Method and apparatus for energy saving in wireless communication system

Abstract

The present disclosure relates to a 5th-Generation (5G) or 6th-Generation (6G) communication system for supporting higher data transmission rates. In addition, the present disclosure provides a method and apparatus for reducing energy consumption of a base station in a mobile communication system. According to the present disclosure, a problem of excessive energy consumption of a base station in a mobile communication system may be solved, and high energy efficiency may be achieved. A method by which a terminal transmits and receives a signal in a wireless communication system according to an embodiment of the present disclosure comprises the steps of: receiving a first control signal from a first cell in synchronization with the first cell, the first control signal including information on cells in which the first cell is controllable; and transmitting data to the second cell based on the first control signal.

Description

Technical Field

[0001] This disclosure relates to wireless communication systems, and more specifically, to methods and apparatus for energy saving for base stations in wireless communication systems. Background Technology

[0002] Fifth-generation (5G) mobile communication technology defines wide bandwidths to enable high data rates and new services, and can be implemented not only in the "sub-6GHz" band, including 3.5GHz, but also in ultra-high frequency bands known as millimeter wave (mmWave) ("above 6GHz"), including 28GHz, 39GHz, etc. Furthermore, for sixth-generation (6G) mobile communication technology, known as Super 5G (Ultra 5G) systems, to achieve data rates fifty times faster than 5G and ultra-low latency one-tenth that of 5G, implementation in terahertz bands (e.g., the 95GHz to 3THz band) is being considered.

[0003] In the early stages of 5G mobile communication technology development, to support services and meet the performance requirements of enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC), standardization is underway for the following technologies: beamforming and massive multiple-input multiple-output (MIMO) to mitigate path loss and increase transmission distance of radio waves in millimeter-wave bands; support for parameter sets (e.g., operating multiple subcarrier spacings) for dynamic operation that effectively utilizes millimeter-wave resources and time slot formats; initial access technologies to support multi-beam transmission and broadband; definition and operation of bandwidth portions (BWP); new channel coding methods, such as low-density parity-check (LDPC) codes for large-volume data transmission and polar codes for highly reliable transmission of control information; L2 preprocessing; and network slicing for providing dedicated networks for specific services.

[0004] Currently, considering the services supported by 5G mobile communication technology, discussions are underway regarding improvements and performance enhancements to the initial 5G mobile communication technology, and physical layer standardization has been implemented for technologies such as: Vehicle-to-Everything (V2X) to assist autonomous vehicle driving decisions and enhance user convenience based on information sent by the vehicle about its location and status; New Radio Unlicensed (NR-U) designed to ensure system operation complies with various regulations related to unlicensed frequency bands; NR User Equipment (NR UE) energy saving; Non-Terrestrial Networks (NTN) for providing coverage in areas where communication with terrestrial networks is unavailable, as UE-satellite direct communication; and positioning.

[0005] Furthermore, standardization is underway for air interface architectures / protocols for technologies such as: Industrial Internet of Things (IIoT) to support new services through interoperability and convergence with other industries; Integrated Access and Backhaul (IAB) for nodes to provide network service area extension by supporting wireless backhaul and access links in an integrated manner; Mobility enhancements including conditional handover and dual active protocol stack (DAPS) handover; and two-step random access (two-step RACH for NR) to simplify the random access process. Standardization is also underway for system architectures / services for technologies such as: 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies; and Mobile Edge Computing (MEC) for UE location-based reception services.

[0006] When 5G mobile communication systems are commercialized, the rapidly growing number of connected devices is anticipated to connect to the communication network. Therefore, it is anticipated that the functionality and performance of 5G mobile communication systems, as well as the integrated operation of connected devices, will need to be enhanced. To this end, new research has been initiated targeting the following technologies: Extended Reality (XR) for effectively supporting Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR), etc.; improving 5G performance and reducing complexity by leveraging Artificial Intelligence (AI) and Machine Learning (ML); AI service support; Metaverse service support; and drone communication, etc.

[0007] Furthermore, this development of 5G mobile communication systems will serve as the foundation for developing not only new waveforms for providing coverage in the terahertz band of 6G mobile communication technology; multi-antenna transmission technologies (e.g., full-dimensional MIMO (FD-MIMO), array antennas, and massive MIMO); metamaterial-based lenses and antennas for improving terahertz band signal coverage; high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM); and reconfigurable smart surfaces (RIS), but also as the foundation for developing technologies such as full-duplex technologies for improving the frequency efficiency of 6G mobile communication technology and enhancing system networks; AI-based communication technologies for system optimization by leveraging satellites and AI from the design phase and internalizing end-to-end AI support capabilities; and next-generation distributed computing technologies for providing services at complexity levels exceeding UE operational capability limits by utilizing ultra-high-performance communication and computing resources. Summary of the Invention

[0008] Technical issues This disclosure provides a method and apparatus for energy saving in wireless communication systems.

[0009] Technical solution According to this disclosure, a method for processing control signals in a wireless communication system includes: receiving a first control signal transmitted from a base station (BS); processing the received first control signal; and transmitting a second control signal generated based on the processing to the BS.

[0010] According to embodiments of the present disclosure, a method for transmitting and receiving signals in a wireless communication system, performed by a terminal, includes: synchronizing with a first cell; receiving a first control signal from the first cell, the first control signal including information about a cell that can be controlled by the first cell; and transmitting data to a second cell based on the first control signal.

[0011] Beneficial effects of the invention According to embodiments of this disclosure, a signal transmission method for a base station is defined in a wireless communication system, which can solve the problem of excessive energy consumption and achieve high energy efficiency. Attached Figure Description

[0012] Figure 1 The basic structure of the time-frequency resource domain of a fifth-generation (5G) system according to an embodiment of the present disclosure is shown.

[0013] Figure 2 A time-domain mapping structure and beam scanning operation for a synchronization signal according to an embodiment of the present disclosure are shown.

[0014] Figure 3 A random access procedure according to an embodiment of the present disclosure is illustrated.

[0015] Figure 4 The process of a user equipment (UE) reporting UE capability information to a base station according to an embodiment of the present disclosure is illustrated.

[0016] Figure 5 A control resource set (CORESET) according to an embodiment of the present disclosure is shown, which is a time-frequency resource on which the physical downlink control channel (PDCCH) is mapped.

[0017] Figure 6 The mapping between downlink control information (DCI) and demodulation reference signal (DMRS) in a resource element group (REG), which is the basic unit of the DL control channel, is shown according to an embodiment of the present disclosure.

[0018] Figure 7 The beam allocation performed by the base station according to the Transmission Configuration Indication (TCI) state configuration is shown according to an embodiment of the present disclosure.

[0019] Figure 8 A hierarchical signaling method for dynamically allocating PDCCH beams in a new radio (NR) is illustrated according to embodiments of the present disclosure.

[0020] Figure 9 The TCI indication media access control (MAC) control element (CE) signaling structure for PDCCH DMRS according to an embodiment of the present disclosure is shown.

[0021] Figure 10 This is a diagram illustrating a method by which a base station and a UE transmit and receive data by taking into account DL data channels and rate matching resources according to embodiments of the present disclosure.

[0022] Figure 11 An aperiodic channel state information (CSI) reporting method is shown according to an embodiment of the present disclosure when the CSI-reference signal (RS) offset is 0.

[0023] Figure 12 A non-periodic CSI reporting method is shown according to an embodiment of the present disclosure when the CSI-RS offset is 1.

[0024] Figure 13 An example of the configuration of the bandwidth portion (BWP) in a 5G communication system according to an embodiment of the present disclosure is shown.

[0025] Figure 14 Discontinuous reception (DRX) in a 5G communication system according to an embodiment of the present disclosure is illustrated.

[0026] Figure 15 It is a diagram used to describe existing network communication systems.

[0027] Figure 16a This is a diagram illustrating an energy-efficient network communication system based on embodiments of the present disclosure.

[0028] Figure 16b This is a diagram illustrating an energy-efficient network communication system based on embodiments of the present disclosure.

[0029] Figure 17a This is a diagram illustrating an energy-efficient network communication system based on embodiments of the present disclosure.

[0030] Figure 17b This is a diagram illustrating an energy-efficient network communication system based on embodiments of the present disclosure.

[0031] Figure 18a The synchronization signal block (SSB) structure (excluding the physical broadcast channel (PBCH)) of the synchronization cell and data cell according to embodiments of the present disclosure is shown.

[0032] Figure 18b The SSB structure (excluding PBCH) of the synchronization cell and data cell according to an embodiment of the present disclosure is shown.

[0033] Figure 18c The SSB structure (excluding PBCH) of the synchronization cell and data cell according to an embodiment of the present disclosure is shown.

[0034] Figure 19 A process for obtaining a Physical Cell Identifier (PCI) among a synchronization cell, a data cell, and a UE, according to an embodiment of the present disclosure, is illustrated.

[0035] Figure 20 A UE transceiver device according to an embodiment of the present disclosure is shown.

[0036] Figure 21 This is a block diagram illustrating a UE according to an embodiment of the present disclosure.

[0037] Figure 22 This is a block diagram illustrating a base station according to an embodiment of the present disclosure.

[0038] For ease of explanation, illustrations and descriptions of devices not directly related to this disclosure may be omitted. Detailed Implementation

[0039] Embodiments of this disclosure will now be described more fully with reference to the accompanying drawings. Furthermore, well-known functions or configurations are not described in detail in the following description of this disclosure, as such detail would obscure the disclosure unnecessarily. The terminology used herein is defined in consideration of the functions described in this disclosure and may vary depending on the intent, conventions, etc., of the user or operator. Therefore, the terminology used herein should be defined based on its meaning and the description throughout the specification.

[0040] The advantages and features of this disclosure, as well as methods of implementing them, will become clear from the following detailed description of embodiments of this disclosure taken in conjunction with the accompanying drawings. However, this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art, and the scope of this disclosure is defined only by the appended claims. In this specification, the same reference numerals denote the same elements.

[0041] It should be understood that each box in a flowchart illustration and combinations of boxes in a flowchart illustration can be implemented by computer program instructions. Because these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate means for performing the functions specified in the flowchart boxes. Because these computer program instructions can also be stored in a computer-executable or computer-readable storage device that can instruct the computer or other programmable data processing apparatus to operate in a particular manner, the instructions stored in the computer-executable or computer-readable storage device can produce an article of writing comprising instruction means for performing the functions stored in the flowchart boxes. Because computer program instructions can also be loaded into a computer or other programmable data processing apparatus, a series of operational steps can be performed on the computer or other programmable data processing apparatus to produce a computer-implemented process, and therefore, the instructions that execute on the computer or other programmable data processing apparatus can provide steps for implementing the functions specified in the flowchart boxes.

[0042] Furthermore, each box may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the boxes may occur out of order. For example, depending on the function involved, two boxes shown consecutively may actually execute substantially simultaneously, or these boxes may sometimes execute in reverse order.

[0043] The term "...unit" as used in this embodiment of the disclosure refers to a software or hardware component that performs certain tasks, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC). However, the term "...unit" is not intended to be limited to software or hardware. A "...unit" can be configured to reside in addressable storage media or can be configured to operate one or more processors. Thus, by way of example, a "...unit" can include components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided in components and "...units" can be combined into fewer components and "...units," or can be further divided into additional components and "...units." Furthermore, components and "...units" can be implemented as one or more central processing units (CPUs) in an operating device or secure multimedia card. Additionally, a "...unit" in the embodiments can include one or more processors.

[0044] In the following description of this disclosure, well-known functions or configurations are not described in detail, as such details would obscure the spirit of the disclosure with unnecessary detail. Embodiments of this disclosure will be described below with reference to the accompanying drawings.

[0045] In the following text, for ease of explanation, terms for identifying access nodes, terms for indicating network entities, terms for indicating messages, terms for indicating interfaces between network entities, and terms for indicating various identifying information used herein are illustrated. Therefore, this disclosure is not limited to the terms described below, and other terms indicating objects having the same technical meaning may be used.

[0046] In the following description, physical channels and signals may be used interchangeably with data or control signals. For example, Physical Downlink Shared Channel (PDSCH) is a term that indicates the physical channel through which data is transmitted, but PDSCH can also be used to indicate data. That is, in this disclosure, when 'physical channel is transmitted', it can be interpreted as 'data or signals are transmitted through the physical channel'.

[0047] In the following, and in this disclosure, higher-layer signaling refers to a method of transmitting signals from a base station to a terminal using a downlink data channel of the physical layer, or from a terminal to a base station using an uplink data channel of the physical layer. Higher-layer signaling may be Radio Resource Control (RRC) signaling or Media Access Control (MAC) control elements (CE).

[0048] For ease of explanation, the terms and names defined in the 3GPP New Radio (NR) standard (5G mobile communication standard) are used. However, this disclosure is not limited to the terms and names stated herein and may also be applied to systems conforming to other standards. Furthermore, the term "terminal (UE)" may refer not only to mobile phones, smartphones, Internet of Things (IoT) devices, and sensors, but also to other wireless communication devices.

[0049] In the following description, a base station is an entity that allocates resources to a UE, and can be at least one of a next-generation Node B (gNode B / gNB), an evolved Node B (eNode B / eNB), a Node B, a base station (BS), a radio access unit, a BS controller, or a node on a network. A terminal may include a UE, a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. However, this disclosure is not limited to the examples described above.

[0050] To meet the exponentially growing demand for wireless data services, initial standards were completed for fifth-generation (5G) systems or NR access technologies, which are the next-generation communication systems following LTE or Evolved Universal Terrestrial Radio Access (E-UTRA) and LTE-A or E-UTRA evolution. Compared to traditional mobile communication systems focused on general voice / data communication, 5G systems are designed to meet a variety of 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 MTC (mMTC) services to support communication between a large number of devices.

[0051] Compared to traditional LTE and LTE-A, where the maximum system transmission bandwidth per carrier is limited to 20MHz, 5G systems aim to provide high-speed data services of several Gbps by using very large ultra-wide bandwidths. Therefore, for 5G systems, ultra-high frequency bands from several GHz to 100 GHz (where frequencies with ultra-wide bandwidths are readily available) are considered candidate frequencies. Furthermore, the wide bandwidth frequencies for 5G systems can be obtained by reallocating or allocating frequencies within the range of several hundred MHz to several GHz used in traditional mobile communication systems.

[0052] Radio waves in the ultra-high frequency (UHF) band have wavelengths of several millimeters (mm) and are also known as millimeter waves (mmWave). However, in the UHF band, the path loss of radio waves increases with increasing frequency, thus reducing the coverage area of ​​mobile communication systems.

[0053] To overcome the reduced coverage in the UHF band, beamforming technology can be applied to increase the distance to reach radio waves by focusing the radiated energy of radio waves onto a target point using multiple antennas. In other words, a signal using beamforming technology has a relatively narrow beamwidth, and the radiated energy is concentrated within this narrow beamwidth, thus increasing the distance to reach the radio waves. Beamforming technology can be applied to both transmitters and receivers. Besides increasing coverage, beamforming technology also reduces interference in areas outside the beamforming direction. Accurate transmit / receive beam measurement and feedback methods are required for proper implementation of beamforming technology. Beamforming technology can be applied to control or data channels with a one-to-one correspondence between a UE and a BS. Furthermore, to increase coverage, beamforming technology can be applied to control and data channels through which the BS transmits common signals (such as synchronization signals, physical broadcast channel (PBCH), and system information) to multiple UEs in the system. When beamforming technology is applied to common signals, beam scanning technology, which transmits signals by changing the beam direction, is also used to allow the common signal to reach UEs located anywhere within the cell.

[0054] Another requirement of 5G systems is the need for ultra-low latency services with a transmission delay of approximately 1ms between the transmitter and receiver. As a method to reduce transmission latency, a frame structure based on a shorter Transmission Time Interval (TTI) compared to that in LTE and LTE-A needs to be designed. The TTI is the basic unit of time used for scheduling, and in traditional LTE and LTE-A systems, the TTI corresponds to a subframe of 1ms in length. For example, to meet the requirements of ultra-low latency services in 5G systems, shorter TTIs such as 0.5ms, 0.25ms, and 0.125ms can be supported compared to those in traditional LTE and LTE-A systems.

[0055] Figure 1 The basic structure of the time-frequency resource domain in a 5G system according to embodiments of the present disclosure is shown. That is, Figure 1 The basic structure of the time-frequency resource domain is shown, which is the radio resource area on which data or control channels of a 5G system are transmitted.

[0056] refer to Figure 1 ,exist Figure 1 In the diagram, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The smallest transmission unit in the time domain of a 5G system is an Orthogonal Frequency Division Multiplexing (OFDM) symbol, which can be collected... Symbol 102 is used to form a time slot 106, and can be collected. Each time slot is used to form a subframe 105. The length of subframe 105 can be 1.0 ms, and 10 subframes can be collected to form a 10 ms frame 114. The smallest transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission band (transmission bandwidth) can include a total of N BW 104 subcarriers.

[0057] The basic unit of resources in the time-frequency domain is the resource element (RE) 112, which can be defined as an OFDM symbol index and subcarrier index. Resource blocks (RBs) or physical resource blocks (PRBs) can be defined in the frequency domain. 110 consecutive subcarriers. In 5G systems... Furthermore, the data rate can be increased proportionally to the number of RBs scheduled to the UE.

[0058] In 5G systems, the BS maps data in units of RBs, and typically, scheduling can be performed on RBs that constitute a time slot for a specific UE. That is to say, in 5G systems, the basic time unit used for scheduling can be a time slot, and the basic frequency unit used for scheduling can be an RB.

[0059] The number of OFDM symbols It is determined based on the length of the cyclic prefix (CP) added to each symbol to prevent interference between symbols, and, for example, when a normal CP is applied, =14, and when applying extended CP, =12. Because extended CP is applied to systems with relatively larger radio transmission distances than normal CP, orthogonality between symbols can be maintained. In the case of normal CP, the ratio of CP length to symbol length remains constant; therefore, the overhead due to CP can remain constant regardless of the subcarrier spacing. That is, when the subcarrier spacing is small, the symbol length can increase, and therefore the CP length can also increase. Conversely, when the subcarrier spacing is large, the symbol length can decrease, and therefore the CP length can also decrease. Symbol length and CP length can be inversely proportional to the subcarrier spacing.

[0060] In 5G systems, various frame structures can be supported by adjusting the subcarrier spacing to meet diverse services and requirements. For example, - In terms of operating frequency band, the larger the subcarrier spacing, the more advantageous it is to recover phase noise in the high frequency band.

[0061] - In terms of transmission time, the larger the subcarrier spacing, the shorter the symbol length and the time slot length in the time domain, and therefore, it is more advantageous to support ultra-low latency services such as URLLC.

[0062] - In terms of cell size, a longer CP length allows for larger cells, and therefore, a smaller subcarrier spacing allows for relatively larger cells. A cell indicates the area covered by a BS in mobile communication.

[0063] Subcarrier spacing, CP length, etc., are fundamental information for OFDM transmission and reception, and seamless transmission and reception can only be performed when the BS and UE recognize the subcarrier spacing, CP length, etc., as common values. Table 1 shows the subcarrier spacing configuration (μ), subcarrier spacing (μ), etc. The relationship between ) and CP length.

[0064] [Table 1]

[0065] Table 2 shows the number of symbols per slot for each subcarrier interval (μ) under normal CP conditions. ), number of time slots per frame ( ) and the number of time slots per subframe ( ).

[0066] [Table 2]

[0067] Table 3 shows the number of symbols per slot for each subcarrier interval (μ) in the case of extended CP ( ), number of time slots per frame ( ) and the number of time slots per subframe ( ).

[0068] [Table 3]

[0069] In the initial phase of introducing 5G systems, coexistence or dual-mode operation with at least traditional LTE and / or LTE-A systems (hereinafter referred to as LTE / LTE-A systems) is expected. Therefore, traditional LTE / LTE-A can provide stable system operation to the UE, while the 5G system can provide improved services to the UE. Consequently, the frame structure of the 5G system may need to include at least the LTE / LTE-A frame structure or basic parameter set (subcarrier spacing = 15kHz).

[0070] For example, comparing a frame structure with a subcarrier spacing configuration of μ=0 (hereinafter referred to as frame structure A) with a subcarrier spacing configuration of μ=1 (hereinafter referred to as frame structure B), compared to frame structure A, frame structure B has a subcarrier spacing and RB size that are doubled, and a slot length and symbol length that are halved. In frame structure B, two slots can constitute one subframe, and 20 subframes can constitute one frame.

[0071] When the frame structure of a 5G system is generalized, high scalability is provided by making the basic parameter set (such as subcarrier spacing, CP length, time slot length, etc.) have integer multiple relationships with respect to each frame structure. Moreover, a subframe with a fixed length of 1ms can be defined as an indicator reference time unit (independent of the frame structure).

[0072] Frame structures can be applied to suit various scenarios. Regarding cell size, a longer CP length allows for larger cells, thus frame structure A can support relatively larger cells compared to frame structure B. Regarding operating frequency bands, a larger subcarrier spacing is more conducive to recovering phase noise in high-frequency bands, thus frame structure B can support relatively higher operating frequencies compared to frame structure A. Regarding services, a shorter time slot length, which serves as the basic time unit for scheduling, is more conducive to supporting ultra-low latency services such as URLLC, thus frame structure B is relatively more suitable for URLLC services compared to frame structure A.

[0073] In the following description of this disclosure, uplink (UL) may refer to a radio link used to transmit data or control signals from UE to BS, and downlink (DL) may refer to a radio link used to transmit data or control signals from BS to UE.

[0074] During the initial access operation of the UE when it first accesses the system, the UE can synchronize DL time and frequency according to the synchronization signal sent from the BS, and can obtain the cell identifier (cell ID) via cell search. The UE can then receive the Physical Broadcast Channel (PBCH) using the obtained cell ID, and can obtain the Master Information Block (MIB) as basic system information from the PBCH. Furthermore, the UE can receive the System Information Block (SIB) sent from the BS, and can therefore obtain cell common transmission and reception control information from the SIB. The cell common transmission and reception control information may include control information associated with random access, control information associated with paging, and common control information regarding various physical channels.

[0075] Synchronization signals serve as reference signals for cell search, and for each frequency band, subcarrier spacing can be applied to adapt to channel conditions such as phase noise. To enable data or control channels to support the various services mentioned above, subcarrier spacing can be applied differently depending on the service type.

[0076] Figure 2 A time-domain mapping structure and beam scanning operation for a synchronization signal according to an embodiment of the present disclosure are shown.

[0077] For description purposes, the following elements can be defined.

[0078] - Master Synchronization Signal (PSS): It is a signal used as a reference for DL ​​time / frequency synchronization and provides partial information about the cell ID.

[0079] - Secondary Synchronization Signal (SSS): It serves as a reference for DL ​​time / frequency synchronization and provides additional information about the cell ID. The SSS can also be used as a reference signal for demodulation of the PBCH.

[0080] - Physical Broadcast Channel (PBCH): The PBCH provides the Master Information Block (MIB), which is the basic system information required by the UE to transmit and receive data and control channels. The basic system information may include search space association control information indicating radio resource mapping information for control channels, scheduling control information for separate data channels used to transmit system information, and information as timing references (e.g., the system frame number (SFN) as a frame-level index).

[0081] - SS / PBCH Block (or SSB): An SS / PBCH block consists of N OFDM symbols and includes a combination of PSS, SSS, and PBCH. For systems using beam scanning technology, the SS / PBCH block is the smallest unit for applying beam scanning. In 5G systems, N=4. The BS can send up to L SS / PBCH blocks, and the L SS / PBCH blocks are mapped within a half-frame (0.5ms). The L SS / PBCH blocks repeat periodically with period P. The BS can notify the UE of period P via signaling. When there is no separate signaling for period P, the UE applies a predefined default value.

[0082] Figure 2 An example of applying beam scanning over time in units of SS / PBCH blocks is shown. Reference Figure 2 The first UE (UE1) 205 receives the SS / PBCH block by using a beam transmitted in direction #d0 203 due to beamforming applied to SS / PBCH block #0 at time point t1 201. Similarly, the second UE (UE2) 206 receives the SS / PBCH block by using a beam transmitted in direction #d4 204 due to beamforming applied to SS / PBCH block #4 at time point t2 202. The UE can obtain optimal synchronization signals via beams transmitted from the BS in directions toward the UE's location. For example, UE1 205 may have difficulty obtaining time / frequency synchronization and basic system information from the SS / PBCH block via beams transmitted in direction #d4 204, which is away from UE1 205's location.

[0083] In addition to receiving SS / PBCH blocks during the initial access procedure, the UE can also receive SS / PBCH blocks to determine whether the radio link quality of the current cell remains above a certain level. Furthermore, during handover from the current cell to a neighboring cell, the UE can receive SS / PBCH blocks from the neighboring cell to determine the radio link quality of the neighboring cell and obtain time / frequency synchronization with the neighboring cell.

[0084] After the UE obtains the MIB and system information from the BS via the initial access procedure, the UE can perform a random access procedure to switch the link with the BS to the connected state (or RRC_connected state). Once the random access procedure is completed, the UE transitions to the connected state, and one-to-one communication is enabled between the BS and the UE. References will be made below. Figure 3 Describe the random access process in detail.

[0085] Figure 3 A random access procedure according to an embodiment of the present disclosure is illustrated.

[0086] refer to Figure 3In the first step 310 of the random access procedure, the UE sends a random access preamble to the gNB. During the random access procedure, the random access preamble, which is the first message sent by the UE, can be referred to as message 1. The gNB can measure the transmission delay between the UE and the gNB based on the random access preamble and perform UL synchronization. In this case, the UE can randomly select the random access preamble to use from a set of random access preambles pre-given by system information. Furthermore, the initial transmission power of the random access preamble can be determined based on the path loss between the gNB and the UE, which is measured by the UE. Additionally, the UE can determine the direction of the transmission beam for the random access preamble based on the synchronization signal received from the gNB, and can transmit the random access preamble in the determined direction of the transmission beam.

[0087] In the second step 320, the gNB sends a UL transmission timing control command to the UE based on the transmission delay value measured according to the random access preamble received in the first step 310. Furthermore, the gNB may send a power control command and UL resources to be used by the UE as scheduling information. The scheduling information may include control information regarding the UE's UL transmission beam.

[0088] If the UE fails to receive a Random Access Response (RAR) (or message 2) as scheduling information for message 3 from the gNB within a specific time period in step 320, the UE may execute step 310 again. When the UE executes step 310 again, the UE may send the random access preamble with a transmission power that increases by a certain step size (power ramp-up), thereby increasing the probability of receiving the random access preamble at the gNB.

[0089] In step 330, the UE transmits UL data (message 3) including its UE ID to the gNB via the Physical Uplink Shared Channel (PUSCH) using the UL resources allocated in step 320. The transmission timing of the UL data channel used to transmit message 3 can be controlled according to the timing control command received from the gNB in ​​step 320. The transmission power of the UL data channel used to transmit message 3 can be determined by considering the power control command received from the gNB in ​​step 320 and the power ramp value applied to the random access preamble. The UL data channel used to transmit message 3 may refer to the first UL data signal transmitted by the UE to the gNB after the UE transmits the random access preamble.

[0090] In step 340, when the gNB determines that the UE has performed the random access procedure without conflicting with another UE, the gNB sends data (message 4) to the UE including the UE ID that was already sent in step 330. When the UE receives the data sent by the gNB in ​​step 340, the UE can determine that the random access procedure was successful. The UE can then send a Hybrid Automatic Repeat Request Acknowledgment (HARQ-ACK) message to the gNB via the Physical UL Control Channel (PUCCH) indicating whether message 4 was successfully received.

[0091] If the data transmitted by the UE in step 330 conflicts with the data transmitted by another UE and the gNB fails to receive the data signal from the UE as a result, the gNB may stop transmitting data to the UE. Therefore, if the UE fails to receive the data transmitted from the gNB in ​​step 340 within a specific time period, the UE can determine that the random access procedure has failed and can restart the random access procedure from step 310.

[0092] Once the random access procedure is successfully completed, the UE transitions to the connected state and enables one-to-one communication between the gNB and the UE. The gNB can receive UE capability information from the UE in the connected state and can adjust scheduling by referring to the UE's capability information. The UE can notify the gNB via its capability information whether it supports specific functions, the maximum allowed value of the functions it supports, etc. Therefore, the UE capability information reported by each UE to the gNB can have different values ​​for each UE.

[0093] For example, a UE can report UE capability information to the gNB, including at least one of the following control information.

[0094] - Control information associated with the frequency bands supported by the UE - Control information associated with the channel bandwidth supported by the UE - Control information associated with the highest modulation scheme supported by the UE - Control information associated with the maximum number of beams supported by the UE - Control information associated with the maximum number of layers supported by the UE - Control information associated with Channel State Information (CSI) reports supported by the UE - Control information regarding whether the UE supports frequency hopping - Control information associated with bandwidth when supporting carrier aggregation (CA) - Control information regarding whether cross-carrier scheduling is supported when CA is supported Figure 4 The process of a UE reporting UE capability information to a gNB according to an embodiment of the present disclosure is illustrated.

[0095] refer to Figure 4 In operation 410, gNB 402 may send a UE capability information request message to UE 401. In response to the UE capability information request from gNB, UE sends UE capability information to gNB.

[0096] A UE connected to the gNB through the above process can become a UE in the RRC_CONNECTED state, and a UE in the RRC connected state can perform one-to-one communication with the gNB. On the other hand, a UE not connected to the gNB is in the RRC_IDLE state, and the operations of a UE in the RRC_IDLE state are classified as follows.

[0097] - Execute UE-specific discontinuous reception (DRX) cycles configured by higher layers. - Receive paging messages from the core network - Obtain system information - Measurement operations associated with neighboring cells and cell reselection A new UE state called RRC_INACTIVE is defined to reduce the energy and time consumed during initial UE access in 5G systems. In addition to the operations performed by the UE in RRC_IDLE, the UE in RRC_INACTIVE also performs the following operations.

[0098] - Store the access stratum (AS) information required for cell access. - Perform UE-specific DRX cycle operations configured by the RRC layer. - The notification area (RNA) based on the radio access network (RAN) that can be used for handover can be configured and periodically updated through the RRC layer. - Monitor RAN-based paging messages transmitted via Inactive Radio Network Temporary Identifier (I-RNTI) The following text will now describe the scheduling method by which the BS sends DL data to the UE or instructs the UE to perform UL data transmission.

[0099] Downlink control information (DCI) can be control information sent from the BS to the UE via the DL, and may include DL data scheduling information or UL data scheduling information for a specific UE. Typically, the BS can independently channel-code the DCI for each UE, and then send it to the corresponding UE via the Physical Downlink Control Channel (PDCCH), which serves as the physical control channel for the DL.

[0100] The BS can apply and operate a predefined DCI format for the UE to be scheduled based on factors such as whether the DCI carries scheduling information for DL ​​data (DL assignment), whether the DCI carries scheduling information for UL data (UL authorization), or whether the DCI is for the purpose of power control.

[0101] The BS can transmit DL data to the UE via the Physical Downlink Shared Channel (PDSCH), which serves as the physical channel for DL ​​data transmission. The BS can notify the UE of scheduling information, such as the specific mapping position of the PDSCH in the time-frequency domain, modulation scheme, control information associated with HARQ, and power control information, in the DCIs transmitted on the PDCCH that are related to DL data scheduling information.

[0102] The UE can send UL data to the BS via the Physical Uplink Shared Channel (PUSCH), which serves as the physical channel for UL data transmission. The BS can notify the UE of scheduling information, such as the specific mapping position of the PUSCH in the time and frequency domain, modulation scheme, control information associated with HARQ, and power control information, in the DCIs transmitted on the PDCCH that are related to UL data scheduling information.

[0103] Figure 5 A control resource set (CORESET) according to an embodiment of the present disclosure is shown, which is a time-frequency resource on which the PDCCH is mapped.

[0104] refer to Figure 5 The UE Bandwidth Part (BWP) 510 can be configured on the frequency axis, and two control resource sets (control resource set #1 501 and control resource set #2 502) can be configured on the time axis in a single timeslot 520. Control resource sets 501 and 502 can be configured along the frequency axis within a specific frequency resource 503 throughout the entire UE BWP 510. Control resource sets 501 and 502 can be configured along the time axis with one or more OFDM symbols and can be defined by the control resource set duration 504.

[0105] Control resource set #1 501 can be configured to have a control resource set duration with two symbols, and control resource set #2 502 can be configured to have a control resource set duration with one symbol.

[0106] The BS can configure one or more CORESETs in the UE via higher-level signaling (e.g., system information, Master Information Block (MIB), or Radio Resource Control (RRC) signaling). When a CORESET is configured for the UE, this may mean that information such as the CORESETID, the frequency location of the CORESET, and the symbol length of the CORESET is provided. The multiple pieces of information provided by the BS to the UE for configuring the CORESET may include at least some of the information included in Table 4.

[0107] [Table 4]

[0108]

[0109] CORESET can be derived from the frequency domain. It consists of RBs, and can be composed of time domain RBs. A CORESET consists of 6 symbols. An NR PDCCH can consist of one or more Control Channel Elements (CCEs). A CCE can include 6 Resource Groups (REGs), and each REG can be defined as a Reference Block (RB) during an OFDM symbol. REGs in a CORESET can be indexed in a time-priority manner, starting from 0 for the first OFDM symbol in the CORESET and the lowest-numbered RB.

[0110] Interleaving and non-interleaving methods can be supported as methods for transmitting PDCCH. The BS can configure whether to perform interleaved or non-interleaved transmission for each CORESET in the UE via higher-layer signaling. Interleaving can be performed on a REG bundle basis. The term "REG bundle" can be defined as a set of one or more REGs. The UE can determine the CCE-to-REG mapping method in the CORESET based on whether to perform interleaved or non-interleaved transmission as configured from the BS, using the following methods as shown in Table 5.

[0111] [Table 5]

[0112] The BS can use signaling to notify the UE of information such as the symbols to which the PDCCH is mapped in the time slot, and configuration information of the transmission period.

[0113] Figure 6 The mapping between the DCI and the demodulation reference signal (DMRS) in the REG, which is the basic unit of the DL control channel according to an embodiment of the present disclosure, is shown.

[0114] refer to Figure 6The basic unit of the DL control channel (i.e., REG 603) can include both the RE to which the DCI is mapped and the region to which the DMRS 605, which serves as a reference signal for decoding the DCI, is mapped. Furthermore, three DMRS 605s can be transmitted within one REG 603.

[0115] The search space for the PDCCH will be described below. Depending on the aggregation level (AL), the number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16, and link adaptation for the DL control channel can be achieved using different numbers of CCEs. For example, when AL=L, a DL control channel can be transmitted with L CCEs. The UE performs blind decoding to detect the signal without knowing information about the DL control channel, and therefore, a search space representing the set of CCEs can be defined for blind decoding. The search space is the set of DL control channel candidates, including the CCEs that the UE must attempt to decode on a given ALA, and because there are various ALs that make 1, 2, 4, 8, or 16 CCEs a bundle, the UE can have multiple search spaces. The search space set can be defined as the set of search spaces under all configured ALs.

[0116] The search space can be categorized into the common search space (CSS) and the UE-specific search space (USS). A specific group of UEs or all UEs can monitor the common search space of the PDCCH to receive dynamic scheduling of system information (System Information Blocks (SIBs)) or cell common control information such as paging messages. For example, a UE can monitor the CSS of the PDCCH to receive PDSCH scheduling allocation information for receiving system information. Because a specific group of UEs or all UEs need to receive the PDCCH, the common search space can be defined as a set of predefined CCEs. UEs can receive UE-specific PDSCH or PUSCH scheduling allocation information by monitoring the USS of the PDCCH. The USS can be defined specifically by the UE as a function of various system parameters and the UE's ID.

[0117] The BS can configure the search space information for the PDCCH for the UE via higher-level signaling (e.g., SIB, MIB, or RRC signaling). For example, the BS can configure the number of PDCCH candidates for each aggregation level L, the monitoring period of the search space, the monitoring timing in symbols within the time slots of the search space, the search space type (CSS or USS), the combination of DCI format and Radio Network Temporary Identifier (RNTI) to be monitored in the search space, and the CORESET index used for monitoring the search space. For example, the parameters regarding the PDCCH search space can include multiple pieces of information as shown in Table 6 below.

[0118] [Table 6]

[0119]

[0120]

[0121]

[0122]

[0123] Based on the configuration information, the BS can configure one or more search space sets in the UE. According to some embodiments, the BS can configure search space set 1 and search space set 2 in the UE. The BS can configure the UE to monitor DCI format A scrambled by X-RNTI in search space set 1 in the CSS, and to monitor DCI format B scrambled by Y-RNTI in search space set 2 in the USS.

[0124] Depending on the configuration information, a CSS or USS can include one or more search space sets. For example, search space set #1 and search space set #2 can be configured as a CSS, and search space set #3 and search space set #4 can be configured as a USS.

[0125] In CSS, UE can detect the following combinations of DCI format and RNTI. However, this disclosure is not limited to the following examples.

[0126] - 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. - DCI format 2_0 with CRC scrambled by SFI-RNTI - DCI format 2_1 with CRC scrambled by INT-RNTI - DCI format 2_2 with CRC scrambled by TPC PUSCH-RNTI and TPC PUCCH-RNTI - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI - DCI format 2_4 with CRC scrambled by CI-RNTI - DCI format 2_5 with CRC scrambled by AI RNTI - DCI format 2_6 with CRC scrambled by PS-RNTI - DCI format 2_7 with CRC scrambled by PEI-RNTI In the USS, the UE can monitor the following combinations of DCI formats and RNTI. However, this disclosure is not limited to the following examples.

[0127] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, and TC-RNTI. - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, and TC-RNTI. RNTI can follow the following definitions and purposes.

[0128] Cell RNTI (C-RNTI): Used for scheduling UE-specific PDSCH or PUSCH Temporary Cell RNTI (TC-RNTI): Used for scheduling UE-specific PDSCH Configured Scheduling RNTI (CS-RNTI): Used to schedule UE-specific PDSCHs with semi-static configuration. Random Access RNTI (RA-RNTI): Used for scheduling PDSCH during random access. Paging RNTI (P-RNTI): Used to schedule the PDSCH for sending paging requests. System Information RNTI (SI-RNTI): Used to schedule the transmission of system information via PDSCH. Interrupt RNTI (INT-RNTI): Used to notify the PDSCH whether a hole has been punched. Transmit Power Control RNTI for PUSCH (TPC-PUSCH-RNTI): Used to indicate power control commands for PUSCH. Transmit Power Control RNTI for PUCCH (TPC-PUCCH-RNTI): Used to indicate power control commands for PUCCH. Transmit Power Control RNTI for SRS (TPC-SRS-RNTI): Used to indicate power control commands for SRS. The DCI format described above can follow the definitions in Table 7 below.

[0129] [Table 7]

[0130] The search space under the aggregation level L of CORESET p and search space set s can be represented by Equation 1 below.

[0131] [Equation 1]

[0132] -L: Aggregation level -n CICarrier index -N CCE,p : The total number of CCEs in the control resource set p - Time slot index - Number of PDCCH candidates for aggregation level L - Indexes of PDCCH candidates at aggregation level L -i=0,…,L-1 -

[0133] -n RNTI UE ID In CSS, The value can correspond to 0.

[0134] The value can correspond to a value that changes based on the UE identifier (C-RNTI or ID configured for the UE by the BS) and the time index in the USS.

[0135] The method for configuring the Transport Configuration Indicator (TCI) state for the PDCCH (or PDCCH DMRS) in a 5G communication system will be described in detail.

[0136] The BS can configure and indicate the TCI state of the PDCCH (or PDCCH DMRS) through appropriate signaling. As described, the BS can configure and indicate the TCI state of the PDCCH (or PDCCH DMRS) through appropriate signaling. The TCI state is used to indicate the quasi-co-location (QCL) relationship between the PDCCH (or PDCCH DMRS) and another RS ​​(or channel), and when the reference antenna port A (reference RS#A) and another target antenna port B (target RS#B) are in QCL, this means that the UE is allowed to apply some or all of the large-scale channel parameters estimated from antenna port A to channel measurements from antenna port B. QCL can require different parameters to be associated with each other depending on the following: 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) radio resource management (RRM) affected by average gain, and 4) beam management (BM) affected by spatial parameters. Therefore, the NR supports four types of QCL relationships, as shown in Table 8.

[0137] [Table 8]

[0138] Spatial Rx parameters can be general terms for all or some of the following parameters, including 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.

[0139] QCL relationships can be configured in the UE using the RRC parameters TCI-State and QCL-Info as shown in Table 9. Referring to Table 9, the BS can configure at least one TCI state in the UE to notify the UE of up to two QCL relationships (qcl-Type1 and qcl-Type2) associated with the RS (i.e., the target RS) of the reference TCI state ID. In this case, each QCL information (QCL-Info) included in each TCI state includes the serving cell index and BWP index of the reference RS indicated by the QCL information, the type and ID of the reference RS, and the QCL type, as shown in Table 8.

[0140] [Table 9]

[0141]

[0142] Figure 7 Beam allocation performed by the BS according to the TCI state configuration according to an embodiment of the present disclosure is shown.

[0143] refer to Figure 7 The BS can send information about N different beams to the UE through N different TCI states. For example, when N is 3, the BS can configure the qcl-Type 2 parameter included in the three TCI states 700, 705 and 710 to be associated with the CSI-RS or SSB corresponding to different beams and set it to QCL type D, so as to notify the antenna ports referencing different TCI states 700, 705 and 710 that they are associated with different spatial Rx parameters (i.e., different beams).

[0144] Specifically, the combinations of TCI states applicable to the PDCCH DMRS antenna port are shown in Table 10 below. In Table 10, the UE assumes the combinations in the fourth row before RRC configuration, and configurations after RRC are not possible.

[0145] [Table 10]

[0146] In NR, dynamic allocation of PDCCH beams is supported, such as Figure 8 The layered signaling method shown.

[0147] Figure 8A hierarchical signaling method for dynamic allocation of PDCCH beams in an NR is illustrated according to an embodiment of the present disclosure.

[0148] refer to Figure 8 The BS can configure N TCI states 805, 810, ..., and 820 for the UE via RRC signaling 800, and can configure some TCI states as TCI states for CORESET (825). Subsequently, the BS can indicate one of the TCI states 830, 835, ..., and 840 for CORESET to the UE via MAC CE signaling (845). Afterwards, the UE receives the PDCCH based on the beam information included in the TCI states indicated by the MAC CE signaling.

[0149] Figure 9 A TCI indication MAC CE signaling structure for PDCCH DMRS according to an embodiment of the present disclosure is shown.

[0150] refer to Figure 9 The TCI indication MAC CE signaling used for PDCCH DMRS consists of 2 bytes (16 bits) and includes a 1-bit reserved field 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 status ID 930.

[0151] The BS can indicate the TCI status in the TCI status list included in the CORESET configuration via MAC CE signaling. Then, until another TCI status is indicated for the CORESET via another MAC CE signaling, the UE considers the same QCL information to be applied to all one or more search spaces connected to the CORESET.

[0152] The problem with the aforementioned PDCCH beam assignment method is that it is difficult to indicate beam switching faster than the MAC CE signaling delay, and the same beam is uniformly applied to each CORESET regardless of search space characteristics, making flexible PDCCH beam operation difficult. In the following, embodiments of this disclosure provide a more flexible PDCCH beam configuration and operation method. Although several different examples will be provided for ease of description of embodiments of this disclosure, these examples are not mutually exclusive and can be applied in appropriate combinations as needed.

[0153] The BS can configure one or more TCI states for a specific control resource set for the UE, and can activate one of the configured TCI states via a MAC CE activation command. For example, TCI states {TCI state #0, TCI state #1, and TCI state #2} can be configured for control resource set #1. The BS can send an activation command to the UE via MAC CE to assume that TCI state #0 is the TCI state for control resource set #1. Based on the activation command for the TCI state received via MAC CE, the UE can correctly receive the DMRS for the corresponding control resource set based on the QCL information in the activated TCI state.

[0154] When the UE fails to receive a MAC CE activation command in the TCI state of CORESET (i.e., CORESET#0) with index 0, the UE may assume that the DMRS sent in CORESET#0 is quasi-co-located with the SS / PBCH block (SSB) identified during the initial access process or during a non-contention-based random access process not triggered by a PDCCH command.

[0155] Regarding a CORESET (CORESET#X) configured with a different index value (X) instead of index 0, when the UE is not configured with a TCI state for CORESET#X or is configured with one or more TCI states but fails to receive a MAC CE activation command to activate one of the configured TCI states, the UE may assume that the DMRS sent in CORESET#X is quasi-co-located with the SS / PBCH block identified during the initial access procedure.

[0156] The downlink control information (DCI) in 5G systems will now be described in detail.

[0157] In 5G systems, scheduling information for UL data (or PUSCH) or DL ​​data (or PDSCH) can be transmitted from the BS to the UE in the DCI. The UE can monitor the fallback DCI format and the non-fallback DCI format used for PUSCH or PDSCH. The fallback DCI format may include predefined fixed fields between the BS and the UE, while the non-fallback DCI format may include configurable fields.

[0158] DCI messages can be transmitted on the Physical Downlink Control Channel (PDCCH) after channel coding and modulation. Cyclic Redundancy Check (CRC) can be added to the DCI message payload, and the CRC can be scrambled by a Radio Network Temporary Identifier (RNTI) corresponding to the UE's ID. Depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, random access responses, etc., different RNTIs can be used. That is, the RNTI can be sent during the CRC calculation process instead of explicitly. Upon receiving a DCI message transmitted on the PDCCH, the UE can check the CRC using the assigned RNTI and can identify that the DCI message was sent to the UE based on the CRC check result.

[0159] For example, the DCI for scheduling PDSCH used for System Information (SI) can be scrambled by SI-RNTI. The DCI for scheduling PDSCH used for Random Access Response (RAR) messages can be scrambled by RA-RNTI. The DCI for scheduling PDSCH used for paging messages can be scrambled by P-RNTI. The DCI for Notification Slot Format Indicator (SFI) can be scrambled by SFI-RNTI. The DCI for Notification Transmit Power Control (TPC) can be scrambled by TPC-RNTI. The DCI for scheduling UE-specific PDSCH or PUSCH can be scrambled by Cell RNTI (C-RNTI).

[0160] DCI format 0_0 can be used for the backoff DCI of PUSCH, and here, the CRC can be scrambled by C-RNTI. DCI format 0_0 with a CRC scrambled by C-RNTI can include multiple pieces of information as shown in Table 11 below.

[0161] [Table 11]

[0162]

[0163] DCI format 0_1 ​​can be used for non-back-off DCI scheduling of PUSCH, and here, the CRC can be scrambled by C-RNTI. DCI format 0_1 ​​with a CRC scrambled by C-RNTI can include multiple pieces of information as shown in Table 12 below.

[0164] [Table 12]

[0165]

[0166]

[0167]

[0168]

[0169] DCI format 1_0 can be used to schedule the backoff DCI of PDSCH, and here, the CRC can be scrambled by C-RNTI. DCI format 1_0 with a CRC scrambled by C-RNTI can include multiple pieces of information as shown in Table 13 below.

[0170] [Table 13]

[0171] DCI format 1_1 can be used for non-back-off DCI scheduling of PDSCH, and here, the CRC can be scrambled by C-RNTI. DCI format 1_1 with a CRC scrambled by C-RNTI can include multiple pieces of information as shown in Table 14 below.

[0172] [Table 14]

[0173]

[0174]

[0175]

[0176] The following section will now describe a method for allocating time-domain resources for data channels in 5G communication systems.

[0177] The BS can configure tables for the UE using higher-layer signaling (e.g., RRC signaling) to provide time-domain resource allocation information for the DL data channel (PDSCH) and UL data channel (PUSCH). For PDSCH, a table with up to 16 entries (maxNrofDL-Allocations=16) can be configured, and for PUSCH, a table with up to 16 entries (maxNrofUL-Allocations=16) can be configured. For example, the time-domain resource allocation information may include PDCCH-PDSCH time slot timing (corresponding to the time interval in time slots between the PDCCH reception time and the PDSCH transmission time scheduled by the received PDCCH, and indicated as K0), PDCCH-PUSCH time slot timing (corresponding to the time interval in time slots between the PDCCH reception time and the PUSCH transmission time scheduled by the received PDCCH, and indicated as K2), information regarding the position and length of the start symbol scheduled on the PDSCH or PUSCH within a time slot, the mapping type of the PDSCH or PUSCH, etc. For example, the BS can notify the UE of multiple pieces of information as shown in Tables 15 and 16 below.

[0178] [Table 15]

[0179] [Table 16]

[0180] The BS can notify the UE of at least one entry from Tables 15 and 16 regarding time-domain resource allocation information via L1 signaling (e.g., DCI). (For example, an entry can be indicated in the "Time-domain Resource Allocation" field of the DCI.) The UE can obtain time-domain resource allocation information for PDSCH or PUSCH based on the DCI received from the BS.

[0181] The frequency domain resource allocation method for data channels in 5G communication systems will now be described below.

[0182] As a method for indicating frequency domain resource allocation information regarding PDSCH and PUSCH, 5G communication systems support two types: resource allocation type 0 and resource allocation type 1.

[0183] Resource allocation type 0 The BS can notify the UE of RB allocation information in the form of a bitmap about a Resource Block Group (RBG). Here, the RBG can consist of a set of Sequential Virtual RBs (VRBs), and the size of the RBG... P It can be based on high-level parameters ( rbg-SizeThe value configured and the value of BWP defined in Table 17 below are used to determine this.

[0184] [Table 17]

[0185] - Size is The total number of RBGs of BWP i ( N RGB It can be defined as follows.

[0186] ,in The size of the first RGB is , if Then the final size of RBG is Otherwise, it is P. The sizes of all other RBGs are P .

[0187] - Size is N RGB The bits of the bitmap can each correspond to an RBG. The RBGs can be indexed in order from the lowest frequency position of the BWP to the highest frequency. Regarding the BWP... N RGB One RBG, RBG#0 to RBG# ( N RGB The RBG can be sequentially mapped from the most significant bit (MSB) to the least significant bit (LSB) in the bitmap. When a specific bit in the bitmap is 1, the UE can determine that an RBG corresponding to that bit value has been allocated, and when a specific bit in the bitmap is 0, the UE can determine that an RBG corresponding to that bit value has not been allocated.

[0188] Resource allocation type 1 This information pertains to the starting position and length of the VRB to which the RB allocation information is sequentially assigned, and can be communicated to the UE from the BS. Here, interleaving or non-interleaving can also be applied to sequentially allocated VRBs. The resource allocation field for Resource Allocation Type 1 can be configured as a Resource Indication Value (RIV), and the RIV can be configured as the VRB starting point. RB start and the length of the sequentially allocated RB L RB More specifically, the size is The RIV in BWP can be defined as follows.

[0189] if ,but

[0190] otherwise

[0191] in, And should not exceed .

[0192] The BS can semi-statically configure the time and frequency transmission resources for PDSCH and PUSCH, as well as various transmit and receive parameters, to the UE to support license-based transmission and reception of DL data channels (PDSCH) or UL data channels (PUSCH).

[0193] More specifically, the BS can configure multiple pieces of information in Table 18 below for the UE through higher-layer signaling (e.g., RRC signaling) to support DL semi-static scheduling (SPS).

[0194] [Table 18]

[0195] DL SPS can be configured in a primary or secondary cell, and within a cell group, DL SPS can be configured in a single cell.

[0196] As a configuration-authorized (or unauthorized) transmission method for PUSCH, two types (Type-1 PUSCH transmission with configuration authorization and Type-2 PUSCH transmission with configuration authorization) can be supported in 5G communication systems.

[0197] Type-1 PUSCH transport with configuration authorization In a Type-1 PUSCH transmission with configuration authorization, the BS can configure specific time / frequency resources 600 for the UE to allow configuration-authorized PUSCH transmissions via higher-layer signaling such as RRC signaling. For example, Figure 6 As shown, the BS can configure resource 600's time axis allocation information 601, frequency axis allocation information 602, period information 603, etc. Furthermore, the BS can configure various parameters for the UE via higher-layer signaling (e.g., frequency hopping, DMRS configuration, modulation and coding scheme (MCS) table, MCS, RBG size, number of repeated transmissions, redundancy version (RV), etc.). More specifically, it can include multiple configuration information items as shown in Table 19.

[0198] [Table 19]

[0199]

[0200] When the UE receives configuration information from the BS for Type-1 PUSCH transmission with configuration authorization, the UE can periodically transmit PUSCH on configuration resource 600 without authorization from the BS. Various parameters (e.g., frequency hopping, DMRS configuration, MCS, RBG size, number of repeated transmissions, RV, number of precoding and layers, antenna port, frequency hopping offset, etc.) can follow the configuration values ​​notified by the BS.

[0201] Type-2 PUSCH transport with configuration authorization In a Type-2 PUSCH transmission with configuration authorization, the BS can configure the UE with some information (e.g., periodic information 603) from information about a specific time / frequency resource 600 on which configuration authorization PUSCH transmission is permitted. Furthermore, the BS can configure various parameters for the UE via higher-layer signaling (e.g., frequency hopping, DMRS configuration, MCS table, RBG size, number of repeated transmissions, RV, etc.). More specifically, the BS can configure the UE with multiple configuration information items as shown in Table 20 via higher-layer signaling.

[0202] [Table 20]

[0203] The BS can send a DCI to the UE that includes a specific DCI field value, which is used to specify DL SPS and UL license type 2 scheduling activation or release.

[0204] More specifically, the BS can configure the Configurable Schedule-RNTI (CS-RNTI) for the UE, and the UE can monitor the DCI format with a CRC scrambled by CS-RNTI. When the CRC of the DCI format received by the UE is scrambled by CS-RNTI, the New Data Indicator (NDI) is set to '0', and the DCI field satisfies Table 21 below, the UE can treat the DCI as an instruction to activate transmission and reception with respect to DL SPS or UL Authorization Type 2.

[0205] [Table 21]

[0206] The BS can configure CS-RNTI for the UE, and the UE can monitor the DCI format with a CRC scrambled by CS-RNTI. When the CRC of the DCI format received by the UE is scrambled by CS-RNTI, the NDI is set to '0', and the DCI field meets the requirements of Table 22 below, the UE can regard the DCI as an instruction to activate the transmission and reception of DL SPS or UL license type 2.

[0207] [Table 22]

[0208] Because the DCI indicating a release of DL SPS or UL license type 2 follows the DCI format corresponding to DCI format 0_0 or DCI format 1_0, and DCI format 0_0 or 1_0 does not include a carrier indicator field (CIF), in order to receive a release command for DL ​​SPS or UL license type 2 for a specific cell, the UE must always perform PDCCH monitoring in the cell for which the corresponding DL SPS or UL license type 2 is configured. Even when a specific cell is configured with cross-carrier scheduling, in order to receive a release command for DL ​​SPS or UL license type 2 for a specific cell, the UE must always monitor DCI format 1_0 or DCI format 0_0 in the corresponding cell.

[0209] The carrier aggregation (CA) and scheduling methods in 5G communication systems will now be described in detail below.

[0210] A UE can be configured with multiple cells (cells or component carriers (CCs)) from the BS, and cross-carrier scheduling can be configured for the cells configured for the UE. If cross-carrier scheduling is configured for a specific cell (cell A, the scheduled cell), PDCCH monitoring for cell A can be performed not in cell A, but in another cell (cell B, the scheduling cell) that is indicated for cross-carrier scheduling. Here, the scheduled cell (cell A) and the scheduling cell (cell B) can be configured with different parameter sets. These parameter sets may include subcarrier spacing, cyclic prefix, etc. When the parameter sets of cell A and cell B are different, and cell B's PDCCH schedules cell B's PDSCH, the following minimum scheduling offset can be considered between the PDCCH and PDSCH.

[0211] Cross-carrier scheduling method When the subcarrier spacing of cell B is (μ B The subcarrier spacing of cell A is less than (μ). AWhen X symbols follow the last symbol of the PDCCH received from cell B, the next PDSCH slot of the PDSCH slot can be scheduled. Here, X can be determined based on μ. B Unlike μ, it can be defined as when μ B When X = 4 symbols, when μ B When X = 4 symbols, and when μ B X = 8 symbols.

[0212] When the subcarrier spacing of cell B is (μ B The subcarrier spacing of cell A is greater than (μ). A When the PDSCH is received from cell B, the PDSCH can be scheduled from the PDSCH slot following the last symbol of the PDCCH received from cell B. Here, X can be determined based on μ. B And it is different, and can be defined as when μ B When X = 4 symbols, when μ B When X = 8 symbols, when μ B X = 12 symbols.

[0213] The rate matching operation and the punching operation will now be described in detail below.

[0214] When the time and frequency resources A for transmitting a random symbol sequence A overlap with random time and frequency resources B, rate matching or puncturing operations can be considered for the transmission and reception of channel A (or symbol sequence A), taking into account resource C in the region where resources A and B overlap. Detailed operations will now be provided.

[0215] Rate matching operation The BS can transmit symbol sequence A by mapping channel A (or symbol sequence A) to the entire resource A on which it plans to transmit symbol sequence A to the UE, except for the area of ​​resource A corresponding to resource C that overlaps with resource B. For example, when symbol sequence A includes {symbol #1, symbol #2, symbol #3, and symbol #4}, resource A includes {resource #1, resource #2, resource #3, and resource #4}, and resource B includes {resource #3 and resource #5}, the BS can transmit symbol sequence A by sequentially mapping symbol sequence A to resources {resource #1, resource #2, and resource #4} of resource A, excluding {resource #3} corresponding to resource C. Therefore, the BS can transmit symbol sequence {symbol #1, symbol #2, and symbol #3} by mapping symbol sequence {symbol #1, symbol #2, and symbol #3} to {resource #1, resource #2, and resource #4} respectively.

[0216] The UE can determine resources A and B based on the scheduling information of symbol sequence A from the BS, and therefore, can determine resource C corresponding to the overlapping area between resources A and B. The UE can assume that symbol sequence A is transmitted by being mapped to the entire resource A excluding resource C, and thus receive symbol sequence A. For example, when symbol sequence A includes {symbol #1, symbol #2, symbol #3, and symbol #4}, resource A includes {resource #1, resource #2, resource #3, and resource #4}, and resource B includes {resource #3 and resource #5}, the UE can receive symbol sequence A, assuming that symbol sequence A is sequentially mapped to resources {resource #1, resource #2, and resource #4} of resource A excluding {resource #3} corresponding to resource C. Therefore, the UE can assume that symbol sequence {symbol #1, symbol #2, and symbol #3} is transmitted by being mapped to {resource #1, resource #2, and resource #4} respectively, and can perform a series of subsequent operations.

[0217] Drilling operation When a resource C exists that corresponds to the overlapping area between the entire resource A and resource B on which symbol sequence A is planned to be transmitted to the UE, the BS can map symbol sequence A to the entire resource A. However, it can perform transmission in the resource area of ​​resource A that does not include resource C, instead of performing transmission in the resource area corresponding to resource C. For example, when symbol sequence A includes {symbol #1, symbol #2, symbol #3, and symbol #4}, resource A includes {resource #1, resource #2, resource #3, and resource #4}, and resource B includes {resource #3 and resource #5}, the BS can map symbol sequence A {symbol #1, symbol #2, symbol #3, and symbol #4} to resource A {resource #1, resource #2, resource #3, and resource #4}, and can transmit symbol sequence {symbol #1, symbol #2, and symbol #4} corresponding to the resource area {resource #1, resource #2, and resource #4} of resource A that does not include {resource #3} corresponding to resource C, instead of transmitting {symbol #3} mapped to {resource #3} corresponding to resource C. Therefore, the BS can send the symbol sequence {symbol #1, symbol #2, and symbol #4} by mapping the symbol sequence {symbol #1, symbol #2, and symbol #4} to {resource #1, resource #2, and resource #4} respectively.

[0218] The UE can determine resources A and B based on the scheduling information of symbol sequence A from the BS, and therefore, can determine resource C corresponding to the overlapping area between resources A and B. The UE can receive symbol sequence A, assuming it is mapped to the entire resource A, but only transmits it over the area of ​​resource A (excluding resource C). For example, when symbol sequence A includes {symbol #1, symbol #2, symbol #3, and symbol #4}, resource A includes {resource #1, resource #2, resource #3, and resource #4}, and resource B includes {resource #3 and resource #5}, the UE can assume that symbol sequence A {symbol #1, symbol #2, symbol #3, and symbol #4} is mapped to resource A {resource #1, resource #2, resource #3, and resource #4}, but the {symbol #1, symbol #2, and symbol #4} of symbol sequence A mapped to {resource #1, resource #2, and resource #4} is transmitted, while the {symbol #3} mapped to the corresponding resource C is not transmitted, thus performing reception. Therefore, the UE can assume that the symbol sequence {symbol #1, symbol #2 and symbol #4} is transmitted by mapping to {resource #1, resource #2 and resource #4} respectively, and can perform a series of subsequent operations.

[0219] Figure 10 This is a diagram illustrating a method by which a BS and a UE transmit or receive data by taking into account DL data channels and rate matching resources according to embodiments of the present disclosure.

[0220] refer to Figure 10 The diagram illustrates a DL data channel (PDSCH) 1001 and rate matching resources 1002. The BS can configure one or more rate matching resources 1002 for the UE via higher-layer signaling (e.g., RRC signaling). Configuration information for rate matching resources 1002 may include time-domain resource allocation information 1003, frequency-domain resource allocation information 1004, and periodic information 1005. In the following text, the bitmap corresponding to the frequency-domain resource allocation information 1004 is referred to as the "first bitmap," the bitmap corresponding to the time-domain resource allocation information 1003 is referred to as the "second bitmap," and the bitmap corresponding to the periodic information 1005 is referred to as the "third bitmap." When all or some of the time and frequency resources of the scheduled data channel 1001 overlap with the configured rate matching resource 1002, the BS can transmit the data channel 1001 by performing rate matching on the data channel 1001 in a portion of the rate matching resource 1002, and the UE can assume that the data channel 1001 has been rate matched in that portion of the rate matching resource 1002, and then can receive and decode the data channel 1001.

[0221] With additional configuration, the BS can dynamically notify the UE via DCI (corresponding to the "rate matching indicator" in the DCI format described above) whether to perform rate matching on the data channel in that portion of the configured rate matching resources. More specifically, the BS can select some configured rate matching resources and group them into rate matching resource groups, and can indicate to the UE via DCI in a bitmap scheme whether to perform rate matching on the data channel for each rate matching resource group. For example, when four rate matching resources are configured (e.g., RMR#1, RMR#2, RMR#3, and RMR#4), the BS can configure rate matching groups RMG#1={RMR#1, RMR#2} and RMG#2={RMR#3, RMR#4}, and can indicate to the UE via a bitmap using 2 bits in the DCI field whether to perform rate matching in each of RMG#1 and RMG#2. For example, the BS can indicate "1" when rate matching is required and "0" when rate matching is not required.

[0222] 5G communication systems support "RB symbol level" and "RE level" granularity for methods used to configure rate matching resources for UEs. For more detailed information, the configuration methods below can be performed.

[0223] RB symbol level The UE can configure up to four RateMatchPatterns for each BWP via higher-layer signaling, and each RateMatchPattern can include the following information.

[0224] - Reserved resources on the BWP can include time and frequency resource regions configured with a combination of symbol-level bitmaps and RB-level bitmaps on the frequency axis. Reserved resources can span one or two time slots. A time-domain pattern (periodicityAndPattern) can be additionally configured, in which time and frequency regions composed of RB-level and symbol-level bitmap pairs are repeated.

[0225] - This can include a time-frequency domain resource region configured with CORESET on the BWP and a resource region corresponding to a time-domain mode configured with a search space, wherein the time-frequency domain resource region is repeated.

[0226] RE Level The UE can be configured with the following features via higher-level signaling.

[0227] - Configuration information of the RE corresponding to the LTE cell-specific reference signal or common reference signal (CRS) mode (lte-CRS-ToMatchAround), which may include the number of LTE CRS ports (nrofCRS-Ports), the LTE CRS-vshift (v-shift) value, the center subcarrier location information of the LTE carrier from the reference frequency point (e.g., reference point A) (carrierFreqDL), the bandwidth information of the LTE carrier (carrierBandwidthDL), and the subframe configuration information corresponding to the Multicast Broadcast Single Frequency Network (MBSFN) (mbsfn-SubframConfigList). The UE can determine the position of the CRS in the NR slot corresponding to the LTE subframe based on the above information.

[0228] - Configuration information about the resource set corresponding to one or more Zero Power (ZP) CSI RS in the BWP.

[0229] The methods for measuring and reporting channel status in 5G communication systems will be described in detail below.

[0230] Channel State Information (CSI) may include Channel Quality Information (CQI), Precoding Matrix Indicator (PMI), CSI Reference Signal (RS) Resource Indicator (CRI), Synchronization Signal / Physical Broadcast Channel (SS / PBCH) Block Resource Indicator (SSBRI), Layer Indicator (LI), Rank Indicator (RI), and / or L1 Reference Signal Received Power (RSRP). The BS can control the time and frequency resources used for CSI measurements and reporting performed by the UE.

[0231] For CSI measurements and reporting, the UE can be configured via higher-layer signaling with settings information (CSI-ReportConfig) for N (≥1) CSI reports, settings information (CSI-ResourceConfig) for M (≥1) RS transmission resources, and one or two trigger states (CSI-AperiodicTriggerStateList, CSI-SemipersistentOnPUSCH-TriggerStateList).

[0232] The configuration information for CSI measurement and reporting is shown in Tables 23 to 29 below.

[0233] [Table 23] IE CSI-ReportConfig is used to configure periodic or semi-static reports sent on the PUCCH of a cell that includes CSI-ReportConfig, or to configure semi-static or non-periodic reports sent on the PUSCH triggered by a DCI received on a cell that includes CSI-ReportConfig (in which case the cell sending the report is determined by the received DCI). See TS 38.214

[19] , Clause 5.2.1.

[0234] CSI-ReportConfig Information Elements

[0235]

[0236]

[0237]

[0238] [Table 24] The IE CSI-ResourceConfig defines one or more groups of NZP-CSI-RS-ResourceSet, CSI-IM-ResourceSet, and / or CSI-SSB-ResourceSet.

[0239] CSI-ResourceConfig Information elements

[0240]

[0241] [Table 25] The IE NZP-CSI-RS-ResourceSet is a collection of non-zero power (NZP) CSI-RS resources (and their IDs) and set-specific parameters.

[0242] NZP-CSI-RS-ResourceSet Information elements

[0243]

[0244] [Table 26] The IE CSI-SSB-ResourceSet is used to configure an SS / PBCH block resource set, which involves the SS / PBCH indicated in ServingCellConfigCommon.

[0245] CSI-SSB-ResourceSet Information elements

[0246] [Table 27] The IE CSI-IM-ResourceSet is used to configure a set of one or more CSI Interference Management (IM) resources (and their IDs) and set-specific parameters.

[0247] CSI-IM-ResourceSet Information elements

[0248]

[0249] [Table 28] The CSI-AperiodicTriggerStateList IE is used to configure an aperiodic trigger state list for the UE. Each code point in the DCI field "CSI request" is associated with a trigger state. Once the value associated with a trigger state is received, the UE will perform measurements on the CSI-RS (reference signal) and generate an aperiodic report on L1 based on all entries in the associatedReportConfigInfo for that trigger state.

[0250] CSI-AperiodicTriggerStateList Information elements

[0251]

[0252]

[0253] [Table 29] The CSI-SemiPersistentOnPUSCH-TriggerStateList IE is a list of trigger states used to configure semi-static reporting of channel state information on L1 for the UE. See also TS 38.214

[19] , Section 5.2.

[0254] CSI-SemiPersistentOnPUSCH-TriggerStateList Information elements

[0255] Regarding the aforementioned CSI report settings (CSI-ReportConfig), each report setting (CSI-ReportConfig) can be associated with a corresponding CSI resource setting and a DL BWP identified by the higher-layer parameter bwp-id given by CSI-ResourceConfig. As for the time-domain reporting operation for each report setting (CSI-ReportConfig), aperiodic, semi-static, or periodic schemes can be supported, and the time-domain reporting operation can be configured for the UE from the BS via the reportConfigType parameter configured by the higher layer. The semi-static CSI reporting method supports either a PUCCH-based semi-static (semi-PersistentOnPUCCH) reporting method or a PUSCH-based semi-static (semi-PersistentOnPUSCH) reporting method. Depending on the periodic or semi-static CSI reporting method, the base station can configure the PUCCH or PUSCH resources for transmitting CSI to the UE via higher-layer signaling. The period and slot offset of the PUCCH or PUSCH resources used for transmitting CSI can be given by the parameter set of the UL BWP configured for transmitting CSI reports. According to the non-periodic CSI reporting method, the UE can receive the scheduling of PUSCH resources for sending CSI from the BS via L1 signaling (DCI format 0_1 ​​above).

[0256] Regarding CSI resource settings (CSI-ResourceConfig), each CSI resource setting (CSI-ReportConfig) can include S (≥1) CSI resource sets (given by the higher-level parameter csi-RS-ResourceSetList). The list of CSI resource sets can be configured as non-zero power (NZP) CSI-RS resource sets and SS / PBCH block sets, or as CSI-Interference Measurement (CSI-IM) resource sets. Each CSI resource setting can reside on a DL BWP identified by the higher-level parameter bwp-id, and CSI resource settings can be associated with CSI reporting settings of the same DL BWP. The time-domain operation of the CSI-RS resources in a CSI resource setting can be configured as 'aperiodic', 'periodic', or 'semi-static' via the higher-level parameter resourceType. For periodic or semi-static CSI resource settings, the number of CSI-RS resource sets can be limited to S=1, and the configured period and slot offset can be given by the parameter set of the DL BWP identified by bwp-id. The BS can configure one or more CSI resource settings for channel or interference measurement to the UE via higher-layer signaling, and for example, the CSI resource settings may include the following CSI resources.

[0257] -CSI-Interference Measurement (IM) Resources for IM - NZP CSI-RS resources for IM - NZP CSI-RS resources for channel measurements For a CSI-RS resource set associated with a resource setting configured as 'aperiodic', 'periodic', or 'semi-static' via the higher-level parameter resourceType, the triggering state for CSI reporting settings where reportType is configured as 'aperiodic' and resource settings for channel or interference measurements for one or more component cells (CCs) can be configured via the higher-level parameter CSI-AperiodicTriggerStateList.

[0258] A non-periodic CSI reporting by the UE can be performed using PUSCH, while periodic CSI reporting can be performed using PUCCH. Semi-static CSI reporting can also be performed using PUSCH when triggered or activated by DCI, and can be performed using PUCCH after activation by a Media Access Control (MAC) CE element (MAC CE). As mentioned above, CSI resource settings can also be configured as 'non-periodic', 'periodic', or 'semi-static'. Combinations of CSI reporting settings and CSI resource settings are supported based on Table 30 below.

[0259] [Table 30]

[0260] 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 relative to the PUSCH. The UE can monitor the PDCCH, obtain DCI format 0_1, and acquire scheduling information about the PUSCH and the CSI request indicator. The CSI request indicator can be configured with N... TS (=0, 1, 2, 3, 4, 5, or 6) bits, and can be determined by higher-level signaling (reportTriggerSize). The CSI request indicator can trigger one of one or more non-periodic CSI report trigger states that can be configured by higher-level signaling (CSI-AperiodicTriggerStateList).

[0261] - When all bits of the CSI request field are 0, this indicates that a CSI report should not be requested.

[0262] - If the number (M) of CSI trigger states in the configured CSI-AperiodicTriggerStateList is greater than 2NTs-1, then the M CSI trigger states can be mapped to 2NTs-1 according to the predefined mapping relationship, and one of the trigger states in the 2NTs-1 CSI trigger states can be indicated by the CSI request field.

[0263] - If the number (M) of CSI trigger states in the configured CSI-AperiodicTriggerStateList is equal to or less than 2NTs-1, one of the M CSI trigger states can be indicated by the CSI Request field.

[0264] Table 31 below shows an example of the relationship between the CSI request indicator and the CSI triggering state indicated by the CSI request indicator.

[0265] [Table 31]

[0266] The UE can perform measurements on CSI resources in a CSI-triggered state triggered by the CSI request field, and can generate a CSI (including at least one of CQI, PMI, CRI, SSBRI, LI, RI, or L1-RSRP) based on the measurement results. The UE can transmit the generated CSI using a PUSCH scheduled by the corresponding DCI format 0_1. When a bit in DCI format 0_1 ​​corresponding to the UL data indicator (UL-SCH indicator) is "1", the UE can utilize the PUSCH resource scheduled by DCI format 0_1, multiplex the UL data (UL-SCH) and the obtained CSI, and can transmit it. When a bit in DCI format 0_1 ​​corresponding to the UL data indicator (UL-SCH indicator) is "0", the UE can map the CSI to the PUSCH resource scheduled by DCI format 0_1 ​​only, without UL data (UL-SCH), and can transmit it.

[0267] Figure 11 and Figure 12 An example of a non-periodic CSI reporting method according to an embodiment of the present disclosure is shown.

[0268] refer to Figure 11The UE can obtain DCI format 0_1 ​​by monitoring PDCCH 1101, and can obtain scheduling information and CSI request information about PUSCH 1105 from DCI format 0_1. The UE can obtain resource information about the CSI RS 1102 to be measured from the received CSI request indicator. The UE can determine at which time point the transmitted CSI-RS 1102 should be measured based on the reception time of DCI format 0_1 ​​and the offset parameter (aperiodicTriggeringOffset mentioned above) in the CSI resource set configuration (e.g., NZP CSI-RS resource set configuration (NZP-CSI-RS-ResourceSet)). Specifically, the BS can configure the offset value X of the parameter aperiodicTriggeringOffset in the NZP-CSI-RS resource set configuration to the UE via higher-layer signaling, and the configured offset value X can indicate the offset between the time slot of the DCI that triggers the aperiodic CSI report and the time slot of the CSI-RS resource to be transmitted. For example, the value of the parameter aperiodicTriggeringOffset and the offset value X can have the mapping relationship described in Table 32 below.

[0269] [Table 32]

[0270] refer to Figure 12 The offset value is configured as X=0. In this case, the UE can receive the DCI format 0_1 ​​slot (corresponding to) that triggers the aperiodic CSI report. Figure 11 The UE receives CSI RS 1102 in time slot 0 and can report CSI information about PUSCH 1105 to the BS, which is measured using the received CSI RS 1102. The UE can obtain scheduling information (multiple pieces of information corresponding to fields in DCI format 0_1) about PUSCH 1105 used for CSI reporting from DCI format 0_1. For example, the UE can obtain information about the time slot in which PUSCH 1105 is to be transmitted from the time-domain resource allocation information in DCI format 0_1 ​​about PUSCH 1105. Figure 11 In the example, the UE can obtain 3 as the K2 value corresponding to the slot offset value used for PDCCH to PUSCH, and therefore, PUSCH 1105 can be transmitted in slot 3 1109, which is 3 slots away from the slot 01106 where PDCCH 1101 was received.

[0271] exist Figure 12In the example, the UE can obtain DCI format 0_1 ​​by monitoring PDCCH 1201, and can obtain scheduling information and CSI information about PUSCH 1205 from DCI format 0_1. The UE can obtain resource information about the CSI RS 1202 to be measured from the received CSI request indicator. Figure 12 In the example, the aforementioned offset value for CSI-RS is configured as X=1. In this case, the UE can receive the DCI format 0_1 ​​slot that triggers an aperiodic CSI report ( Figure 13 The CSI RS 1202 is received in time slot 0 (1206) and can be reported to the BS via PUSCH 1205 using CSI information measured by the received CSI RS.

[0272] Next, the BWP configuration in the 5G communication system will be described in detail.

[0273] Figure 13 An example of the configuration of a BWP in a 5G communication system according to an embodiment of the present disclosure is shown.

[0274] refer to Figure 13 The UE bandwidth of 1400 can be configured as two BWPs, namely BWP#1 1301 and BWP#2 1302. The BS can configure one or more BWPs for the UE, and can configure multiple pieces of information for each BWP, as shown in Table 33 below.

[0275] [Table 33]

[0276] Multiple messages can be sent from the BS to the UE via higher-level signaling (e.g., RRC signaling). At least one of the configured BWPs can be activated. Whether a configured BWP is activated can be semi-statically notified to the UE via RRC signaling or dynamically via DCI.

[0277] Before the UE is connected via RRC, the UE can be configured with an initial BWP for initial access by the BS in the Master Information Block (MIB). More specifically, during the initial access process, the UE can receive configuration information for CORESET and search space (where PDCCH can be transmitted) via the MIB to receive system information requested for initial access (e.g., Residual System Information (RMSI) or System Information Block 1 (SIB1)). Each of the CORESETs and search spaces configured in the MIB can be considered to have an ID (ID) of 0. The BS can notify the UE of the configuration information for CORESET#0 in the MIB, such as frequency allocation information, time allocation information, parameter sets, etc. In addition, the BS can notify the UE of configuration information in the MIB, such as the monitoring period and timing of CORESET#0, i.e., the configuration information of search space #0. The UE can regard the frequency area configured as CORESET#0 obtained from the MIB as the initial BWP for initial access. Here, the ID of the initial BWP can be considered as 0.

[0278] BWP configurations supported by 5G communication systems can be used for a variety of purposes.

[0279] According to the embodiment, when the bandwidth supported by the UE is less than the system bandwidth, the BS can support additional bandwidth through the configuration of the BWP. For example, the BS can configure the frequency position of the BWP for the UE (configuration information 2), so that the UE can send or receive data at a specific frequency position in the system bandwidth.

[0280] To support different parameter sets, the BS can configure multiple BWPs for the UE. For example, to support data transmission and reception for a UE using both 15kHz and 30kHz subcarrier intervals, the BS can configure two BWPs with 15kHz and 30kHz subcarrier intervals respectively. Different BWPs can be frequency-division multiplexed, and the BWP configured with that subcarrier interval can be activated when the UE attempts to transmit and receive data with a specific subcarrier interval.

[0281] Furthermore, to reduce UE power consumption, the BS can configure BWPs with different bandwidth sizes for the UE. For example, very high power consumption can occur when the UE supports a very large bandwidth (e.g., 100 MHz bandwidth) and always transmits or receives data within that bandwidth. In particular, monitoring unnecessary DL control channels within a large 100 MHz bandwidth in the absence of service can be very inefficient in terms of power consumption. To reduce UE power consumption, the BS can configure BWPs with relatively smaller bandwidths, such as a 20 MHz BWP. In the absence of service, the UE can perform monitoring within the 20 MHz BWP, and when data occurs, the UE can transmit or receive data on the 100 MHz BWP based on indications from the BS.

[0282] In the method of configuring the BWP, the UE can receive configuration information for the initial BWP during the initial access procedure via the MIB before being connected by RRC. More specifically, the UE can be configured with a control resource set for the DL control channel based on the MIB of the Physical Broadcast Channel (PBCH), on which DCI for scheduling SIBs can be transmitted. The bandwidth of the CORESET configured based on the MIB can be regarded as the initial BWP, and the UE can receive PDSCHs on which SIBs are transmitted on the initial BWP. In addition to receiving SIBs, the initial BWP can also be used for other System Information (OSI), paging, or random access.

[0283] When one or more BWPs are configured for a UE, the BS can indicate the BWP handover to the UE using the BWP indicator field in the DCI. For example, in Figure 3 In the process, when the UE's currently active BWP is BWP#1 1301, the BS can use the bandwidth indicator in the DCI to indicate BWP#2 1302 to the UE, and the UE can perform a BWP handover to BWP#2 1302 indicated by the BWP indicator in the received DCI.

[0284] As mentioned above, DCI-based BWP handover can be indicated by the DCI scheduling PDSCH or PUSCH. Therefore, when the UE receives a BWP handover request, the UE may need to perform the transmission or reception of the PDSCH or PUSCH scheduled by the DCI without difficulty in the BWP being handed over. For this purpose, the delay time T required for BWP handover... BWP The requirements are defined in the standard, and may be defined, for example, in Table 34 below.

[0285] [Table 34]

[0286] Depending on the UE's capabilities, the requirement for BWP handover latency time supports either Type 1 or Type 2. The UE can report the supported BWP latency time type to the BS.

[0287] Based on the requirements for BWP handover delay time, when the UE receives the DCI including the BWP handover indicator in time slot n, the UE can receive the DCI no later than time slot n+T. BWP The handover to the new BWP indicated by the BWP handover indicator is completed, and data channels scheduled by the DCI can be transmitted or received on the new BWP. When the BS attempts to schedule data channels on the new BWP, the BS can take into account the UE's BWP handover delay time (T). BWP The method for determining the allocation of time-domain resources for the data channel is as follows: This means that when the BS schedules a data channel on a new BWP, the BS can schedule the data channel after the BWP handover delay time, depending on the method used to determine the allocation of time-domain resources for the data channel. Therefore, the UE may not expect the DCI indication instructing the BWP handover to be less than the BWP handover delay time T. BWP The time slot offset value (K0 or K2).

[0288] If the UE receives a DCI indicating a BWP handover (e.g., DCI format 1_1 or 01), the UE may refrain from any transmission or reception for a period from the third symbol of the slot in which the PDCCH including the DCI is received to the start point of the slot indicated by the slot offset value (K0 or K2) in the time domain resource allocation indicator field of the DCI. For example, if the UE has already received a DCI indicating a BWP handover in slot n and the slot offset value indicated by the DCI is K, the UE may refrain from any transmission or reception from the third symbol of slot n to the symbols preceding slot n+k (i.e., the last symbol of slot n+K-1).

[0289] The following will now describe a method for configuring parameters associated with transmission and reception for each BWP in a 5G wireless communication system.

[0290] The UE can be configured by the BS to have one or more BWPs, and can be further configured with transmission and reception parameters for each configured BWP (e.g., configuration information related to UL and DL data channels and control channels, etc.). For example, refer to Figure 13When the UE is configured with BWP#1 1301 and BWP#2 1302, the UE can be configured with transmit / receive parameter #1 for BWP#1 1301 and transmit / receive parameter #2 for BWP#2 1302. When BWP#1 1301 is activated, the UE can perform transmit and receive operations with the BS based on transmit / receive parameter #1, and when BWP#2 1302 is activated, the UE can perform transmit and receive operations with the BS based on transmit / receive parameter #2.

[0291] More specifically, the UE can be configured by the BS with the following parameters.

[0292] First, you can configure multiple pieces of information as shown in Table 35 for the UL BWP.

[0293] [Table 35]

[0294]

[0295] According to Table 35, the UE can be configured by the BS with cell-specific (or cell-common or common) transmission-related parameters (e.g., parameters associated with the Random Access Channel (RACH), PUCCH, and PUSCH) (corresponding to BWP-UplinkCommon). Furthermore, the UE can be configured by the BS with UE-specific (or dedicated) transmission-related parameters (e.g., parameters associated with PUCCH, PUSCH, configured licensed UL transmission (configured licensed PUSCH), and sounding reference signal (SRS) (corresponding to BWP-UplinkDedicated).

[0296] Next, you can configure several pieces of information for DL ​​BWP as shown in Table 36.

[0297] [Table 36]

[0298]

[0299] According to Table 36, the UE can be configured by the BS with cell-specific (or cell-common or common) reception-related parameters (e.g., parameters associated with PDCCH and PDSCH) (corresponding to BWP-D ownlinkCommon). Furthermore, the UE can be configured by the BS with UE-specific (or dedicated) reception-related parameters (e.g., parameters associated with PDCCH, PDSCH, configured authorized DL transmissions (PDSCH semi-statically scheduled), and radio link monitoring (RLM) (corresponding to BWP-UplinkDedicated).

[0300] The discontinuous reception (DRX) configuration in a 5G communication system will now be described in detail below.

[0301] Figure 14 A DRX in a 5G communication system according to an embodiment of the present disclosure is shown.

[0302] DRX refers to UE operation, where, when the radio link between the UE and the BS is configured in RRC connection state, the UE using the service receives data discontinuously. When DRX is applied, the UE can turn on the receiver at specific times to monitor the control channel, and turn it off when no data is received for a certain period, thereby reducing UE power consumption. DRX operation can be controlled by MAC layer entities based on various parameters and timers.

[0303] refer to Figure 14 Activity time 1405 is the period during which the UE is woken up and monitors the PDCCH in each DRX cycle. Activity time 1405 can be defined as follows.

[0304] -drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or ra-ContentionResolutionTimer is running; or - The scheduling request is sent on the PUCCH and is pending processing; or - After successfully receiving a random access response from the MAC entity that did not select a random access preamble in a contention-based random access preamble, and before receiving a PDCCH indicating a new transmission addressing to the MAC entity for the C-RNTI. drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, ra-ContentionResolutionTimer, etc. are timers whose values ​​are configured by the BS, and have the function of configuring the UE to monitor the PDCCH when specific conditions are met.

[0305] `drx-onDurationTimer` 1415 is a parameter used to configure the minimum time for the UE to remain awake. `drx-InactivityTimer` 1420 is a parameter used to configure an additional time period for the UE to remain awake when a PDCCH (1430) indicating a new UL transmission or DL ​​transmission is received. `drx-RetransmissionTimerDL` is a parameter used to configure the maximum time period for the UE to remain awake to receive DL retransmissions during DL HARQ. `drx-RetransmissionTimerUL` is a parameter used to configure the maximum time period for the UE to remain awake to receive UL retransmission grants during UL HARQ. `drx-onDurationTimer`, `drx-InactivityTimer`, `drx-RetransmissionTimerDL`, and `drx-RetransmissionTimerUL` can be configured with time, number of subframes, number of time slots, etc. `ra-ContentionResolutionTimer` is a parameter used to monitor the PDCCH during random access.

[0306] Inactive 1410 is the period during which the UE does not monitor or receive the PDCCH during DRX operation, and can correspond to the remainder of the entire DRX operation time excluding the active time 1405. During the active time 1405, when the UE does not monitor the PDCCH, the UE can enter a sleep or inactive state to reduce power consumption.

[0307] The DRX cycle refers to the period during which the UE is woken up and monitors the PDCCH. In other words, the DRX cycle is the time interval from when the UE monitors the PDCCH to when it monitors the next PDCCH, or the period during which the DRX cycle occurs. There are two types of DRX cycles: short DRX cycles and long DRX cycles. Short DRX cycles can be optionally applied.

[0308] The long DRX period 1425 can be the longer of the two DRX periods configured for the UE. The UE can re-initiate drx-onDurationTimer 1415 during long DRX operation from the start point (e.g., the start symbol) of drx-onDurationTimer 1415 after the long DRX period 1425. When the UE operates within the long DRX period 1425, the UE can initiate drx-onDurationTimer 1415 from a slot following the drx-SlotOffset of a subframe satisfying Equation 2 below. Here, drx-SlotOffset can refer to the delay before drx-onDurationTimer 1415 is initiated. drx-SlotOffset can be configured with time, the number of slots, etc.

[0309] [Equation 2] [(SFN 10) + subframe number] mod(drx - LongCycle) = drx - StartOffset Here, drx-LongCycleStartOffset can include a long DRX period of 1525 and drx-StartOffset, and can be used to define the subframe used to start a long DRX period of 1425. drx-LongCycleStartOffset can be configured with time, the number of subframes, the number of time slots, etc.

[0310] A short DRX cycle can be the shorter of the two DRX cycles configured for the UE. While the UE is operating in a long DRX cycle 1425, the UE can initiate or restart the drx-InactivityTimer 1420 when an event occurs (e.g., receiving a PDCCH (1430) indicating a new UL or DL ​​transmission), and the UE can operate in a short DRX cycle when the drx-InactivityTimer 1420 expires or the UE receives a DRX command MAC CE. For example, refer to... Figure 14The UE can initiate the drx-ShortCycleTimer when the previous drx-onDurationTimer 1415 or drx-InactivityTimer 1420 expires, and can operate in the short DRX cycle until the drx-ShortCycleTimer expires. When the UE receives a PDCCH (1430) indicating a new UL or DL ​​transmission, the UE can anticipate the additional UL or DL ​​transmission at a later time, and thus can extend the active time 1405 or delay the arrival of the InActive time 1410. During the UE's operation in the short DRX cycle, the UE restarts the drx-onDurationTimer 1415 after the short DRX cycle has elapsed from the start of the onDuration. Afterwards, when the drx-ShortCycleTimer expires, the UE again operates in the long DRX cycle 1425.

[0311] When the UE operates within a short DRX cycle, the UE can initiate drx-onDurationTimer 1415 after the drx-SlotOffset of the subframe that satisfies Equation 3 below. Here, drx-SlotOffset can refer to the delay before drx-onDurationTimer 1415 is initiated. For example, drx-SlotOffset can be configured with time, the number of time slots, etc.

[0312] [Equation 3] [(SFN 10) + subframe number] modulo(drx-ShortCycle) = (drx-StartOffset) modulo(drx-ShortCycle) Here, drx-ShortCycle and drx-StartOffset can be used to define the subframe in which the short DRX cycle will begin. drx-ShortCycle and drx-StartOffset can be configured with time, the number of subframes, the number of time slots, etc.

[0313] So far, references have been made Figure 14 DRX operation is described. According to embodiments of this disclosure, a UE can reduce its power consumption by performing DRX operation. However, even when the UE performs DRX operation, the UE does not always receive the PDCCH associated with the UE during activity time 1405. Therefore, embodiments of this disclosure can provide signals for controlling the operation of the UE to further save the UE's power more effectively.

[0314] As mentioned above, to achieve high-speed data services of several Gbps, 5G communication systems use spatial multiplexing methods that support signal transmission and reception in ultra-wide bandwidth or use multiple transmit and receive antennas, and support various power-saving modes to reduce UE power consumption. The BS also experiences high power consumption. For example, the number of power amplifiers (PAs) required increases proportionally to the number of transmit antennas in the BS or UE. The maximum output of each in the BS and UE depends on the characteristics of the PAs, and generally, the maximum output of the BS varies depending on the cell size covered by the BS. Typically, the maximum output is expressed in dBm. The maximum output of the UE is typically 23dBm or 26dBm. As an example of a commercial 5G BS, the BS can have 64 transmit antennas and 64 PAs corresponding to a 3.5 GHz frequency band and can operate in a 100MHz bandwidth. That is, the energy consumption of the BS increases proportionally to the PA output and PA operating time. Compared to LTE BS, 5G BS has a wider bandwidth and more transmit antennas because of its relatively higher operating frequency band. These features increase data rates, but also lead to significant energy consumption costs for the BS (Base Station). Therefore, the more BSs are deployed in a mobile communication network, the more the network's energy consumption increases proportionally.

[0315] As mentioned above, the energy consumption of the BS is significantly dependent on the operation of the PA. Since the PA is involved in the BS's transmission operations, the BS's DL transmission operations are highly correlated with its energy consumption. A portion of the BS's UL reception operations have a relatively small impact on its energy consumption. The physical channels and physical signals transmitted by the BS via the DL are as follows.

[0316] -PDSCH: The DL data channel that includes data to be sent to one or more UEs.

[0317] -PDCCH: A DL control channel that includes scheduling information about PDSCH and PUSCH. Alternatively, the PDCCH may only transmit control information such as slot format and power control commands, without PDSCH or PUSCH for scheduling. Scheduling information includes resource information mapped to the PDSCH or PUSCH, HARQ association information, power control information, etc.

[0318] -PBCH: Provides the DL broadcast channel for the MIB, which contains the basic system information required by the UE to transmit and receive data and control channels.

[0319] -PSS: It is a signal used as a reference for DL ​​time / frequency synchronization and provides partial information about the cell ID.

[0320] -SSS: It is a signal used as a reference for DL ​​time and / or frequency (hereinafter referred to as time / frequency) synchronization, and provides other information about the cell ID.

[0321] -DM-RS: Reference signal used by the UE to estimate the channels of each of the PDSCH, PDCCH, and PBCH. -CSI-RS: The DL signal used as a reference when the UE measures the DL channel state.

[0322] - Phase Tracking Reference Signal (PT-RS): The DL signal used for phase tracking. Regarding BS energy saving, when the BS stops DL transmission operations, the PA operation also stops accordingly, increasing the BS's energy saving effect. Not only does the PA's operation decrease, but the operation of other BS devices, such as baseband equipment, also decreases, thus additional energy savings are possible. Similarly, if UL reception operations can be stopped, even if a portion of UL reception operations is relatively small in the overall energy consumption of the BS, additional energy savings can still be achieved.

[0323] The BS's DL transmission operations are largely dependent on the DL traffic volume. For example, when the BS has no data to send to the UE, the BS does not need to send the PDCCH or PDSCH used for scheduling the PDSCH. Alternatively, if data transmission can be temporarily suspended because the data is not sensitive to transmission delay, the BS may not send the PDSCH and / or PDCCH.

[0324] Conversely, physical channels and signals, including PSS, SSS, PBCH, and CSI-RS, are characterized by being repeatedly transmitted based on a predefined period, regardless of the data transmission to the UE. Therefore, even when the UE is not receiving data, it may continuously update DL time / frequency synchronization, DL channel state, radio link quality, etc. In other words, PSS, SSS, PBCH, and CSI-RS must be transmitted via DL, regardless of DL data traffic, thus leading to BS energy consumption. Therefore, BS energy saving can be achieved by adjusting the transmission of signals unrelated to (or with low correlation to) data traffic to occur less frequently.

[0325] During the period when the BS does not perform DL transmission via two BS power-saving methods, the operation of the BS's PA, the operation of its associated radio frequency (RF) equipment, the operation of the baseband equipment, etc., can be stopped or minimized, thereby maximizing the power-saving effect of the BS.

[0326] As another method, energy consumption of the BS can be saved by turning off some antennas or PAs (hereinafter referred to as "BS energy saving method 2"). In this case, in response to the energy saving effect of the BS, it may lead to a reduction in cell coverage or throughput. For example, when a BS with 64 transmit antennas and corresponding 64 PAs in the 3.5 GHz band and operating in a 100 MHz bandwidth activates only 4 transmit antennas and 4 PAs during a preset time period to reduce BS energy consumption and turns off the other transmit antennas and PAs, the BS energy consumption during that time period can be reduced by about 1 / 16 (=4 / 64). However, due to the reduction in maximum transmit power and beamforming gain, it is difficult to achieve cell coverage and throughput with 64 antennas and 64 PAs.

[0327] Base station (BS) power saving methods can be reclassified into three types: frequency domain BS power saving methods, which adjust the size of the base station power buddy (BWP) according to the BS's services; spatial domain BS power saving methods, which adaptively reduce the number of antenna ports; and time domain BS power saving methods, which adjust the periods of CSI-RS, SSB, and DRX. These three BS power saving methods can be used individually or in combination depending on BS characteristics (such as base station services or coverage area), and require sharing the corresponding change information with the UE.

[0328] Therefore, when sharing changed information or power-saving modes with the UE, it is also necessary to examine the impact of coexistence between power-saving modes and technologies that lead to high power consumption (such as CA / DC, PDSCH / PUSCH / PUCCH repetition, and mTRP).

[0329] In the following, a method for instructing the BS energy-saving method proposed in this disclosure will now be described by way of specific embodiments.

[0330] <First Embodiment> The first embodiment describes the structure of a network communication system for achieving energy saving.

[0331] Figure 15 It is a diagram used to describe existing network communication systems.

[0332] refer to Figure 15 The diagram shows multiple cells, such as cell 1, cell 2, cell 3, and cell 4. Because all cells should support not only connected UEs (or connected UEs) but also idle UEs (or idle UEs), energy-saving measures, such as light sleep or micro sleep, are inevitably performed in short cycles for periodic reference signal (e.g., SSB) transmission, even when there is no service.

[0333] Despite Figure 15Multiple cells are shown, but it should be noted that each cell may correspond to at least one of a Distributed Unit (DU), Radio Unit (RU), Transmit and Receive Point (TRP), or carrier, and is not limited thereto. References Figure 15 An idle UE can synchronize with the cell that sends the synchronization signal, can select the cell for initial access, and can eventually access the cell by performing the random access channel (RACH) procedure. Figure 15 This illustrates the scenario where a UE accesses cell 1 and performs communication. Figure 15 In existing communication systems, all cells are activated to synchronize / access with the UEs, taking into account the mobility of idle UEs, which may make it difficult to achieve network energy saving.

[0334] Figure 16a and Figure 16b This is a diagram used to describe a network communication system for achieving energy saving according to embodiments of the present disclosure.

[0335] refer to Figure 16a This shows multiple cells, such as cell 1 and cell 2 (cell 2A, cell 2B, and cell 2C). (and...) Figure 15 Unlike other cells, cell 1 is a cell used for synchronization / access (synchronization / access cell), while cells 2 (cell 2A, cell 2B, and cell 2C) can be data cells that only perform data communication with the UE and do not perform synchronization / access functions. Although in Figure 16a Multiple cells are shown, but it should be noted that each cell may correspond to at least one of DU, RU, TRP or carrier, and is not limited thereto.

[0336] refer to Figure 16a An idle UE can synchronize with cell 1, which is sending a synchronization signal, and can eventually perform initial access to cell 1 by executing the RACH procedure. After initial access to cell 1, the UE will eventually attempt to access the cell where it will actually send and receive data (e.g., cell 2A, cell 2B, or cell 2C). Figure 16a In this context, it is assumed that cell 1 can control cells 2A, 2B, and 2C to save network power. Therefore, cell 1 can provide the UE with configuration information of the cells controlled by cell 1 (1601), and can determine the cells to be controlled through the inter-cell interface (1602).

[0337] In detail, cell 1 can control the Tx / Rx power on / off of controlled cells (e.g., cell 2A, cell 2B, and / or cell 2C). Therefore, when cell 1 requests the controlled cell to enable Tx / Rx power (1603), the cell can send signals to and receive signals from the UE. Various methods can exist for enabling / disabling the Tx / Rx power of cells controlled by cell 1. For example, the UE's location information can be utilized. However, it should be noted that this disclosure does not limit the method to any particular method.

[0338] pass Figure 16a The method allows cells 2A, 2B, and 2C to be in deep sleep, and only cells whose Tx / Rx is requested to be activated by cell 1 can be activated (activated state) and can send signals to the UE. Although in Figure 16a The reference signal is shown as a signal transmitted by a cell whose Tx / Rx is enabled; however, it should be noted that this disclosure does not limit the signal transmitted by a cell whose Tx / Rx is enabled to a specific signal. Therefore, the UE can receive the reference signal from a cell whose Tx / Rx is enabled and can perform data communication. Figure 16a This illustrates the situation where the UE performs data communication with cell 2A.

[0339] Next, refer to Figure 16b This shows multiple cells, such as cell 1 and cell 2 (cell 2A, cell 2B, and cell 2C). (and...) Figure 16a Unlike other cells, cell 1 is used for synchronization (synchronization cell), while cells 2 (cell 2A, cell 2B, and cell 2C) can be access / data cells that perform initial access and data communication with the UE without performing synchronization functions. Although in Figure 16b Multiple cells are shown, but it should be noted that each cell may correspond to a DU, RU, TRP, or carrier, and is not limited to these.

[0340] refer to Figure 16b An idle UE can synchronize with the cell that sends the synchronization signal and can select that cell. Figure 16b This shows the case where cell 1 is selected. Figure 16b In this context, it is assumed that cell 1 can control cell 2 (cell 2A, cell 2B, and cell 2C) to save network energy. Therefore, cell 1 can provide configuration information for the cells controlled by cell 1 (1604) and can determine which cells to control through the inter-cell interface (1605).

[0341] In detail, cell 1 can control the Tx / Rx power of the controlled cell (e.g., cell 2A, cell 2B, and / or cell 2C) to be turned on / off. Therefore, when cell 1 requests the Tx / Rx power to be turned on from the controlled cell (1606), the cell can send signals to the UE and receive signals from the UE. Various methods can exist for turning the Tx / Rx power of the cell controlled by cell 1 on / off. For example, the UE's location information can be utilized. However, it should be noted that this disclosure does not limit the method to any particular method.

[0342] pass Figure 16b The method allows cell 2 (cell 2A, cell 2B, and cell 2C) to be in deep sleep, and only cells whose Tx / Rx is requested to be activated by cell 1 can be activated (activated state) and can send signals to the UE. Although in Figure 16b The reference signal is shown as a signal transmitted by a cell whose Tx / Rx is enabled; however, it should be noted that this disclosure does not limit the signal transmitted by a cell whose Tx / Rx is enabled to a specific signal. Figure 16a different, Figure 16b This illustrates the case where a cell whose Tx / Rx is enabled by cell 1, rather than cell 1 itself, performs the RACH procedure. Figure 16b This illustrates the scenario where the UE performs the RACH procedure with cell 2A and then performs access and data communication.

[0343] Figure 17a and Figure 17b This is a diagram used to describe a network communication system for achieving energy saving according to embodiments of the present disclosure.

[0344] refer to Figure 17a The diagram shows multiple cells, such as cell 1 and cell 2 (cell 2A, cell 2B, and cell 2C). Cell 1 can be a synchronization / access cell, and cell 2 (cell 2A, cell 2B, and cell 2C) can be a data cell that only performs data communication with the UE and does not perform synchronization / access functions. Figure 16a and Figure 16b The difference lies in Figure 17a and Figure 17b In the system, cells 2A, 2B, and 2C may include a wake-up receiver (WUR). When a WUR is included, cells 2 (cells 2A, 2B, and 2C) can shut down their main radio (MR) and enter a deep sleep state, which may be more beneficial for energy saving. Although in Figure 17a Multiple cells are shown, but it should be noted that each cell may correspond to at least one of DU, RU, TRP or carrier, and is not limited thereto.

[0345] refer to Figure 17aAn idle UE can synchronize with cell 1 that sends the synchronization signal, and can select a cell for initial access from cell 1, cell 2A, cell 2B, or cell 2C, and can eventually access that cell by performing the RACH procedure. Figure 17a In this example, assume that cell 1 can provide information about cell 2 (cell 2A, cell 2B, and cell 2C). Therefore, cell 1 can provide the UE with configuration information for other cells (cell 2A, cell 2B, and cell 2C) (1701). The UE, having received the configuration information, can send a wake-up signal (WUS) to the other cells (cell 2A, cell 2B, and cell 2C) (1702). Cells (cell 2A, cell 2B, and cell 2C) already in deep sleep can receive the WUS, can enable MR to enter the on state, and can send a signal to the UE. In this case, the configuration information for other cells (cell 2A, cell 2B, and cell 2C) may include configuration information for power-saving mode operation for each cell.

[0346] When MR is enabled in all cells (cell 2A, cell 2B, and cell 2C), network energy saving may be reduced. Therefore, it is necessary to allow only the desired cells to be woken up using various methods. For example, a method could be considered to enable MR only when the WUS received by cells already in deep sleep (cell 2A, cell 2B, and cell 2C) is greater than or equal to a certain threshold. The WUS strength can be referred to as the Wake-up Signal Received Power (WUSRP). Various methods can be considered for setting the threshold. Specifically, the setting can be performed via RRC, MAC CE, DCI, or a combination thereof. Furthermore, it should be noted that this disclosure does not limit the methods for improving network energy saving to the methods described above.

[0347] Despite Figure 17a The reference signal is shown as a signal transmitted by a cell whose MR is enabled; however, it should be noted that this disclosure does not limit the signal to a specific signal. Figure 17a The diagram illustrates a scenario where the MR (Mobile Reference) of cell 2A, which receives WUS (Wireless Receiver's Information), is activated to send reference signals to the UE and perform data communication. In this case, the MRs of cells 2B and 2C remain in a deep sleep state.

[0348] Next, refer to Figure 17b This shows multiple cells, such as cell 1 and cell 2 (cell 2A, cell 2B, and cell 2C). (and...) Figure 17aUnlike Figure 16, in the system of Figure 17, cell 1 can be a synchronization cell, and cell 2 (cell 2A, cell 2B, and cell 2C) can be an access / data cell that performs initial access and data communication with the UE without performing synchronization functions. Unlike Figure 16, in the system of Figure 17, cell 2 (cell 2A, cell 2B, and cell 2C) can include a WUR. When including a WUR, cell 2 (cell 2A, cell 2B, and cell 2C) can disable MR and enter a deep sleep state, which may be more beneficial for energy saving. Although in Figure 17b Multiple cells are shown, but it should be noted that each cell may correspond to at least one of DU, RU, TRP or carrier, and is not limited thereto.

[0349] refer to Figure 17b An idle UE can synchronize with the cell that sends the synchronization signal and can select the cell. Figure 17b This shows the case where cell 1 is selected. Figure 17b In this scenario, assume that cell 1 can provide information about cell 2 (cell 2A, cell 2B, and cell 2C). Therefore, cell 1 can provide the UE with configuration information for other cells (cell 2A, cell 2B, and cell 2C) (1703). The UE, having received the configuration information, can send WUS (Warnings Information) to the other cells (cell 2A, cell 2B, and cell 2C) (1704). Cells already in deep sleep (cell 2A, cell 2B, and cell 2C) can receive WUS, enable MR (Mobile Response) to enter the on state, and send signals to the UE. In this case, the configuration information for other cells (cell 2A, cell 2B, and cell 2C) may include configuration information for power-saving mode operation for each cell.

[0350] When MR is enabled in all cells (cell 2A, cell 2B, and cell 2C), network energy saving may be reduced. Therefore, it is necessary to allow only the necessary cells to be awakened through various methods. For example, a method could be considered to enable MR only when the strength of WUS received by cells already in a deep sleep state (cell 2A, cell 2B, and cell 2C) is greater than or equal to a certain threshold. The strength of WUS can be referred to as WUSRP. However, it should be noted that this disclosure does not limit the methods for improving network energy saving to the methods described above.

[0351] Despite Figure 17b The reference signal is shown as a signal transmitted by a cell whose MR is enabled; however, it should be noted that this disclosure does not limit the signal to any particular signal. Figure 17a different, Figure 17b The diagram illustrates the RACH procedure performed by the UE and the access / data cells (cell 2A, cell 2B, and cell 2C). Figure 17bThis illustrates a scenario where the UE performs a RACH procedure with cell 2A and then performs access and data communication. In this case, the MRs of cells 2B and 2C remain in a deep sleep state.

[0352] <Second Embodiment> The second embodiment involves the allocation of Physical Cell ID (PCI). The PCI is mainly used by the UE to decode the DL PHY layer channel.

[0353] In the case of LTE, PCI is typically used for the initialization of the following sequence generation.

[0354] -CRS sequence generation - Scrambling sequence generation for DL ​​PHY channels (i.e., PDCCH, PDSCH, PMCH, PBCH, etc.) - RS group frequency hopping mode for PUCCH and PUSCH - RS sequence frequency hopping for PUSCH In the case of NR, PCI is typically used for initialization of the following sequence generation.

[0355] -Scrambling sequence generation for PBCH - Used for scrambling sequence generation for PDCCH (if pdcch-DMRS-ScramblingID is not configured) - Generation of scrambled sequences in PXSCH and PUCCH formats 2 / 3 / 4 (if dataScrablingIdentityPXSCH is not configured) - DMRS sequence generation for PDCCH (if pdcch-DMRS-ScramblingID is not configured) - Used for DMRS sequence generation in PDSCH and PUCCH formats 2 / 3 / 4 (if scrapmblingID is not configured). - DMRS sequence generation for PUSCH (if scramblingID is not configured in the case of OFDM, or if nPUSCH-Identity is not configured in the case of DFT-s-OFDM) For example, as shown in Equation 4, a DMRS sequence for PDSCH is generated.

[0356] [Equation 4]

[0357] Here, c(i) represents a Gold sequence of length 31, and the initialization of the generated sequence is shown in the following equation.

[0358] [Equation 5]

[0359] here, This represents the number of symbols per time slot. This represents the number of time slots within a frame, where l represents the number of OFDM symbols within a time slot.

[0360] When providing high-level parameters DMRS-DownlinkConfig When IE and PDSCH are scheduled by PDCCH using DCI format 1_1 (the CRC of DCI format 1_1 is scrambled by C-RNTI or CS-RNTI), for n SCID {0,1} N , N ∈{0,1,…,65536} by DMRS-DownlinkConfig In IE scramblingID0 and scramblingID1 instruct.

[0361] When providing high-level parameters DMRS-DownlinkConfig When IE and PDSCH are scheduled by PDCCH using DCI format 1_0 (the CRC of DCI format 1_0 is scrambled by C-RNTI or CS-RNTI), for n SCID =0 N ∈{0,1,…,65536} by DMRS- DownlinkConfig In IE scramblingID0 instruct.

[0362] In addition to the above situations, In other words, in most cases, as PCI... This involves the initialization of most sequence generation, and each UE obtains PCI from the SSB and uses PCI to decode the DL PHY layer channel.

[0363] PCI It consists of two parts as shown in the following equation, and can be obtained from PSS and SSS respectively.

[0364] [Equation 6]

[0365] here, This indicates the cell group ID that can be obtained from the SSS. This indicates the sector ID that can be obtained from PSS. It can have three sequences from 0 to 2, and LTE uses the Zadoff-Chu sequence, while NR uses the M sequence. In LTE, 168 sequences from 0 to 167 can be obtained by concatenating two M sequences, while in NR, 336 sequences from 0 to 335 can be obtained by using PN Gold sequences (generated by XORing two M sequences).

[0366] Therefore, the PCI calculated by Equation 6 can have 504 unique sequences in LTE, while the PCI can have a total of 1008 unique sequences in NR, thereby enhancing sequence randomization and increasing robustness against inter-cell interference.

[0367] Considering the scenario of the first embodiment, an existing gNB can perform function partitioning based on functions suitable for idle / inactive UEs and connected UEs. However, when two functions are partitioned in an already deployed gNB, the coverage of the data cell or access data cell for connected UEs may be reduced, and the data rate may also be reduced. Therefore, to meet the coverage and data rate requirements of connected UEs, the gNB may switch to a data cell or access / data cell to primarily support connected UEs, and may require additional synchronization cells or synchronization / access cells to support idle / inactive UEs. Therefore, the following description relates to PCI allocation during initial access in the case of coexistence of synchronization cells or synchronization / access cells (collectively referred to as synchronization cells for convenience) and access / data cells or data cells (collectively referred to as data cells for convenience).

[0368] As can be seen from the first embodiment, a synchronous cell manages multiple data cells. In this case, the PCI of a data cell can be the same as or different from the PCI of the synchronous cell. When the PCI of a data cell is the same as the PCI of the synchronous cell, the UE may not be able to distinguish each data cell because all data cells sharing the PCI use the same scrambling. Therefore, each data cell can use a separate ID, such as a logical ID defined by the synchronous cell, thereby allowing the UE to distinguish each data cell. On the other hand, when the PCI of a data cell is different from the PCI of the synchronous cell, the UE can already distinguish each data cell because each data cell uses a different scrambling sequence. However, in the target scenario, because the number of cells per unit area increases compared to the existing scenario (due to the addition of synchronous cells), more sequence randomization is required to reduce inter-cell interference. Therefore, in this case, more PCIs may be needed.

[0369] When the data cell is in deep sleep, the UE may not receive the SSB from the data cell, and therefore may not obtain the PCI of the data cell. Therefore, in this case, each synchronization cell should send the data cell information, including the PCI, to the UE (e.g., the data cell's WUS configuration, SSB configuration, carrier frequency bandwidth, etc.). This information can be sent from the synchronization cell to the UE via the 'Configuration for Data Cell' transmission performed in Figures 1601 and 1604 and Figures 1701 and 1703. During this process, when the UE... Figure 16b and Figure 17b When receiving 'configuration for data cell' without accessing a synchronization cell, as in the example, because no RRC connection is established in the UE, 'configuration for data cell' can be received via SIB. On the other hand, as... Figure 16a and Figure 17a As shown, when the UE receives 'Configuration for Data Cell' after performing random access to the synchronous cell, the UE can receive 'Configuration for Data Cell' through SIB or RRC configuration because an RRC connection has been established in the UE.

[0370] However, when sending PCI information about a data cell from a synchronization cell, significant overhead can occur due to PCI. This overhead can be reduced by providing correlation between the PCIs of the synchronization cell and the data cell.

[0371] For example, specific methods for reducing PCI overhead can vary depending on whether the PCI of the synchronous cell and the PCI of the data cell are the same or different. First, let's assume the PCI of the synchronous cell and the PCI of the data cell are the same. In this case, because the PCI of the synchronous cell and the PCI of the data cell are the same, the initialization values ​​of various channel / signal sequences, such as DMRS, are also the same. Therefore, when the frequency bands of the synchronous cell and the data cell are the same, the UE may be unsure whether the received information comes from the synchronous cell or the data cell. When the frequency bands of the synchronous cell and the data cell are different, the UE may not be able to distinguish multiple data cells within a single synchronous cell. Therefore, to address this issue, the 'configuration for data cells' sent from the synchronous cell can include a logical cell ID that can distinguish each data cell, instead of the PCI of each data cell.

[0372] Secondly, assume that the PCI of the synchronous cell and the PCI of the data cell are different from each other. In this case, because the initial values ​​of the sequences of various channels / signals are different, the UE can easily distinguish between the synchronous cell, the data cell, and each data cell. However, a large amount of PCI overhead may occur, and interference randomization may be insufficient as the number of PCIs increases. To mitigate this drawback, it may be necessary to configure the PCIs of the synchronous cell and the data cell in a hierarchical structure as much as possible. Specific embodiments of this will be described in the third embodiment.

[0373] To reduce the overhead caused by PCI, the method by which the UE obtains the PCI or logical ID is also important. In a first method, the synchronizing cell can send configuration information for the data cell to the UE via 'Configuration for Data Cell'. This operation increases the overhead linearly with the number of data cells. In a second method, each UE can obtain the PCI of the data cell via SSB detection without the assistance of the synchronizing cell. In this case, the overhead is not significantly different from the existing situation. However, there may be a method that appropriately considers both methods, which will be described through a third embodiment.

[0374] <Third Embodiment> The third embodiment relates to the PCI configuration and SSB structure when the PCIs of the synchronization cell and the data cell are different or the same.

[0375] First, assume that the PCI of the synchronization cell is different from that of the data cell. As described in the second embodiment, the PCIs of the synchronization cell and the data cell may need to have a hierarchical structure. In this case, the synchronization cell and the data cell can share some or all of their respective PCI settings.

[0376] Table 37 shows the possible PCIs that a data cell can have when the PCI of the synchronization cell and the PCI of the data cell are different from each other.

[0377] [Table 37]

[0378] Alt 1 corresponds to the case where the synchronization cell and data cell fully or partially share the PCI, and Alt 2 corresponds to the case where the synchronization cell and data cell have completely different PCIs. Alt 1-1 corresponds to the case where the synchronization cell and data cell only share the PCI of the synchronization cell. and The ones that can be detected in PSS (The shaded values ​​in Table 37) are examples of this. In this case, the data cell needs... Additional definitions (unshaded values ​​in Table 37). At least for Because the PCI of a data cell has a different setting than that of a synchronous cell, a separate sequence should be used that is different from the sequence used in the synchronous cell (e.g., the concatenation of two M sequences in LTE, and the XOR of two M sequences, i.e., the PN Gold sequence in NR) so that the minimum sequence distance between the synchronous cell and the data cell does not decrease. When multiple data cells exist within a synchronous cell, the data cell's... It can be greater than or equal to the synchronous cell. And the PCI can be represented for a data cell. This is the same as before.

[0379] Alt 1-2 corresponds to synchronization cells and data cells sharing information that can only be detected in SSS. In this situation, the data cell needs... Additional definitions (unshaded values ​​in Table 37). At least for Because the PCI of a data cell has a different setting than that of a synchronous cell, a separate sequence (e.g., the Zadoff-Chu sequence in LTE and the M sequence in NR) should be used, different from the sequence used in the synchronous cell, so that the minimum sequence distance between the synchronous cell and the data cell does not decrease. When multiple data cells exist within a synchronous cell, the data cell's... It can be greater than or equal to the synchronous cell. And the PCI represented for a data cell can be... This is the same as before.

[0380] Alt 1-3 correspond to synchronization cells and data cells sharing information that can be detected in PSS and SSS. and However, a third ID exists. In this situation, the data cell needs... Additional definitions (unshaded values ​​in Table 37). At least for Because the PCI of the data cell has different settings than that of the synchronous cell, a separate sequence (e.g., a third-level SS (TSS)) should be used, different from the PSS and SSS used in the synchronous cell, so that the minimum sequence distance between the synchronous cell and the data cell is not reduced. Alternatively, without a separate sequence (e.g., TSS), the configuration for the data cell can be sent from the synchronous cell to the UE via "Configuration for Data Cell". The value of . The PCI that can be represented for a data cell is . .here, N express The maximum number of IDs that can be present.

[0381] Figures 18a to 18c The SSB structure (excluding PBCH) of the synchronization cell and data cell according to an embodiment of the present disclosure is shown.

[0382] The UE should synchronize with the synchronization cell in order to receive information from the data cell, regardless of whether the UE is connected to the synchronization cell. For this purpose, the SSB structure of the synchronization cell can include PSS 1801 and SSS 1802, such as... Figure 18a As shown. The UE that receives the SSB including PSS 1801 and SSS 1802 obtains the synchronization cell. and Then, it searches for data cells, receives SSBs from active data cells, and calculates the PCI of the data cell. When the SSB structure of the data cell is consistent with... Figure 18a As shown, for Alt 1-1 and Alt 1-2 in Table 37, one of the PSS and SSS can be the same as that of the synchronizing cell. On the other hand, for a PSS or SSS different from that of the synchronizing cell, there can be values ​​with sequences different from those of the synchronizing cell. Or, as... Figure 18b As shown, since it is not necessary to obtain the value known through the synchronization cell, only one of the PSS and SSS can be sent (1805). Alternatively, only one of the PSS, SSS, or TSS can be sent.

[0383] In the case of Alt 1-3, because additional... Value, such as Figure 18c As shown, and It can be received via SSS 1811 and PSS 1812 respectively, and It can be received via TSS 1813. In this case, because the SSB structure of the data cell is changed, additional configurations for the TSS should be defined. First, the type and number of sequences need to be defined. Assuming the PSS and SSS are the same as in NR, the TSS can increase linearly with the number of added data cells and should have a sufficiently large value to provide adequate interference randomization. Second, the resource location of the TSS needs to be defined. For example... Figure 18c As shown, there may be a symbol difference between SSS and TSS (in which case PBCH can be sent in that symbol), or TSS can be sent in the symbol immediately following SSS. In the case of Alt 1-3, it can be as follows: Figure 18a and Figure 18b The transmission is performed as described above. For example, when... Figure 18b When the transmission is performed as shown, because and It has already been sent from the synchronous cell and therefore only needs to be sent about The information is such that only one SS can be sent. Or, as in Figure 18b In this case, since it may be difficult to achieve synchronization using only one SS, it can be used as is. Figure 18a The existing SSB structure in the UE, and the UE can base its decisions on the scrambled values ​​in the received PSS or SSS. The ID is used to determine whether the desired data cell belongs to the selected synchronization cell, and for the remaining SSS or PSS, it can be determined via PCI. To extract the actual value.

[0384] In Table 37, Alt 2 involves cases where the PCI settings for the synchronization cell and each data cell are completely different. Therefore, the sequence of PCIs used in the synchronization cell and the sequence of PCIs used in each data cell should be completely different from each other. In this case, the UE can receive the PCI of each data cell via the SSB, and the UE can compare the PCI of each data cell received via synchronization and the SSB with the pre-shared data cell list via Alt 2 of the synchronization cell.

[0385] Figure 19 The process for obtaining PCI between a synchronization cell, a data cell, and a UE according to an embodiment of the present disclosure is illustrated.

[0386] First, the synchronization cell transmits an SSB as a periodic signal (1901), and the UE synchronizes with the synchronization cell and performs random access based on whether the UE accesses the synchronization cell (1902). Next, the UE receives configuration for the data cell from the synchronization cell and obtains information about the data cell based on the received configuration. The data cell information may include at least one of the information that the UE can obtain via the SSB, such as the data cell's carrier frequency and bandwidth, SSB structure or location, or complete or partial PCI information. For example, in the case of partial information, assuming the synchronization cell and data cell have a hierarchical structure, it may include information as shown in Alt 1-3. The UE receiving the configuration for the data cell (1903) can transmit a WUS (1904) depending on its capabilities. In this case, the UE can transmit the WUS by scrambling the PCI of the selected synchronization cell or by scrambling the UE ID, which is the unique ID of the UE, so that the data cell within the selected synchronization cell receives the WUS. When the WUS is transmitted (1904), the data cell measures the strength of the received WUS and determines, through coordination with the synchronization cell, whether to wake up the data cell's master radio. For example, the data cell can indicate whether to wake up the master radio by receiving a wake-up indication (1905) from the synchronization cell. When the data cell does not have WUS functionality, the synchronization cell can determine whether to wake up the data cell's master radio and can transmit a wake-up indication. The data cell receiving the wake-up indication wakes up the master radio and transmits an SSB (1906) to synchronize with the UE. Although not shown, the UE can receive an indication to receive an SSB from the synchronization cell, or it can receive an SSB from the data cell after a certain period of time following the transmission of the WUS (e.g., after a timer expires following the transmission of the WUS).

[0387] The SSB of the data cell can vary depending on whether the PCI is fully or partially shared with the synchronous cell. For example, when the PCI of the synchronous cell and the PCI of the data cell are completely different from each other as shown in Alt-2 of Table 37, the synchronous cell can provide the complete PCI of the data cell in the configuration for the data cell (1903), or the data cell can scramble and transmit the PCI in the sequence initialization of the PSS and SSS, similar to the existing SSB. On the other hand, in an environment where some or all parts are shared as shown in Alt-1 of Table 37, since the UE can extract a part of the PCI of the data cell based on the PCI of the synchronous cell, the structure of the SSB can be changed and transmitted as shown in Alt 1-1 to 1-3. Such an SSB structure can be transmitted through the configuration for the data cell of the synchronous cell (1903).

[0388] Next, there is a case where the PCI of the synchronization cell and the PCI of the data cell are the same. As described in the second embodiment, the PCIs of the synchronization cell and the data cell can have a hierarchical structure. In this case, since the PCIs of the synchronization cell and the data cell appear to be the same, the data cell in the synchronization cell should be distinguished by using a logical cell ID. Just as the PCI is used for scrambling or DMRS sequence generation for each channel, the logical cell ID can also be used for sequence generation. When the logical cell ID and the PCI perform the same function, the logical cell ID may not be significantly different from the virtual cell ID used in existing CA or mTRP. However, unlike the virtual cell ID, the logical cell ID can be sent to idle / inactive UEs. When the logical cell ID is not operated in the same way as the PCI, it is difficult for the UE to distinguish each data cell because all data cells have the same cell ID. Therefore, as in the former case, the logical ID should be involved in each sequence generation, and the logical cell ID should be transmitted as shown in Table 38.

[0389] [Table 38]

[0390] Alt 1 corresponds to the following situation: For data cells, only the synchronization cell's... and The ones that can be detected in PSS 0 (shaded value in Table 38), and received via SSS. N logicalID The UE first verifies the signal received via PSS. Is it synchronized with the cell? Same, then received via SSS N logicalID And calculate the cell ID of the data cell. Based on three ID values: received from the SSS of the synchronization cell. ,as well as and N logicalID To determine the cell ID calculation.

[0391] Alt 2 corresponds to the data cell retransmission that can only be detected in the SSS. And receive additional data via PSS. N logicalID The UE first verifies the signal received via SSS. Is it synchronized with the cell? Same, then received via PSS. N logicalID And calculate the cell ID of the data cell. Based on three ID values: received from the PSS of the synchronization cell. ,as well as and N logicalID Determine the cell ID calculation 。

[0392] Alt 3 corresponds to the value that can be detected in both PSS and SSS. and It was retransmitted, and N logicalID In the case where the data is received separately via TSS, the UE first verifies the data received via PSS. and received via SSS Whether it is the same as the synchronous cell, and then receive it through TSS. N logicalID And calculate the cell ID of the data cell. Based on three ID values: received via TSS. N logicalID ,as well as and To determine the cell ID calculation.

[0393] Alt 4 corresponds to the SSB sent from the data cell, including the PSS and SSS sent from the synchronization cell. and In this situation, after the UE identifies that the SSB is a data cell controlled by the synchronous cell, the UE bases its decisions on the data transmitted from the synchronous cell through joint consideration. N logicalID The cell ID, calculated using the PCI of the synchronization cell, is used to perform scrambling or DMRS sequence generation for other channels. The synchronization cell can notify the UE only through "Configuration for Data Cells". N logicalID Alternatively, when the UE has the ability to access a synchronous cell, when the UE sends a PRACH and then receives a Random Access Response (RAR), it can receive information about the data cell together.

[0394] Figure 20 A UE transceiver apparatus according to an embodiment of the present disclosure is shown. For ease of description, devices not directly related to the present disclosure may not be shown or described.

[0395] refer to Figure 20 The UE may include: a transmitter 2004, which includes a UL transmission processing block 2001, a multiplexer 2002, and a transmission RF block 2003; a receiver 2008, which includes a DL reception processing block 2005, a demultiplexer 2006, and a reception RF block 2007; and a controller 2009. As described above, the controller 2009 can control the configuration block of the receiver 2008 for receiving data channels or control channels transmitted from the BS and the configuration block of the transmitter 2004 for transmitting UL signals.

[0396] The UL transmission processing block 2001 of the UE's transmitter 2004 can perform processes including channel coding and modulation to generate the signal to be transmitted. The multiplexer 2002 can multiplex the signal generated in the UL transmission processing block 2001 with another UL signal, and the signal can be processed by the transmission RF block 2003 before it can be sent to the BS.

[0397] The UE receiver 2008 demultiplexes the signal received from the BS to the DL receive processing block. The DL receive processing block 2005 can perform processes including DL signal demodulation and channel decoding from the BS to obtain control information or data sent by the BS. The UE receiver 2008 can apply the output of the DL receive processing block to the controller 2009 to support the operation of the controller 2009.

[0398] Figure 21 This is a block diagram illustrating a UE according to an embodiment of the present disclosure.

[0399] like Figure 21 As shown, the UE of this disclosure may include a processor 2130, a transceiver 2110, and a memory 2120. However, the components of the UE are not limited thereto. For example, the UE may include more components than those shown, or it may include fewer components than those shown. Furthermore, the processor 2130, transceiver 2110, and memory 2120 may be implemented as a single chip. According to an embodiment, Figure 21 The transceiver 2110 may include Figure 20 The transmitter 2004 and receiver 2008. Furthermore, Figure 21 The processor 2130 may include Figure 20 The controller 2009.

[0400] In embodiments, processor 2130 may control a series of processes of the UE to be operated according to the foregoing embodiments of this disclosure. For example, according to embodiments of this disclosure, components of the UE may be controlled to perform UE transmit / receive methods depending on whether the BS mode is an energy-saving mode or a normal BS mode. Processor 2130 may include one or more processors, and processor 2130 may execute programs stored in memory 2120 to perform UE transmit / receive operations in a wireless communication system applying carrier aggregation of this disclosure.

[0401] Transceiver 2110 can transmit signals to and receive signals from the BS. The signals transmitted to and received from the BS may include control information and data. Transceiver 2110 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal and an RF receiver for low-noise amplification and down-converting the frequency of the received signal. However, this is merely an example of transceiver 2110, and therefore the components of transceiver 2110 are not limited to RF transmitters and RF receivers. Furthermore, transceiver 2110 can receive signals via a wireless channel and output signals to processor 2130, and can also transmit signals output from processor 2130 via a wireless channel.

[0402] According to an embodiment, memory 2120 may store programs and data required for operating the UE. Furthermore, memory 2120 may store control information or data included in signals transmitted and received by the UE. Memory 2120 may include storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or combinations thereof. Additionally, memory 2120 may include multiple memories, and according to an embodiment, memory 2620 may store programs according to embodiments of the present disclosure for performing UE transmission and reception operations based on whether the BS mode is BS power-saving mode or BS normal mode.

[0403] Figure 22 This is a block diagram illustrating a BS according to an embodiment of the present disclosure.

[0404] like Figure 22 As shown, the BS may include a processor 2230, a transceiver 2210, and a memory 2220. However, the components of the BS are not limited to these. For example, the BS may include more components than those shown, or it may include fewer components than those shown. Furthermore, the processor 2230, transceiver 2210, and memory 2220 may be implemented as a single chip.

[0405] According to embodiments of this disclosure, processor 2230 can control a series of processes of a BS to be operated. For example, according to embodiments of this disclosure, components of the BS can be controlled to perform a method for scheduling a UE based on whether the BS mode is a BS power-saving mode or a BS normal mode. Processor 2230 may include one or more processors, and processor 2230 can perform the method of scheduling the UE based on whether the BS mode is a BS power-saving mode or a BS normal mode by executing a program stored in memory 2220.

[0406] Transceiver 2210 can transmit signals to and receive signals from the UE. Signals transmitted to and received from the UE may include control information and data. Transceiver 2210 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal and an RF receiver for low-noise amplification and down-converting the frequency of the received signal. However, this is merely an example of transceiver 2210, and therefore the components of transceiver 2210 are not limited to RF transmitters and RF receivers. Furthermore, transceiver 2210 can receive signals via a wireless channel and output signals to processor 2230, and can also transmit signals output from processor 2230 via a wireless channel.

[0407] In one embodiment, memory 2220 may store programs and data required for the operation of the BS. Furthermore, memory 2220 may store control information or data included in signals sent or received by the BS. Memory 2220 may be implemented as a storage medium including ROM, RAM, hard disk, CD-ROM, DVD, etc., or any combination thereof. Additionally, multiple memories 2220 may be provided. According to an embodiment, memory 2220 may store a program for performing a method according to embodiments of the present disclosure for scheduling the UE based on whether the BS mode is BS power-saving mode or BS normal mode.

[0408] In the specific embodiments of this disclosure described above, the elements included in this disclosure are represented as singular or plural. However, for ease of description, singular or plural representations have been appropriately selected for the provided conditions, and this disclosure is not limited to singular or plural components; a component expressed in plural form may be configured as a single component, and a component expressed in singular form may be configured as multiple components.

[0409] While embodiments of the present disclosure have been disclosed and specific terminology has been used throughout the specification and drawings, these are intended only in a general sense to provide an easy description and aid in understanding the disclosure, and are not intended to limit the scope of the disclosure. Therefore, it will be apparent to those skilled in the art that the present disclosure is not limited to the embodiments provided for illustrative purposes only. Furthermore, embodiments of the present disclosure may be used in combination where necessary.

[0410] Although specific embodiments have been described in the detailed description of this disclosure, various modifications may be made without departing from the scope of this disclosure. Therefore, the scope of this disclosure is not limited to the above embodiments, and its definition includes not only the contents of the following claims, but also their equivalents.

Claims

1. A method for operating a terminal in a wireless communication system, the method comprising: Obtain the synchronization signal SS of the first cell from the first cell; Based on the SS of the first cell, synchronize with the first cell; Receive configuration information about at least one second cell from the first cell, wherein the at least one second cell can be controlled by the first cell; Based on the synchronization information of the first cell and the configuration information of the at least one second cell, the physical cell identifier (PCI) of the data cell to be accessed in the at least one second cell is obtained; as well as Access the data cell based on the PCI.

2. The operating method according to claim 1, wherein, The configuration information for the at least one second cell includes the synchronization information for each of the at least one second cell.

3. The operating method according to claim 2, wherein, The synchronization information of each of the at least one second cell includes at least one of the PSS being the same as the primary synchronization signal PSS of the first cell or the SSS being the same as the secondary synchronization signal SSS of the first cell.

4. The operating method according to claim 3, wherein, When the synchronization information of each of the at least one second cell has the same PSS as the PSS of the first cell and the same SSS as the SSS of the first cell, the synchronization information of each of the at least one second cell also includes an additional SS.

5. The operating method according to claim 1, wherein, The at least one second cell includes a wake-up receiver (WUR).

6. The operating method according to claim 1, further comprising: Send a wake-up signal WUS to the data cell; as well as Receive synchronization signal block (SSB) from the data cell.

7. The operating method according to claim 1, wherein, The terminal operates in idle mode or inactive mode.

8. A terminal operating in a wireless communication system, the terminal comprising: transceiver; as well as At least one processor, operatively coupled to the transceiver and configured to: Control the transceiver to obtain the synchronization signal SS of the first cell from the first cell; Based on the SS of the first cell, synchronize with the first cell; The transceiver is controlled to receive configuration information about at least one second cell from the first cell, the at least one second cell being controllable by the first cell; Based on the synchronization information of the first cell and the configuration information of the at least one second cell, the physical cell identifier (PCI) of the data cell to be accessed in the at least one second cell is obtained; as well as Control the transceiver to access the data cell based on the PCI.

9. The terminal according to claim 8, wherein, The configuration information for the at least one second cell includes the synchronization information for each of the at least one second cell.

10. The terminal according to claim 9, wherein, The synchronization information of each of the at least one second cell includes at least one of the PSS being the same as the primary synchronization signal PSS of the first cell or the SSS being the same as the secondary synchronization signal SSS of the first cell.

11. The terminal according to claim 10, wherein, When the synchronization information of each of the at least one second cell has the same PSS as the PSS of the first cell and the same SSS as the SSS of the first cell, the synchronization information of each of the at least one second cell also includes an additional SS.

12. The terminal according to claim 8, wherein, The at least one second cell includes a wake-up receiver (WUR).

13. The terminal according to claim 8, wherein, The at least one processor is further configured to: Control the transceiver to send a wake-up signal WUS to the data cell, and Control the transceiver to receive the synchronization signal block (SSB) from the data cell.

14. The terminal according to claim 8, wherein, The terminal operates in idle mode or inactive mode.

15. A wireless communication system, the wireless communication system comprising: terminal; First residential area; as well as At least one second cell, which can be controlled by the first cell, wherein the terminal is configured to: Obtain the synchronization signal SS of the first cell from the first cell; Based on the SS of the first cell, synchronize with the first cell; Receive configuration information about the at least one second cell from the first cell; Based on the synchronization information of the first cell and the configuration information of the at least one second cell, the Physical Cell Identifier (PCI) of the data cell to be accessed in the at least one second cell is obtained; and Access to the data cell is based on the PCI.

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