a reference signal for decoding the REs, to which the DMRS is mapped. Additionally, three DMRSs (605) may be transmitted within one REG (603).

[0143] The search space of a PDCCH is described below. The number of CCEs required to transmit a PDCCH can be 1, 2, 4, 8, or 16 depending on the Aggregation Level (AL), and different numbers of CCEs can be used for link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel can be transmitted through L CCEs. The terminal performs blind decoding to detect a signal without knowing information about the downlink control channel; to this end, a search space representing a set of CCEs can be defined. The search space is a set of downlink control channel candidates consisting of CCEs that the terminal must attempt to decode at a given aggregation level. Since there are various aggregation levels that form a group of 1, 2, 4, 8, or 16 CCEs, the terminal may have multiple search spaces. A Search Space Set can be defined as a set of search spaces at all established aggregation levels.

[0144] Search spaces can be classified into Common Search Spaces (CSS) and UE-specific Search Spaces (USS). A certain group of terminals or all terminals may examine the Common Search Space of a PDCCH to receive cell-common control information, such as dynamic scheduling or paging messages for System Information Blocks (SIBs). For example, a terminal may receive scheduling allocation information for a PDSCH for receiving system information by examining the Common Search Space of the PDCCH. In the case of the Common Search Space, since a certain group of terminals or all terminals must receive the PDCCH, it may be defined as a pre-agreed set of CCEs. Scheduling allocation information for a UE-specific PDSCH or PUSCH may be received by a terminal by examining the UE-specific Search Space of the PDCCH. The UE-specific Search Space may be defined specifically as a function of the terminal's ID (Identity) and various system parameters.

[0145] The base station can configure configuration information for the search space of the PDCCH to the terminal through upper-layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can configure the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the occasion for monitoring in slot-symbol units for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the search space, and the CORESET index to be monitored for the search space to the terminal. For example, parameters for the search space of the PDCCH may include information such as [Table 6] below.

[0146] [Table 6]

[0147]

[0148]

[0149]

[0150] According to the configuration information, the base station may set one or more sets of search spaces for the terminal. According to some embodiments, the base station may set search space set 1 and search space set 2 for the terminal. In search space set 1, the terminal may be configured to monitor DCI format A scrambled with X-RNTI in a common search space, and in search space set 2, the terminal may be configured to monitor DCI format B scrambled with Y-RNTI in a terminal-specific search space.

[0151] According to the configuration information, one or more sets of search spaces may exist in a common search space or a terminal-specific search space. For example, Search Space Set #1 and Search Space Set #2 may be configured as a common search space, and Search Space Set #3 and Search Space Set #4 may be configured as a terminal-specific search space.

[0152] In the common search space, terminals can monitor the following combinations of DCI formats and RNTI. Of course, they are not limited to the following examples.

[0153] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0154] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0155] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0156] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0157] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0158] - DCI format 2_4 with CRC scrambled by CI-RNTI

[0159] - DCI format 2_5 with CRC scrambled by AI-RNTI

[0160] - DCI format 2_6 with CRC scrambled by PS-RNTI

[0161] - DCI format 2_7 with CRC scrambled by PEI-RNTI

[0162] Terminal—In a specific search space, the terminal can monitor the following combinations of DCI formats and RNTI. Of course, it is not limited to the following examples.

[0163] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0164] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0165] The above RNTIs may follow the following definitions and uses.

[0166] C-RNTI (Cell RNTI): Used for terminal-specific PDSCH or PUSCH scheduling

[0167] TC-RNTI (Temporary Cell RNTI): Used for terminal-specific PDSCH scheduling

[0168] CS-RNTI (Configured Scheduling RNTI): Used for semi-statically configured terminal-specific PDSCH scheduling.

[0169] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling during the random access phase

[0170] P-RNTI (Paging RNTI): Used for PDSCH scheduling where paging is transmitted.

[0171] SI-RNTI (System Information RNTI): Used for PDSCH scheduling where system information is transmitted.

[0172] INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH is pucturing.

[0173] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to instruct power control commands to the PUSCH

[0174] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to instruct power control commands to the PUCCH

[0175] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to instruct power regulation commands to the SRS

[0176] The DCI formats described above may follow the definitions in [Table 7] below.

[0177] [Table 7]

[0178]

[0179] In CORESET p and search space set s, the search space of aggregation level L can be expressed as Equation 1 below.

[0180]

[0181] The value may be 0 for the common search space.

[0182] In the case of a terminal-specific search space, the value may correspond to a value that changes according to the terminal's ID (C-RNTI or the ID set for the terminal by the base station) and the time index.

[0183] In the following, we will specifically explain how to set the TCI state for the PDCCH (or PDCCH DMRS) in a 5G communication system.

[0184] A base station may be able to set and indicate a TCI state for a PDCCH (or PDCCH DMRS) through appropriate signaling. According to the above description, a base station may be able to set and indicate a TCI state for a PDCCH (or PDCCH DMRS) through appropriate signaling. The TCI state is intended to announce a Quasi-Co-location (QCL) relationship between a PDCCH (or PDCCH DMRS) and another RS ​​or channel. When a reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) are QCLed with each other, it may mean that the terminal is allowed to apply some or all of the large-scale channel parameters estimated from the antenna port A to channel measurements from the antenna port B. Depending on the situation, QCL may need to associate different parameters, such as 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) RRM (radio resource management) affected by average gain, and 4) BM (beam management) affected by spatial parameters. Accordingly, NR can support four types of QCL relationships as shown in Table 8 below. Of course, it is not limited to the examples below.

[0185] [Table 8]

[0186]

[0187] The above spatial RX parameter may collectively refer to some or all of various parameters, such as Angle of arrival (AoA), Power Angular Spectrum (PAS) of AoA, Angle of departure (AoD), PAS of AoD, transmit / receive channel correlation, transmit / receive beamforming, and spatial channel correlation.

[0188] The above QCL relationship may be configured for the terminal through RRC parameters TCI-State and QCL-Info as shown in Table 9 below. Referring to Table 9 below, the base station may configure one or more TCI states for the terminal and provide up to two QCL relationships (qcl-Type1, qcl-Type2) for the RS that references the ID of the TCI state, i.e., the target RS. At this time, each QCL information (QCL-Info) included in each of the above TCI states may include the serving cell index and BWP index of the reference RS pointed to by the corresponding QCL information, the type and ID of the reference RS, and the QCL type as shown in Table 8 above.

[0189] [Table 9]

[0190]

[0191] FIG. 7 illustrates base station beam allocation according to TCI state setting according to one embodiment of the present disclosure.

[0192] Referring to FIG. 7, the base station can transmit information about N different beams to the terminal through N different TCI states. For example, when N=3, the base station can notify that antenna ports referencing the different TCI states 700, 705, or 710 are associated with different spatial Rx parameters, i.e., different beams, by setting the qcl-Type2 parameters included in the three TCI states (700, 705, 710) to be associated with CSI-RS or SSB corresponding to different beams and set to QCL type D.

[0193] Specifically, the TCI state combinations applicable to the PDCCH DMRS antenna port are as shown in Table 10 below. The fourth row of Table 10 below represents the combinations assumed by the terminal prior to RRC configuration, and configuration after RRC may not be possible. Of course, it is not limited to the examples below.

[0194] [Table 10]

[0195]

[0196] NR can support a hierarchical signaling method as shown in Fig. 8 for dynamic allocation of PDCCH beams.

[0197] FIG. 8 illustrates a hierarchical signaling method for dynamic allocation of a PDCCH beam of NR according to one embodiment of the present disclosure.

[0198] Referring to FIG. 8, the base station can set N TCI states (805, 810, ..., 820) to the terminal through RRC signaling (800), and some of these can be set as TCI states for CORESET (825). Subsequently, the base station can instruct the terminal to one of the TCI states for CORESET (830, 835, 840) through MAC CE signaling (845). Subsequently, the terminal can receive PDCCH based on beam information included in the TCI state indicated by the MAC CE signaling.

[0199] FIG. 9 illustrates a TCI indication MAC CE signaling structure for a PDCCH DMRS according to one embodiment of the present disclosure.

[0200] Referring to FIG. 9, the TCI indication MAC CE signaling for the PDCCH DMRS is composed of 2 bytes (16 bits) and may include a 1-bit reserved bit (910), a 5-bit serving cell ID (915), a 2-bit BWP ID (920), a 2-bit CORESET ID (925), and a 6-bit TCI state ID (930).

[0201] The base station may indicate one of the TCI state lists included in the CORESET configuration through MAC CE signaling. Subsequently, until another TCI state is indicated to the corresponding CORESET through another MAC CE signaling, the terminal may consider that the same QCL information applies to all one or more search spaces connected to the said CORESET.

[0202] The PDCCH beam allocation method described above has the disadvantage that it is difficult to instruct a beam change faster than the MAC CE signaling delay, and that the same beam is applied uniformly to all CORESETs regardless of search space characteristics, thereby making flexible PDCCH beam operation difficult. The embodiments of the present disclosure below provide a more flexible method for setting and operating PDCCH beams. In describing the embodiments of the present disclosure below, several distinct examples are provided for convenience of explanation, but these are not mutually exclusive and can be appropriately combined and applied depending on the situation.

[0203] The base station may set one or more TCI states for a specific control resource set for the terminal, and may activate one of the set TCI states through a MAC CE activation command. For example, if {TCI state#0, TCI state#1, TCI state#2} are set as TCI states for control resource set #1, the base station may transmit a command to the terminal via MAC CE to activate TCI state#0 as the TCI state for control resource set #1. Based on the activation command for the TCI state received via MAC CE, the terminal can correctly receive the DMRS of the corresponding control resource set based on the QCL information within the activated TCI state.

[0204] For a control resource set (control resource set #0) with an index set to 0, if the terminal has not received a MAC CE activation command for the TCI state of control resource set #0, it can be assumed that the terminal has QCL with the SS / PBCH block identified in the initial connection process or the non-contention-based random access process that was not triggered by the PDCCH command for the DMRS transmitted from control resource set #0.

[0205] For a control resource set (control resource set #X) with an index set to a value other than 0, if the terminal has not received a TCI state for control resource set #X, or has received one or more TCI states but has not received a MAC CE activation command to activate one of them, it can be assumed that the terminal has QCL with the SS / PBCH block identified during the initial connection process for the DMRS transmitted from control resource set #X.

[0206] Next, Downlink Control Information (DCI) in 5G systems will be explained in detail.

[0207] In a 5G system, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or Physical Downlink Shared Channel (PDSCH)) can be transmitted from a base station to a terminal via DCI. The terminal can monitor the fallback DCI format and the non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format may consist of fixed fields selected between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

[0208] DCI can be transmitted through the Physical Downlink Control Channel (PDCCH) after undergoing channel coding and modulation processes. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled into a Radio Network Temporary Identifier (RNTI) corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. In other words, the RNTI may not be transmitted explicitly but may be included in the CRC calculation process. Upon receiving a DCI message transmitted over the PDCCH, the terminal checks the CRC using the assigned RNTI; if the CRC check result is correct, the terminal knows that the message has been transmitted to it.

[0209] For example, a DCI scheduling a PDSCH for System Information (SI) can be scrambled to SI-RNTI. A DCI scheduling a PDSCH for Random Access Response (RAR) messages can be scrambled to RA-RNTI. A DCI scheduling a PDSCH for Paging messages can be scrambled to P-RNTI. A DCI notifying a Slot Format Indicator (SFI) can be scrambled to SFI-RNTI. A DCI notifying Transmit Power Control (TPC) can be scrambled to TPC-RNTI. A DCI scheduling a terminal-specific PDSCH or PUSCH can be scrambled to C-RNTI (Cell RNTI).

[0210] DCI format 0_0 can be used as a countermeasure DCI for scheduling PUSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI may include, for example, the information in Table 11 below.

[0211] [Table 11]

[0212]

[0213]

[0214]

[0215] DCI format 0_1 ​​can be used as a non-defense DCI for scheduling PUSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI may include the following information, for example, as shown in Table 12.

[0216] [Table 12]

[0217]

[0218]

[0219]

[0220]

[0221]

[0222]

[0223]

[0224]

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232] DCI format 1_0 can be used as a countermeasure DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI may include, for example, the information in Table 13 below.

[0233] [Table 13]

[0234]

[0235]

[0236]

[0237] DCI format 1_1 can be used as a non-defense DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI may include, for example, the information in Table 14 below.

[0238] [Table 14]

[0239]

[0240]

[0241]

[0242]

[0243]

[0244]

[0245]

[0246]

[0247]

[0248] The following describes the time domain resource allocation method for data channels in a 5G communication system.

[0249] The base station may set a table for time-domain resource allocation information for the Physical Downlink Shared Channel (PDSCH) and the Physical Uplink Shared Channel (PUSCH) for the terminal using upper-layer signaling (e.g., RRC signaling). For PDSCH, a table consisting of a maximum of maxNrofDL-Allocations = 16 entries may be set, and for PUSCH, a table consisting of a maximum of maxNrofUL-Allocations = 16 entries may be set. For example, time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted as K0) or PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information on the position and length of the start symbol for which the PDSCH or PUSCH is scheduled within the slot, and the mapping type of the PDSCH or PUSCH. For example, information such as that shown in Tables 15 and 16 below may be notified from the base station to the terminal.

[0250] [Table 15]

[0251]

[0252] [Table 16]

[0253]

[0254] The base station may notify the terminal of one of the entries in the table for the time domain resource allocation information via L1 signaling (e.g., DCI) (e.g., by indicating the 'time domain resource allocation' field within the DCI). The terminal may obtain time domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

[0255] The following describes the frequency domain resource allocation method for data channels in a 5G communication system.

[0256] In 5G, two types, resource allocation type 0 and resource allocation type 1, are supported as a method of indicating frequency domain resource allocation information for the Physical Downlink Shared Channel (PDSCH) and the Physical Uplink Shared Channel (PUSCH).

[0257] [ Resource Allocation Type 0 ]

[0258] RB allocation information may be notified from the base station to the terminal in the form of a bitmap for the RBG (Resource Block Group). In this case, the RBG may be composed of a set of consecutive VRBs (Virtual RBs), and the size P of the RBG may be determined based on the value set by the upper layer parameter (rbg-Size) and the size value of the bandwidth part defined in Table 17 below.

[0259] [Table 17]

[0260]

[0261] - Size Total number of RGBs in bandwidth part i (N RBG ) can be defined as follows.

[0262]

[0263] - N RBG Each bit of a bitmap of bit size can correspond to a respective RGB. The RGBs can be indexed in increasing order of frequency, starting from the lowest frequency position in the bandwidth part. N within the bandwidth part RBG For the RBGs, from RBG#0 to RBG#(N RBG -1) This RGB bitmap can be mapped from MSB to LSB. The terminal can determine that the RGB corresponding to the bit value is assigned when a specific bit value in the bitmap is 1, and can determine that the RGB corresponding to the bit value is not assigned when a specific bit value in the bitmap is 0.

[0264] [ Resource Allocation Type 1 ]

[0265] - RB allocation information can be notified from the base station to the terminal as information regarding the starting position and length of consecutively allocated VRBs. At this time, interleaving or non-interleaving may be additionally applied to the consecutively allocated VRBs. The resource allocation field of Resource Allocation Type 1 may be composed of a Resource Indication Value (RIV), and the RIV is the starting point of the VRB ( ) and the length of consecutively allocated RB ( It can be composed of. More specifically, The RIV within the bandwidth part of the size can be defined as follows.

[0266]

[0267] A base station may semi-statically configure time and frequency transmission resources and various transmit / receive parameters for the Physical Downlink Shared Channel (PDSCH) and the Physical Uplink Shared Channel (PUSCH) for the purpose of supporting unauthorized-based transmission and reception for the terminal.

[0268] To explain in more detail, it is as follows.

[0269] For the purpose of supporting Downlink (DL) Semi-Persistent Scheduling (SPS) to the terminal, the base station may set the information in Table 18 below as upper layer signaling (e.g., RRC signaling).

[0270] [Table 18]

[0271]

[0272] DL SPS can be set in a primary cell or a secondary cell, and within a cell group, DL SPS can be set in a single cell.

[0273] In 5G, two types of non-authorization-based transmission methods (named Configured Grant, Grant free, etc.) for the uplink data channel (PUSCH) can be supported (Type-1 PUSCH transmission with a configured grant, Type-2 PUSCH transmission with a configured grant).

[0274] [ Non-acknowledgment-based PUSCH transfer type-1 ]

[0275] In unauthorized-based PUSCH transmission type-1, the base station may configure specific time / frequency resources that allow unauthorized-based PUSCH transmission to the terminal using upper-layer signaling, e.g., RRC signaling. For example, time-axis allocation information, frequency-axis allocation information, period information, etc., for the resources may be configured. Additionally, the base station may configure various parameters for PUSCH transmission to the terminal using upper-layer signaling (e.g., frequency hopping, DMRS settings, MCS table, MCS, RBG (Resource Block Group) size, number of repeated transmissions, RV (Redundancy Version), etc.). More specifically, the configuration information in Table 19 below may be included.

[0276] [Table 19]

[0277]

[0278]

[0279]

[0280]

[0281] When the terminal receives configuration information for unauthorized-based PUSCH transmission type-1 from the base station, the terminal may transmit PUSCH without authorization from the base station using a periodically configured resource (600). Various parameters required to transmit PUSCH (e.g., frequency hopping, DMRS configuration, MCS, RBG (Resource Block Group) size, number of repeated transmissions, RV (Redundancy Version), number of precoding and layers, antenna port, frequency hopping offset, etc.) may all follow the configuration values ​​notified by the base station.

[0282] [ Non-acknowledgment-based PUSCH transfer type-2 ]

[0283] In unauthorized-based PUSCH transmission type-2, the base station may set some of the information regarding specific time / frequency resources that allow unauthorized-based PUSCH transmission to the terminal (e.g., period information, etc.) as upper-layer signaling (e.g., RRC signaling). Additionally, the base station may set various parameters for PUSCH transmission to the terminal (e.g., frequency hopping, DMRS settings, MCS table, RBG (Resource Block Group) size, number of repeated transmissions, RV (Redundancy Version), etc.) as upper-layer signaling. More specifically, the base station may set the configuration information in Table 20 below to the terminal as upper-layer signaling.

[0284] [Table 20]

[0285]

[0286]

[0287]

[0288] The base station may transmit a DCI composed of specific DCI field values ​​to the terminal for the purpose of activating or releasing scheduling for DL ​​SPS and UL grant Type 2.

[0289] To explain in more detail, it is as follows.

[0290] The base station can configure CS-RNTI (Configured Scheduling-RNTI) for the terminal, and the terminal can monitor a DCI format in which the CRC is scrambled with CS-RNTI. If the CRC of the DCI format received by the terminal is scrambled with CS-RNTI, the New Data Indicator (NDI) is set to '0', and the DCI field satisfies Table 21 below, the terminal may regard the DCI as a command to enable transmission and reception for DL ​​SPS or UL grant Type 2.

[0291] [Table 21]

[0292]

[0293] The base station can configure CS-RNTI (Configured Scheduling-RNTI) for the terminal, and the terminal can monitor a DCI format in which the CRC is scrambled with CS-RNTI. If the CRC of the DCI format received by the terminal is scrambled with CS-RNTI, the New Data Indicator (NDI) is set to '0', and the DCI field satisfies Table 22 below, the terminal may regard the DCI as a command to release transmission and reception for DL ​​SPS or UL grant Type 2.

[0294] [Table 22]

[0295]

[0296] The DCI instructing the release for the above DL SPS or UL grant Type 2 follows a DCI format corresponding to DCI format 0_0 or DCI format 1_0, and since DCI format 0_0 or 1_0 does not include a Carrier Indicator Field (CIF), the terminal must always monitor the PDCCH in the cell where the corresponding DL SPS or UL grant Type 2 is set in order to receive a release command for the DL SPS or UL grant Type 2 for a specific cell. Even if a specific cell is set to cross-carrier scheduling, the terminal must always monitor DCI format 1_0 or DCI format 0_0 in that cell to receive a release command for the DL SPS or UL grant Type 2 set in that cell.

[0297] In the following, we will specifically explain the carrier aggregation and scheduling methods in 5G communication systems.

[0298] A terminal may receive multiple cells (Cell or CC (Component Carrier)) from a base station and may receive a setting regarding whether cross-carrier scheduling is enabled for the cells configured in the terminal. If cross-carrier scheduling is enabled for a specific cell (Cell A, Scheduled Cell), PDCCH monitoring for Cell A is not performed at Cell A but may be performed at another cell (Cell B, Scheduling Cell) designated for cross-carrier scheduling. In this case, the Scheduled Cell (Cell A) and the Scheduling Cell (Cell B) may be configured with different numerologies. Here, the numerology may include subcarrier spacing, cyclic prefix, etc. When the numerologies of cell A and cell B are different, when cell B's PDCCH schedules cell A's PDSCH, a minimum scheduling offset as follows may be additionally considered between PDCCH and PDSCH.

[0299] [ Cross-Carrier Scheduling Method ]

[0300] - Subcarrier spacing of Cell B (μ B ) is the subcarrier spacing (μ) of cell A A If it is smaller than ), the PDSCH can be scheduled starting from the next PDSCH slot corresponding to X symbols after the last symbol of the PDCCH received at Cell B. Here, X is μ B It may vary depending on, and μ B= At 15kHz, X=4 symbols, μ B= At 30kHz, X=4 symbols, μ B= At 60kHz, X can be defined as 8 symbols.

[0301] - Subcarrier spacing of Cell B (μ B ) is the subcarrier spacing (μ) of cell A AIf it is greater than ), the PDSCH can be scheduled starting from the point X symbols after the last symbol of the PDCCH received by Cell B. Here, X is μ B It may vary depending on, and μ B= At 30kHz, X=4 symbols, μ B= At 60kHz, X=8 symbols, μ B= When it is 120kHz, X can be defined as 12 symbols.

[0302] In the following, the rate matching operation and puncturing operation will be described in detail.

[0303] When a time and frequency resource A intended to transmit an arbitrary symbol sequence A overlaps with an arbitrary time and frequency resource B, rate matching or puncturing operations may be considered as transmission and reception operations of channel A, taking into account the area resource C where resource A and resource B overlap. Specific operations may follow the details below.

[0304] [ Rate Matching Operation ]

[0305] - A base station may transmit a symbol sequence A to a terminal by mapping Channel A only to the remaining resource area, excluding Resource C which corresponds to the area overlapping with Resource B, from the entire Resource A. For example, if symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol #4}, Resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and Resource B is {Resource #3, Resource #5}, the base station may transmit symbol sequence A by sequentially mapping it to the remaining resources {Resource #1, Resource #2, Resource #4}, excluding {Resource #3} which corresponds to Resource C within Resource A. Consequently, the base station may transmit the symbol sequence {Symbol #1, Symbol #2, Symbol #3} by mapping it to {Resource #1, Resource #2, Resource #4}, respectively.

[0306] The terminal can determine Resource A and Resource B from scheduling information regarding Symbol Sequence A from the base station, and thereby determine Resource C, which is the area where Resource A and Resource B overlap. The terminal can receive Symbol Sequence A by assuming that Symbol Sequence A was transmitted by mapping it to the remaining area of ​​Resource A, excluding Resource C. For example, if Symbol Sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol 4}, Resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and Resource B is {Resource #3, Resource #5}, the terminal can receive Symbol Sequence A by assuming that it was sequentially mapped to the remaining resources {Resource #1, Resource #2, Resource #4}, excluding {Resource #3}, which corresponds to Resource C. Consequently, the terminal can perform a series of subsequent reception operations by assuming that Symbol Sequence {Symbol #1, Symbol #2, Symbol #3} was transmitted by mapping it to {Resource #1, Resource #2, Resource #4}, respectively.

[0307] [ Puncturing Action ]

[0308] If there is a resource C corresponding to an area overlapping with resource B among all resources A to which the base station intends to transmit symbol sequence A to a terminal, the base station maps symbol sequence A to the entire resource A, but does not perform transmission in the resource area corresponding to resource C, and can perform transmission only in the remaining resource area of ​​resource A excluding resource C. For example, if symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol #4}, resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource B is {Resource #3, Resource #5}, the base station can map symbol sequence A {Symbol #1, Symbol #2, Symbol #3, Symbol #4} to resource A {Resource #1, Resource #2, Resource #3, Resource #4} respectively, and can transmit only the symbol sequence {Symbol #1, Symbol #2, Symbol #4} corresponding to the remaining resources {Resource #1, Resource #2, Resource #4}, excluding {Resource #3} corresponding to resource C, and may not transmit {Symbol #3} mapped to {Resource #3} corresponding to resource C. Consequently, the base station can map and transmit the symbol sequence {Symbol #1, Symbol #2, Symbol #4} to {Resource #1, Resource #2, Resource #4} respectively.

[0309] The terminal can determine resources A and B from scheduling information for symbol sequence A from the base station, and thereby determine resource C, which is the area where resources A and B overlap. The terminal can receive symbol sequence A by assuming that symbol sequence A is mapped to the entire resource A, but is transmitted only in the remaining area of ​​resource A excluding resource C. For example, if symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol #4}, resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource B is {Resource #3, Resource #5}, the terminal can assume that symbol sequence A {Symbol #1, Symbol #2, Symbol #3, Symbol #4} is mapped to resource A {Resource #1, Resource #2, Resource #3, Resource #4} respectively, but {Symbol #3} mapped to {Resource #3} corresponding to resource C is not transmitted, and can receive by assuming that symbol sequence {Symbol #1, Symbol #2, Symbol #4} corresponding to the remaining resources {Resource #1, Resource #2, Resource #4}—excluding {Resource #3} corresponding to resource C—is mapped and transmitted. Consequently, the terminal can perform a subsequent series of receiving operations by assuming that the symbol sequence {Symbol #1, Symbol #2, Symbol #4} is transmitted and mapped to {Resource #1, Resource #2, Resource #4}, respectively.

[0310] FIG. 10 is a diagram illustrating a method for transmitting and receiving data by a base station and a terminal in consideration of a downlink data channel and rate matching resources according to one embodiment of the present disclosure.

[0311] Referring to FIG. 10, a downlink data channel (PDSCH, 1001) and a rate matching resource (1002) are illustrated. A base station may set one or more rate matching resources (1002) to a terminal through upper layer signaling (e.g., RRC signaling). The rate matching resource (1002) setting information may include time-axis resource allocation information (1003), frequency-axis resource allocation information (1004), and period information (1005). In the following, the bitmap corresponding to the frequency-axis resource allocation information (1004) is named the "first bitmap," the bitmap corresponding to the time-axis resource allocation information (1003) is named the "second bitmap," and the bitmap corresponding to the period information (1005) is named the "third bitmap." If all or part of the time and frequency resources of a scheduled data channel (1001) overlap with a set rate matching resource (1002), the base station can transmit the data channel (1001) by rate matching it in the rate matching resource (1002) portion, and the terminal can perform reception and decoding after assuming that the data channel (1001) is rate matched in the rate matching resource (1002) portion.

[0312] The base station can dynamically notify the terminal via DCI whether to rate match a data channel in the above-mentioned rate matching resource portion through additional settings (corresponding to the "rate matching indicator" within the aforementioned DCI format). Specifically, the base station can select some of the above-mentioned rate matching resources and group them into rate matching resource groups, and can indicate to the terminal via DCI using a bitmap method whether to rate match a data channel for each rate matching resource group. For example, if four rate matching resources, RMR#1, RMR#2, RMR#3, and RMR#4, are set, the base station can set RMG#1={RMR#1, RMR#2} and RMG#2={RMR#3, RMR#4} as rate matching groups, and can indicate to the terminal via a bitmap whether to rate match in RMG#1 and RMG#2, respectively, using 2 bits within the DCI field. For example, the base station can instruct the terminal to "1" if rate matching is required, and "0" if rate matching is not required.

[0313] In 5G, the granularity of "RB symbol level" and "RE level" is supported by setting the aforementioned rate matching resources to the terminal. More specifically, the following setting method may be followed.

[0314] [ RB Symbol Level ]

[0315] The terminal can receive up to four RateMatchPatterns as upper layer signaling for each bandwidth part, and one RateMatchPattern may include the following contents.

[0316] - As a Reserved Resource within the Bandwidth Part, a resource may be included in which the time and frequency resource domains of the said Reserve Resource are set by a combination of an RB level bitmap and a symbol level bitmap along the frequency axis. The said Reserve Resource may span one or two slots. In one embodiment, a span may be a continuous symbol within a slot and may be a continuous symbol capable of monitoring the PDCCH. A time domain pattern (periodicityAndPattern) in which the time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may be additionally set.

[0317] - It may include time and frequency domain resource areas set as control resource sets within the bandwidth part, and resource areas corresponding to time domain patterns set as search space settings where the resource areas are repeated.

[0318] [ RE Level ]

[0319] The terminal can receive the following settings through upper-layer signaling.

[0320] - Configuration information for an RE corresponding to an LTE CRS (Cell-specific Reference Signal or Common Reference Signal) pattern (lte-CRS-ToMatchAround) may include the number of ports of the LTE CRS (nrofCRS-Ports) and the LTE-CRS-vshift(s) value (v-shift), the location information of the LTE carrier's center subcarrier (carrierFreqDL) from a reference frequency point (e.g., reference point A), the LTE carrier's bandwidth size (carrierBandwidthDL) information, and subframe configuration information corresponding to a Multiast-broadcast single-frequency network (mbsfn-SubframConfigList). Based on the aforementioned information, the terminal can determine the location of the CRS within an NR slot corresponding to an LTE subframe.

[0321] - It may include configuration information for resource sets corresponding to one or more ZP (Zero Power) CSI-RS within the bandwidth part.

[0322] The following describes in detail the method for measuring and reporting channel status in a 5G communication system.

[0323] Channel state information (CSI) may include channel quality information (CQI), precoding matrix index (PMI), CSI-RS resource indicator (CRI), SS / PBCH block resource indicator (SSSBRI), layer indicator (LI), rank indicator (RI), and / or L1-RSRP (Reference Signal Received Power). The base station may control time and frequency resources for the aforementioned CSI measurement and reporting of the terminal.

[0324] For the aforementioned CSI measurement and reporting, the terminal can receive setting information for N (≥1) CSI reports (CSI-ReportConfig), setting information for M (≥1) RS transmission resources (CSI-ResourceConfig), and one or two trigger state lists (CSI-AperiodicTriggerStateList, CSI-SemiPersistentOnPUSCH-TriggerStateList) through upper layer signaling.

[0325] The setting information for the aforementioned CSI measurement and reporting may be more specifically as described in Tables 23 to 29 below.

[0326] [Table 23]

[0327]

[0328]

[0329]

[0330]

[0331]

[0332]

[0333]

[0334]

[0335]

[0336]

[0337] [Table 24]

[0338]

[0339] [Table 25]

[0340]

[0341] [Table 26]

[0342]

[0343] [Table 27]

[0344]

[0345] [Table 28]

[0346]

[0347]

[0348] [Table 29]

[0349]

[0350] Regarding the aforementioned CSI report settings (CSI-ReportConfig), each report setting CSI-ReportConfig can be associated with a single downlink (DL) bandwidth portion identified by the upper-layer parameter bandwidth portion identifier (bwp-id) given by the CSI-ResourceConfig, which is associated with the corresponding report setting. As for the time domain reporting operation for each report setting CSI-ReportConfig, 'Aperiodic', 'Semi-Persistent', and 'Periodic' methods are supported, and these can be configured from the base station to the terminal by the reportConfigType parameter set from the upper layer. The semi-persistent CSI reporting methods support 'PUCCH-based semi-persistent (semi-PersistentOnPUCCH)' and 'PUSCH-based semi-persistent (semi-PersistentOnPUSCH)'. In the case of a periodic or semi-permanent CSI reporting method, the terminal may receive a PUCCH or PUSCH resource to transmit the CSI from the base station via upper layer signaling. The period and slot offset of the PUCCH or PUSCH resource to transmit the CSI may be given as the numerology of the uplink (UL) bandwidth portion configured for transmitting the CSI report. In the case of a non-periodic CSI reporting method, the terminal may receive a PUSCH resource to transmit the CSI scheduled from the base station via L1 signaling (the aforementioned DCI format 0_1).

[0351] For the aforementioned CSI resource setting (CSI-ResourceConfig), each CSI resource setting CSI-ReportConfig may include S (≥1) CSI resource sets (given by the upper-level parameter csi-RS-ResourceSetList). The CSI resource set list may consist of non-zero power (NZP) CSI-RS resource sets and SS / PBCH block sets, or may consist of CSI-interference measurement (CSI-IM) resource sets. Each CSI resource setting may be located in a downlink (DL) bandwidth portion identified by the upper-level parameter bwp-id, and the CSI resource setting may be linked to a CSI report setting in the same downlink bandwidth portion. The time domain operation of the CSI-RS resources within the CSI resource setting may be set to one of 'non-periodic', 'periodic', or 'semi-permanent' by the upper-level parameter resourceType. For periodic or semi-permanent CSI resource settings, the number of CSI-RS resource sets may be limited to S=1, and the set period and slot offset may be given by the numerology of the downlink bandwidth portion identified by bwp-id. The terminal may receive one or more CSI resource settings for channel or interference measurement from the base station via upper layer signaling, and may include, for example, the following CSI resources.

[0352] - CSI-IM resources for interference measurement

[0353] - NZP CSI-RS resources for interference measurement

[0354] - NZP CSI-RS resources for channel measurement

[0355] For CSI-RS resource sets associated with a resource setting where the upper-level parameter resourceType is set to 'Aperiodic', 'Periodic', or 'Semi-permanent', the Trigger State for a CSI reporting setting where reportType is set to 'Aperiodic' and the resource setting for channel or interference measurements for one or more component cells (CC) can be set as the upper-level parameter CSI-AperiodicTriggerStateList.

[0356] Non-periodic CSI reporting of the terminal can be performed using PUSCH, periodic CSI reporting can be performed using PUCCH, and semi-permanent CSI reporting can be performed using PUSCH when triggered or activated by DCI, and using PUCCH after being activated by the MAC control element (MAC CE). As described above, CSI resource settings can also be configured as non-periodic, periodic, or semi-permanent. Combinations between CSI reporting settings and CSI resource settings can be supported based on Table 30 below.

[0357] [Table 30]

[0358]

[0359] Non-periodic CSI reporting can be triggered by the "CSI request" field of the aforementioned DCI format 0_1, which corresponds to the scheduling DCI for PUSCH. The terminal can monitor PDCCH, obtain DCI format 0_1, and obtain scheduling information and CSI request indicators for PUSCH. The CSI request indicator is N TSIt can be set to bits (=0, 1, 2, 3, 4, 5, or 6) and can be determined by the upper layer signaling (reportTriggerSize). One of the trigger states among one or more non-periodic CSI report trigger states that can be set by the upper layer signaling (CSI-AperiodicTriggerStateList) can be triggered by the CSI request indicator.

[0360] - If all bits of the CSI request field are 0, this may mean that a CSI report is not requested.

[0361] - If the number of CSI trigger states (M) in the configured CSI-AperiodicTriggerStateLite is greater than 2NTs-1, then M CSI trigger states can be mapped to 2NTs-1 according to the selected mapping relationship, and one of the trigger states of 2NTs-1 can be indicated as a CSI request field.

[0362] - If the number of CSI trigger states (M) in the configured CSI-AperiodicTriggerStateLite is less than or equal to 2NTs-1, one of the M CSI trigger states may be indicated as a CSI request field.

[0363] Table 31 below shows an example of the relationship between a CSI request indicator and a CSI trigger state that can be indicated by that indicator.

[0364] [Table 31]

[0365]

[0366] For a CSI resource within a CSI trigger state triggered by a CSI request field, the terminal can perform a measurement and generate a CSI therefrom (including at least one of the aforementioned CQI, PMI, CRI, SSBRI, LI, RI, or L1-RSRP, etc.). The terminal can transmit the acquired CSI using a PUSCH scheduled by the corresponding DCI format 0_1. When the 1 bit corresponding to the uplink data indicator (UL-SCH indicator) in DCI format 0_1 ​​indicates "1", the terminal can multiplex the uplink data (UL-SCH) and the acquired CSI and transmit them to the PUSCH resource scheduled by DCI format 0_1. When the 1 bit corresponding to the uplink data indicator (UL-SCH indicator) in DCI format 0_1 ​​indicates "0", the terminal can transmit by mapping only the CSI without the uplink data (UL-SCH) to the PUSCH resource scheduled by DCI format 0_1.

[0367] FIGS. 11 and FIGS. 12 are drawings for illustrating non-periodic CSI reporting methods according to a CSI-RS offset according to an embodiment of the present disclosure. FIG. 11 illustrates non-periodic CSI reporting methods when the CSI-RS offset is 0 according to an embodiment of the present disclosure. FIG. 12 illustrates a non-periodic CSI reporting method when the CSI-RS offset is 1 according to an embodiment of the present disclosure.

[0368] Referring to FIG. 11, the terminal can monitor PDCCH (1101) to obtain DCI format 0_1, from which it can obtain scheduling information and CSI request information for PUSCH (1105). The terminal can obtain resource information for CSI-RS (1102) to be measured from the received CSI request indicator. The terminal can determine at what point in time it should perform a measurement on the CSI-RS (1102) resource being transmitted based on the time it receives the DCI format 0_1 ​​and the parameter for the offset within the CSI resource set setting (e.g., the aperiodicTriggeringOffset described above) within the NZP CSI-RS resource set setting (NZP-CSI-RS-ResourceSet). More specifically, the terminal may receive the offset value X of the parameter aperiodicTriggeringOffset within the NZP-CSI-RS resource set setting as an upper layer signaling from the base station, and the set offset value X may represent the offset between the slot in which the DCI triggering the aperiodic CSI report is received and the slot in which the CSI-RS resource is transmitted. For example, the aperiodicTriggeringOffset parameter value and the offset value X may have a mapping relationship as described in Table 32 below.

[0369] [Table 32]

[0370]

[0371] Referring to FIG. 11, the aforementioned offset value may be set to X=0. In this case, the terminal may receive CSI-RS (1102) in a slot (corresponding to slot 0 in FIG. 11) that receives DCI format 0_1, which triggers a non-periodic CSI report, and may report the CSI information measured by the received CSI-RS to the base station via PUSCH (1105). The terminal may obtain scheduling information for PUSCH (1105) for CSI reporting (information corresponding to each field of the aforementioned DCI format 0_1) from DCI format 0_1. For example, the terminal may obtain information about the slot to transmit PUSCH (1105) from the aforementioned time domain resource allocation information for PUSCH (1105) in DCI format 0_1. In one example of FIG. 11, the terminal obtains a K2 value corresponding to the slot offset value for PDCCH-to-PUSCH as 3, and accordingly, at the time when PUSCH (1105) receives PDCCH (1101), it can be transmitted from slot 3 (1109), which is 3 slots away from slot 0 (1106).

[0372] In one example of FIG. 12, the terminal can monitor the PDCCH (1201) to obtain DCI format 0_1, from which it can obtain scheduling information and CSI request information for PUSCH (1205). The terminal can obtain resource information for the CSI-RS (1202) to be measured from the received CSI request indicator. One example of FIG. 12 shows an example in which the offset value for the aforementioned CSI-RS is set to X=1. In this case, the terminal can receive the CSI-RS (1202) in the slot (corresponding to slot 1 (1207) in FIG. 12) that received the DCI format 0_1 ​​triggering a non-periodic CSI report, and can report the CSI information measured by the received CSI-RS to the base station via PUSCH (1205).

[0373] Next, we will explain in detail the Bandwidth Part (BWP) settings in the 5G communication system.

[0374] FIG. 13 illustrates the configuration of a bandwidth part in a 5G communication system according to one embodiment of the present disclosure.

[0375] Referring to FIG. 13, the terminal bandwidth (UE bandwidth) (1300) can be configured into two bandwidth parts, namely Bandwidth Part #1 (BWP#1) (1301) and Bandwidth Part #2 (BWP#2) (1302). The base station may configure one or more bandwidth parts for the terminal and may configure the information in Table 33 below for each bandwidth part. Of course, it is not limited to the following examples.

[0376] [Table 33]

[0377]

[0378] The above information can be transmitted by the base station to the terminal via upper-layer signaling, for example, Radio Resource Control (RRC) signaling. Among one or more configured bandwidth parts, at least one bandwidth part may be activated. Whether a configured bandwidth part is activated can be transmitted quasi-statically from the base station to the terminal via RRC signaling or dynamically via Downlink Control Information (DCI).

[0379] Prior to the RRC (Radio Resource Control) connection, the terminal can receive the Initial Bandwidth Part (Initial BWP) for initial connection from the base station via the MIB (Master Information Block). More specifically, during the initial connection phase, the terminal can receive configuration information regarding the Control Resource Set (CORESET) and Search Space via the MIB, through which the Physical Downlink Control Channel (PDCCH) can be transmitted to receive the system information required for initial connection (Remaining System Information; which may correspond to RMSI or System Information Block 1; SIB1). The Control Resource Set and Search Space configured via the MIB can each be regarded as Identity (ID) 0. The base station can notify the terminal via the MIB of configuration information, such as frequency allocation information, time allocation information, and numerology, for Control Resource Set #0. In addition, the base station may notify the terminal via the MIB of configuration information regarding the monitoring period and occasion for control area #0, i.e., configuration information for search area #0. The terminal may regard the frequency area set as control area #0 obtained from the MIB as an initial bandwidth part for initial access. At this time, the identifier (ID) of the initial bandwidth part may be considered as 0.

[0380] The settings for the bandwidth part supported by the above 5G can be used for various purposes.

[0381] According to one embodiment, if the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through the bandwidth part setting. For example, by setting the frequency location of the bandwidth part (setting information 2) to the terminal, the terminal can transmit and receive data at a specific frequency location within the system bandwidth.

[0382] For the purpose of supporting different numerologies, a base station may set multiple bandwidth parts for a terminal. For example, to support data transmission and reception using both a 15 kHz subcarrier interval and a 30 kHz subcarrier interval for a terminal, two bandwidth parts may be set to subcarrier intervals of 15 kHz and 30 kHz, respectively. Different bandwidth parts may be frequency division multiplexed, and when data transmission and reception is to be performed with a specific subcarrier interval, the bandwidth part set to that subcarrier interval may be activated.

[0383] In addition, for the purpose of reducing the power consumption of the terminal, the base station may set bandwidth parts with different bandwidth sizes for the terminal. For example, if the terminal supports a very large bandwidth of 100 MHz and always transmits and receives data using that bandwidth, very large power consumption may occur. In particular, in a situation where there is no traffic, monitoring unnecessary downlink control channels using a large bandwidth of 100 MHz can be very inefficient in terms of power consumption. To reduce the power consumption of the terminal, the base station may set a bandwidth part with a relatively small bandwidth, for example, a bandwidth part of 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth part, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth part according to the instructions of the base station.

[0384] In the method for configuring the above bandwidth part, terminals prior to RRC connection (Connected) can receive configuration information for the Initial Bandwidth Part through the Master Information Block (MIB) during the initial connection phase. More specifically, the terminal can receive a Control Resource Set (CORESET) for a downlink control channel through which Downlink Control Information (DCI) scheduling System Information Blocks (SIB) can be transmitted from the MIB of the Physical Broadcast Channel (PBCH). The bandwidth of the control resource set by the MIB can be considered as the Initial Bandwidth Part, and through the configured Initial Bandwidth Part, the terminal can receive the Physical Downlink Shared Channel (PDSCH) through which SIBs are transmitted. In addition to receiving SIBs, the Initial Bandwidth Part may also be utilized for Other System Information (OSI), paging, and Random Access.

[0385] When one or more bandwidth parts are set for a terminal, the base station may instruct the terminal to change the bandwidth part using the Bandwidth Part Indicator field within the DCI. For example, referring to FIG. 13, if the currently active bandwidth part of the terminal is Bandwidth Part #1 (1301), the base station may instruct the terminal to Bandwidth Part #2 (1302) using the Bandwidth Part Indicator within the DCI, and the terminal may perform a bandwidth part change to Bandwidth Part #2 (1302) indicated by the received Bandwidth Part Indicator within the DCI.

[0386] As mentioned above, since DCI-based bandwidth part changes can be directed by a DCI that schedules a PDSCH or PUSCH (Physical Uplink Shared Channel), when a terminal receives a request to change a bandwidth part, it must be able to receive or transmit the PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth part. To this end, the standard specifies requirements for the delay time (TBWP) required when changing a bandwidth part, which can be defined, for example, as shown in Table 34 below.

[0387] [Table 34]

[0388]

[0389] The requirements for bandwidth part change delay time support Type 1 or Type 2 depending on the terminal's capability. The terminal can report the supported bandwidth part delay time type to the base station.

[0390] In accordance with the requirements for the aforementioned bandwidth part change delay time, when a terminal receives a DCI containing a bandwidth part change indicator in slot n, the terminal can complete the change to the new bandwidth part indicated by the bandwidth part change indicator at a time not later than slot n + TBWP, and can perform transmission and reception for the data channel scheduled by the corresponding DCI in the changed new bandwidth part. When the base station intends to schedule a data channel to the new bandwidth part, it may determine the time domain resource allocation for the data channel by considering the terminal's bandwidth part change delay time (TBWP). That is, when the base station schedules a data channel to the new bandwidth part, in the method of determining the time domain resource allocation for the data channel, it may schedule the data channel after the bandwidth part change delay time. Accordingly, the terminal may not expect the DCI indicating the bandwidth part change to indicate a slot offset (K0 or K2) value smaller than the bandwidth part change delay time (TBWP).

[0391] If a terminal receives a DCI (e.g., DCI format 1_1 or 0_1) instructing a change in the bandwidth part, the terminal may not perform any transmission or reception during a time interval corresponding to the time interval from the third symbol of the slot in which the PDCCH containing the said DCI was received to the beginning of the slot indicated by the slot offset value (K0 or K2) indicated by the time domain resource allocation indicator field within the said DCI. For example, if a terminal receives a DCI instructing a change in the bandwidth part in slot n, and the slot offset value indicated by the said DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0392] Next, we will explain how to set transmission and reception related parameters for each bandwidth part in 5G.

[0393] A terminal may receive one or more bandwidth parts from a base station, and may additionally receive parameters to be used for transmission and reception (e.g., uplink data channel and control channel related setting information, etc.) for each configured bandwidth part. For example, referring to FIG. 13, when a terminal receives bandwidth part #1 (1301) and bandwidth part #2 (1302), the terminal may receive transmission / reception parameter #1 for bandwidth part #1 (1301) and transmission / reception parameter #2 for bandwidth part #2 (1302). When bandwidth part #1 (1301) is activated, the terminal can perform transmission and reception with the base station based on transmission / reception parameter #1, and when bandwidth part #2 (1302) is activated, the terminal can perform transmission and reception with the base station based on transmission / reception parameter #2.

[0394] More specifically, the following parameters can be set from the base station to the terminal.

[0395] First, regarding the uplink bandwidth part, the information in Table 35 below can be set.

[0396] [Table 35]

[0397]

[0398]

[0399] According to [Table 35], the terminal may receive cell-specific (or cell-common or common) transmission-related parameters from the base station (e.g., parameters related to Random Access Channel (RACH), Physical Uplink Control Channel (PUCCH), and Physical Uplink Shared Channel) (corresponding to BWP-UplinkCommon). Additionally, the terminal may receive terminal-specific (or dedicated) transmission-related parameters from the base station (e.g., parameters related to PUCCH, PUSCH, Configured Grant PUSCH, and Sounding Reference Signal (SRS)) (corresponding to BWP-UplinkDedicated).

[0400] Next, regarding the downlink bandwidth part, information according to Table 36 below can be set.

[0401] [Table 36]

[0402]

[0403]

[0404] According to [Table 36], the terminal may receive cell-specific (or cell-common or common) reception-related parameters from the base station (e.g., parameters related to the Physical Downlink Control Channel (PDCCH) and Physical Downlink Shared Channel) (corresponding to BWP-DownlinkCommon). Additionally, the terminal may receive terminal-specific (or dedicated) reception-related parameters from the base station (e.g., parameters related to PDCCH, PDSCH, Semi-persistent Scheduled PDSCH, and Radio Link Monitoring (RLM)) (corresponding to BWP-UplinkDedicated).

[0405] Below, we will explain in detail the DRX (Discontinuous Reception) settings in a 5G communication system.

[0406] FIG. 14 illustrates Discontinuous Reception (DRX) in a 5G communication system according to one embodiment of the present disclosure.

[0407] DRX is an operation in which a terminal using a service receives data discontinuously while in an RRC connected state, where a wireless link is established between the base station and the terminal. When DRX is applied, the terminal can turn on the receiver at specific points to monitor the control channel, and turn off the receiver if no data is received for a certain period to reduce the terminal's power consumption. The DRX operation can be controlled by a MAC layer device based on various parameters and timers.

[0408] Referring to FIG. 14, Active time (1405) is the time during which the terminal wakes up at every DRX cycle to monitor the PDCCH. Active time (1405) can be defined as follows.

[0409] - drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or ra-ContentionResolutionTimer is running; or

[0410] - a Scheduling Request is sent on PUCCH and is pending; or

[0411] - a PDCCH indicating a new transmission addressed to the C-RNTI of the MAC entity has not been received after successful reception of a Random Access Response for the Random Access Preamble not selected by the MAC entity among the contention-based Random Access Preamble

[0412] drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, ra-ContentionResolutionTimer, etc. are timers whose values ​​are set by the base station, and may include a function to set the terminal to monitor the PDCCH when certain conditions are satisfied.

[0413] drx-onDurationTimer (1415) may be a parameter for setting the minimum time the terminal stays awake in a DRX cycle. drx-InactivityTimer (1420) may be a parameter for setting the additional time the terminal stays awake when receiving a PDCCH (1430) instructing a new uplink transmission or downlink transmission. drx-RetransmissionTimerDL may be a parameter for setting the maximum time the terminal stays awake to receive a downlink retransmission in a downlink HARQ procedure. drx-RetransmissionTimerUL may be a parameter for setting the maximum time the terminal stays awake to receive an uplink retransmission grant in an uplink HARQ procedure. drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, and drx-RetransmissionTimerUL may be set as, for example, time, number of subframes, number of slots, etc. ra-ContentionResolutionTimer can be a parameter for monitoring PDCCH in a random access procedure.

[0414] The inActive time (1410) is a time during which the PDCCH is not monitored or / or the PDCCH is not received during the DRX operation, and the remaining time after subtracting the Active time (1405) from the total time of performing the DRX operation may be the inActive time (1410). If the terminal does not monitor the PDCCH during the Active time (1405), it may enter a sleep or inActive state to reduce power consumption.

[0415] The DRX cycle can refer to the period during which a terminal wakes up and monitors the PDCCH. In other words, it can refer to the time interval or on-duration occurrence cycle between when the terminal monitors a PDCCH and when it monitors the next PDCCH. There are two types of DRX cycles: short DRX cycle and long DRX cycle. The short DRX cycle can be applied optionally.

[0416] Long DRX cycle (1425) is the longer of the two DRX cycles set in the terminal. While operating as Long DRX, the terminal can restart drx-onDurationTimer (1415) at a point where Long DRX cycle (1425) has elapsed from the starting point (e.g., start symbol) of drx-onDurationTimer (1415). When operating as Long DRX cycle (1425), the terminal can start drx-onDurationTimer (1415) in a slot after drx-SlotOffset in a subframe satisfying [Equation 2] below. Here, drx-SlotOffset may represent a delay before starting drx-onDurationTimer (1415). drx-SlotOffset may be set to, for example, time, number of slots, etc.

[0417] [Mathematical Formula 2]

[0418]

[0419] At this time, drx-LongCycleStartOffset may include Long DRX cycle (1525) and drx-StartOffset, and may be used to define the subframe to start Long DRX cycle (1425). For example, drx-LongCycleStartOffset may be set to time, number of subframes, number of slots, etc.

[0420] A short DRX cycle may be the shorter of the two DRX cycles defined in the terminal. The terminal may operate in a long DRX cycle (1425), and when a specific event occurs during the active time (1405), such as receiving a PDCCH (1430) instructing a new uplink transmission or downlink transmission, it may start or restart the drx-InactivityTimer (1420), and if the drx-InactivityTimer (1420) expires or a DRX command MAC CE is received, it may operate in a short DRX cycle. For example, in FIG. 14, the terminal may start the drx-ShortCycleTimer at the time of the previous drx-onDurationTimer (1415) or drx-InactivityTimer (1420) expiration, and operate in a short DRX cycle until the drx-ShortCycleTimer expires. When the terminal receives a PDCCH (1430) instructing a new uplink transmission or downlink transmission, it may extend the Active Time (1405) or delay the arrival of the InActive Time (1410) in anticipation of additional uplink transmission or downlink transmission in the future. While the terminal is operating in short DRX, it may start the drx-onDurationTimer (1415) again at a time when a short DRX cycle has elapsed from the start of the previous On duration. After that, when the drx-ShortCycleTimer expires, the terminal may operate in Long DRX cycle (1425) again.

[0421] When operating in a short DRX cycle, the terminal may start drx-onDurationTimer (1415) after drx-SlotOffset in a subframe satisfying [Equation 3] below. Here, drx-SlotOffset represents a delay before starting drx-onDurationTimer (1415). For example, drx-SlotOffset can be set to time, the number of slots, etc.

[0422] [Mathematical Formula 3]

[0423]

[0424] Here, drx-ShortCycle and drx-StartOffset can be used to define the subframe to start the Short DRX cycle. drx-ShortCycle and drx-StartOffset can be set, for example, to time, number of subframes, number of slots, etc.

[0425] Up to this point, the DRX operation has been described with reference to FIG. 14. According to one embodiment, the terminal can reduce the power consumption of the terminal by performing the DRX operation. However, even if the terminal performs the DRX operation, the terminal does not always receive the PDCCH associated with the terminal during Active Time (1405). Therefore, in one embodiment of the present disclosure, a signal controlling the operation of the terminal can be provided to save the power of the terminal more efficiently.

[0426] In 5G systems, a new terminal state called RRC_INACTIVE has been defined to reduce the energy and time consumed for the initial access of terminals. In addition to the operations performed by RRC_IDLE terminals, RRC_INACTIVE terminals can perform the following processes. Of course, they are not limited to the examples below.

[0427] - Stores AS (Access stratum) information required for cell access

[0428] - Terminal-specific DRX cycle operation set by the RRC layer

[0429] - Configure RNA (RAN (radio access network)-based notification area) that can be utilized during handover by the RRC layer and perform periodic updates.

[0430] - Monitoring RAN-based paging messages transmitted via I-RNTI (inactive-radio network temporary identifier)

[0431] A terminal in the RRC_CONNECTED state can change from the RRC_CONNECTED state to the RRC_INACTIVE or RRC_IDLE state upon receiving an RRC Release instruction from the base station.

[0432] A terminal in the RRC_INACITVE or RRC_IDLE state can change from the RRC_INACTIVE or RRC_IDLE state to the RRC_CONNECTED state by performing random access and completing all random access procedures.

[0433] A scheduling method is described below in which a base station transmits downlink data to a terminal or instructs the terminal to transmit uplink data.

[0434] Downlink Control Information (DCI) may be control information transmitted by a base station to a terminal via the downlink. Downlink Control Information may include downlink data scheduling information or uplink data scheduling information for a specific terminal. Generally, the base station may perform channel coding for the DCI independently for each terminal and then transmit it to each terminal via the Physical Downlink Control Channel (PDCCH), which is a downlink physical control channel.

[0435] A base station may operate by applying a predetermined DCI format to a terminal to be scheduled, depending on the purpose, such as whether it is scheduling information for downlink data (downlink assignment), scheduling information for uplink data (uplink grant), or DCI for power control.

[0436] The base station can transmit downlink data to the terminal via the Physical Downlink Shared Channel (PDSCH), which is a physical channel for transmitting downlink data. The base station can provide the terminal with scheduling information, such as specific mapping locations in the time and frequency domains of the PDSCH, modulation schemes, HARQ-related control information, and power control information, through the DCIs related to downlink data scheduling information among the DCIs transmitted via the PDSCH.

[0437] The terminal can transmit uplink data to the base station via the PUSCH (Physical Uplink Shared Channel), which is a physical channel for uplink data transmission. The base station can provide the terminal with scheduling information, such as specific mapping locations in the time and frequency domains of the PUSCH, modulation schemes, HARQ-related control information, and power control information, through the DCI related to uplink data scheduling information among the DCIs transmitted via the PDCCH.

[0438] For the RRC_IDLE / RRC_INACTIVE terminal, the aforementioned DRX operation is performed, and a paging message can be received. The terminal can monitor one Paging Occasion (PO) during the DRX cycle. The PO may be a set of PDCCH monitoring occasions and may include multiple time slots (or subframes, or OFDM symbols) in which paging control information can be transmitted and received. The Paging Frame (PF) may be a single radio frame (10ms) and may include one or more POs or the start point of the PO (e.g., an offset).

[0439] PF and PO can be determined by the following formulas.

[0440] The System Frame Number (SFN) for the PF can be determined by (SFN + PF_offset) mod T = (T div N) * (UE_ID mod N), where PF_offset is an offset for determining the PF, T is a DRX cycle, and N is the number of PFs per DRX cycle (e.g., cell common, cell specific), which can be determined by a higher signal such as system information, and UE_ID is a terminal ID (e.g., 5G-S-TMSI), which can be determined by the core network.

[0441] The PFs determined by N may refer to paging frames that are commonly applied to terminals within a cell, and may be referred to as cell common PFs for convenience.

[0442] i_s, which indicates the PO index, can be determined by i_s = floor (UE_ID / N) mod Ns, where Ns can represent the number of POs in a single PF and can be determined by higher signals such as system information.

[0443] For example, assuming PF_offset=3, T=128, N=T / 4=32, Ns=4, UE_ID mod 32 is 1, and floor(UE_ID / 32) mod 4 is 1, the parameter values ​​can be determined by the following formula.

[0444] (SFN + 3) mod 128 = (128 div 32)*(UE_ID mod 32) = 4*1 = 4,

[0445] i_s = floor (UE_ID / 32) mod 4 = 1

[0446] Therefore, the paging frame PF that a terminal with the above UE_ID must receive can be determined as a radio frame with SFN 1, 129, 257, ... among the cell common PFs, and the PO can be determined as the (i_s + 1)th PO among the 4 POs within the PF.

[0447] The reception of PEI (Paging Early Indication) is described in more detail below. In order to reduce terminal power consumption while monitoring and receiving the paging control channel and paging data channel in every DRX cycle, the terminal may receive PEI.

[0448] According to various embodiments of the present disclosure, a terminal may monitor or receive a PEI Occasion (PEI-O) once before receiving paging during a DRX cycle. When the terminal receives a PEI and the PEI indicates a subgroup and paging occasion to which the terminal belongs, the terminal belonging to the subgroup may monitor the associated paging occasion (PO). If the terminal does not detect the PEI in the PEI occasion, or if the PEI does not indicate a subgroup and paging occasion to which the terminal belongs, the terminal does not need to monitor the associated paging occasion (PO), thereby reducing terminal power consumption.

[0449] The terminal can determine the PEI occlusion as follows. The PEI occlusion may be located backward by a subframe offset relative to the radio frame of a reference point that is located forward by pei-FrameOffset relative to the PF containing the associated PO. The terminal can monitor the PEI at the PEI occlusion determined by the above method. Here, pei-FrameOffset, subframe offset, etc., may be determined by higher-level signals such as system information.

[0450] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The contents of the present disclosure are applicable to FDD, TDD and / or XDD (and / or SBFD, full duplex) systems. In the present disclosure, upper signaling (or upper layer signaling) is a signal transmission method transmitted from a base station to a terminal using a physical layer downlink data channel, or from a terminal to a base station using a physical layer uplink data channel, and may be referred to as RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC control element; MAC CE).

[0451] For convenience in the following description of the present disclosure, cells, transmission points, panels, beams, and / or transmission directions that can be distinguished through upper layer / L1 parameters such as TCI state or spatial relation information, or indicators such as cell ID, TRP ID, and panel ID, may be described uniformly as TRP (transmission reception point), beam, or TCI state. Accordingly, when applying the present disclosure in practice, TRP, beam, or TCI state may be appropriately replaced with one of the above terms.

[0452] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, gNB, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. Although embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and mobile communication technologies developed after 5G may be included therein. Accordingly, embodiments of the present disclosure may be applied to other communication systems with some modifications, provided that they do not deviate significantly from the scope of the present disclosure, in the judgment of a person skilled in the art. The contents of the present disclosure are applicable to FDD, TDD, XDD (or SBFD, full duplex) systems.

[0453] Furthermore, in describing the present disclosure, if it is determined that a detailed description of related functions or configurations could unnecessarily obscure the essence of the present disclosure, such detailed description is omitted. Additionally, the terms described below are defined in consideration of their functions within the present disclosure, and these definitions may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0454] In describing the present disclosure below, the term "upper layer signaling" may refer to a signaling corresponding to at least one or a combination of at least one of the following signalings.

[0455] - MIB (Master Information Block)

[0456] - SIB (System Information Block) or SIB

[0457] - RRC (Radio Resource Control)

[0458] - MAC (Medium Access Control) CE (Control Element)

[0459] In addition, L1 signaling may be a signaling corresponding to at least one or a combination of at least one of the following physical layer channels or signaling methods using signaling.

[0460] - PDCCH (Physical Downlink Control Channel)

[0461] - DCI (Downlink Control Information)

[0462] - Terminal-specific (UE-specific) DCI

[0463] - Group common DCI

[0464] - Common DCI

[0465] - Scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data)

[0466] - Non-scheduling DCI (e.g., DCI not intended for scheduling downlink or uplink data)

[0467] - PUCCH (Physical Uplink Control Channel)

[0468] - UCI (Uplink Control Information)

[0469] The term "slot" used in the present disclosure below is a general term that may refer to a specific time unit corresponding to TTI (Transmit Time Interval), and specifically, it may refer to a slot used in a 5G NR system, or a slot or subframe used in a 4G LTE system.

[0470] <1st Embodiment>

[0471] The first embodiment relates to a joint framework of DL-RS (e.g., CSI-RS) and UL-RS (e.g., SRS). In this embodiment, CSI-RS is set as the representative DL-RS and SRS is set as the representative UL-RS for description, and RSs other than CSI-RS or SRS may also be used in the joint framework.

[0472] The joint framework for CSI-RS and SRS enables base stations to obtain more sophisticated CSI information and derive a more precise DL precoder by additionally performing SRS / CSI feedback in addition to CSI feedback / SRS transmission. For example, in the case of TDD, a base station can calculate a sophisticated DL precoder solely through SRS reception. However, SRS has disadvantages such as high overhead, power imbalance issues between ports, and short coverage. Therefore, while cell center UEs can achieve good performance with full-port SRS transmission, cell edge UEs lack sufficient SRS coverage, necessitating a substitution with CSI-RS transmission and CSI feedback. However, CSI feedback may be less effective than SRS for obtaining channel information, such as codebook quantization errors. Thus, by utilizing CSI feedback information and SRS simultaneously, cell edge UEs can also assist base stations in obtaining more precise channel information.

[0473] There are two methods for utilizing the joint framework of CSI-RS and SRS: reusing existing resource sets or defining a new integrated resource set. The method of reusing existing resource sets may involve configuring resources for CSI-RS and SRS separately based on the RRC settings of each RS, triggering CSI-RS and SRS individually using separate settings, or configuring both CSI-RS and SRS with a single trigger. The method of defining a new integrated resource set may involve existing RRC settings for the integrated resource set, where resources for CSI-RS and SRS are configured based on those settings, or where both CSI-RS and SRS are configured with a single trigger.

[0474] Figure 15 is a diagram showing the timeline for the joint framework for CSI-RS and SRS.

[0475] Referring to FIG. 15, according to one embodiment, in operation 1510, the base station (1501) may provide an RRC configuration for CSI-RS and SRS to the terminal (1502). For example, the detailed settings of this RRC configuration may vary depending on whether an existing resource set is reused or a new integrated resource set is utilized. However, the method regarding the detailed settings of the RRC configuration is not limited to this.

[0476] According to one embodiment, a base station may transmit periodic or semi-persistent CSI-RS / SRS according to operation 1510. A terminal may receive CSI-RS according to operation 1512. A terminal may transmit SRS according to operation 1513.

[0477] According to one embodiment, when RSs are transmitted aperiodicly, each RS may be triggered based on DCI or MAC-CE, or a procedure according to operation 1512 and operation 1513 may be triggered through a joint trigger.

[0478] According to one embodiment, the transmission of CSI-RS and SRS may be transmitted periodically or non-periodically. For example, the transmission of CSI-RS and SRS may be transmitted periodically. Or the transmission of CSI-RS and SRS may be transmitted non-periodically. Or CSI-RS may be transmitted periodically and SRS may be transmitted non-periodically. Or CSI-RS may be transmitted non-periodically and SRS may be transmitted periodically. However, it is not limited to the examples described above. Also, in one embodiment, a trigger may be transmitted immediately before the RS that is transmitted non-periodically. For example, if CSI-RS is transmitted periodically and SRS is transmitted non-periodically, operation 1511 may be performed after operation 1512. Also, the CSI-RS according to operation 1512 may be transmitted after operation 1513.

[0479] According to one embodiment, when utilizing only SRS for sophisticated DL precoder calculation, the terminal previously transmitted SRS by switching antennas equal to the number of DL receiving antennas through the usage of antenna switching for SRS. For example, if the terminal's capability is 1T4R (capable of transmitting UL with one antenna and receiving DL with four antennas), it transmitted SRS by switching four antennas. However, when transmitting CSI feedback and SRS together, the terminal can transmit K partial ports instead of antenna switching a full port in operation 1513. For example, if there is power imbalance between ports and a port with high power loss transmits SRS, the SNR may be low, which may degrade the base station's channel estimation performance. To resolve this, the terminal can select only K ports with low power loss among the full ports to transmit SRS.

[0480] According to one embodiment, if a terminal selects only K ports with low power loss among full ports to transmit SRS, the base station may not know channel information for ports that do not transmit SRS. To compensate for this, the terminal can inform the base station of channel information for the relevant ports through CSI feedback, and a per-port PMI can be defined as the new report quantity instead of the existing PMI-based report quantity. Codebook-based PMI is determined based on the channel's eigenvectors, determines the rank through an internal metric, and can report to the base station vectors found within the codebook that are close to the eigenvectors. Since the purpose of the joint framework of CSI-RS and SRS is to obtain a more sophisticated explicit CSI, the terminal can send a rank 1 PMI per port to the base station instead of a rank-based PMI. For example, in 1T4R where K=2, two rank 1 PMIs can be sent for the two ports that do not transmit SRS.

[0481] According to one embodiment, to prevent channel aging between ports, the SRS according to operation 1513 and the CSI feedback according to operation 1514 may need to be transmitted to the base station almost simultaneously. Since the minimum time interval between CSI-RS and CSI feedback is defined by the CSI processing time, SRS transmission may need to be performed accordingly. Therefore, a requirement for a maximum time for SRS transmission based on CSI-RS or CSI feedback may be required. For example, the SRS may need to be transmitted in the same slot as the PUCCH or PUSCH transmitting the CSI feedback, or at least within a specific slot offset. Alternatively, if SBFD is considered, since UL transmission is possible in the DL slot as well, the SRS may be transmitted in the DL slot adjacent to the time of CSI-RS reception or CSI feedback.

[0482] In one embodiment, when CSI-RS and SRS have a joint framework, an existing resource set may be shared or a new integrated resource set may be defined for CSI-RS and SRS, and RRC messages for these two methods are described.

[0483] Figure 16 is a diagram of an RRC message for operating a joint framework that shares an existing resource set for CSI-RS and SRS.

[0484] According to one embodiment, when an existing resource set is shared for CSI-RS and SRS, a separate configuration may exist for each RS. For example, in NR, CSI-ReportConfig (1601) is configured for CSI-RS at the terminal, and CSI-ReportConfig (1601) may contain an ID for a CSI-ResourceConfig (1602) or information for a reportQuantity (1611).

[0485] In one embodiment, for parts requiring CSI feedback in addition to SRS transmission, if the CSI feedback is based on the existing codebook method, the reportQuantity (1611) uses the existing PMI reporting method. If CSI reporting is performed for a port other than the SRS transmission port, a per port PMI (1612) may be defined in the reportQuantity (1611). In addition to the per port PMI, alternative feedback using CSI compression may also be considered. Furthermore, a per port phase difference may be included in the CSI reporting. The per port phase difference may be a phase difference between the channel and the PMI estimated by the terminal via CSI-RS, or it may be a phase difference that occurs due to the difference between the time of CSI-RS reception and the time of SRS transmission.

[0486] According to one embodiment, since the base station can only recognize the channel direction of the corresponding port with the per port PMI (1612), the base station can be informed of the channel direction as well as the size by additionally transmitting the per port CQI (1613).

[0487] In one embodiment, CSI-ResourceConfig (1602) may include information for one or more NZP-CSI-RS-ResourceSets, CSI-IM-ResourceSets, and CSI-SSB-ResourceSets. Here, since the purpose is for the terminal to transmit PMI in some form through channel estimation, information for NZP-CSI-RS-ResourceSets may be indicated. Through the NZP-CSI-RS-ResourceSet (1603) indicated in CSI-ResourceConfig (1602), the terminal is indicated for an ID for the NZP-CSI-RS-Resource (1604 or 1605) to perform CSI feedback, and can finally obtain information for the NZP-CSI-RS-Resource. Here, for joint operation with a specific CSI-RS and SRS, the associatedSRS-ResourceSet (1614) may indicate which SRS resource or which SRS resource set the corresponding CSI-RS is associated with. For example, by pointing to the associated SRS-ResourceSet (1614) within the NZP-CSI-RS-ResourceSet (1603) of the NZP-CSI-RS-ResourceSet, the CSI-RS can be received and then used to transmit SRS through the associated SRS resource set.

[0488] According to one embodiment, SRS-Config (1621) indicates an ID for an SRS resource set, and an ID for an SRS resource can be indicated through an SRS-ResourceSet (1622) corresponding to that ID. Finally, information about an SRS-Resource (1623) can be obtained. Similar to the associated SRS-ResourceSet (1614), the terminal can be informed of which CSI-RS resource set or CSI-RS resource is associated with the corresponding SRS resource set. A partial SRS-Resource (1631) can be configured by considering both joint operations and independent operations. When a partial SRS-Resource (1631) is configured, SRS can be transmitted through K SRS resources. When a partial SRS-Resource (1631) is configured, SRS can be transmitted through all SRS resources. This can be considered together with the reportQuantity (1611). For example, if CSI reporting is requested with an existing report quantity in reportQuantity (1611), the SRS may be transmitted through the entire SRS resource, ignoring the port defined in partialSRS-Resource (1631). However, if Per port PMI & per pory phase difference (1612) and / or Per port CQI (1613) are set in reportQuantity (1611), the SRS may be transmitted through K SRS resources set in partialSRS-Resource (1631).

[0489] Figure 17 is a diagram of an RRC message for operating a joint framework that shares an existing resource set for non-periodic CSI-RS and SRS.

[0490] Referring to FIG. 17, according to one embodiment, a base station may set additional RRC parameters for integrated TCI-state settings within CSI-RS resource settings during the RRC setting process of a specific terminal. The base station may set additional parameters using at least one of CSI-AperiodicTriggerState (1701) and CSI-AssociatedReportConfigInfo (1703) during the RRC setting process. During the RRC setting process, the base station may set at least one of CORESETPoolindex and followUnifiedTCI-State, which are parameters for integrated TCI-state settings within CSI-AperiodicTriggerStateList or CSI-AperiodicTriggerState, to the terminal, thereby configuring the CORESETPoolindex corresponding to the TRP to associate the CSI-RS resource with the CSI-RS resource. For example, the base station may set coresetPoolIndex-r18 corresponding to TRP1 and TRP2 in CSI-AperiodicTriggerState to 0 or 1 for the terminal. Additionally, the base station may select followUnifiedTCI-State-r18 as either first or second to set multiple unified TCI states in CSI-AperiodicTriggerState to the terminal. In one embodiment, if followUnifiedTCI-State-r18 is set to first, the terminal may apply the value of qcl-info or TCI-stateId of the NZP-CSI-RS resource Set set in resourcesForChannel (1706) within CSI-AssociatedReportConfigInfo (1703).In one embodiment, when followUnifiedTCI-State-r18 is set to second, the terminal may apply the value of qcl-info or TCI-stateId of the NZP-CSI-RS resource set set in resourcesForChannel2 within CSI-AssociatedReportConfigInfo. In one embodiment, nzp-CSI-RS (1711) indicated in resourcesForChannel (1706) indicates NZP-CIS-RS-Resource (1710) indicated in CSI-ResourceConfig (1707). In one embodiment, to specify an SRS resource set associated with a CSI-RS resource, associatedSRS-ResourceSet (1712) is indicated in resourcesForChannel (1706), and the SRS resource set indicated therein may indicate an SRS-ResourceSet (1722) in SRS-Config (1721) or specific SRS-Resources in (1722).

[0491] Figure 18 is a diagram of an RRC message for a new integrated resource set to operate a joint framework for CSI-RS and SRS.

[0492] Referring to FIG. 18, according to one embodiment, joint-CSI-SRS-Config (1801) may be a top-level configuration for a new integrated resource set for CSI-RS and SRS. The joint-CSI-SRS-Config (1801) configuration may be configured by separating it into a common part and an RS-specific part based on existing CSI-RS and SRS configurations. In the common part, if the two RSs have periodicity, a period for the RS may be included, and if the RSs are non-periodic, a triggering mechanism, BWP association, etc. may be included.

[0493] According to one embodiment, configurations for RS-specific parts can be specified through SRS-Config (1802) or CSI-Config (1803), respectively. For example, in CSI-Config (1803), details related to the number of ports, cdm-Type, density, and CSI-RS mapping can be set, and in SRS-Config (1802), details related to the number of SRS ports, comb type, frequency hopping, sequence ID, and usage SRS mapping can be set.

[0494] According to one embodiment, a joint framework based on an integrated resource set can retrieve two resources at once with a single trigger in the case of aperiodic. To this end, a Joint-CSI-SRS-ResourceSet (1811) is configured, and an NZP-CSI-RS-Resource (1812) and an SRS-Resource (1813) may be indicated, respectively. In one embodiment, a unique ID for the joint resource set, a list of CSI-RS or SRS resources within the resource set, and usage may be indicated together in the Joint-CSI-SRS-ResourceSet (1811). In one embodiment, offset information for time / frequency axis offsets for the NZP-CSI-RS-Resource (1812) and the SRS-Resource (1813) may be indicated in the Joint-CSI-SRS-ResourceSet (1811).

[0495] Referring to FIG. 15, according to one embodiment, when triggering for aperiodic RS based on a joint framework timeline is directed through operation 1511, various considerations may exist. There may be separate requests for CSI-RS and SRS, or both resources may be triggered with a single request.

[0496] According to one embodiment, if separate requests exist for CSI-RS and SRS, for example, request fields for both SRS and CSI may exist through the DCI format 0_1 ​​of the NR. According to one embodiment, the SRS according to operation 1513 may need to be transmitted in close proximity to the CSI-RS according to operation 1512 or the CSI feedback according to operation 1514 under specific requirements. That is, the required time / frequency offset may be dynamically set. To this end, in the DCI format 0_1 ​​of the NR, the SRS may be transmitted at a distance of a specific slotOffset from the NZP-CSI-RS resource, limited to NonCodebook usage as shown in Table 37 below.

[0497] [Table 37]

[0498]

[0499] According to one embodiment, due to the characteristics of the Joint framework, this can be indicated through usage regarding antennaSwitching in addition to NonCodebook. Therefore, it can be extended to 'Cond NonCodebook or antennaSwitching', etc. However, it is not limited thereto.

[0500] According to one embodiment, an additional DCI field for the joint framework may be defined. For example, the Tx mode may indicate whether to transmit SRS to a full port or to K ports. In this case, although the resource set to be used is already defined by the RRC configuration, this can be indicated via DCI for dynamic operation. For example, if K port transmission is indicated, the transmission may be made to a port defined in advance by RRC, or by mapping it to K resources defined for a port with less power imbalance. Alternatively, it may be directly indicated which SRS resources to transmit for SRS transmission to K ports. That is, it may be indicated in the form of a bitmap proportional to the number of resources. For example, in the case of 1T4R, it may be transmitted as shown in Table 38 below.

[0501] [Table 38]

[0502]

[0503] According to one embodiment, a method for triggering both types of resources with a single trigger may be similar to a separate request instruction, and new DCI fields, etc., may all be available. One difference is that even if only one of the CSI request or SRS request is received, the associated-SRS / CSI can be defined in the corresponding RRC, and the joint framework can be operated through a combination with the reportQuantity.

[0504] Figure 19 is a diagram illustrating the operation of a base station requesting a non-periodic SRS port through a joint framework trigger.

[0505] According to one embodiment, the SRS can influence the channel estimation performance of a base station depending on the coverage. Therefore, the base station can measure the UL SINR while receiving the periodic SRS.

[0506] Referring to FIG. 19, according to one embodiment, in operation 1901, the base station has a UL SINR based on a specific standard (γ th You can determine whether it exceeds ).

[0507] According to one embodiment, in operation 1901, UL SINR is a specific criterion (γ th If it is greater than ), the base station may consider it a terminal of the cell center according to operation 1902 and not request additional AP-SRS.

[0508] According to one embodiment, in operation 1901, UL SINR is γ th If it is smaller, the base station may consider it a cell edge terminal according to operation 1903 and request AP-SRS for SRS ports with low SINR. At this time, the terminal may consider it a joint framework according to operation 1904, receive CSI-RS for ports that are not sent to AP-SRS, and send CSI feedback.

[0509] According to one embodiment, in the case of a request for a periodic SRS port rather than a request for a non-periodic SRS port, a periodic SRS may be requested to the full port in operation 1902. In one embodiment, when the joint framework is limited to a request for a non-periodic SRS port, a periodic SRS may be requested to the full port instead of an operation that does not request additional AP-SRS in operation 1902.

[0510] According to one embodiment, a joint resource set can coexist with existing independent CSI-RS and SRS transmissions. A priority rule may exist for the joint resource set. For example, if a conflict occurs between a joint resource set and a CSI-RS resource set, consideration may be given to which resource set should be prioritized. The joint resource set may be prioritized. Alternatively, the aperiodic resource set between the joint resource set and the CSI-RS resource set may be prioritized.

[0511] According to one embodiment, a priority rule may exist within a joint set. If a UE cannot receive and / or transmit both CSI-RS and SRS within a jointly triggered set (e.g., due to power limits or processing constraints), the terminal may need to define which joint set to prioritize. The option may determine priority based on usage parameters, set CSI-RS / SRS related to scheduling to the highest priority, or set a related priority order within the Joint-CSI-SRS-ResourceSet IE.

[0512] FIG. 20 illustrates a terminal transceiver device according to one embodiment of the present disclosure. For convenience of explanation, devices not directly related to the present disclosure may be omitted from illustration and description.

[0513] Referring to FIG. 20, the terminal may include a transmitter (2004) comprising an uplink transmission processing block (2001), a multiplexer (2002), and a transmission RF block (2003), a receiver (2008) comprising a downlink reception processing block (2005), a demultiplexer (2006), and a reception RF block (2007), and a control unit (2009). The control unit (2009) can control each of the constituent blocks of the receiver (2008) for receiving a data channel or control channel transmitted by the base station as described above, and each of the constituent blocks of the transmitter (2004) for transmitting an uplink signal.

[0514] In the transmission unit (2004) of the terminal, the uplink transmission processing block (2001) can generate a signal to be transmitted by performing processes such as channel coding and modulation. The signal generated in the uplink transmission processing block (2001) can be multiplexed with other uplink signals by a multiplexer (2002), then processed by a transmission RF block (2003), and then transmitted to a base station.

[0515] The terminal receiver (2008) demultiplexes the signal received from the base station and distributes it to each downlink reception processing block. The downlink reception processing block (2005) can obtain control information or data transmitted by the base station by performing processes such as demodulation and channel decoding on the downlink signal of the base station. The terminal receiver (2008) can support the operation of the control unit (2009) by applying the output result of the downlink reception processing block to the control unit (2009).

[0516] FIG. 21 is a block diagram of a terminal according to one embodiment of the present disclosure.

[0517] As illustrated in FIG. 21, the terminal of the present disclosure may include a processor (2130), a transceiver (2110), and a memory (2120). However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. Furthermore, the processor (2130), the transceiver (2110), and the memory (2120) may be implemented in the form of a single chip. According to one embodiment, the transceiver (2110) of FIG. 21 may include the transceiver (2004) and the receiver (2008) of FIG. 20. Additionally, the processor (2130) of FIG. 21 may include the control unit (2009) of FIG. 20.

[0518] According to one embodiment, the processor (2130) can control a series of processes that allow the terminal to operate according to the embodiments of the present disclosure described above. For example, according to the embodiments of the present disclosure, the components of the terminal can be controlled to perform a transmission and reception method of the terminal depending on whether the base station mode is a base station energy saving mode or a base station general mode. The processor (2130) may be one or a plurality of processors, and the processor (2130) can perform a transmission and reception operation of the terminal in a wireless communication system applying the carrier band of the present disclosure described above by executing a program stored in memory (2120).

[0519] The transceiver (2110) can transmit and receive signals with a base station. The signals transmitted and received with the base station may include control information and data. The transceiver (2110) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that amplifies a received signal with low noise and down-converts the frequency. However, this is merely one embodiment of the transceiver (2110), and the components of the transceiver (2110) are not limited to an RF transmitter and an RF receiver. Additionally, the transceiver (2110) can receive a signal through a wireless channel and output it to a processor (2130), and transmit the signal output from the processor (2130) through a wireless channel.

[0520] According to one embodiment, the memory (2120) may store programs and data necessary for the operation of the terminal. Additionally, the memory (2120) may store control information or data included in signals transmitted and received by the terminal. The memory (2120) may be composed of a storage medium or a combination of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, the memory (2120) may be a plurality of. According to one embodiment, the memory (2120) may store a program for performing the transmission and reception operation of the terminal depending on whether the base station mode, which is an embodiment of the present disclosure described above, is a base station energy saving mode or a base station general mode.

[0521] FIG. 22 is a block diagram of a base station according to one embodiment of the present disclosure.

[0522] As illustrated in FIG. 22, the base station of the present disclosure may include a processor (2230), a transceiver (2210), and a memory (2220). However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. In addition, the processor (2230), the transceiver (2210), and the memory (2220) may be implemented in the form of a single chip.

[0523] The processor (2230) can control a series of processes to enable the base station to operate according to the embodiments of the present disclosure described above. For example, according to the embodiments of the present disclosure, the components of the base station can be controlled to perform a method of scheduling a terminal depending on whether the base station mode is a base station energy saving mode or a base station general mode. The processor (2230) may be one or a plurality of processors, and the processor (2230) can perform the method of the present disclosure described above by executing a program stored in memory (2220).

[0524] The transceiver (2210) can transmit and receive signals with a terminal. The signals transmitted and received with the terminal may include control information and data. The transceiver (2210) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver (2210), and the components of the transceiver (2210) are not limited to an RF transmitter and an RF receiver. Additionally, the transceiver (2210) can receive a signal through a wireless channel and output it to a processor (2230), and transmit the signal output from the processor (2230) through a wireless channel.

[0525] According to one embodiment, the memory (2220) may store programs and data necessary for the operation of the base station. Additionally, the memory (2220) may store control information or data included in signals transmitted and received by the base station. The memory (2220) may be composed of a storage medium or a combination of storage media such as ROM, RAM, a hard disk, a CD-ROM, and a DVD. Additionally, there may be multiple memories (2220). According to one embodiment, the memory (2220) may store a program for performing the methods of the embodiments of the present disclosure described above.

[0526] In the following description, the base station is N BS One can consider a TDD system with multiple antennas, where the terminal is 1T4R (capable of UL transmission with one antenna and DL reception with four antennas). The downlink (DL) channel between the base station and the terminal is It can be expressed as a complex matrix of the form, where each row represents a channel coming from all antennas of the base station for one of the four antenna ports of the terminal, and the above expression may be based on the k-th subcarrier (k ∈ {1,2,...,K}).

[0527] According to one embodiment, according to the principle of channel reciprocity in a TDD system, UL channel and the downlink channel silver It may be related to. To estimate the DL channel based on UL SRS transmission, since the terminal can only use one antenna port at the time of UL transmission, it may be necessary to sequentially transmit SRS from each of the four antenna ports via antenna switching. The SRS signal transmitted for the k-th subcarrier from the UE's i-th antenna port. Regarding, the signal received at the base station (BS). It can be modeled by the following formula:

[0528]

[0529] Here, can represent the UL channel vectors from the i-th antenna port of the UE to all antennas of the BS for the k-th subcarrier, and It can represent additive white Gaussian noise.

[0530] In actual system environments, each antenna port of the UE may experience different levels of insertion loss during SRS transmission.

[0531] In the present disclosure, port power imbalance can be modeled as follows:

[0532]

[0533] Here, is the insertion loss coefficient corresponding to the i-th antenna port of the UE, and It can represent an ideal UL channel with no insertion loss. This port power imbalance can become a problem when combined with the inherent coverage limitations of the SRS.

[0534] For example, insertion loss is large (i.e., In the case of antenna ports with small values, the power strength of the transmitted SRS becomes excessively weak, making reliable channel restoration difficult.

[0535] Below, we examine a method to effectively obtain explicit and accurate downlink channel state information (DL CSI) despite port power imbalance occurring during the SRS transmission process.

[0536] According to one embodiment, insertion loss is low (i.e., For UE antenna ports with large values, reliable explicit DL CSI can be obtained by utilizing channel reciprocity through the existing SRS-based method.

[0537] According to one embodiment, the insertion loss is large (i.e., For antenna ports with small values, even if the base station (BS) has full channel estimation capabilities, it may be difficult to obtain a reliable explicit DL CSI because the quality of the received SRS is low.

[0538] In the present disclosure, the mean squared error between the reconstructed DL channel and the actual DL channel can be formulated as follows in a manner that minimizes the mean squared error.

[0539]

[0540] Here, Φ may be a Neural Network (NN) function that reflects CSI-related signal exchange between a base station (gNB) and a terminal (UE), and can be a reconfigured downlink channel, and can represent the actual downlink channel.

[0541] In this disclosure, a method for resolving port power imbalance through a hybrid transmission scheme is proposed. To address problems arising during the process of acquiring SRS-based DL channel status information (DL CSI), this disclosure may apply an artificial intelligence (AI)-based approach utilizing DL measurement information.

[0542] FIG. 23 is a drawing illustrating a hybrid transmission method and system architecture according to one embodiment of the present disclosure.

[0543] According to one embodiment, FIG. 23 may illustrate a process in which antenna ports with different insertion losses (e.g., -0dB, -3dB, -6dB, -9dB) are processed through an SRS path or a PMI path, respectively, and then input into a neural network (NN) of a base station (gNB). This hybrid transmission method can compensate for the disadvantages of each method and promote mutually complementary performance improvement by applying SRS-based processing to ports with relatively low insertion loss (e.g., Port 1 and Port 2) and applying PMI-based processing to ports with high insertion loss (e.g., Port 3 and Port 4).

[0544] For the sake of convenience of explanation, the UE's antenna ports insertion loss threshold Based on , it can be divided into two sets as follows:

[0545] 1) Set S: UE antenna ports with low insertion loss, where the insertion loss coefficient of the corresponding port go Includes cases where it is more than that. .

[0546] 2) Set P: UE antenna ports with high insertion loss, where the insertion loss coefficient of the corresponding port go Includes cases where it is less than .

[0547] Here, the union of set S and set P may be identical to the entire set of 4 antenna ports of the UE {1,2,3,4}, and there may be no intersection of set S and set P( , ).

[0548] According to one embodiment, under the assumption that perfect channel estimation is performed at the base station (BS) side, the downlink (DL) channel It can be divided as follows:

[0549]

[0550] can represent the DL channel components of ports with small insertion loss.

[0551] can represent the DL channel components of ports with high insertion loss.

[0552] According to one embodiment, for ports included in set S, a base station (BS) can directly obtain explicit downlink channel state information (DL CSI) through SRS reception and channel reciprocity. At this time, the port Regarding, the DL channel is It can be expressed as.

[0553] According to one embodiment, for ports included in set P, the channel can be approximated using a Precoding Matrix Indicator (PMI) based on a legacy codebook. Accordingly, ports Regarding, the DL channel is It can be approximated as. In this case, can refer to the port-specific PMI reported by the terminal.

[0554] In one embodiment, the above-described hybrid transmission method can provide complementary information that can be combined to reconfigure the entire downlink channel (DL channel) for all ports.

[0555] According to one embodiment, an NN architecture may be applied to effectively combine and enhance heterogeneous information input from SRS and PMI. For example, a ResNet-based Neural Network (NN) architecture may be applied, and the entire channel reconstruction function may be formulated as follows:

[0556]

[0557] In the above formula, W may refer to the weights of the neural network layer that need to be optimized.

[0558] FIG. 24 is a diagram comparing the performance of various DL CSI acquisition methods in one embodiment of the present disclosure. FIG. 24 may be a diagram comparing four different methods: a 4-port SRS method, a PMI-only method using an enhanced Type 2 codebook method, a hybrid method before neural network (NN) processing, and a hybrid method after neural network (NN) processing.

[0559] Referring to Fig. 24, the results of comparing the average Squared Generalized Cosine Similarity (SGCS) between the hybrid method and other methods can be seen in (a) the case without power imbalance and (b) the case where power imbalance exists.

[0560] According to one embodiment, the DL CSI acquisition method can be compared in the absence of power imbalance. Referring to FIG. 24 (a), a hybrid method with neural network (NN) processing applied can achieve a level of performance similar to that of a 4-port SRS method.

[0561] According to one embodiment, a DL CSI acquisition method can be compared when power imbalance exists. Referring to FIG. 24(b), it can be seen that the hybrid method applying neural network processing exhibits significantly superior performance compared to the 4-port SRS method and the PMI-only method. Additionally, referring to FIG. 24(b), for an antenna port with power imbalance, the hybrid method according to the present disclosure can show an average improvement in Squared Generalized Cosine Similarity (SGCS) of 20% and 26% at Layer 1 and Layer 2, respectively, compared to the 4-port SRS method. Considering that most terminals can operate at Rank 1 or Rank 2, securing high performance for Layer 1 and Layer 2 may be particularly important. Therefore, using the hybrid method can effectively resolve port power imbalance issues occurring in a 1T4R environment. Furthermore, in one embodiment, when comparing whether a neural network (NN) is applied, it can be seen that the application of a neural network (NN) is important for improving channel restoration quality. By applying a neural network (NN), the mutually complementary strengths of SRS information and PMI information can be effectively combined, and by performing learning that compensates for the weaknesses of each method, the channel restoration performance can be improved.

[0562] According to one embodiment, the hybrid method described above can effectively enable efficient beamforming and precoding by enabling the effective acquisition of explicit downlink (DL) channel data for each antenna port of the terminal even when port power imbalance exists. Furthermore, the hybrid method described above can be applied more effectively in 6G systems where SRS transmission power imbalance can have a significant impact on performance.

[0563] In the specific embodiments of the present disclosure described above, the components included in the present disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0564] Meanwhile, the present specification and drawings disclose preferred embodiments of the present disclosure. Although specific terms have been used, they are used merely in a general sense to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the disclosure, and are not intended to limit the scope of the present disclosure. It is obvious to those skilled in the art that, in addition to the embodiments disclosed herein, other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated together as needed.

[0565] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is understood that various modifications are possible within the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

Claims

1. A method performed by a terminal (user equipment, UE) in a wireless communication system, A step of receiving a radio resource control (RRC) message from a base station (BS) that includes setting information for the joint operation of a channel state information-reference signal (CSI-RS) and a sounding reference signal (SRS); A step of receiving downlink control information (DCI) for the joint operation from the base station; A step of receiving the CSI-RS from the base station based on the DCI and the setting information; A step of transmitting the SRS to the base station through a first antenna port based on the DCI and the setting information; and A method comprising the step of transmitting a CSI report including a per-port precoding matrix indicator (PMI) and a per-port phase difference through a second antenna port different from the first antenna port, based on the CSI-RS and the configuration information, to the base station.

2. In Paragraph 1, A method in which the transmission time of the above SRS and the transmission time of the above CSI report are located within a pre-set slot offset.

3. In Paragraph 1, A method in which the above setting information indicates the association between a CSI-RS resource set including the resource of the CSI-RS and an SRS resource set including the resource of the SRS.

4. In Paragraph 3, A method in which the above-mentioned configuration information indicates the association through at least one of CSI-report configuration information, CSI-aperiodicTriggerState configuration information, or an information element (IE) for the joint operation.

5. In a method performed by a base station (BS) in a wireless communication system, A step of transmitting a radio resource control (RRC) message containing setting information for the joint operation of a channel state information-reference signal (CSI-RS) and a sounding reference signal (SRS) to a terminal (user equipment, UE); A step of transmitting downlink control information (DCI) for the joint operation to the terminal; A step of transmitting the CSI-RS to the above terminal based on the DCI and the setting information; A step of receiving the SRS through a first antenna port from the terminal based on the DCI and the setting information; and A method comprising the step of receiving a CSI report including a per-port precoding matrix indicator (PMI) and a per-port phase difference through a second antenna port different from the first antenna port, based on the CSI-RS and the setting information from the terminal.

6. In Paragraph 5, A method in which the transmission time of the above SRS and the transmission time of the above CSI report are located within a pre-set slot offset.

7. In Paragraph 5, A method in which the above setting information indicates the association between a CSI-RS resource set including the resource of the CSI-RS and an SRS resource set including the resource of the SRS.

8. In Paragraph 7, A method in which the above-mentioned configuration information indicates the association through at least one of CSI-report configuration information, CSI-aperiodicTriggerState configuration information, or an information element (IE) for the joint operation.

9. In a terminal (user equipment, UE) in a wireless communication system: At least one transceiver; At least one processor communicatively coupled to the above at least one transceiver; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, so that the terminal: Receive a radio resource control (RRC) message from a base station (BS) that includes configuration information for the joint operation of the channel state information-reference signal (CSI-RS) and the sounding reference signal (SRS), and Receive downlink control information (DCI) for the joint operation from the above base station, and From the base station, the CSI-RS is received based on the DCI and the configuration information, and Transmitting the SRS through the first antenna port to the base station based on the DCI and the configuration information, and A terminal that transmits a CSI report including a per-port precoding matrix indicator (PMI) and a per-port phase difference through a second antenna port different from the first antenna port, based on the CSI-RS and the configuration information to the base station.

10. In Paragraph 9, A terminal in which the transmission time of the above SRS and the transmission time of the above CSI report are located within a pre-set slot offset.

11. In Paragraph 9, A terminal in which the above configuration information indicates the association between a CSI-RS resource set including the resource of the CSI-RS and an SRS resource set including the resource of the SRS.

12. In Paragraph 11, A terminal that indicates the association through at least one of the above setting information, CSI-report setting information, CSI-aperiodicTriggerState setting information, or information element (IE) for the joint operation.

13. Regarding a base station (BS) in a wireless communication system: At least one transceiver; At least one processor communicatively coupled to the above at least one transceiver; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, so that the base station: To the above terminal, downlink control information (DCI) for the joint operation is transmitted, and Transmit the CSI-RS to the above terminal based on the DCI and the setting information, and From the above terminal, the SRS is received through the first antenna port based on the DCI and the setting information, and A base station that receives a CSI report including a per-port precoding matrix indicator (PMI) and a per-port phase difference through a second antenna port different from the first antenna port, based on the CSI-RS and the setting information from the terminal.

14. In Paragraph 13, A base station in which the transmission time of the above SRS and the transmission time of the above CSI report are located within a pre-set slot offset.

15. In Paragraph 13, A base station in which the above setting information indicates the association between a CSI-RS resource set including the resource of the CSI-RS and an SRS resource set including the resource of the SRS.

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