Method and apparatus for energy saving of wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission. The present disclosure may be applied to intelligent services (e.g., smart residences, smart buildings, smart cities, smart cars or connected cars, health care, digital education, retail businesses, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. The invention discloses a method for saving energy for a base station.

Description

Technical Field

[0001] The present disclosure relates to an energy-saving method and apparatus for a wireless communication system. Background Art

[0002] The 5G mobile communication technology defines a wide frequency band capable of achieving high transmission rates and new services, and can be implemented not only in the "sub-6 GHz" frequency band such as 3.5 GHz, but also in the "above 6 GHz" frequency band called millimeter waves including 28 GHz and 39 GHz. In addition, it has been considered to implement the 6G mobile communication technology (referred to as the ultra-5G system) in the terahertz frequency band (e.g., 95 GHz to 3 THz frequency band) in order to achieve a transmission rate fifty times faster than the 5G mobile communication technology and an ultra-low latency that is one-tenth of the 5G mobile communication technology.

[0003] At the beginning of the development of the 5G mobile communication technology, in order to support services and meet the performance requirements regarding enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC), standardization has been ongoing for technologies such as beamforming and massive MIMO for reducing radio wave path loss and increasing radio wave transmission distance in millimeter waves, support parameters for dynamic operations for efficiently utilizing millimeter wave resources and time slot formats (e.g., operating multiple subcarrier spacings), initial access technologies for supporting multi-beam transmission and wide frequency bands, the definition and operation of bandwidth parts (BWPs), new channel coding methods such as low-density parity-check (LDPC) codes for large data transmission and polar codes for highly reliable transmission of control information, L2 preprocessing, and network slicing for providing dedicated networks dedicated to specific services.

[0004] Currently, regarding the services supported by the 5G mobile communication technology, the industry is continuously discussing improvements and performance enhancements to the initial 5G mobile communication technology, and physical layer standardization has been completed for technologies such as vehicle-to-everything (V2X) for assisting the driving decision-making of autonomous vehicles based on information about the position and status of the vehicle sent by the vehicle and for improving user convenience, new radio unlicensed (NR-U) aiming for system operation to comply with various regulatory requirements in unlicensed frequency bands, NR UE energy saving, non-terrestrial networks (NTN) as UE satellite direct communication for ensuring coverage in areas where communication with the terrestrial network is not possible, and positioning.

[0005] In addition, the standardization of air interface architectures / protocols for the following technologies has been continuously advancing, such as: Industrial Internet of Things (IIoT) for supporting new services through interoperability and integration with other industries, Integrated Access and Backhaul (IAB) for expanding the network service area by supporting wireless backhaul links and access links in an integrated manner, mobility enhancements including conditional handover and Dual-Active Protocol Stack (DAPS) handover, and two-step random access (2-step RACH for NR) for simplifying the random access process. At the same time, the standardization of system architectures / services for the following technologies has also been continuously advancing: 5G baseline architectures for combining Network Function Virtualization (NFV) and Software Defined Network (SDN) technologies (e.g., service-based architectures or service-based interfaces), and Mobile Edge Computing (MEC) for receiving services based on UE location.

[0006] With the commercialization of 5G mobile communication systems, exponentially growing connected devices will be connected to the communication network, and thus enhanced functions and performance of 5G mobile communication systems and integrated operation of connected devices are expected. For this purpose, new research on the following technologies has been put on the agenda: Extended Reality (XR) for efficiently supporting Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR), etc., 5G performance improvement and complexity reduction by leveraging Artificial Intelligence (AI) and Machine Learning (ML), AI service support, Metaverse service support, and drone communication.

[0007] In addition, this development of 5G mobile communication systems will not only lay the foundation for the development of the following technologies: new waveforms for providing coverage in the terahertz band of 6G mobile communication technology, Full-Dimensional MIMO (FD-MIMO), multi-antenna transmission technologies such as array antennas and massive antennas, metamaterial-based lenses and antennas for improving the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS), but also lay the foundation for the development of the following technologies: full-duplex technology for improving the frequency efficiency of 6G mobile communication technology and enhancing the system network, AI-based communication technology for achieving system optimization by leveraging satellites and AI from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for realizing services with ultra-high performance communication and computing resources at a complexity level beyond the UE operation capacity limit.

[0008] Looking at the development of wireless communication generation by generation, these technologies have mainly been developed for human-oriented services such as voice calls, multimedia services, and data services. However, with the commercialization of the fifth-generation (5G) communication system, an exponentially increasing number of connected devices are expected to be connected to the communication network. Examples of things connected to the network include vehicles, robots, drones, household appliances, displays, smart sensors connected to various infrastructures, construction machines, factory equipment, etc. Mobile devices are expected to evolve into various forms such as augmented reality glasses, virtual reality headsets, and holographic devices. In order to provide various services in the sixth-generation (6G) era by connecting hundreds of billions of devices and things, the industry has been working hard to develop improved 6G communication systems. For this purpose, the 6G communication system can be called a super 5G system.

[0009] The 6G communication system, expected to be realized around 2030, will have a maximum transmission rate (in bps) of the tera level (i.e., 1000 GHz) and a radio latency of 100 μsec. That is to say, the transmission rate in the 6G communication system will be fifty times that of the 5G communication system and have one-tenth of the radio latency of the 5G communication system.

[0010] To achieve such a high data transmission rate and ultra-low latency, the industry is considering implementing the 6G communication system in the terahertz band (e.g., the 95 GHz to 3 THz band). Since more severe path loss and atmospheric absorption are expected in the terahertz band than in the millimeter wave band introduced in 5G, technologies capable of ensuring the signal transmission distance (i.e., coverage) will become more critical. As the main technologies for ensuring coverage, it is necessary to develop multi-antenna transmission technologies including radio frequency (RF) components, antennas, new waveforms with better coverage than orthogonal frequency division multiplexing (OFDM), beamforming, and massive multiple input and multiple output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and massive antennas. In addition, new technologies such as metasurface-based lenses and antennas, high-dimensional space multiplexing technologies using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RIS) are being discussed to enhance the coverage of terahertz band signals.

[0011] In addition, to improve frequency efficiency and the system network, technologies developed for 6G communication systems include: full-duplex technology that allows the simultaneous use of the same frequency resources for uplink and downlink; network technologies that comprehensively utilize satellites, high-altitude platform stations (HAPS), etc.; for 6G communication systems, the technologies cover full-duplex technology, improved network architectures that support mobile base stations, etc. and achieve optimized and automated network operation, dynamic spectrum sharing technology that avoids conflicts through prediction of spectrum usage, AI-based communication technology that realizes system optimization by applying AI from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology that provides services beyond the computing capacity limit of UEs by leveraging ultra-high-performance communication and computing resources (e.g., mobile edge computing (MEC) or cloud computing). In addition, through the design of new protocols for 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for secure data usage, and the development of privacy protection technologies, continuous attempts have been made to enhance connectivity between devices, further optimize the network, promote the implementation of network entities at the software level, and improve the openness of wireless communication.

[0012] This kind of research and development for 6G communication systems is expected to realize the next-generation hyper-connectivity experience through the hyper-connectivity of 6G communication systems, and the hyper-connectivity includes the connection between people and things and the connection between things and things. Specifically, the 6G communication system will be able to provide services such as, for example, truly immersive extended reality (XR), high-fidelity mobile holograms, and digital replicas. In addition, with enhanced security and reliability, services such as remote surgery, industrial automation, and emergency response will be provided through the 6G communication system, and the 6G communication system will have wide applications in fields such as industry, healthcare, transportation, or home appliances.

[0013] With the recent development of environmentally conscious 5G / 6G communication systems, there is an emerging need for methods to reduce the power consumption of base stations. Summary of the Invention

[0014] [Technical Problem]

[0015] Various embodiments of the present disclosure provide a method for enabling a base station by using a wake-up signal (WUS) when the base station is inactive (or in a sleep mode) for a terminal to reduce the power consumption of the base station in a wireless communication system.

[0016] Various embodiments of the present disclosure provide a method for a terminal to wake up a base station in an inactive state to achieve base station energy saving, and a method for activating a base station through a wake-up signal (WUS) by defining WUS and configuring reference signal (RS) information and synchronization for WUS through higher layer signaling (Radio Resource Control (RRC) or System Information Block). In this way, the base station can operate in an inactive state and achieve energy saving without sacrificing latency.

[0017] The technical objectives achieved by the present disclosure are not limited to the above technical objectives, and those skilled in the art can clearly understand other technical objectives not mentioned from the following description.

[0018] [Technical Solutions]

[0019] According to various embodiments, a method for a terminal to reduce base station energy consumption in a wireless communication system may include: deactivating the base station through higher layer signaling or L1 signaling to achieve base station energy saving; performing synchronization before the terminal sends a WUS to activate the deactivated base station; and sending a WUS after synchronization.

[0020] In various embodiments, a method for a base station to reduce energy consumption in a wireless communication system may include: configuring WUS configuration information and reference signal (RS) configuration information for synchronization through higher layer signaling or L1 signaling; monitoring WUS during an inactive mode based on the above configured information; and operating the base station after receiving a WUS.

[0021] In various embodiments, a method performed by a terminal in a communication system includes: receiving a wake-up signal (WUS) configuration from a base station; receiving control information for activating the WUS from the base station; monitoring a synchronization signal; and sending a WUS to the base station at a WUS occasion based on the WUS configuration.

[0022] In various embodiments, a method performed by a base station in a communication system includes: sending a wake-up signal (WUS) configuration to a terminal; sending control information for activating the WUS to the terminal; sending a synchronization signal to the terminal; and receiving a WUS from the terminal at a WUS occasion based on the WUS configuration.

[0023] In various embodiments, a terminal in a communication system includes: a transceiver and a controller operably coupled to the transceiver, the controller being configured to receive a wake-up signal (WUS) configuration from a base station, receive control information for activating the WUS from the base station, monitor a synchronization signal, and send a WUS to the base station at a WUS occasion based on the WUS configuration.

[0024] In various embodiments, a base station in a communication system includes: a transceiver and a controller operably coupled to the transceiver, the controller being configured to send a wake-up signal (WUS) configuration to a terminal, send control information for activating the WUS to the terminal, send a synchronization signal to the terminal, and receive a WUS from the terminal at a WUS occasion based on the WUS configuration.

[0025] [Advantages of the Invention]

[0026] According to embodiments of the present disclosure, in a 5G system, by defining a signal transmission method for a base station in a mobile communication system, the problem of excessive energy consumption can be solved and high energy efficiency can be achieved.

[0027] According to embodiments of the present disclosure, in a 5G system, by defining a state for energy saving and a WUS configuration method for a base station in a mobile communication system, the problem of excessive energy consumption can be solved, high energy efficiency can be achieved, and the latency of uplink transmission can be improved.

[0028] The effects that can be obtained from the present disclosure are not limited to the above effects, and those skilled in the art can clearly understand other effects not mentioned from the following description.

[0029] Before proceeding with the following detailed description, it may be advantageous to set forth the definitions of certain words and phrases used in this patent document: The terms "include" and "comprise" and their derivatives mean including but not limited to; the term "or" is inclusive and means and / or; the phrases "associated with" and "associated therewith" and their derivatives may mean including, being included within, interconnected with, containing, being contained within, connected to or coupled with, coupled to or joined with, capable of communicating with, cooperating with, interlacing, juxtaposing, adjacent to, bound to or bound with, having, having the property of, etc.; and the term "controller" means any device, system, or part thereof that controls at least one operation, and such a device may be implemented in hardware, firmware, software, or a combination of at least two thereof. It should be noted that the functions associated with any particular controller may be centralized or distributed, whether local or remote.

[0030] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed of computer-readable program code and is contained in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data, or portions thereof suitable for implementation in appropriate computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, optical disc (CD), digital video disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium does not include a wired communication link, a wireless communication link, an optical communication link, or other communication links that transmit transient electrical signals or other signals. Non-transitory computer-readable media include media in which data can be permanently stored and media in which data can be stored and subsequently overwritten, such as rewritable optical discs or erasable storage devices.

[0031] Throughout this patent document, definitions of certain words and phrases are provided. Those of ordinary skill in the art should understand that, in many if not most instances, such definitions apply to the prior and future use of the defined words and phrases. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To more fully understand the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like components:

[0033] Figure 1 Shows the basic structure of the time-frequency domain as a radio resource domain in the wireless communication system to which the present disclosure is applied;

[0034] Figure 2 Shows the time slot structure considered in the wireless communication system to which the present disclosure is applied;

[0035] Figure 3 Shows an example of the time-domain mapping structure and beam scanning operation for the synchronization signal applied to the present disclosure;

[0036] Figure 4 Shows the synchronization signal block considered in the wireless communication system to which the present disclosure is applied;

[0037] Figure 5 Shows various cases of transmitting the synchronization signal block in a frequency band less than 6 GHz considered in the communication system to which the present disclosure is applied;

[0038] Figure 6 Illustrate various cases of transmitting synchronization signal blocks in a frequency band of 6 GHz or higher, which are considered in the communication system to which the present disclosure is applied;

[0039] Figure 7 Illustrate the case of transmitting synchronization signal blocks according to the subcarrier spacing within 5 ms in the wireless communication system to which the present disclosure is applied;

[0040] Figure 8 Illustrate DMRS modes (type 1 and type 2) for communication between a base station and a terminal in the 5G system to which the present disclosure is applied;

[0041] Figure 9 Illustrate an example of channel estimation using DMRS received through one PUSCH in a time band in the 5G system to which the present disclosure is applied;

[0042] Figure 10 Illustrate a method for reconfiguring SSB transmission through dynamic signaling in the 5G system to which the present disclosure is applied;

[0043] Figure 11 Illustrate a method for reconfiguring BWP and BW through dynamic signaling in the 5G system to which the present disclosure is applied;

[0044] Figure 12 Illustrate a method for reconfiguring DRX through dynamic signaling in the 5G system to which the present disclosure is applied;

[0045] Figure 13 Illustrate a base station antenna adaptation method for energy saving in the 5G system to which the present disclosure is applied;

[0046] Figure 14 Illustrate a DTx method for energy saving of the base station to which the present disclosure is applied;

[0047] Figure 15 Illustrate the base station operation according to the gNB wake-up signal to which the present disclosure is applied;

[0048] Figure 16 Illustrate the mode of the gNB WUS timing and synchronization signal to which the present disclosure is applied;

[0049] Figure 17 Illustrate a flowchart of the energy saving method applied by the terminal to the 5G system to which the present disclosure is applied;

[0050] Figure 18 Illustrate a flowchart of the energy saving method applied by the base station to the 5G system to which the present disclosure is applied;

[0051] Figure 19 Illustrate a terminal according to an embodiment of the present disclosure; and

[0052] Figure 20 Shows a base station according to an embodiment of the present disclosure. Detailed implementation

[0053] Discussed below Figures 1 to 20 And various embodiments used to describe the principles of the present disclosure in this patent document are merely exemplary and should not be construed in any way as limiting the scope of the present disclosure. Those skilled in the art should understand that the principles of the present disclosure can be implemented in any appropriately configured system or device.

[0054] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In describing the embodiments of the present disclosure, descriptions related to well-known technical content in the art and not directly related to the present disclosure will be omitted. This omission of unnecessary descriptions is intended to prevent obscuring the main idea of the present disclosure and to more clearly convey the main idea.

[0055] For the same reason, in the drawings, some elements may be shown exaggeratedly, omitted, or schematically. In addition, the size of each element does not fully reflect the actual size. In the drawings, the same or corresponding elements have the same reference numerals.

[0056] By referring to the embodiments described in detail below in conjunction with the accompanying drawings, the advantages and features of the present disclosure and the ways to achieve them will be obvious. However, the present disclosure is not limited to the embodiments set forth below, but can be implemented in various different forms. The provided embodiments are only used to fully disclose the present disclosure and fully inform those skilled in the art of the scope of the present disclosure, and the present disclosure is only defined by the scope of the appended claims. Throughout the specification, the same or similar reference numerals represent the same or similar elements. In addition, when describing the present disclosure, if it is considered that the key points of the present disclosure are unnecessarily obscured, the detailed description of the relevant functions or configurations will be omitted. In addition, the terms described below are terms defined by considering the functions in the present disclosure and may vary according to the intention or practice of the user, operator, etc. Therefore, each term should be defined based on the content throughout the specification.

[0057] In the following, the base station is the subject of resource allocation for the terminal and can be at least one of a gNode B, an eNode B, a NodeB, a base station (BS), a radio access unit, a base station controller, and a node on the network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing communication functions. In the present disclosure, the downlink (DL) is a wireless transmission path of a signal transmitted from the base station to the terminal. The uplink (UL) refers to a wireless transmission path of a signal transmitted from the terminal to the base station. In addition, in the following, the LTE or LTE-A system may be described as an example, but the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel form. For example, the fifth-generation mobile communication technology (5G or New Radio (NR)) developed after LTE-A may be included in other communication systems. In the following, 5G may be a concept including existing LTE, LTE-A, and other similar services. In addition, based on the judgment of those with professional technical knowledge, the present disclosure may also be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure.

[0058] Here, it should be understood that each block of the flowchart and combinations of multiple blocks in the flowchart can be executed by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine such that the instructions run by the processor of the computer or other programmable data processing device create a means for implementing the functions specified in one or more blocks of the flowchart. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can direct the computer or other programmable data processing device to operate in a specific manner such that the instructions stored in the computer-usable or computer-readable memory produce a manufacture including an instruction means for implementing the functions specified in one or more blocks of the flowchart. Instructions that run on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable data processing device to produce a computer-implemented process can provide steps for implementing the functions specified in one or more blocks of the flowchart.

[0059] In addition, each block in the flowchart may represent a module, a segment, or a part of code including one or more executable instructions for implementing the specified logical function. In addition, it should also be noted that in some alternative implementations, the functions mentioned in the blocks may not occur in sequence. For example, two consecutive blocks shown may actually be executed substantially simultaneously, or these blocks may sometimes be executed in the reverse order, depending on the functions involved.

[0060] As used herein, the term "unit" refers to a software element or a hardware element that performs a predetermined function, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, the meaning of "unit" is not always limited to software or hardware. A "unit" can be configured to be stored in an addressable storage medium or to run on one or more processors. Thus, a "unit" includes elements such as, for example, software elements, object-oriented software elements, class elements and task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data architectures, tables, arrays, and parameters. The functions provided within an element and a "unit" can be combined into a smaller number of elements and "units" or can be further separated into additional elements and "units". In addition, an element and a "unit" can be implemented as one or more CPUs within a reproducing apparatus or a secure multimedia card. In addition, a "... unit" in an embodiment can include one or more processors.

[0061] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Hereinafter, the methods and apparatuses provided in the embodiments of the present disclosure are described by taking improving the uplink coverage when performing a random access procedure as an example to illustrate the embodiments of the present disclosure, but are not limited to the respective embodiments, and can be used for a frequency resource allocation method corresponding to another channel by using all or some combinations of one or more embodiments provided in the present disclosure. Therefore, as judged by those skilled in the art, the embodiments of the present disclosure can be applied with some modifications within a certain range without significantly departing from the scope of the present disclosure.

[0062] In addition, when describing the present disclosure, a detailed description of well-known functions or configurations incorporated herein will be omitted when it is determined that such description may unnecessarily obscure the subject matter of the present disclosure. The terms to be described below are terms defined in consideration of the functions in the present disclosure and may vary according to the intention or practice of a user or an operator. Therefore, the terms should be defined based on the content throughout the specification.

[0063] Wireless communication systems have evolved from wireless communication systems centered on voice services to broadband wireless communication systems that provide high-speed and high-quality packet data services, such as the following communication standards: High Speed Packet Access (HSPA) of 3GPP, Long Term Evolution (LTE or Evolved Universal Terrestrial Radio Access (E-UTRA)), LTE-Advanced (LTE-A) and LTE-Pro, High Rate Packet Data (HRPD) and Ultra Mobile Broadband (UMB) of 3GPP2, and 802.17e of IEEE.

[0064] The LTE system, a representative example of a broadband wireless communication system, adopts an Orthogonal Frequency Division Multiplexing (OFDM) scheme in the downlink (DL) and a Single Carrier Frequency Division Multiple Access (SC-FDMA) scheme in the uplink (UL). The UL refers to the radio link through which a terminal (hereinafter referred to as a User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNodeB (eNB) or BS), and the DL refers to the radio link through which the base station transmits data or control signals to the UE. The multiple access schemes described above generally allocate and operate time-frequency resources including data or control information to be transmitted according to each user, in order to prevent time-frequency resources from overlapping with each other, that is, to establish orthogonality for differentiating data or control information of each user.

[0065] As a communication system following the LTE system, the 5G communication system should support services that meet various requirements simultaneously, in order to freely reflect the various needs of users and service providers. The services considered in the 5G communication system include Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), or Ultra-Reliable Low-Latency Communication (URLLC).

[0066] eMBB aims to provide a higher data transmission rate than that supported by LTE, LTE-A, or LTE-Pro. For example, in the 5G communication system, from the perspective of a base station, eMBB should be able to provide a peak data rate of 20 Gbps in the DL and 10 Gbps in the UL. In addition, the 5G communication system should improve the data rate perceived by end-users while providing the peak data rate. To meet these requirements, various transmit / receive technologies including further improved Multiple-Input Multiple-Output (MIMO) transmission technology need to be improved. In addition, in the 2 GHz frequency band used by LTE, a transmission bandwidth of up to 20 MHz is used to transmit signals, but the 5G communication system uses a bandwidth wider than 20 MHz in the frequency band from 3 GHz to 6 GHz or greater than 6 GHz, thus meeting the data transmission rate required in the 5G communication system.

[0067] At the same time, mMTC is regarded as supporting application services such as the Internet of Things (IoT) in the 5G communication system. To efficiently provide the IoT, mMTC requires access support for a large number of terminals in a cell, enhanced coverage of terminals, improved battery life, and cost reduction of terminals. The IoT needs to be able to support a large number of terminals in a cell (for example, 1,000,000 terminals / km 2) because it is connected to various sensors and devices to provide communication functions. In addition, due to the nature of the services, terminals supporting mMTC are more likely to be located in shadow areas where the cell coverage is unavailable (e.g., the basement of a building), so the terminals need a wider coverage than other services provided by the 5G communication system. Terminals supporting mMTC should be manufactured as low-cost terminals and require a very long battery life, such as 10 to 16 years, because it is difficult to replace the terminal battery frequently.

[0068] Finally, URLLC is a cellular-based wireless communication service for mission-critical purposes. For example, URLLC can consider services used in remote control of robots or machines, industrial automation, drones, remote healthcare, or emergency alerts. Therefore, the communication provided by URLLC should offer very low latency and very high reliability. For example, services supporting URLLC need to meet an air interface latency of less than 0.5 milliseconds and at the same time include requirements of a packet error rate of 10 -5 or less. Therefore, for services supporting URLLC, the 5G system can be required to provide a shorter transmission time interval (TTI) than other services, while protecting the reliable communication link by allocating wide resources in the frequency band.

[0069] Among the three services considered in the above 5G communication system (which can be used interchangeably with the 5G system hereinafter), namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. The services can use different transmit / receive techniques and transmit / receive parameters to meet different requirements.

[0070] Hereinafter, the frame structure of the 5G system will be described in more detail with reference to the accompanying drawings. Hereinafter, a wireless communication system to which the present disclosure is applied will be described by taking the configuration of the 5G system as an example for ease of description. However, even in a 5G or higher system or other communication systems to which the present disclosure is applicable, the embodiments of the present disclosure can be applied in the same or similar manner.

[0071] Figure 1 Shows the basic structure of the time-frequency domain as the radio resource domain in the wireless communication system to which the present disclosure is applied.

[0072] In Figure 1 , the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time domain and the frequency domain, i.e., the resource element (RE) 101, can be defined as one orthogonal frequency division multiplexing (OFDM) symbol (or discrete Fourier transform spread OFDM (DFT-s-OFDM) symbol) 102 on the time axis and one subcarrier 103 on the frequency axis. The A number of consecutive REs (e.g., 12) can form a resource block (RB) 104. In addition, the number of consecutive OFDM symbols indicating the number of symbols per subframe in the time domain can form a subframe 110.

[0073] Figure 2 Fig. shows the slot structure considered in the wireless communication system to which the present disclosure is applied.

[0074] Figure 2 Fig. shows an example of a slot structure including a frame 200, a subframe 201, and slots 202 or 203. A frame 200 can be defined as 10 ms. A subframe 201 can be defined as 1 ms, and thus, a frame 200 can include a total of 10 subframes 201. In addition, a slot 202, 203 can be defined as 14 OFDM symbols (i.e., the number of symbols per slot

[0075] A subframe 201 can include one or more slots 202 or 203, and the number of slots 202 or 203 in each subframe 201 can vary according to the configured value μ204 or 205 of the subcarrier spacing (SCS).

[0076] For the cases of μ = 0 204 and μ = 1 205 as subcarrier spacing configuration values, the slot structure is shown. In the case of μ = 0 204, a subframe 201 can include one slot 202, and in the case of μ = 1 205, a subframe 201 can include two slots 203 (e.g., including slot 203). That is, the number of slots per subframe can vary according to the configured value μ of the subcarrier spacing, and thus, the number of slots per frame can vary. For example, according to each subcarrier spacing configuration μ and can be defined in Table 1 below.

[0077] [Table 1]

[0078]

[0079] In a 5G wireless communication system, a synchronization signal block (which can be interchanged with an SS block (SSB) or an SS / PBCH block, etc.) can be transmitted for the initial access of a UE, and the synchronization signal block can include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH).

[0080] In the initial access phase when the UE accesses the system, the UE first obtains downlink time-domain and frequency-domain synchronization from the synchronization signals through cell search and obtains the cell ID. The synchronization signals include the PSS and SSS. In addition, the UE receives the PBCH through which the base station transmits the master information block (MIB) and obtains system information related to transmission and reception, such as system bandwidth or related control information, and basic parameter values. Based on this information, the UE can perform decoding on the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH) to obtain the system information block (SIB). Thereafter, the UE exchanges UE-related identification information with the base station through the random access process and initializes access to the network through processes such as registration and authentication.

[0081] In addition, the UE can obtain cell common control information related to transmission and reception by receiving the system information (SIB) transmitted from the base station. The cell common control information related to transmission and reception may include random access related control information, paging related control information, common control information for various physical channels, etc.

[0082] The synchronization signal is a reference signal for cell search, and the subcarrier spacing can be adaptively applied to the synchronization signal on a frequency band basis according to the channel environment such as phase noise. In the case of a data channel or a control channel, different subcarrier spacings can be applied according to the service type to support various services as described above.

[0083] Figure 3 An example of the time-domain mapping structure and beam scanning operation of the synchronization signal applied in this disclosure is shown.

[0084] For the purpose of description, the following elements can be defined.

[0085] - Primary Synchronization Signal (PSS): It is a signal that serves as a reference for DL time / frequency synchronization and provides information related to a part of the cell ID.

[0086] Secondary Synchronization Signal (SSS): It is a signal that serves as a reference for DL time / frequency synchronization and provides information related to the remaining part of the cell ID information. Additionally, it can be used as a reference signal for PBCH demodulation.

[0087] - Physical Broadcast Channel (PBCH): It provides the master information block (MIB), which is the necessary system information required for the terminal to transmit and receive data channels and control channels. The necessary system information may include search space related control information representing information related to the mapping of control channels to radio resources, scheduling control information for the independent data channel carrying system information, information related to the frame unit index used as a timing reference, the system frame number (SFN), etc.

[0088] - Synchronization Signal (SS) / PBCH Block or SSB: The SS / PBCH block consists of N OFDM symbols and is a combination of PSS, SSS, and PBCH. In the case of a system using beam scanning, the SS / PBCH block is the smallest unit to which beam scanning is applied. In the 5G system, N = 4. The base station can transmit up to L SS / PBCH blocks, and the L SS / PBCH blocks are mapped within a half-frame (0.5 ms). The L SS / PBCH blocks are repeated periodically with a specific period P. The base station can indicate the period P to the UE by signaling. When there is no independent signaling for the period P, the UE applies a preset default value.

[0089] Reference Figure 3 , beam scanning is applied over time based on the SS / PBCH block. In Figure 3 the example, at time t1 301, UE1 305 receives the SS / PBCH block on the beam radiated in the direction #d0 303 by applying beamforming to the SS / PBCH block #0. In addition, at time t2 302, UE2 306 receives the SS / PBCH block on the beam radiated in the direction #d4 304 by applying beamforming to the SS / PBCH block #4. The UE can obtain the best synchronization signal on the beam radiated by the base station in its direction. For example, for UE1 305, it may be difficult to obtain time / frequency synchronization and necessary system information from the SS / PBCH block transmitted from the beam radiated in the direction #d4, which is away from the location of UE1 305.

[0090] In addition to the initial access procedure, the UE can receive the SS / PBCH block to determine whether the radio link quality of the current cell remains at a certain level or is higher than a certain level. Further, during the handover process from the current cell to an adjacent cell, the UE can receive the SS / PBCH block of the adjacent cell to determine the radio link quality of the adjacent cell and obtain time / frequency synchronization with the adjacent cell.

[0091] Hereinafter, the cell initial access operation procedure of the 5G wireless communication system will be described in more detail with reference to the accompanying drawings.

[0092] The synchronization signal, which is a reference signal for cell search, can be transmitted by applying a subcarrier spacing suitable for the channel environment (e.g., phase noise) to each frequency band. The 5G base station can transmit multiple synchronization signal blocks according to the number of analog beams to be operated. For example, PSS and SSS can be mapped to 12 RBs and then transmitted, and PBCH can be mapped to 24 RBs and then transmitted. Hereinafter, the structure for transmitting the synchronization signal and PBCH in the 5G communication system will be described.

[0093] Figure 4Shows a synchronization signal block considered in the wireless communication system to which the present disclosure is applied.

[0094] According to Figure 4 , the synchronization signal block (SS block) 400 may include a PSS 401, an SSS 403, and a PBCH (Broadcast Channel) 402.

[0095] The SS block 400 is mapped to four OFDM symbols 404 on the time axis. The PSS 401 and the SSS 403 may be transmitted through 12 RBs 405 on the frequency axis and through the first OFDM symbol and the third OFDM symbol on the time axis, respectively. In a 5G system, for example, a total of 1008 different cell IDs may be defined. According to the physical layer ID (PCI) of the cell, the PSS 401 may have 3 different values, and the SSS 403 may have 336 different values. Based on the combination of the PSS 401 and the SSS 403, the UE may obtain one of the (336×3 =) 1008 cell IDs by detecting them. This can be expressed as Equation 1 below.

[0096] [Equation 1]

[0097]

[0098] Here, can be estimated from the SSS 403 and may have a value between 0 and 335. can be estimated from the PSS 401 and may have a value between 0 and 2. The UE may estimate and from the combination of values (cell ID).

[0099] The PBCH 402 may be transmitted through a resource including 24 RBs 406 on the frequency axis and 6 RBs 407, 408 on both sides, except for the central 12 RBs 405 through which the SSS 403 is transmitted, in the second OFDM symbol to the fourth OFDM symbol of the SS block on the time axis. The PBCH 402 may include a PBCH payload and a PBCH demodulation reference signal (DMRS), and various system information called MIB may be transmitted in the PBCH payload. For example, the MIB may include the information shown in Table 2 below.

[0100] [Table 2]

[0101]

[0102] - Synchronization signal block information: The offset in the frequency domain of the synchronization signal block is indicated by 4 bits (ssb-SubcarrierOffset) in the MIB. The index of the synchronization signal block including the PBCH can be indirectly obtained by decoding the PBCH DMRS and the PBCH. In one embodiment, in a frequency band below 6 GHz, 3 bits obtained by decoding the PBCH DMRS can indicate the synchronization signal block index, and in a frequency band of 6 GHz or higher, a total of 6 bits including 3 bits obtained by decoding the PBCH DMRS and 3 bits included in the PBCH payload and obtained by PBCH decoding can indicate the synchronization signal block index including the PBCH.

[0103] - Physical downlink control channel (PDCCH) configuration information: The subcarrier spacing of the common downlink control channel is indicated by 1 bit (subCarrierSpacingCommon) in the MIB, and the time-frequency resource composition information of the control resource set (CORESET) and the search space (SS) is indicated by 8 bits (pdcch-ConfigSIB1).

[0104] - System frame number (SFN): 6 bits (systemFrameNumber) in the MIB are used to indicate a part of the SFN. The 4 least significant bits (LSB) of the SFN are included in the PBCH payload to be indirectly obtained by the UE through PBCH decoding.

[0105] - Timing information in the radio frame: The UE can indirectly identify whether the synchronization signal block is transmitted in the first half-frame or the second half-frame of the radio frame through 1 bit (half-frame) included in the above synchronization signal block index and PBCH payload and obtained by PBCH decoding.

[0106] The 12 resource blocks (RBs) 405 corresponding to the transmission bandwidth of the PSS 401 and the SSS 403 and the 24 resource blocks (RBs) 406 corresponding to the transmission bandwidth of the PBCH 402 are different from each other, such that in the first OFDM symbol of the PSS 401 within the transmission bandwidth of the PBCH 402, in addition to the central 12 resource blocks for transmitting the PSS 401, there are 6 resource blocks 407 and 6 resource blocks 408 on both sides, and the 6 resource blocks 407 and the 6 resource blocks 408 can be used to transmit another signal or can be empty.

[0107] The same analog beam can be used to transmit the synchronization signal block. For example, the PSS 401, SSS 403, and PBCH 402 can all be transmitted through the same beam. The analog beam cannot be applied differently on the frequency axis, such that in a specific OFDM symbol where a specific analog beam is applied, the same analog beam is applied on any frequency-axis RB. For example, all four OFDM symbols used to transmit the PSS 401, SSS 403, and PBCH 402 can be transmitted through the same analog beam.

[0108] Figure 5 Shows various cases of transmitting the synchronization signal block in a frequency band below 6 GHz considered in the communication system to which the present disclosure is applied.

[0109] Reference Figure 5 , in a 5G communication system, the 15 kHz subcarrier spacing (SCS) 520 and the 30 kHz subcarrier spacings 530, 540 can be used for transmitting the synchronization signal block in a frequency band of 6 GHz or lower. In the case of the 15 kHz subcarrier spacing 520, there can be one transmission case of the synchronization signal block (e.g., case #1 501), and in the case of the 30 kHz subcarrier spacings 530, 540, there can be two transmission cases of the synchronization signal block (e.g., case #2 502 and case #3 503).

[0110] In Figure 5 , in the case of #1 501 with a 15 kHz subcarrier spacing 520, up to 2 synchronization signal blocks can be transmitted within a time of 1 ms 504 (or in the case where one time slot includes 14 OFDM symbols, corresponding to the length of one time slot). As an example, Figure 4 shows the synchronization signal block #0 507 and the synchronization signal block #1 508. For example, the synchronization signal block #0 507 can be mapped to four consecutive symbols starting from the third OFDM symbol, and the synchronization signal block #1 508 can be mapped to four consecutive symbols starting from the ninth OFDM symbol.

[0111] Different analog beams can be applied to the synchronization signal block #0 507 and the synchronization signal block #1 508. In addition, the same beam can be applied to the third OFDM symbol to the sixth OFDM symbol to which the synchronization signal block #0 507 is mapped, and the same beam can be applied to the ninth OFDM symbol to the twelfth OFDM symbol to which the synchronization signal block #1 508 is mapped. For the seventh OFDM symbol, the eighth OFDM symbol, the thirteenth OFDM symbol, and the fourteenth OFDM symbol to which the synchronization signal block is not mapped, the base station can freely determine which analog beam to use.

[0112] In Figure 5In , in the case of #2 502 with a 30 kHz subcarrier spacing of 530, up to 2 synchronization signal blocks can be transmitted within 0.5 ms 505 (or, in the case where one time slot includes 14 OFDM symbols, corresponding to the length of one time slot), and thus, up to 4 synchronization signal blocks can be transmitted within 1 ms (or, in the case where one time slot includes 14 OFDM symbols, corresponding to the length of two time slots). As an example, Figure 5 shows the case where synchronization signal block #0 509, synchronization signal block #1 510, synchronization signal block #2 511, and synchronization signal block #3 512 are transmitted within 1 ms (i.e., two time slots). Synchronization signal block #0 509 and synchronization signal block #1 510 can start mapping from the fifth OFDM symbol and the ninth OFDM symbol of the first time slot respectively, and synchronization signal block #2 511 and synchronization signal block #3 512 can start mapping from the third OFDM symbol and the seventh OFDM symbol of the second time slot respectively.

[0113] Different analog beams can be applied to synchronization signal block #0 509, synchronization signal block #1 510, synchronization signal block #2 511, and synchronization signal block #3 512. In addition, the same analog beam can be applied to the fifth OFDM symbol to the eighth OFDM symbol of the first time slot through which synchronization signal block #0 509 is transmitted, the ninth OFDM symbol to the twelfth OFDM symbol of the first time slot through which synchronization signal block #1 510 is transmitted, the third symbol to the sixth symbol of the second time slot through which synchronization signal block #2 511 is transmitted, and the seventh symbol to the tenth symbol of the second time slot through which synchronization signal block #3 512 is transmitted. For the OFDM symbols to which the synchronization signal blocks are not mapped, the base station can freely determine which analog beam to use.

[0114] In Figure 5 In , in the case of a 30 kHz subcarrier spacing of 540, up to 2 synchronization signal blocks can be transmitted within 0.5 ms (or, in the case where one time slot includes 14 OFDM symbols, corresponding to the length of one time slot), and thus, up to 4 synchronization signal blocks can be transmitted within 1 ms (or, in the case where one time slot includes 14 OFDM symbols, corresponding to the length of two time slots). As an example, Figure 5It shows the transmission of synchronization signal block #0 513, synchronization signal block #1 514, synchronization signal block #2 515, and synchronization signal block #3 516 within a time of 1 ms (i.e., two time slots). Synchronization signal block #0 513 and synchronization signal block #1 514 can be mapped starting from the third OFDM symbol and the ninth OFDM symbol of the first time slot respectively, and synchronization signal block #2 515 and synchronization signal block #3 516 can be mapped starting from the third OFDM symbol and the ninth OFDM symbol of the second time slot respectively.

[0115] Different analog beams can be used for synchronization signal block #0 513, synchronization signal block #1 514, synchronization signal block #2 515, and synchronization signal block #3 516. As described in the above example, the same analog beam can be used for all four OFDM symbols through which the corresponding synchronization signal blocks are transmitted, and for the OFDM symbols to which the synchronization signal blocks are not mapped, the base station can freely determine which analog beam to use.

[0116] Figure 6 It shows various cases of transmitting synchronization signal blocks in a frequency band of 6 GHz or higher considered in the communication system to which the present disclosure is applied.

[0117] In a 5G communication system, in a frequency band of 6 GHz or higher, a 120 kHz subcarrier spacing 630 as in the example of case #4 610 can be used for synchronization signal block transmission, and a 240 kHz subcarrier spacing 640 as in the example of case #5 620 can be used for synchronization signal block transmission.

[0118] In case #4 610 with a 120 kHz subcarrier spacing 630, up to 4 synchronization signal blocks can be transmitted within a time of 0.25 ms 601 (or corresponding to the length of two time slots in the case where one time slot includes 14 OFDM symbols). As an example, Figure 6 It shows the transmission of synchronization signal block #0 603, synchronization signal block #1 604, synchronization signal block #2 605, and synchronization signal block #3 606 within 0.25 ms (i.e., two time slots). Synchronization signal block #0 603 can be mapped to four consecutive symbols starting from the fifth OFDM symbol of the first time slot, and synchronization signal block #1 604 can be mapped to four consecutive symbols starting from the ninth OFDM symbol of the first time slot. Synchronization signal block #2 605 can be mapped to four consecutive symbols starting from the third OFDM symbol of the second time slot, and synchronization signal block #3 606 can be mapped to four consecutive symbols starting from the seventh OFDM symbol of the second time slot.

[0119] As described in the above embodiments, different analog beams can be used for Synchronization Signal Block #0 603, Synchronization Signal Block #1 604, Synchronization Signal Block #2 605, and Synchronization Signal Block #3 606. Additionally, the same analog beam can be used for all four OFDM symbols through which the corresponding synchronization signal block is transmitted, and for OFDM symbols to which the synchronization signal block is not mapped, the base station can freely determine which analog beam to use.

[0120] In the case #5 620 of a 240 kHz subcarrier spacing 640, up to 8 synchronization signal blocks can be transmitted within a time of 0.25 ms 602 (or, in the case where one time slot includes 14 OFDM symbols, corresponding to the length of four time slots). As an example, Figure 6 shows the case where Synchronization Signal Block #0 607, Synchronization Signal Block #1 608, Synchronization Signal Block #2 609, Synchronization Signal Block #3 610, Synchronization Signal Block #4 611, Synchronization Signal Block #5 612, Synchronization Signal Block #6 613, and Synchronization Signal Block #7 614 are transmitted within 0.25 ms (i.e., four time slots).

[0121] Synchronization Signal Block #0 607 can be mapped to four consecutive symbols starting from the ninth OFDM symbol of the first time slot, Synchronization Signal Block #1 608 can be mapped to four consecutive symbols starting from the thirteenth OFDM symbol of the first time slot, Synchronization Signal Block #2 609 can be mapped to four consecutive symbols starting from the third OFDM symbol of the second time slot, Synchronization Signal Block #3 610 can be mapped to four consecutive symbols starting from the seventh OFDM symbol of the second time slot, Synchronization Signal Block #4 611 can be mapped to four consecutive symbols starting from the fifth OFDM symbol of the third time slot, Synchronization Signal Block #5 612 can be mapped to four consecutive symbols starting from the ninth OFDM symbol of the third time slot, Synchronization Signal Block #6 613 can be mapped to four consecutive symbols starting from the thirteenth OFDM symbol of the third time slot, and Synchronization Signal Block #7 614 can be mapped to four consecutive symbols starting from the third OFDM symbol of the fourth time slot.

[0122] As described in the above embodiments, different analog beams can be used for Synchronization Signal Block #0 607, Synchronization Signal Block #1 608, Synchronization Signal Block #2 609, Synchronization Signal Block #3 610, Synchronization Signal Block #4 611, Synchronization Signal Block #5 612, Synchronization Signal Block #6 613, and Synchronization Signal Block #7 614. Additionally, the same analog beam can be used for all four OFDM symbols through which the corresponding synchronization signal block is transmitted, and for OFDM symbols to which the synchronization signal block is not mapped, the base station can freely determine which analog beam to use.

[0123] Figure 7 It shows a situation in which a synchronization signal block is transmitted according to a subcarrier interval within 5 ms in a wireless communication system to which the present disclosure is applied.

[0124] refer to Figure 7 In the 5G communication system, the synchronization signal block can be periodically transmitted in a time interval unit of 5 ms (corresponding to five subframes or half frames) 710.

[0125] In a frequency band of 3 GHz or lower, a maximum of 4 synchronization signal blocks may be transmitted in a 5 ms time 710. A maximum of 8 synchronization signal blocks may be transmitted in a frequency band higher than 3 GHz and lower than or equal to 6 GHz. A maximum of 64 synchronization signal blocks may be transmitted in a frequency band higher than 6 GHz. As described above, a 15 kHz subcarrier spacing and a 30 kHz subcarrier spacing may be used at a frequency of 6 GHz or lower.

[0126] As Figure 7 Examples include Figure 5 In the case of 15kHz subcarrier spacing of one time slot #1 501, mapping can be performed on the first time slot and the second time slot in a frequency band of 3 GHz or lower, and thus, a maximum of 4 synchronization signal blocks 721 can be transmitted. In addition, mapping can be performed on the first time slot, the second time slot, the third time slot, and the fourth time slot in a frequency band higher than 3 GHz and lower than or equal to 6 GHz, and thus, a maximum of 8 synchronization signal blocks 722 can be transmitted. Figure 5 In case #2 502 or case #3 503 of a 30 kHz subcarrier spacing of two time slots, mapping can be performed starting from the first time slot in a frequency band of 3 GHz or lower, and therefore, a maximum of 4 synchronization signal blocks 731, 741 can be transmitted. In addition, mapping can be performed starting from the first time slot and the third time slot in a frequency band higher than 3 GHz and lower than or equal to 6 GHz, and therefore, a maximum of 8 synchronization signal blocks 732, 742 can be transmitted.

[0127] 120kHz subcarrier spacing and 240kHz subcarrier spacing can be used at frequencies above 6GHz. Figure 6 In the example that includes Figure 6 In case #4 610 of 120kHz subcarrier spacing of two time slots, mapping can be performed starting from the first time slot, the third time slot, the fourth time slot, the fifth time slot, the seventh time slot, the eleventh time slot, the thirteenth time slot, the fifteenth time slot, the seventeenth time slot, the twenty-first time slot, the twenty-third time slot, the twenty-fifth time slot, the twenty-seventh time slot, the thirty-first time slot, the thirty-third time slot, the thirty-fifth time slot, and the thirty-seventh time slot in a frequency band higher than 6GHz, and therefore, a maximum of 64 synchronization signal blocks 751 can be transmitted.Figure 7 In the example of Figure 6 in a 240 kHz subcarrier spacing with four time slots including

[0128] #5 620, mapping can be performed starting from the first time slot, the fifth time slot, the ninth time slot, the thirteenth time slot, the twenty-first time slot, the twenty-fifth time slot, the twenty-ninth time slot, and the thirty-third time slot in a frequency band higher than 6 GHz, and thus, up to 64 synchronization signal blocks 761 can be transmitted.

[0129] Generally, the UE can establish a radio link with the network through a random access procedure based on the system information obtained during the cell search process of the cell and synchronization with the network. A contention-based or contention-free scheme can be used for random access. When the UE performs cell selection and reselection during the initial access operation of the cell, for example, a contention-based random access scheme can be used for the purpose of transitioning from the RRC_IDLE state to the RRC_CONNECTED state. In the case of DL data arrival, in the case of handover, or in the case of location measurement, contention-free random access can be used to reconfigure UL synchronization. Table 3 below illustrates the conditions (events) for triggering the random access procedure in the 5G system.

[0130] [Table 3]

[0131]

[0132]

[0133] Hereinafter, a method for configuring the measurement time for radio resource management (RRM) based on the synchronization signal block (SS block or SSB) of the 5G wireless communication system will be described.

[0134] Through higher layer signaling, the UE is configured with MeasObjectNR in MeasObjectToAddModList for intra-frequency / inter-frequency measurement based on SSB and intra-frequency / inter-frequency measurement based on CSI-RS. For example, MeasObjectNR can be configured as shown in [Table 4] below.

[0135] [Table 4]

[0136]

[0137]

[0138] -ssbFrequency: It can configure the frequency of the synchronization signal related to MeasObjectNR.

[0139] -ssbSubcarrierSpacing: It configures the subcarrier spacing of the SSB. For FR1, only 15 kHz or 30 kHz can be applied, and for FR2, only 120 kHz or 240 kHz can be applied.

[0140] -smtc1: It represents the SS / PBCH block measurement timing configuration, can configure the primary measurement timing configuration, and can configure the timing offset and duration for the SSB.

[0141] -smtc2: It can configure the secondary measurement timing configuration of the SSB related to MeasObjectNR using the PCI listed in the pci list.

[0142] In addition, it can be configured through other higher-layer signaling. For example, SIB2 for cell reselection between same-frequency, different-frequency, and different RATs can be configured for the UE, or SMTC can be configured for the UE through reconfigurationWithSync for NR PSCell change and NR PS Cell change. In addition, SMTC can be configured for the UE through SCellConfig to add an NRSCell.

[0143] The UE can configure the first SS / PBCH block measurement timing configuration (SMTC) according to the periodicityAndOffset in smtc1 configured for SSB measurement through higher-layer signaling, which provides the period (Periodicity) and offset (Offset). In one embodiment, the first subframe of each SMTC occasion can start from the subframe and system frame number (SFN) of the SPcell that meet the conditions in Table 5 below.

[0144] [Table 5]

[0145]

[0146] If smtc2 is configured, for the cells indicated by the pci-List value of smtc2 in the same MeasObjectNR, the UE can configure additional SMTC according to the configured period of smtc2 and the offset and duration of smtc1. In addition, the UE can receive SMTC configurations via the smtc3 list for smtc2-LP (with a long period) and IAB-MT (Integrated Access and Backhaul-Mobile Terminal) for the same frequency (e.g., the frequency for intra-frequency cell reselection) or different frequencies (e.g., the frequency for inter-frequency cell reselection), and can measure SSB. In one embodiment, for SSB-based RRM measurements, on the configured ssbFrequency, the UE may not consider the SSBs transmitted outside the SMTC occasion in a subframe.

[0147] The base station can use various multi-transmit / receive point (TRP) operation methods according to the serving cell configuration and physical cell identifier (PCI) configuration. Among them, when two TRPs that are far apart in two physical locations have different PCIs, there are two methods to operate these two TRPs.

[0148] [Operation Method 1]

[0149] Two TRPs with different PCIs can be operated in two serving cell configurations.

[0150] In [Operation Method 1], the base station can configure the channels and signals transmitted from different TRPs to be included in different serving cell configurations. That is, each TRP has an independent serving cell configuration, and the band value FrequencyInfoDL indicated by DownlinkConfigCommon in each serving cell configuration can indicate at least some overlapping bands. Since various TRPs operate based on multiple ServCellIndex (e.g., ServCellIndex#1 and ServCellIndex#2), each TRP can use an independent PCI. That is, the base station can allocate one PCI per serving cell index.

[0151] In this case, when transmitting multiple SSBs in TRP 1 and TRP 2, the SSBs have different PCIs (e.g., PCI#1 and PCI#2), and the base station can appropriately select the value of ServCellIndex indicated by the cell parameters in QCL-Info, map the PCI suitable for each TRP, and specify the SSB transmitted in TRP 1 or TRP 2 as the source reference RS of the QCL configuration information. However, since this configuration applies the configuration of one serving cell available for carrier aggregation (CA) of the UE to multiple TRPs, there is a problem of restricting the freedom of CA configuration or increasing the signaling burden.

[0152] [Operation Method 2]

[0153] Two TRPs with different PCIs can be operated in one serving cell configuration.

[0154] In [Operation Method 2], the base station can configure the channels and signals transmitted from different TRPs through one serving cell configuration. Since the UE operates based on one ServCellIndex (e.g., ServCellIndex#1), it is impossible to identify the PCI (e.g., PCI#2) assigned to the second TRP. [Operation Method 2] may have more freedom in terms of CA configuration than [Operation Method 1] above, but if multiple SSBs are transmitted in TRP 1 and TRP 2, the SSBs have different PCIs (e.g., PCI#1 and PCI#2), and the base station may not be able to map the PCI (e.g., PCI#2) of the second TRP through the ServCellIndex indicated by the cell parameters in QCL-Info. The base station can only specify the SSB transmitted in TRP 1 as the source reference RS of the QCL configuration information and cannot specify the SSB transmitted in TRP 2.

[0155] As described above, [Operation Method 1] can perform multi-TRP operation on two TRPs with different PCIs through additional serving cell configuration without the need for additional standard support, but [Operation Method 2] can operate based on the following base station additional UE capability report and configuration information.

[0156] Regarding the UE capability report for [Operation Method 2].

[0157] - The UE can report to the base station through UE capabilities that it may be configured with additional PCIs different from the serving cell PCI through higher layer signaling from the base station. The corresponding UE capabilities can include two independent values X1 and X2, or X1 and X2 can each be reported as independent UE capabilities.

[0158] - X1 refers to the maximum number of additional PCIs that can be configured for a UE, and this PCI may be different from the serving cell PCI. In this case, the time domain position and period of the SSB corresponding to the additional PCI can mean the same situation as that of the serving cell's SSB.

[0159] - X2 refers to the maximum number of additional PCIs that can be configured for a UE. This PCI may be different from the serving cell PCI. In this case, the time domain position and period of the SSB corresponding to the additional PCI can mean a different situation from that of the SSB corresponding to the PCI reported as X1.

[0160] - By definition, the PCIs corresponding to the values reported as X1 and X2 cannot be configured simultaneously with each other.

[0161] - The values reported as X1 and X2 through the UE capability report can each have an integer value ranging from 0 to 7.

[0162] - The values reported as X1 and X2 can be different values reported in FR1 and FR2.

[0163] Regarding the high-layer signaling configuration for [operation method 2].

[0164] - The UE can receive the configuration of the high-layer signaling SSB-MTCAdditionalPCI-r17 from the base station based on the above UE capability report, and the corresponding high-layer signaling can include multiple additional PCIs with at least values different from the serving cell, the SSB transmission power corresponding to each additional PCI, and ssb-PositionInBurst corresponding to each additional PCI, and the maximum number of additional PCIs that can be configured can be 7.

[0165] - For the SSB corresponding to an additional PCI with a value different from that of the serving cell, the UE can assume that it has the same center frequency, subcarrier spacing, and subframe number offset as the serving cell's SSB.

[0166] - The UE can assume that the reference RS (e.g., SSB or CSI-RS) corresponding to the PCI of the serving cell is always connected to the active TCI state. In the case of an additional configured PCI with a value different from that of the serving cell, when there is one or more PCIs, it can be assumed that only one of the PCIs is connected to the active TCI state.

[0167] - In the case where the UE has received two different coresetPoolIndex configurations, the reference RS corresponding to the serving cell PCI is connected to one or more active TCI states, and the reference RS corresponding to the PCI with an additional configuration having a different value from the serving cell is connected to one or more active TCI states. The UE may expect that the active TCI state connected to the serving cell PCI is connected to one of the two coresetPoolIndex, and the active TCI state connected to the PCI with an additional configuration having a different value is connected to the remaining coresetPoolIndex.

[0168] Through the UE capability report and the high-layer signaling of the base station in the above [Operation Method 2], an additional PCI can be configured with a value different from the PCI of the serving cell. In the absence of the above configuration, the SSB corresponding to the additional PCI having a value different from the PCI of the serving cell that cannot be designated as the source reference RS can be used to specify the source reference RS for the QCL configuration information. In addition, similar to the configuration information of the SSB that can be configured in the high-layer signaling smtc1 and smtc2, different from the SSB that can be configured for purposes such as RRM, mobility, or handover, multiple TRP operations with different PCIs can be used as the QCL source RS to support multiple TRP operations with different PCIs.

[0169] Next, the demodulation reference signal (DMRS), which is one of the reference signals in the 5G system, will be described in detail.

[0170] The DMRS may include multiple DMRS ports, and each port maintains orthogonality by using code division multiplexing (CDM) or frequency division multiplexing (FDM) to avoid mutual interference. However, depending on the user's intention and the purpose of using the reference signal, the term "DMRS" may be represented by other terms. The term "DMRS" only gives a specific example to facilitate the explanation of the technical features of the present disclosure and help understand the present disclosure, rather than limiting the scope of the present disclosure. That is, it is obvious to those skilled in the art that this term can be applied to the reference signal based on the technical concept of the present disclosure.

[0171] Figure 8 Illustrate the DMRS modes (Type 1 and Type 2) for communication between the base station and the terminal in the 5G system. In the 5G system, two DMRS modes can be supported. Figure 8 Illustrate two DMRS modes.

[0172] Reference Figure 8, reference numerals 801 and 802 correspond to DMRS type 1. Here, reference numeral 801 represents one symbol pattern, and reference numeral 802 represents two symbol patterns. The DMRS type 1 of reference numerals 801 and 802 is the DMRS pattern of the comb structure 2 and can be composed of two CDM groups, and different CDM groups can undergo frequency-division multiplexing (FDM).

[0173] According to one symbol pattern 801, CDM in the frequency domain can be applied to the same CDM group to distinguish two DMRS ports, and thus, a total of 4 orthogonal DMRS ports can be configured. One symbol pattern 801 can include DMRS port IDs mapped to respective CDM groups (the DMRS port IDs for the downlink can be shown as the numbers shown + 1000).

[0174] According to two symbol patterns 802, CDM in the time / frequency domain can be applied to the same CDM group to distinguish four DMRS ports, and thus, a total of 8 orthogonal DMRS ports can be configured. The second symbol pattern 802 can include DMRS port IDs mapped to respective CDM groups (the DMRS port IDs for the downlink can be shown as the numbers shown + 1000).

[0175] The DMRS type 2 of reference numerals 803 and 804 is the following DMRS mode structure: in this structure, frequency-domain orthogonal cover code (FD-OCC) is applied to adjacent subcarriers in the frequency domain and can be composed of three CDM groups, and different CDM groups can undergo FDM.

[0176] In one symbol pattern 803, CDM in the frequency domain can be applied to the same CDM group to distinguish two DMRS ports, so a total of 6 orthogonal DMRS ports can be configured. One symbol pattern 803 can include DMRS port IDs mapped to respective CDM groups (the DMRS port IDs for the downlink can be shown as the numbers shown + 1000). The two symbol patterns 804 can include CDM in the time / frequency domain applied to the same CDM group to distinguish four DMRS ports, and thus, a total of 12 orthogonal DMRS ports can be configured. The second symbol pattern 804 can include DMRS port IDs mapped to respective CDM groups (the DMRS port IDs for the downlink can be shown as the numbers shown + 1000).

[0177] As described above, in the NR system, two different DMRS modes can be configured (e.g., DMRS mode 801, 802 or DMRS mode 803, 804), and the corresponding DMRS mode can be configured as a single-symbol mode 801 or 803 or two adjacent symbol modes 802 or 804. In addition, in the NR system, the DMRS port number can be scheduled, and for PDSCH rate matching, the number of CDM groups scheduled together can be configured and signaled. In addition, in the case of cyclic prefix-based orthogonal frequency division multiplexing (CP-OFDM), the above two DMRS modes can be supported in both DL and UL, and in the case of discrete Fourier transform spread OFDM (DFT-S-OFDM), only DMRS type 1 among the above DMRS modes can be supported in UL.

[0178] In addition, the configuration of additional DMRS can be supported. The precursory DMRS can indicate the first DMRS transmitted and received at the foremost symbol in the time domain among all DMRSs, and the additional DMRS can indicate the DMRS transmitted and received at the symbol after the precursory DMRS in the time domain. In the NR system, the number of additional DMRSs can be configured to be at least 0 and at most 3. In addition, in the case where additional DMRSs are configured, the same mode as the precursory DMRS can be adopted. In one embodiment, when information related to whether the above DMRS mode type of the precursory DMRS is type 1 or type 2, information related to whether the DMRS mode is a single-symbol mode or two adjacent symbol modes, and information related to the number of CDM groups used with the DMRS port is indicated, and in the case where additional DMRSs are additionally configured, it can be assumed that the additional DMRSs are configured with the same DMRS information as the precursory DMRS.

[0179] In one embodiment, the above downlink DMRS configuration can be configured by RRC signaling as shown in Table 6 below.

[0180] [Table 6]

[0181]

[0182] Here, dmrs-Type can configure the DMRS type, dmrs-AdditionalPosition can configure the additional DMRS OFDM symbol, maxLength can configure a single-symbol DMRS mode or a two-symbol DMRS mode, scramblingID0 and scramblingID1 can configure the scrambling ID, and phaseTrackingRS can configure the phase tracking reference signal (PTRS).

[0183] In addition, the above uplink DMRS configuration can be configured by RRC signaling, as shown in [Table 7] below.

[0184] [Table 7]

[0185]

[0186] Here, dmrs-Type can configure the DMRS type, dmrs-AdditionalPosition can configure the additional DMRS OFDM symbol, phaseTrackingRS can configure the PTRS, and maxLength can configure a one-symbol DMRS mode or a two-symbol DMRS mode. scramblingID0 and scramblingID1 can configure the scrambling ID0, nPUSCH-Identity can configure the cell ID for DFT-s-OFDM, sequenceGroupHopping can disable sequence group hopping, and sequenceHopping can enable sequence hopping.

[0187] Figure 9 An example of channel estimation using DMRS received through one PUSCH in a time band in the 5G system to which the present disclosure is applied is shown.

[0188] Reference Figure 9 , when performing channel estimation for decoding data by using DMRS, physical resource blocks (PRBs) locked to the system frequency band in a bundling manner can be used in the frequency band, and channel estimation can be performed within a precoding resource block group as a corresponding bundling unit. In addition, assuming that the DMRS received only through one PUSCH undergoes the same precoding, channel estimation can be performed in units of time.

[0189] Hereinafter, a method for time-domain resource allocation (TDRA) of a data channel in a 5G communication system will be described. The base station can configure, for the UE, a table of time-domain resource allocation information regarding a downlink data channel (physical downlink shared channel (PDSCH)) and an uplink data channel (PUSCH) through higher-layer signaling (e.g., RRC signaling).

[0190] The base station may configure a table formed by at most 17 (= maxNrofDL-Allocation) entries of the PDSCH, and may configure a table formed by at most 17 (= maxNrofUL-Allocation) entries of the PUSCH. The time-domain resource allocation information may include at least one of the following: for example, at least one of the PDCCH-to-PDSCH slot timing (corresponding to the time interval in slots between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted by K0), or the PDCCH-to-PUSCH slot timing (corresponding to the time interval in slots between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted by K2), information related to the position and length of the start symbol that schedules the PDSCH or PUSCH within a slot, and the mapping type of the PDSCH or PUSCH.

[0191] In one embodiment, the time-domain resource allocation information related to the PDSCH may be configured for the UE by RRC signaling, as shown in Table 8 below.

[0192] [Table 8]

[0193]

[0194] Here, k0 represents the PDCCH-to-PDSCH timing in slots (i.e., the slot offset between the DCI and the PDSCH it schedules), mappingType represents the PDSCH mapping type, startSymbolAndLength represents the start symbol and length of the PDSCH, and repetitionNumber may represent the number of PDSCH transmission opportunities according to the slot-based repetition method.

[0195] In one embodiment, the time-domain resource allocation information for the PUSCH may be configured for the UE by RRC signaling, as shown in [Table 9] below.

[0196] [Table 9]

[0197]

[0198] Here, k2 represents the timing of PDCCH to PUSCH in terms of time slots (i.e., the time slot offset between DCI and the PUSCH it schedules), mappingType represents the PUSCH mapping type, startSymbolAndLength or StartSymboland length represents the start symbol and length of the PUSCH, and numberOfRepetitions can represent the number of repetitions applied to the PUSCH transmission.

[0199] The base station can indicate at least one entry in the table for time domain resource allocation information to the UE via L1 signaling (e.g., downlink control information (DCI)) (e.g., this can be indicated by the "time domain resource allocation" field in DCI). The UE can obtain time domain resource allocation information regarding the PDSCH or PUSCH based on the DCI received from the base station.

[0200] Hereinafter, the transmission of the uplink data channel (physical uplink shared channel (PUSCH)) in the 5G system will be described. The PUSCH transmission can be dynamically scheduled by UL grant in DCI (e.g., referred to as dynamic grant (DG)-PUSCH), or can be scheduled by configured grant type 1 or configured grant type 2 (e.g., referred to as configured grant (CG)-PUSCH). The dynamic scheduling for PUSCH transmission can be indicated by, for example, DCI format 0_0 or 0_1.

[0201] The PUSCH transmission of configured grant type 1 can be semi-statically configured by receiving configuredGrantConfig including rrc-ConfiguredUplinkGrant in Table 10 via higher layer signaling without receiving UL grant in DCI. After receiving configuredGrantConfig that does not include rrc-ConfiguredUplinkGrant in Table 10 via higher layer signaling, the PUSCH transmission of configured grant type 2 can be semi-persistently scheduled by UL grant in DCI.

[0202] In one embodiment, when PUSCH transmission is scheduled by configured grant, in addition to the specific parameters provided by pusch-Config (such as dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, scaling of UCI-OnPUSCH, etc.) which is a higher layer signaling in Table 11, the parameters applied to PUSCH transmission can be configured by configuredGrantConfig which is a higher layer signaling in Table 10. For example, if the UE receives transformPrecoder in configuredGrantConfig which is a higher layer signaling in Table 10, then the UE can apply tp-pi2BPSK in pusch-Config of Table 11 to the PUSCH transmission operated by configured grant.

[0203] [Table 10]

[0204]

[0205]

[0206] Next, the PUSCH transmission method will be described. The DMRS antenna port for PUSCH transmission can be the same as the antenna port for SRS transmission. Depending on whether the value of txConfig in Pusch-Config which is a higher layer signaling in Table 7 indicates "codebook" or "non-codebook", the PUSCH transmission can follow a codebook-based transmission method and a non-codebook-based transmission method. As described above, the PUSCH transmission can be dynamically scheduled by DCI format 0_0 or 0_1, and can be semi-statically configured by configured grant.

[0207] If the UE receives an indication of PUSCH transmission scheduling by DCI format 0_0, the UE can perform beam configuration for PUSCH transmission by using pucch-spatialRelationInfoID corresponding to the UE-specific and dedicated PUCCH resource with the lowest ID within the uplink bandwidth part (BWP) activated in the serving cell. In one embodiment, the PUSCH transmission can be performed based on a single antenna port. The UE may not expect PUSCH transmission to be scheduled by DCI format 0_0 within a BWP that does not configure a PUCCH resource including pucch-spatialRelationInfo. If the UE does not receive the configuration of txConfig in Pusch-Config of Table 11, the UE may not expect to be scheduled by DCI format 0_1.

[0208] [Table 11]

[0209]

[0210] Next, codebook-based PUSCH transmission will be described. Codebook-based PUSCH transmission can be dynamically scheduled by DCI format 0_0 or 0_1, and can be operated semi-statically by configured grant. When dynamically scheduled by codebook-based PUSCH DCI format 0_1 or configured semi-statically by configured grant, the UE can determine the precoder for PUSCH transmission based on the SRS resource indicator (SRI), transmission precoding matrix indicator (TPMI), and transmission rank (i.e., the number of PUSCH transmission layers).

[0211] In one embodiment, the SRI can be given by the SRS resource indicator field in the DCI, or can be configured by srs-ResourceIndicator as high-layer signaling. The UE can be configured with at least one SRS resource during codebook-based PUSCH transmission, and for example, can be configured with at most two SRS resources. In the case where the UE receives the SRI by DCI, the SRS resource indicated by the corresponding SRI can refer to the SRS resource corresponding to the SRI among the SRS resources transmitted earlier than the PDCCH including the corresponding SRI. In addition, the TPMI and transmission rank can be given by the "precoding information and number of layers" field in the DCI, or can be configured by precodingAndNumberOfLayers as high-layer signaling. The TPMI can be used to indicate the precoder applied to PUSCH transmission.

[0212] The precoder for PUSCH transmission can be selected from the uplink codebook, which has the same number of antenna ports as the nrofSRS-Ports value in SRS-Config as high-layer signaling. In codebook-based PUSCH transmission, the UE can determine the codebook subset based on the TPMI and codebookSubset in Pusch-Config as high-layer signaling. In one embodiment, based on the UE capability reported by the UE to the base station, the codebookSubset in Pusch-Config as high-layer signaling can be configured as one of "fullyAndPartialAndNonCoherent", "partialAndNonCoherent", and "nonCoherent".

[0213] If the UE uses the UE capability report "partialAndNonCoherent", the UE may not expect the value of codebookSubset as a higher layer signaling to be configured as "fullyAndPartialAndNonCoherent". If the UE uses the UE capability report "nonCoherent", the UE may not expect the value of codebookSubset as a higher layer signaling to be configured as "fullyAndPartialAndNonCoherent" or "partialAndNonCoherent". In the case where the nrofSRS ports in the SRS-ResourceSet as a higher layer signaling indicates two SRS antenna ports, the UE may not expect the value of codebookSubset as a higher layer signaling to be configured as "partialAndNonCoherent".

[0214] The UE can receive a configuration of an SRS resource set, in which the value of usage in the SRS resource set as a higher layer signaling is configured as "codebook", and can indicate one SRS resource in the corresponding SRS resource set through SRI. If various SRS resources are configured in the SRS resource set where the value of usage in the SRS-ResourceSet as a higher layer signaling is configured as "codebook", the UE can expect that the value of nrofSRS-Ports in the SRS-Resource as a higher layer signaling is the same value for all SRS resources.

[0215] The UE can transmit one or more SRS resources included in the SRS resource set where the value of usage is configured as "codebook" to the base station according to higher layer signaling, and the base station can select one of the SRS resources transmitted by the UE, and can indicate that the UE performs PUSCH transmission by using the transmission beam information of the corresponding SRS resource. In one embodiment, in the codebook-based PUSCH transmission, the SRI can be used as the information of the index for selecting an SRS resource, and can be included in the DCI. In addition, the base station can include the information indicating the TPMI and rank for the UE to perform PUSCH transmission in the DCI, and can transmit the DCI. The UE can perform PUSCH transmission by using the SRS resource indicated by the SRI and applying the precoder indicated by the TPMI and rank indicated by the transmission beam based on the corresponding SRS resource.

[0216] Next, non-codebook based PUSCH transmission will be described. Non-codebook based PUSCH transmission can be dynamically scheduled by DCI format 0_0 or 0_1, or can be operated semi-statically by configured grant. If at least one SRS resource is configured in an SRS resource set where the value of usage in the SRS-ResourceSet as higher layer signaling is configured to "nonCodebook", the UE can receive scheduling of non-codebook based PUSCH transmission by DCI format 0_1.

[0217] Regarding an SRS resource set where the value of usage in the SRS-ResourceSet as higher layer signaling is configured to "nonCodebook", the UE can receive configuration of non-zero power (NZP) CSI-RS resources associated with an SRS resource set. The UE can perform calculations related to the precoder for SRS transmission by measuring the NZP CSI-RS resources configured in association with the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource associated with the SRS resource set and the first symbol of the aperiodic SRS transmission in the UE is less than a specific number of symbols (e.g., 42 symbols), the UE may not expect to update the information related to the precoder for SRS transmission.

[0218] When the value of resourceType in the SRS-ResourceSet as higher layer signaling is configured to "aperiodic", the NZP CSI-RS associated with the SRS-ResourceSet can be indicated by an SRS request, which is a field in DCI format 0_1 or 1_1. In one embodiment, in the case where the NZP CSI-RS resource associated with the SRS-ResourceSet is an aperiodic NZP CSI-RS resource and the value of the "SRS request" field in DCI format 0_1 or 1_1 is not "00", the existence of NZP CSI-RS associated with the SRS-ResourceSet can be indicated. The above DCI may not indicate cross-carrier or cross-BWP scheduling. In the case where the value of the SRS request indicates the existence of NZP CSI-RS, the above NZP CSI-RS can be located in the time slot transmitting the PDCCH including the SRS request field. The TCI state configured in the scheduled subcarriers may not be configured as QCL-TypeD.

[0219] If a periodic or semi-static SRS resource set is configured, the NZP CSI-RS associated with the SRS resource set can be indicated by the associated CSI-RS in the SRS-ResourceSet which is a higher layer signaling. For non-codebook based transmission, the UE may not expect the associated CSI-RS in the spatialRelationInfo for the SRS resource as higher layer signaling and the SRS-ResourceSet as higher layer signaling to be configured simultaneously.

[0220] In the case where the UE receives the configuration of multiple SRS resources, the UE can determine the precoder and transmission rank to be applied to the PUSCH transmission based on the SRI indicated by the base station. In one embodiment, the SRI can be indicated by a field "SRS resource indicator" in the DCI, or can be configured by the srs-ResourceIndicator which is a higher layer signaling. Similar to the above codebook based PUSCH transmission, in the case where the UE receives the SRI through the DCI, the SRS resource indicated by the corresponding SRI can refer to the SRS resource corresponding to the SRI among the SRS resources transmitted earlier than the PDCCH including the corresponding SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources and the maximum number of SRS resources that can be transmitted simultaneously in the same symbol in an SRS resource set can be determined by the UE capability to be reported to the base station. The SRS resources transmitted simultaneously by the UE can occupy the same RB. The UE can configure one SRS port for each SRS resource. Only one SRS resource set can be configured, in which the value of usage in the SRS-ResourceSet which is a higher layer signaling is configured as "nonCodebook", and the number of SRS resources for non-codebook based PUSCH transmission can be configured to be at most 4.

[0221] The base station may transmit one NZP CSI-RS associated with an SRS resource set to the UE, and the UE may calculate a precoder for transmitting one or more SRS resources within the corresponding SRS resource based on the result of measuring when the corresponding NZP CSI-RS is received. The UE may apply the calculated precoder when transmitting one or more SRS resources in an SRS resource set whose usage is configured as "nonCodebook" to the base station, and the base station may select one or more SRS resources from the received one or more SRS resources. In non-codebook-based PUSCH transmission, the SRI may indicate an index representing a combination of one or more SRS resources, and the SRI may be included in the DCI. The number of SRS resources indicated by the SRI transmitted by the base station may be the number of transmission layers of the PUSCH, and the UE may transmit the PUSCH by applying the precoder applied to the SRS resource transmission to each layer.

[0222] Hereinafter, an uplink data channel (PUSCH) retransmission and a single TB transmission method through multiple time slots in a 5G system will be described. The 5G system may support two types of retransmissions of the uplink data channel (e.g., PUSCH retransmission type A and PUSCH retransmission type B) and a TB handling of multiple PUSCHs across multiple time slots (TBoMS) for transmitting multiple PUSCHs across multiple time slots on a single TB. In addition, the UE may receive a configuration of one of PUSCH retransmission types A and B through higher layer signaling. In addition, the UE may receive a configuration of "numberOfSlotsTBoMS" through a resource allocation table and transmit TBoMS.

[0223] PUSCH retransmission type A

[0224] - As described above, the start symbol and length of the uplink data channel are determined in one time slot according to the time domain resource allocation method, and the base station may send the number of retransmissions to the UE through higher layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI). The number N of time slots configured for numberOfSlotsTBoMS to determine the TBS is 1.

[0225] - The UE can repeatedly transmit an uplink data channel with the same start symbol and length as the above-configured uplink data channel in consecutive time slots based on the number of received repeated transmissions. In one embodiment, if at least one symbol in the time slot configured for the UE as a downlink or at least one symbol in the time slot of the repeated transmission of the uplink data channel configured for the UE is configured as a downlink, the UE can omit the uplink data channel transmission in the corresponding time slot. For example, the UE can refrain from transmitting the uplink data channel within the number of repeated transmissions of the uplink data channel. Meanwhile, the UE supporting Rel-17 uplink data repeated transmission determines the time slots in which uplink data repeated transmission can be performed as available time slots, and the time slots determined as available time slots can be counted in the number of transmissions during the repeated transmission of the uplink data channel. In the case where the repeated transmission of the uplink data channel determined as an available time slot is omitted, the repeated transmission can be performed through a transmissible time slot after a delay. Using the following [Table 12], the redundancy version can be applied according to the redundancy version pattern configured for each nth PUSCH transmission occasion.

[0226] PUSCH Repeated Transmission Type B

[0227] - As described above, the start symbol and length of the uplink data channel are determined in a time slot according to the time-domain resource allocation method, and the base station can send the number of repeated transmissions numberOfRepetitions to the UE through higher-layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI). In one embodiment, the number N of time slots configured for numberOfSlotsTBoMS to determine the TBS is 1.

[0228] - Based on the start symbol and length of the above-configured uplink data channel, the nominal repetition of the uplink data channel can be determined as follows. Here, the nominal repetition can refer to the resource of the symbol configured by the base station for PUSCH repeated transmission, and the UE can determine the resource to be used for the uplink in the configured nominal repetition. In this case, the time slot at which the nth nominal repetition starts can be given by and the symbol at which the nominal repetition starts in the start time slot can be given by The time slot at which the nth nominal repetition ends can be given by

[0229] and the symbol at which the nominal repetition ends in the last time slot can be given by Here, n = 0... numberOfRepetitions - 1, S can indicate the start symbol of the configured uplink data channel, and L can indicate the symbol length of the configured uplink data channel. K The time slot at which the nth nominal repetition ends can be given by SThe time slot that can indicate the start of PUSCH transmission, and the number of symbols per time slot can be indicated.

[0230] The UE can determine the invalid symbols for PUSCH repetition transmission type B. The symbols configured as downlink by tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated can be determined as the invalid symbols for PUSCH repetition transmission type B. In addition, the invalid symbols can be configured based on higher layer parameters (e.g., InvalidSymbolPattern). For example, the higher layer parameter (e.g., InvalidSymbolPattern) can configure the invalid symbols by providing a symbol-level bitmap over one time slot or two time slots. In one embodiment, a 1 shown on the bitmap can indicate an invalid symbol. In addition, the period and pattern of the bitmap can be configured by higher layer parameters (e.g., periodicityAndPattern). If the higher layer parameter (e.g., InvalidSymbolPattern) is configured and the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter indicates 1, the UE can apply the invalid symbol pattern, and if the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter indicates 0, the UE can not apply the invalid symbol pattern. Alternatively, if the higher layer parameter (e.g., InvalidSymbolPattern) is configured and the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter is not configured, the UE can apply the invalid symbol pattern.

[0231] After determining the invalid symbols in each nominal repetition, the UE may consider the symbols other than the determined invalid symbols as valid symbols. If one or more valid symbols are included in each nominal repetition, the nominal repetition may include one or more actual repetitions. Here, each actual repetition may refer to the symbols configured for the configured nominal repetition that are actually used for PUSCH repeated transmission, and may include a continuous set of valid symbols for PUSCH repeated transmission type B in one time slot. In the case where an actual repetition with one symbol is configured as valid, the UE may omit the actual repeated transmission except when the symbol length of the configured uplink data channel L is 1. By using [Table 8] below, the redundancy version (RV) may be applied according to the redundancy version pattern configured for each nth actual repetition.

[0232] Transport Block processing over Multiple Slots (TBoMS)

[0233] As described above, the start symbol and length of the uplink data channel are determined by the time domain resource allocation method in one time slot, and the base station may send the number of repeated transmissions to the UE via higher layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI). In one embodiment, the TBS may be determined using an N value greater than or equal to 1 and the number of time slots configured as numberOfSlotsTBoMS.

[0234] Based on the number of time slots used to determine the TBS received from the base station and the number of repeated transmissions, the UE may transmit an uplink data channel with the same start symbol and length as the uplink data channel configured above in consecutive time slots. In one embodiment, in a time slot configured as downlink for the UE by the base station, or in the case where at least one symbol in the time slot used for the uplink data channel repeated transmission configured for the UE is configured as downlink, the UE may skip the uplink data channel transmission in the corresponding time slot. For example, the UE may count the number of uplink data channel repeated transmissions but does not perform the uplink data channel repeated transmission.

[0235] On the other hand, a UE supporting Rel-17 uplink data repeated transmission determines the time slots in which uplink data repeated transmission can be performed as available time slots, and the time slots determined as available time slots may be counted as the number of transmissions during the uplink data channel repeated transmission. In the case where the uplink data channel repeated transmission determined as an available time slot is omitted, the repeated transmission may be performed via a transmittable time slot after a delay. In one embodiment, by using [Table 12] below, the redundancy version may be applied according to the redundancy version pattern configured for each nth PUSCH transmission occasion.

[0236] [Table 12]

[0237]

[0238] In the following, a method for determining an uplink available time slot for single or multiple PUSCH transmissions in a 5G system will be described.

[0239] In one embodiment, when the UE is configured to enable AvailableSlotCounting, the UE can determine available time slots for PUSCH repetition transmission type A and TBoMS PUSCH transmissions based on the tdd-UL-DL-ConfigurationCommon, tdd-UL-DL-ConfigurationDedicated, ssb-PositionsInBurst, and time domain resource allocation (TDRA) information field values. That is, if at least one symbol of the TDRA configured for PUSCH in the time slot for PUSCH transmission overlaps with at least one symbol for purposes other than uplink transmission, the time slot can be determined as an unavailable time slot.

[0240] In the following, a method for reducing the SSB density by dynamic signaling to save the base station energy in a 5G system will be described.

[0241] Figure 10 A method for reconfiguring SSB transmission by dynamic signaling according to an embodiment of the present disclosure is shown.

[0242] Refer to Figure 10 , the UE can receive the configuration of ssb-PositionsInBurst = "11110000" (1002) from the base station through high-layer signaling (SIB1 or ServingCellConfigCommon), and in a subcarrier spacing of 30 kHz, it can transmit up to 2 synchronization signal blocks within a time of 0.5 ms (or in the case where one time slot includes 14 OFDM symbols, which corresponds to one time slot length). In addition, the UE can receive 4 synchronization signal blocks (SSBs) within a time of 1 ms (or in the case where one time slot includes 14 OFDM symbols, it corresponds to two time slot lengths). In this case, in order for the base station to reduce the density of SSB transmissions to save energy, the base station can reconfigure the SSB transmission configuration information by broadcasting the bitmap "1010xxxx" (1004) through group / cell common DCI (1003) using the network energy-saving radio network temporary identifier (nwes-RNTI) (or es-RNTI). In this case, the base station can cancel the transmissions of SS block #1 (1005) and SS block #3 (1006) based on the bitmap (1004) configured for the group / cell common DCI. The above Figure 10A method (1001) for reconfiguring SSB transmission through bitmap-based group / cell common DCI is provided.

[0243] In addition, the base station can reconfigure ssb-periodicity configured through higher layer signaling via group / cell common DCI. Further, by additionally configuring timer information to indicate when to apply the group / cell common DCI, the base station can transmit the SSB by reconfiguring the SSB transmission information to the group / cell common DCI during the configured timer. When the timer ends, the base station can operate based on the SSB transmission information configured to the existing higher layer signaling. That is, the SSB configuration information can be reconfigured accordingly by switching the configuration from the normal mode to the energy saving mode through the timer. As another method, the base station can use offset and duration information to configure the application time and period of the SSB configuration information reconfigured to the UE via group / cell common DCI. In this case, the UE may not monitor the SSB during the duration starting from the moment when the group / cell common DCI is received and the offset is applied.

[0244] Hereinafter, a BWP or BW adaptation method for saving base station energy through dynamic signaling in a 5G system will be described.

[0245] Figure 11 A method for reconfiguring BWP and BW through dynamic signaling according to an embodiment of the present disclosure is shown.

[0246] Reference Figure 11 , the UE can operate under a BWP or BW activated by higher layer signaling and L1 signaling received from the base station (1101). For example, the UE can operate at the full BW of 100 MHz using a fixed power PSDB. In this case, the base station can adapt the BW and BWP so that the UE operates at a narrower BW of 40 MHz using the same power PSDB to save energy (1102). In this case, the operation of the base station adapting the BW or BWP to save energy can be configured by group common DCI and cell-specific DCI to exactly match the UE-specific BWP and BW configuration (1103). For example, UE#0 and UE#1 can be configured to different BWP with different compositions and positions. In this case, in order to save energy by reducing the used BW, the base station can configure the BW and BWP of all UEs to be the same. In this case, the BWP or BW in the energy saving operation can be configured as one or more, which can be used to configure the BWP for each UE group.

[0247] Hereinafter, a DRX alignment method for saving base station energy through dynamic signaling in a 5G system will be described.

[0248] Figure 12Disclosed is a method for reconfiguring DRX through dynamic signaling according to an embodiment of the present disclosure.

[0249] Reference Figure 12 , the base station can configure DRX specifically for the UE through higher layer signaling. For example, each UE can be configured with different drx-LongCycle, drx-ShortCycle, drx-onDurationTimer, and drx-InactivityTimer.

[0250] After that, for energy saving, the base station can configure the UE-specific DRX for the UE group specifically or cell-specifically through L1 signaling to the UE group (1201). In this way, the same effect as the UE saving power through DRX can be obtained to save energy at the base station.

[0251] Hereinafter, a method for dynamically turning on / off the antennas (i.e., TxRUs) of the base station to save the energy of the base station in a 5G system will be described.

[0252] Figure 13 Disclosed is a method for adapting the base station antennas for energy saving according to an embodiment of the present disclosure.

[0253] Reference Figure 13 , the base station can adapt the Tx antenna ports per RU for energy saving. Since the power amplifiers (PAs) of the base station account for most of the energy consumption of the base station, the base station can turn off the Tx antennas for energy saving (1301). In this case, to determine whether the Tx antennas can be turned off, the base station can perform transmission by adapting the number of active Tx antennas for each UE group or UE by referring to the RSRP, CQI, RSRQ, etc. of the UE.

[0254] In this case, the base station can configure beam information, reference signal information, etc. according to the antenna on / off of the UE through DCI signaling. In addition, by configuring different antenna information for each BWP, the base station can reconfigure the antenna information according to the change of the BWP.

[0255] Hereinafter, the discontinuous transmission (DTx) operation for reducing the energy consumption of the base station in a 5G system will be described.

[0256] Figure 14 Disclosed is a DTx method for base station energy saving according to an embodiment of the present disclosure.

[0257] Reference Figure 14The base station can configure discontinuous transmission (DTx) for energy saving through higher layer signaling (new system information block (SIB) for DTx or RRC signaling) and L1 signaling (DCI). In this case, the base station can configure dtx-onDurationTimer (1405) for the physical downlink control channel (PDCCH) that schedules the downlink shared channel (DL SCH) or RRM measurements, beam management, and transmission of reference signals for measuring path loss, etc. for DTx operation, configure dtx-InactivityTimer (1406) for receiving the physical downlink shared channel (PDSCH) after receiving the PDCCH that schedules the DL SCH, configure the synchronization signal (SS) (1403) configuration information for synchronization before dtx-onDurationTimer, configure dtx-offset (1404) for the offset between after configuring the SS transmission and dtx-onDurationTimer, and configure dtx-(Long)Cycle (1402) for the periodic operation of DTx based on the configuration information. In this case, dtx-cycle can be configured in various forms as long cycles and short cycles. During DTx operation, the base station considers the transmitter to be in the off (or inactive) state, so it may not transmit the downlink control channel (DL CCH), SCH, and DLRS. That is, the base station can transmit SS during dtx-InactiveTimer and transmit the downlink (PDCCH, PDSCH, RS, etc.) during dtx-onDurationTimer. In this case, the number of SS-gapbetweenBurst or SS bursts can be configured as additional information to the above-configured SS configuration information.

[0258] Through the above method, the energy consumption of the base station can be reduced. In addition, the above method can be configured simultaneously through one or more combinations.

[0259] To reduce the energy consumption of the base station, the embodiments of the present disclosure provide a method for the user equipment (UE) to convert the mode (or state) of the base station through the gNB wake-up signal (WUS) when the base station is inactive (or in sleep mode, energy saving mode). In addition, the present disclosure provides a method for the base station to perform RS configuration for WUS configuration and synchronization and enable / disable the application of WUS through higher layer signaling and dynamic L1 signaling.

[0260] <The First Embodiment>

[0261] As the first embodiment of the present disclosure, a method for activating the base station through the gNB wake-up signal (WUS) to save energy when the base station is in an inactive state will be described.

[0262] Figure 15Shows the operation of a base station for a gNB wake-up signal according to an embodiment of the present disclosure.

[0263] Reference Figure 15 , the base station can maintain the transmitter in an off (or inactive) state to save energy when the base station is in an inactive state (or sleep mode). After that, the base station can receive the gNB wake-up signal 1502 from the UE to activate the base station.

[0264] In the case where the base station receives the WUS from the UE through the Rx terminal (receiver), the base station can convert the Tx terminal (transmitter) to an on (or active) state (1503). After that, the base station can perform a downlink transmission to the UE.

[0265] In this case, the base station can perform synchronization after the Tx is turned on, and perform control signal transmission and data transmission. In addition, various uplink signals such as the physical random access channel (PRACH), scheduling request (SR PUCCH), PUCCH including Ack, etc. can be considered as gNB WUS. Through the above method, the base station can save energy, and at the same time the UE can improve latency.

[0266] At the same time, the base station can configure the WUS timing for receiving the gNB WUS and the synchronization RS for synchronization before the UE transmits the gNB WUS. In this case, the synchronization RS can consider the SSB, TRS, lightweight SSB (PSS+SSS), continuous SSB, or new RS (continuous PSS+SSS), etc., and the WUS can consider the PRACH, PUCCH with SR, or sequence-based signals, etc. The transmission of the synchronization RS 1504 for synchronization between the base station and the UE and the WUS transmission at the WUS timing can be repeatedly performed with the WUS-RS period (1505). In Figure 15 the example of, the one-to-one mapping of the synchronization RS and the WUS timing is described as one embodiment, but the mapping is not limited thereto, and the synchronization RS and the WUS timing can be mapped as N to 1, 1 to N, or N to M.

[0267] Figure 16 Shows the pattern of the gNB WUS timing and the synchronization signal according to an embodiment of the present disclosure.

[0268] Reference Figure 16, the base station can configure for the UE the timing to receive the synchronization signal for synchronization before transmitting gNB WUS and the timing to transmit gNB WUS. The UE can be configured with RACH timings corresponding to the current SSB burst and SSB, and each SSB and RACH timing can have a period (1603) and a repetition pattern (1602). In this case, depending on the channel state, the UE may need to receive one or more SSB bursts to achieve synchronization. As a result, a delay problem may occur.

[0269] To solve this problem, the UE can perform the gNB WUS operation based on the newly configured synchronization signal and gNB WUS timing pattern of the base station. For example, the base station can configure for the UE the gNB WUS timing (1605) that is separated from three consecutive SSB bursts and the last SSB burst by a specific gap. The configured SSB bursts and gNB WUS timing can be repeated (1604) at a specific period (e.g., ss-WakeupOccasion-periodicity 1606). At the same time, in the present disclosure, the gNB WUS operation can not only include the operation of the UE transmitting WUS, but also include the operation of the UE determining whether to transmit WUS by determining whether the base station is activated. That is to say, in the present disclosure, in the operation of the UE performing gNB WUS, when the UE determines whether to activate the base station at the WUS timing and activation is not necessary (e.g., in the case where there is no UL service), the UE can not transmit WUS.

[0270] In addition, the UE can be configured by the base station with SSB bursts and TRS bursts as synchronization signals, and the gNB WUS timing (1608) with a specific gap can be configured by the TRS. The configured SSB bursts, TRS bursts, and gNB WUS timing can be repeated (1607) at a specific period (e.g., ss-WakeupOccasion-perioidicity 1609).

[0271] In another method, to optimize the delay performance, the gNB WUS timing is allocated after one SSB burst or TRS burst, and the SSB burst or TRS burst + gNB WUS timing is sequentially allocated to form a set (1611), and the optimized delay performance (1610) can be achieved at a specific period (e.g., ss-WakeupOccasion-perioidicity 1612) through the repeated operation of this set. Through the above mode, the UE can perform synchronization with a faster delay, and then the UE can save energy within the period. The mode of the present disclosure is an example and is not limited to the above method, and more combinations of the number of SSBs or TRSs and the mode combinations of the gNB WUS timing can be considered.

[0272] More specifically, the WUS and synchronization RS configuration information can be configured by including the following information. The synchronization RS configuration information can include at least one of information such as RS index, RS period, RS-resourceSetConfig, and RS pattern. The WUS configuration information can include information related to the number of WUS occasions (WO) for one FDM, information related to the number of synchronization signals (SS) for each WUS (or RACH) occasion, the gap between SS and WO, the number of gNB occasions, and at least one of the positions according to the function and purpose of WUS. Additionally, the WUS configuration information can include information such as the burst for gNB WO+SS. Further, the WUS configuration information and the synchronization RS configuration information can be configured using one or a combination of the following methods according to the UE state (RRC connected, RRC idle, RRC inactive).

[0273] In one embodiment, a method is provided for a base station to configure gNB WUS configuration information for a UE in the RRC connected state to save energy.

[0274] The base station can configure the gNB WUS configuration information for the UE through RRC signaling for base station energy saving. For example, the gNB-WUS-config as shown below can be transmitted to the UE through the RRC signaling shown in Table 13.

[0275] [Table 13]

[0276]

[0277] Through the gNB-WUS-Config RRC configuration, the base station can configure the gNB-WUS occasion configuration information for gNB-WUS and the reference signal configuration information for synchronization before gNB-WUS transmission for the UE. In addition to the information included above, the RRC message can also include additional information (e.g., the gNB WUS occasions separated according to the function of gNB WUS and the number of FDM gNB WUS occasions at one time point).

[0278] In one embodiment, a method is provided for a base station to configure the configuration information for gNB WUS for all UEs in the RRC connected and RRC idle / inactive states to save energy.

[0279] For base station energy saving, the base station can configure gNB WUS configuration information for UEs in the RRC connected state, RRC idle state, and RRC inactive state, as well as for all UEs newly accessing the cell through the new system information block. More specifically, the UE can identify SIB1 through the SSB after receiving the SSB and TRS for synchronization. In this case, if the value of gNB WUS indicated in the system information block (SIB1 or the new SIBX configured through SIB1) is configured to be enabled or activated, the UE can determine that the base station is performing energy saving operations. In addition, the UE can determine the function of the base station's energy saving operations through the system information block. For example, the UE can be configured by the base station with gNB WUS through SIBXX, as shown in Table 14.

[0280] [Table 14]

[0281]

[0282] The system information can be broadcast by the base station and configured for the UE. A UE attempting initial access can receive SIBXX through the SSB (with or without SIB1) transmitted for the synchronization signal and determine whether gNB WUS is working. The UE can instruct the base station to wake up and perform the access procedure to the base station through WUS.

[0283] In addition, it can be indicated through the paging message whether the UEs in the RRC idle / inactive state update SIBXX to indicate whether the base station's energy saving operations and gNB WUS operations are performed. In addition, DCI can be newly defined cell-specifically or UE-group-specifically and can be referred to as DCI for base station energy saving. DCI can be scrambled with a new RNTI (DCI is scrambled with NWES-RNTI CRC), and the gNB WUS configuration information can be configured and changed through DCI. Therefore, DCI can include some or all of the content of the WUS configuration information to be configured or changed.

[0284] Through at least one of the above two methods, the UE can receive the configuration information for gNB WUS from the base station. In addition, the configured gNB WUS configuration information can be negotiated through the UE assistance information or PUSCH / PUCCH of the UE in the RRC connection. Based on the reference signal for synchronization related to the gNB WUS transmission, gNB WUS can be QCL with the reference signal for synchronization. In addition, the configuration of the synchronization signal for gNB WUS can be configured by including it in MeasConfig.

[0285] <Second Embodiment>

[0286] In a second embodiment of the present disclosure, a method for activating or deactivating the operation of the gNB WUS for energy saving will be described. The UE may receive gNB WUS configuration information from the base station via higher layer signaling (e.g., RRC or SIB). Then, the UE may be instructed to activate / deactivate the gNB operation by one or a combination of the following methods according to the state. In this case, activating / deactivating the gNB operation may be considered as activating / deactivating the base station energy saving mode.

[0287] In one embodiment, a method for enabling and disabling the gNB WUS operation by cell-specific DCI or UE-group-specific DCI is provided. The UE may receive an indication to activate the gNB WUS operation from the base station via cell-specific DCI or UE-group-specific DCI with a new RNTI (e.g., NWES-RNTI). In this case, the UE group may be configured by the base station or determined independently by the UE ID. In this case, information related to the cell may be included in the DCI so that for UEs supporting carrier aggregation, one or more cells can be pointed to.

[0288] The UE may monitor the DCI through a Type3-PDCCH CSS set configured as SearchSpace in the PDCCH-Config with searchSpaceType = Common. Additionally, in the case where the synchronization signal is configured as SSB, the UE may receive the DCI via Coreset0.

[0289] After that, when the UE receives an indication to activate and deactivate the gNB WUS, the UE may apply the gNB WUS operation after a processing time from the last symbol of the received DCI. Alternatively, when the UE receives an indication to activate and deactivate the gNB WUS, the UE may apply the gNB WUS operation to a symbol or a time slot after a processing time from the time slot of the received DCI.

[0290] In one embodiment, a method for enabling and disabling the gNB WUS operation by MAC CE is provided. The UE may receive a configuration from the base station on whether to activate or deactivate the gNB WUS operation via a MAC CE with a new eLCID. In this case, the MAC CE may include reference signal ID information of the synchronization signal for synchronization and cell information. For example, the MAC CE may have the following structure, and in Table 15, the size of the MAC CE may vary according to the number of the shown cell information.

[0291]

[0292] The above MAC CE structure describes a MAC CE structure with seven cell information and reference signal ID information of synchronization signals in each active cell. As described above, the MAC CE may include information for activating and deactivating the gNW WUS operation in 1 byte. In this case, in the case of supporting 32 cells, the information for indicating the activation and deactivation of the gNW WUS operation may be extended to 4 bytes. In the case of bytes 2 to byte N, the reference signal ID of the synchronization signal for gNB WUS in the active cell may be configured. Through the MAC CE, the UE can receive the configuration of whether the gNB WUS is activated and the synchronization signal information. After receiving the MAC CE, the UE may perform the DTx operation after transmitting the PUCCH including the processing time and the Ack / Nack signal.

[0293] In one embodiment, a method for activating and deactivating the gNB WUS operation for a UE not in the RRC connection is provided through a new DCI and a DCI for paging. The UE may be instructed to activate the gNB WUS operation through a DCI with a new RNTI or a DCI with a P-RNTI. The UE may monitor the DCI through a Type2-PDCCH CSS configured as a pagingSearchSpace in the PDCCH-ConfigCommon to receive a DCI format 1_0 with a new RNTI (e.g., NWES-RNTI) or a P-RNTI from the base station. Additionally, in the case where the synchronization signal is configured as an SSB, the UE may receive the DCI through Coreset0. In this case, the information related to the cell may be included in the DCI so that the UE supporting carrier aggregation can point to one or more cells. After that, when the UE receives an indication for activating and deactivating the gNB WUS, the UE may perform the gNB WUS operation after a processing time from the last symbol of the received DCI. Alternatively, when the UE receives an indication for activating and deactivating the gNB WUS, the UE may apply the gNB WUS operation to a symbol or a time slot after a processing time from the time slot of the received DCI.

[0294] The base station may indicate the activation and deactivation of the gNB WUS operation through the above method, and the UE may transmit the gNB WUS and process the UL service based on the DCI or MAC CE configuration of the above method. In addition, the UE may always perform the gNB WUS operation through the RRC configuration, or may be configured to perform the gNB WUS operation for each BWP, and the UE may always perform the WUS operation. In this way, both the base station and the UE can achieve an energy-saving effect.

[0295] <The Third Embodiment>

[0296] The third embodiment of the present disclosure describes a flowchart and a block diagram of a UE and a base station for configuring gNB WUS operations for energy saving.

[0297] Figure 17 A flowchart of a terminal showing an application energy saving method of a 5G system to which the present disclosure is applied.

[0298] The UE may receive configuration information for gNB WUS operations from the base station through higher layer signaling (e.g., RRC or SIB) (1701). Thereafter, based on the gNB WUS configuration information, the UE may receive a configuration of whether to activate the gNB WUS operation from the base station through DCI or MAC CE signaling (1702).

[0299] In the case where gNB WUS is activated, the UE monitors the synchronization signal based on the above-configured gNB WUS configuration information. Then, when UL traffic occurs, the UE may send gNB WUS through the gNB WUS occasion (1703).

[0300] Figure 18 A flowchart of a base station showing an application energy saving method of a 5G system to which the present disclosure is applied.

[0301] The base station may transmit configuration information for gNB WUS operations to the UE through higher layer signaling (e.g., RRC or SIB) (1801). Thereafter, based on the gNB WUS configuration information, the base station may configure whether to activate the gNB WUS operation for the UE through DCI or MAC CE signaling (1802).

[0302] Thereafter, during the gNB WUS operation, the base station periodically sends a synchronization signal for gNB WUS and may monitor gNB WUS based on the gNB WUS occasion. In this case, when gNB WUS is configured, the base station may perform a scheduling operation for processing the UL traffic of the UE (1803).

[0303] Figure 19 A terminal showing an embodiment according to the present disclosure.

[0304] Reference Figure 19, the UE 1900 may include a transceiver 1901, a controller (e.g., a processor) 1902, and a memory (e.g., a memory) 1903. The transceiver 1901, the controller 1902, and the memory 1903 of the terminal 1900 may operate according to at least one or a combination of the methods corresponding to the above-described embodiments. However, the components of the UE 1900 are not limited to the illustrated examples. According to another embodiment, the UE 1900 may include more components than those described above, or may include fewer components. In addition, in certain cases, the transceiver 1901, the controller 1902, and the memory 1903 may be implemented in the form of a single chip.

[0305] The transceiver 1901 may include a transmitter and a receiver according to an embodiment. The transceiver 1901 may transmit and receive signals with the base station. The signals may include control information and data. The transceiver 1901 may include a radio frequency (RF) transmitter for frequency up-converting and amplifying the transmitted signal, and an RF receiver for low-noise amplifying the received signal and frequency down-converting. The transceiver 1901 may receive a signal through a wireless channel, output the signal to the controller 1902, and transmit the signal output from the controller 1902 through the wireless channel.

[0306] The controller 1902 may control a series of processes for operating the UE 1900 according to the above-described embodiments of the present disclosure. For example, the controller 1902 may execute or control the operation of the UE to perform at least one or a combination of the methods according to the embodiments of the present disclosure. The controller 1902 may include at least one processor. For example, the controller 1902 may include a communication processor (CP) for performing communication control and an application processor (AP) for controlling a higher layer (e.g., an application).

[0307] The memory 1903 may store control information (e.g., information related to channel estimation of DMRS transmitted using PUSCH included in the signal obtained through the UE 1900) or data, and may have an area for storing data required for the control of the controller 1902 and data generated when the controller 1902 controls.

[0308] Figure 20 A base station according to an embodiment of the present disclosure is shown.

[0309] Reference Figure 20, the base station 2000 may include a transceiver 2001, a controller (e.g., a processor) 2002, and a memory (e.g., a memory) 2003. The transceiver 2001, the controller 2002, and the memory 2003 of the base station 2000 may operate according to at least one or a combination of the methods corresponding to the above embodiments. However, the components of the base station 2000 are not limited to the illustrated examples. According to another embodiment, the base station 2000 may include more components than the above components, or may include fewer components. In addition, in certain cases, the transceiver 2001, the controller 2002, and the memory 2003 may be implemented in the form of a single chip.

[0310] The transceiver 2001 may include a transmitter and a receiver according to an embodiment. The transceiver 2001 may exchange signals with the UE. The signals may include control information and data. The transceiver 2001 may include an RF transmitter for frequency up-converting and amplifying the transmitted signal, and an RF receiver for low-noise amplifying the received signal and frequency down-converting it. The transceiver 2001 may receive signals through a wireless channel, output the signals to the controller 2002, and transmit the signals output from the controller 2002 through the wireless channel.

[0311] The controller 2002 may control a series of processes for operating the base station 2000 according to the above embodiments of the present disclosure. For example, the controller 2002 may execute or control the operation of the base station to perform at least one or a combination of the methods according to the embodiments of the present disclosure. The controller 2002 may include at least one processor. For example, the controller 2002 may include a communication processor (CP) for performing communication control and an application processor (AP) for controlling a higher layer (e.g., an application).

[0312] The memory 2003 may store control information (e.g., information related to channel estimation generated using DMRS transmitted through PUSCH determined by the base station 2000), data, control information received from the UE, or data, and may have an area for storing data required for the control of the controller 2002 and data generated when the controller 2002 controls.

[0313] Although the present disclosure has been described with various embodiments, those skilled in the art may make various changes and modifications. This means that the present disclosure includes such changes and modifications that fall within the scope of the appended claims.

Claims

1. A method performed by a terminal in a communication system, the method comprising: Receiving a Wake-up Signal (WUS) configuration from a base station; Receiving control information for activating the WUS from the base station; Monitoring a synchronization signal; And Sending the WUS to the base station in a WUS occasion based on the WUS configuration.

2. The method according to claim 1, wherein, The WUS configuration includes resource information related to the synchronization signal, and Wherein, the WUS configuration further includes at least one of an offset between the WUS and the synchronization signal or a number of synchronization signals per WUS occasion.

3. The method according to claim 1, wherein The WUS configuration is received via a Radio Resource Control (RRC) message or a System Information Block (SIB), and Wherein, the control information includes Downlink Control Information (DCI) or a Medium Access Control Control Element (MAC CE).

4. The method according to claim 3, wherein, The DCI is scrambled based on a Radio Network Temporary Identifier (RNTI) defined for the WUS, and Wherein, the MAC CE includes information indicating activation of the WUS and an identifier of the synchronization signal.

5. A method performed by a base station in a communication system, the method comprising: Sending a Wake-up Signal (WUS) configuration to a terminal; Sending control information for activating the WUS to the terminal; Sending a synchronization signal to the terminal; And Receiving the WUS from the terminal in a WUS occasion based on the WUS configuration.

6. The method according to claim 5, wherein, The WUS configuration includes resource information related to the synchronization signal, and Wherein, the WUS configuration further includes at least one of an offset between the WUS and the synchronization signal or a number of synchronization signals per WUS occasion.

7. The method according to claim 5, wherein The WUS configuration is sent via a Radio Resource Control (RRC) message or a System Information Block (SIB), and Wherein, the control information includes Downlink Control Information (DCI) or a Medium Access Control Control Element (MAC CE).

8. The method according to claim 7, wherein, The DCI is scrambled based on a Radio Network Temporary Identifier (RNTI) defined for the WUS, and Wherein, the MAC CE includes information indicating activation of the WUS and an identifier of the synchronization signal.

9. A terminal in a communication system, the terminal comprising: A transceiver; And A controller operatively coupled to the transceiver, the controller configured to: Receive a Wake-up Signal (WUS) configuration from a base station, Receive control information for activating the WUS from the base station, Monitor a synchronization signal, and Send the WUS to the base station in a WUS occasion based on the WUS configuration.

10. The terminal according to claim 9, wherein, The WUS configuration includes resource information related to the synchronization signal, and Wherein, the WUS configuration further includes at least one of an offset between the WUS and the synchronization signal or a number of synchronization signals per WUS occasion.

11. The terminal according to claim 9, wherein, The WUS configuration is received via a Radio Resource Control (RRC) message or a System Information Block (SIB), and Wherein, the control information includes Downlink Control Information (DCI) or a Medium Access Control Control Element (MAC CE).

12. The terminal according to claim 11, wherein, The DCI is scrambled based on a Radio Network Temporary Identifier (RNTI) defined for the WUS, and Wherein, the MAC CE includes information indicating activation of the WUS and an identifier of the synchronization signal.

13. A base station in a communication system, the base station comprising: A transceiver; And A controller operatively coupled to the transceiver, the controller configured to: Send a wake-up signal WUS configuration to a terminal. Send control information for activating the WUS to the terminal, Send a synchronization signal to the terminal, and Receive the WUS from the terminal in a WUS occasion based on the WUS configuration.

14. The base station according to claim 13, wherein, The WUS configuration includes resource information related to the synchronization signal, and Wherein, the WUS configuration further includes at least one of an offset between the WUS and the synchronization signal or the number of synchronization signals per WUS occasion.

15. The base station according to claim 13, wherein, The WUS configuration is sent via a radio resource control RRC message or a system information block SIB, Wherein, the control information includes downlink control information DCI or a media access control control element MAC CE, Wherein, the DCI is scrambled based on a radio network temporary identifier RNTI defined for the WUS, and Wherein, the MAC CE includes information indicating activation of the WUS and an identifier of the synchronization signal.

Images