Method for performing LTM in wireless communication system, and device using method

Abstract

An operation method of a device in a wireless communication system, and a device using the method are provided. According to the method, a terminal transmits, to a base station, a specific channel state information (CSI) report from among a plurality of CSI reports on the basis of a priority related to the CSI report, receives, from the base station, an L1 / L2 triggered mobility (LTM) cell switch command through a MAC CE, and performs a handover procedure for a target cell on the basis of the MAC CE. In this process, parameters related to the type of measurement resource to be measured by the terminal is included among parameters for determining the priority.

Description

Method for performing LTM in a wireless communication system and device using the method

[0001] The present disclosure relates to a method for performing LTM (L1 / L2 Triggered Mobility) of a device in a wireless communication system and a device using the method.

[0002] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communications over existing radio access technology (RAT) is emerging. Furthermore, massive Machine Type Communications (MTC), which connects numerous devices and objects to provide diverse services anytime, anywhere, is also a key issue to be considered in next-generation communications. Furthermore, communication system design that considers reliability and latency-sensitive services / terminals is being discussed. The introduction of next-generation radio access technologies that take enhanced mobile broadband communications, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) into account is being discussed. For convenience, these technologies are referred to herein as new RAT or NR.

[0003] Meanwhile, in wireless communication systems, mobility has been continuously developed for handover of terminals to base stations. For example, the conventional 3GPP (3 rd In the Generation Partnership Project (NR Release)-18, LTM (L1 / L2 triggered mobility) was introduced.

[0004] LTM aims to reduce interruption time and improve mobility robustness compared to conventional handover.

[0005] Conventional handovers are primarily based on Layer 3 (L3) measurement reports. The terminal measures the signal quality of neighboring cells and transmits an L3 report to the network (base station), which then makes a handover decision based on this report. However, this conventional handover method can have the following drawbacks.

[0006] 1) Long disconnect times: L3 signaling is time-consuming and may result in disconnect times during handover, which can be critical for delay-sensitive services such as extended reality or real-time communications.

[0007] 2) Possibility of Radio Link Failure: If the signal quality deteriorates rapidly, L3 reports may not be transmitted in time or the network's handover decision may be delayed, which may lead to radio link failure.

[0008] LTM is a method to perform handover faster by utilizing L1 (physical layer, layer 1) and L2 (MAC layer, layer 2) signals to compensate for the shortcomings of the existing L3-based handover.

[0009] However, in the LTM in Release 18, since the CSI (channel state information) report was performed using only the SSB (synchronization signal / physical broadcast channel (SS / PBCH) block) using a broad beam, it was necessary to design a more efficient LTM operation.

[0010] Additionally, LTM requires CSI measurement reports (L1 measurement reports) from the terminal. When multiple CSI reports are available at the time of CSI reporting, priority rules are required to determine which CSI report to transmit. However, the existing priority rules for CSI reporting are based on the assumption that LTM measures and reports SSB. Therefore, it may not be desirable to apply the existing priority rules as they are when a different type of L1 measurement report is introduced to LTM.

[0011] The technical problem to be solved by the present disclosure is to provide a method for performing LTM of a device in a wireless communication system and a device using the method.

[0012] A method for performing LTM of a terminal in a wireless communication system is provided. According to the method, a terminal (user equipment: UE) transmits a specific CSI report among a plurality of CSI reports to a base station based on a priority related to a CSI (channel state information) report, receives an LTM (L1 / L2 triggered mobility) cell switch command from the base station through a MAC CE, and performs a handover procedure for a target cell based on the MAC CE. In this process, a parameter related to a type of measurement resource to be measured by the terminal is included among the parameters determining the priority.

[0013] In another aspect, a terminal, chipset and computer-readable medium for executing the above method are provided.

[0014] In another aspect, a method of operating a base station and a base station using the method are provided. According to the method, the base station receives a specific CSI report among a plurality of CSI reports from a terminal based on a priority related to the CSI report, transmits an LTM (L1 / L2 triggered mobility) cell switch command to the terminal through a MAC CE, and performs a handover procedure between the terminal and a target cell based on the MAC CE. In this process, it is characterized in that a parameter related to the type of measurement resource that the terminal should measure is included among the parameters determining the priority.

[0015] According to the method according to the present disclosure, mobility delay can be minimized in LTM.

[0016] Additionally, considering that LTM can operate based on CSI-RS measurements / reports, priority is set when reporting CSI. Therefore, when multiple CSI reports are present, it is possible to clearly specify which CSI report to transmit, enabling more efficient LTM operation.

[0017] Figure 1 illustrates the system architecture of a New Generation Radio Access Network (NG-RAN) to which NR is applied.

[0018] Figure 2 is a block diagram showing a radio protocol architecture for a user plane.

[0019] Figure 3 is a block diagram showing the wireless protocol structure for the control plane.

[0020] Figure 4 illustrates the functional division between NG-RAN and 5GC.

[0021] Figure 5 illustrates a frame structure that can be applied in NR.

[0022] Figure 6 shows an example of a resource grid in NR.

[0023] Figure 7 shows an example of a physical resource block in NR.

[0024] Figure 8 illustrates the slot structure of an NR frame.

[0025] Figure 9 illustrates a core set.

[0026] Figure 10 illustrates an example of a slot structure for a new wireless access technology.

[0027] Figure 11 illustrates the structure of a self-contained slot.

[0028] Figure 12 illustrates physical channels and typical signal transmission.

[0029] Figure 13 illustrates the signaling process for LTM.

[0030] Figure 14 illustrates the operation method of the terminal.

[0031] Figure 15 illustrates the signaling process and operation between a base station and a terminal.

[0032] Figure 16 illustrates a wireless device applicable to the present specification.

[0033] Figure 17 illustrates another example of a wireless device.

[0034] Figure 18 illustrates an example of a signal processing module structure.

[0035] Figure 19 illustrates another example of the structure of a signal processing module within a transmission device.

[0036] FIG. 20 illustrates an example of a wireless communication device according to an implementation example of the present disclosure.

[0037] Fig. 21 illustrates a communication system (1) applied to this specification.

[0038] As used herein, "A or B" can mean "only A," "only B," or "both A and B." In other words, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0039] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0040] In this specification, "at least one of A and B" may mean "only A", "only B" or "both A and B". Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted identically to "at least one of A and B".

[0041] Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0042] Additionally, parentheses used herein may mean "for example." Specifically, when "control information (ABC)" is indicated, "ABC" may be described as an example of "control information." For example, "control information" may include DEF as another example. In other words, "control information" in this specification is not limited to "ABC," and "ABC" may be described as an example of "control information." Furthermore, even when indicated as "control information (i.e., ABC)," "ABC" may be described as an example of "control information."

[0043] Additionally, in this specification, terms such as “first,” “second,” etc. are used only for the purpose of distinguishing one component from another, and are not used to limit the components, and do not limit the order or importance between the components unless specifically limited. Accordingly, a first component in one embodiment of this specification may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0044] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0045] Technical features individually described within a single drawing in this specification may be implemented individually or simultaneously. The following drawings are designed to illustrate specific examples of this specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and therefore, the technical features of this specification are not limited to the specific names used in the drawings.

[0046] In this specification, a terminal is a user equipment (UE) or a consumer-side device, and may also be referred to as a base station / second node / IAB node / TRP (Transmission-Reception Point) that receives / transmits signals from / to. A terminal may correspond to a physical node or a logical node. A terminal may correspond to an endpoint on the user side, or may correspond to an intermediate point between other endpoints. In communication between two points that are not limited to endpoints (including one-to-one / many-to-one / one-to-many / many-to-many communication), a terminal may correspond to a served node. A terminal may be a node with a fixed location, or a node with an unfixed location (or mobile).

[0047] In this specification, a base station (BS) is a device on the network side, and may be referred to as a second node / IAB node / x-NodeB (x-NodeB, x may be an abbreviation related to radio access technology (RAT)) / TRP. A BS may correspond to a physical node or a logical node. A BS may correspond to an endpoint on the network side, or may correspond to an intermediate point between other endpoints. In communication between two points that are not limited to endpoints (including one-to-one / many-to-one / one-to-many / many-to-many communication), a BS may correspond to a serving node. A BS may be a node with a fixed location, or a node with an unfixed location.

[0048] In this specification, higher layer parameters may be set for the terminal, preset, or predefined. For example, the base station may transmit higher layer parameters to the terminal. For example, the terminal may transmit parameters such as capabilities to the base station as higher layer parameters. For example, the higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0049] In this specification, the information / state / parameter being “configured or pre-configured” can be interpreted as the information / state / parameter being provided / pre-provided to the terminal through pre-defined signaling (e.g., SIB, MAC, RRC) from the base station. In this specification, the information / state / parameter being “defined or pre-defined” can be interpreted as the information / state / parameter being known in advance or pre-stored at the base station and the terminal without signaling between the base station and the terminal.

[0050] The technology described in this specification can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), LTE (long term evolution), and 5G NR.

[0051] The technology described in this specification can be implemented with 6G wireless technology and applied to various 6G systems. For example, the 6G system can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), artificial intelligence (AI) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0052] Hereinafter, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station. A base station may be expressed as a first communication device, and a terminal may be expressed as a second communication device. A base station (BS) may be replaced by terms such as a fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP: Access Point), network (5G network), AI (Artificial Intelligence) system / module, RSU (road side unit), robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, RSU (road side unit), robot, AI (Artificial Intelligence) module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

[0053] The following technologies can be used in various wireless access systems, such as CDMA, FDMA, TDMA, OFDMA, and SC-FDMA. UTRA is part of UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A (Advanced) / LTE-A pro is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A / LTE-A pro.

[0054] For clarity, the description is based on the 3GPP communication system (e.g., LTE-A, NR), but the technical idea of ​​the present disclosure is not limited thereto. LTE refers to technology after 3GPP TS 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR refers to technology after TS 38.xxx Release 15. LTE / NR may be referred to as a 3GPP system. "xxx" refers to a standard document detail number. LTE / NR may be collectively referred to as a 3GPP system. For background technology, terms, abbreviations, etc. used in the description of the present disclosure, reference may be made to matters described in standard documents published prior to the present disclosure. For example, reference may be made to the following documents:

[0055] 3GPP LTE

[0056] - 36.211: Physical channels and modulation

[0057] - 36.212: Multiplexing and channel coding

[0058] - 36.213: Physical layer procedures

[0059] - 36.300: Overall description

[0060] - 36.331: Radio Resource Control (RRC)

[0061] 3GPP NR

[0062] - 38.211: Physical channels and modulation

[0063] - 38.212: Multiplexing and channel coding

[0064] - 38.213: Physical layer procedures for control

[0065] - 38.214: Physical layer procedures for data

[0066] - 38.300: NR and NG-RAN Overall Description

[0067] - 36.331: Radio Resource Control (RRC) protocol specification

[0068] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technologies is emerging. Furthermore, massive Machine Type Communications (MTC), which connects numerous devices and objects to provide various services anytime, anywhere, is also a key issue to be considered in next-generation communications. Furthermore, communication system design that considers reliability and latency-sensitive services / terminals is being discussed. Accordingly, the introduction of next-generation wireless access technologies such as enhanced mobile broadband communication (eMBB), massive MTC (MMTC), and Ultra-Reliable and Low Latency Communication (URLLC) is being discussed, and for convenience, these technologies are referred to as NR in this specification. NR is an expression representing an example of 5G radio access technology (RAT).

[0069] A new RAT system, including NR, uses OFDM transmission scheme or a similar transmission scheme. The new RAT system may follow OFDM parameters different from those of LTE. Alternatively, the new RAT system may follow the existing LTE / LTE-A numerology but have a larger system bandwidth (e.g., 100 MHz). Alternatively, a single cell may support multiple numerologies. For example, terminals operating under different numerologies may coexist within a single cell.

[0070] A numerology corresponds to a single subcarrier spacing in the frequency domain. Different numerologies can be defined by scaling the reference subcarrier spacing by an integer N.

[0071] The three key requirement areas for 5G include (1) Enhanced Mobile Broadband (eMBB), (2) Massive Machine Type Communication (mMTC), and (3) Ultra-reliable and Low Latency Communications (URLLC).

[0072] Some use cases may require optimization across multiple domains, while others may focus on just one Key Performance Indicator (KPI). 5G supports these diverse use cases in a flexible and reliable manner.

[0073] eMBB extends far beyond basic mobile internet access, encompassing rich interactive tasks, cloud computing, and augmented reality media and entertainment applications. Data is a key driver of 5G, and dedicated voice services may not be the first to emerge in the 5G era. In 5G, voice is expected to be handled as an application, simply using the data connection provided by the communication system. The primary drivers of increased traffic volume are the increasing size of content and the growing number of applications requiring high data rates. Streaming services (audio and video), interactive video, and mobile internet connectivity will become more prevalent as more devices connect to the internet. Many of these applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are rapidly growing on mobile communication platforms, applicable to both work and entertainment. Cloud storage is a particular use case driving the growth of uplink data rates. 5G is also used for remote work in the cloud, requiring significantly lower end-to-end latency to maintain a superior user experience when tactile interfaces are used. Entertainment, for example, cloud gaming and video streaming are other key factors driving the demand for mobile broadband. Entertainment is essential on smartphones and tablets, regardless of location, including in highly mobile environments such as trains, cars, and airplanes. Another use case is augmented reality and information retrieval for entertainment, where augmented reality requires extremely low latency and instantaneous data volumes.

[0074] Additionally, one of the most anticipated 5G use cases involves the ability to seamlessly connect embedded sensors across all sectors, such as mMTC. The number of potential IoT devices is projected to reach 20.4 billion by 2020. Industrial IoT is one area where 5G will play a key role, enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure.

[0075] URLLC encompasses new services that will transform industries through ultra-reliable, low-latency links, such as remote control of critical infrastructure and self-driving vehicles. Reliability and latency are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0076] Let's take a more specific look at several use cases.

[0077] 5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) by delivering streams rated at hundreds of megabits per second to gigabits per second. These high speeds are required to deliver TV at resolutions beyond 4K (6K, 8K, and beyond), as well as virtual and augmented reality. Virtual reality (VR) and augmented reality (AR) applications include near-immersive sports events. Certain applications may require specialized network configurations. For example, for VR games, game companies may need to integrate their core servers with the network operator's edge network servers to minimize latency.

[0078] Automotive is expected to be a significant new driver for 5G, with numerous use cases for in-vehicle mobile communications. Passenger entertainment, for example, demands simultaneous high-capacity and high-mobility mobile broadband. This is because future users will expect high-quality connectivity regardless of their location or speed. Another automotive application is an augmented reality dashboard, which overlays information on what the driver sees through the windshield, identifying objects in the dark and informing the driver about their distance and movement. In the future, wireless modules will enable communication between vehicles, the exchange of information between vehicles and supporting infrastructure, and between vehicles and other connected devices (e.g., devices accompanying pedestrians). Safety systems can guide drivers on alternative courses of action to ensure safer driving, reducing the risk of accidents. The next step will be remotely controlled or self-driving vehicles, which will require highly reliable and fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, self-driving cars will perform all driving tasks, leaving drivers to focus solely on traffic anomalies that the vehicles themselves cannot detect. The technological requirements for self-driving cars will require ultra-low latency and ultra-high-speed reliability, increasing traffic safety to levels unattainable by humans.

[0079] Smart cities and smart homes, often referred to as "smart societies," will be embedded with dense wireless sensor networks. A distributed network of intelligent sensors will identify conditions for cost- and energy-efficient maintenance of cities or homes. A similar setup can be implemented for each home. Temperature sensors, window and heating controllers, burglar alarms, and appliances will all be connected wirelessly. Many of these sensors typically have low data rates, low power, and low cost. However, for example, real-time HD video may be required for certain types of devices for surveillance purposes.

[0080] The consumption and distribution of energy, including heat and gas, are becoming increasingly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect these sensors using digital information and communication technologies to collect and act on information. This information can include the behavior of suppliers and consumers, enabling smart grids to improve efficiency, reliability, economic efficiency, sustainable production, and automated distribution of fuels like electricity. Smart grids can also be viewed as another low-latency sensor network.

[0081] The health sector has numerous applications that can benefit from mobile communications. Telecommunications systems can support telemedicine, which provides clinical care in remote locations. This can help reduce distance barriers and improve access to health services that are otherwise unavailable in remote rural areas. It can also be used to save lives in critical care and emergency situations. Mobile-based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0082] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Therefore, the potential to replace cables with reconfigurable wireless links presents an attractive opportunity for many industries. However, achieving this requires wireless connections to operate with similar latency, reliability, and capacity to cables, while simplifying their management. Low latency and extremely low error rates are new requirements for 5G connectivity.

[0083] Logistics and freight tracking are important use cases for mobile communications, enabling the tracking of inventory and packages anywhere using location-based information systems. Logistics and freight tracking typically require low data rates but wide coverage and reliable location information.

[0084] Multi-Input Multi-Output (MIMO) technology in NR systems provides a scalable and flexible MIMO framework. Basically, it includes beam-based operation, scalable and flexible Channel State Information (CSI) codebook, reference signal (RS) design, and codebook design for CSI Type I and CSI Type II. Additionally, improvements have been introduced to support a CSI Type II codebook for multi-user (MU)-MIMO, multiple transmit / receive points (TRPs) or multiple panel transmission operations depending on backhaul conditions, multi-beam operation, high uplink transmit power support, and reference signals with low Peak-to-Average Power Ratio (PAPR) characteristics. Furthermore, beam management methods to reduce beam failure for wireless devices moving at high frequencies, expansion of multi-TRP transmission in uplink and downlink, sounding reference signals (SRSs) for capacity and coverage expansion, and improvements to Type II CSI-RSs can be supported.

[0085] Describes a conventional wireless communication system. This may also be called the Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or the Long Term Evolution (LTE) / LTE-A system.

[0086] E-UTRAN includes a base station (BS), which provides a control plane and a user plane to user equipment (UE). A UE may be fixed or mobile, and may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, or a terminal. A base station (BS) is a fixed point that communicates with a UE, and may be referred to by other terms such as an evolved-NodeB (eNB), a gNodeB (gNB), a base transceiver system (BTS), or an access point.

[0087] Base stations can be interconnected via the X2 interface. Base stations are connected to the Evolved Packet Core (EPC) via the S1 interface, more specifically, to the Mobility Management Entity (MME) via the S1-MME, and to the Serving Gateway (S-GW) via the S1-U.

[0088] The EPC consists of an MME, an S-GW, and a P-GW (Packet Data Network Gateway). The MME holds information about terminal access and capabilities, and this information is primarily used for terminal mobility management. The S-GW is a gateway that terminates on the E-UTRAN, and the P-GW is a gateway that terminates on the PDN.

[0089] Figure 1 illustrates the system architecture of a New Generation Radio Access Network (NG-RAN) to which NR is applied.

[0090] Referring to Fig. 1, the NG-RAN may include gNBs and / or eNBs that provide user plane and control plane protocol termination to the UE. Fig. 1 exemplifies a case including only gNBs. The gNBs (eNBs) are connected to each other via Xn interfaces. The gNBs and eNBs are connected to the 5th generation core network (5G Core Network: 5GC) via the NG interface. More specifically, they are connected to the access and mobility management function (AMF) via the NG-C interface, and to the user plane function (UPF) via the NG-U interface.

[0091] The layers of the radio interface protocol between the terminal and the network can be divided into L1 (layer 1), L2 (layer 2), and L3 (layer 3) based on the three lower layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems. Among these, the physical layer belonging to layer 1 provides information transfer service using physical channels, and the RRC (Radio Resource Control) layer located in layer 3 controls radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0092] Figure 2 is a block diagram illustrating the radio protocol architecture for the user plane. Figure 3 is a block diagram illustrating the radio protocol architecture for the control plane. The user plane is a protocol stack for transmitting user data, and the control plane is a protocol stack for transmitting control signals.

[0093] Referring to Figures 2 and 3, the physical layer (PHY layer) provides information transfer services to upper layers using physical channels. The PHY layer is connected to its upper layer, the Medium Access Control (MAC) layer, through a transport channel. Data is transferred between the MAC layer and the PHY layer via the transport channel. Transport channels are classified based on how and with what characteristics data is transmitted over the wireless interface.

[0094] Data travels between different physical layers, i.e., between the physical layers of a transmitter and receiver, via a physical channel. This physical channel can be modulated using Orthogonal Frequency Division Multiplexing (OFDM) and utilizes time and frequency as radio resources.

[0095] The MAC layer's functions include mapping between logical channels and transport channels, and multiplexing / demultiplexing MAC service data units (SDUs) belonging to logical channels into transport blocks provided as physical channels on the transport channels. The MAC layer provides services to the RLC (Radio Link Control) layer through logical channels.

[0096] The functions of the RLC layer include concatenation, segmentation, and reassembly of RLC SDUs. To guarantee the various Quality of Service (QoS) required by radio bearers (RBs), the RLC layer provides three operating modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through automatic repeat request (ARQ).

[0097] The RRC (Radio Resource Control) layer is defined only in the control plane. The RRC layer is responsible for controlling logical, transport, and physical channels, including the configuration, reconfiguration, and release of radio bearers. An RB is a logical path provided by Layer 1 (PHY layer) and Layer 2 (MAC layer, RLC layer, PDCP layer) for data transmission between a terminal and the network.

[0098] The functions of the Packet Data Convergence Protocol (PDCP) layer in the user plane include the transmission of user data, header compression, and ciphering. The functions of the Packet Data Convergence Protocol (PDCP) layer in the control plane include the transmission of control plane data and encryption / integrity protection.

[0099] Establishing an RB refers to the process of defining the characteristics of the radio protocol layer and channel to provide a specific service, and setting specific parameters and operating methods for each. RBs can be further divided into two types: signaling RBs (SRBs) and data RBs (DRBs). SRBs are used as a conduit for transmitting RRC messages in the control plane, while DRBs are used as conduits for transmitting user data in the user plane.

[0100] When an RRC connection is established between the RRC layer of the terminal and the RRC layer of the E-UTRAN, the terminal is in an RRC connected state, otherwise it is in an RRC idle state.

[0101] Downlink transmission channels that transmit data from the network to the terminal include the Broadcast Channel (BCH), which transmits system information, and the downlink Shared Channel (SCH), which transmits user traffic or control messages. Traffic or control messages for downlink multicast or broadcast services may be transmitted through the downlink SCH or a separate downlink Multicast Channel (MCH). Meanwhile, uplink transmission channels that transmit data from the terminal to the network include the Random Access Channel (RACH), which transmits initial control messages, and the uplink Shared Channel (SCH), which transmits user traffic or control messages.

[0102] Logical channels that are located above the transport channel and are mapped to the transport channel include BCCH (Broadcast Control Channel), PCCH (Paging Control Channel), CCCH (Common Control Channel), MCCH (Multicast Control Channel), and MTCH (Multicast Traffic Channel).

[0103] A physical channel consists of multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. A single subframe consists of multiple OFDM symbols in the time domain. A resource block is a resource allocation unit and consists of multiple OFDM symbols and multiple subcarriers. Additionally, each subframe can use specific subcarriers of specific OFDM symbols (e.g., the first OFDM symbol) of the subframe for a Physical Downlink Control Channel (PDCCH), for example, an L1 / L2 control channel. A Transmission Time Interval (TTI) is a unit time for subframe transmission.

[0104] Figure 4 illustrates the functional division between NG-RAN and 5GC.

[0105] Referring to FIG. 4, the gNB can provide functions such as inter-cell radio resource management (Inter Cell RRM), radio bearer management (RB control), connection mobility control (Connection Mobility Control), radio admission control (Radio Admission Control), measurement configuration and provision, and dynamic resource allocation. The AMF can provide functions such as NAS security and idle state mobility processing. The UPF can provide functions such as mobility anchoring and PDU processing. The SMF (Session Management Function) can provide functions such as terminal IP address allocation and PDU session control.

[0106] Figure 5 illustrates a frame structure that can be applied in NR.

[0107] Referring to FIG. 5, a radio frame (hereinafter abbreviated as a frame) can be used for uplink and downlink transmission in NR. A frame has a length of 10 ms and can be defined as two 5 ms half-frames (Half-Frames, HF). A half-frame can be defined as five 1 ms sub-frames (Subframes, SF). A frame can include 10 sub-frames. A sub-frame can be divided into one or more slots, and the number of slots in a sub-frame depends on the Subcarrier Spacing (SCS). Each slot includes 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP). When a normal CP is used, each slot includes 14 symbols. When an extended CP is used, each slot includes 12 symbols. Here, the symbol may include an OFDM symbol (or CP-OFDM symbol), an SC-FDMA symbol (or a DFT-s-OFDM symbol). A mini-slot may include, for example, 2, 4, or 7 symbols, or may include more or fewer symbols.

[0108] NR systems can support multiple numerologies. Numerologies can be defined by subcarrier spacing and cyclic prefix (CP) overhead. Multiple subcarrier spacings can be derived by scaling the basic subcarrier spacing by an integer N. Furthermore, even if it is assumed that very low subcarrier spacing is not utilized at very high carrier frequencies, the numerologies utilized can be selected independently of the frequency band. Furthermore, NR systems can support various frame structures corresponding to multiple numerologies.

[0109] Below, we examine the Orthogonal Frequency Division Multiplexing (OFDM) numerologies and frame structures that can be considered in NR systems. Table 1 lists the various OFDM numerologies supported in NR systems.

[0110] Table 1 below illustrates the subcarrier spacing configuration μ (also referred to as subcarrier spacing configuration).

[0111] [Table 1]

[0112]

[0113] Regarding the frame structure in the NR system, the sizes of the various fields in the time domain are T s =1 / (Δf max ·N f ) can be expressed as a multiple of the time unit. Here, Δf max =480·10 3 and N f =409. Downlink and uplink transmissions are T f =(Δf max ·N f / 100)·T s = It consists of a radio frame with a duration of 10ms. Here, each radio frame is T sf =(Δf max ·N f / 1000)·T s = It consists of 10 subframes with a duration of 1ms. In this case, there may be one set of frames for uplink and one set of frames for downlink. In addition, the transmission of uplink frame number i from a terminal (User Equipment, UE) is T earlier than the start of the corresponding downlink frame from the terminal. TA =N TA ·T sIt must start before. For numerology μ, slots are n within a subframe. μ s ∈{0, ..., N slots,μ subframe -1} are numbered in increasing order, and n within a radio frame μ s,f ∈{0, ..., N slots,μ frame -1} are numbered in increasing order. One slot is N μ symb It consists of consecutive OFDM symbols, and N μ symb is determined by the numerology and slot configuration used. Slot n in a subframe μ s The start of OFDM symbol n in the same subframe μ s N μ symb are aligned temporally with the start of the OFDM signal. Not all terminals can transmit and receive simultaneously, which means that not all OFDM symbols in a downlink slot or uplink slot can be utilized.

[0114] Table 2 below shows the number of slots (N) in a frame according to the subcarrier spacing setting μ. frame,μ slot ), number of slots in a subframe (N subframe,μ slot ), number of symbols in the slot (N slot symb ) are examples.

[0115] [Table 2]

[0116]

[0117] Table 2-1 below illustrates that when extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe change depending on the SCS.

[0118] [Table 2-1]

[0119]

[0120] In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0121] In relation to physical resources in an NR system, antenna ports, resource grids, resource elements, resource blocks, and carrier parts can be considered. Hereinafter, the physical resources that can be considered in an NR system will be described in detail. First, with respect to antenna ports, an antenna port is defined such that the channel through which a symbol on the antenna port is carried can be inferred from the channel through which another symbol on the same antenna port is carried. If the large-scale properties of the channel through which a symbol on one antenna port is carried can be inferred from the channel through which a symbol on another antenna port is carried, then the two antenna ports can be said to be in a QC / QCL (quasi co-located or quasi co-location) relationship. Here, the large-scale properties include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

[0122] Figure 6 shows an example of a resource grid in NR.

[0123] Referring to Figure 6, the resource grid is N in the frequency domain. μ RB N RB sc It consists of subcarriers, and one subframe is 14·2 μ It is described as an example, but not limited to, that it consists of OFDM symbols. In an NR system, the transmitted signal is N μ RB N RB sc One or more resource grids consisting of subcarriers and 2 μ N (μ) symb is described by OFDM symbols. Here, N μ RB≤ N max,μ RB is. The above N max,μ RB represents the maximum transmission bandwidth, which may vary between numerologies as well as between uplink and downlink. In this case, one resource grid may be configured for each numerology μ and each antenna port p. Each element of the resource grid for numerology μ and each antenna port p is referred to as a resource element and is uniquely identified by an index pair {index in the frequency domain, position of the symbol within the subframe}. If there is no risk of confusion or if a particular antenna port or numerology is not specified, the indices p and μ may be dropped. In addition, a resource block (RB) is defined as N in the frequency domain. RB sc = is defined as 12 consecutive subcarriers.

[0124] Point A serves as a common reference point of the resource block grid and is obtained as follows.

[0125] offsetToPointA for primary cell (Pcell) downlink represents the frequency offset between the lowest subcarrier of the lowest resource block overlapping the SS / PBCH block used by the terminal for initial cell selection and point A, expressed in resource block units assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier spacing for FR2, and absoluteFrequencyPointA represents the frequency-location of point A expressed as in absolute radio-frequency channel number (ARFCN).

[0126] Common resource blocks (CRBs) are numbered from 0 upwards in the frequency domain for a subcarrier spacing setting μ. The center of subcarrier 0 of CRB 0 for a subcarrier spacing setting μ coincides with 'point A'. CRB number n in the frequency domain μ CRB The resource elements (k,l) for the subcarrier spacing setting μ are given by the following equation.

[0127] [Formula 1]

[0128]

[0129] k is defined relative to point A so that k=0 corresponds to the subcarrier centered at point A. Physical resource blocks are numbered from 0 to N within the bandwidth part (BWP). size BWP,i - Numbered from 1 to 1, where i is the number of BWP. Physical resource block n in BWP i PRB and common resource block n CRBThe relationship between them is given by the equation below.

[0130] [Formula 2]

[0131]

[0132] N start BWP,i is a common resource block where BWP starts relative to common resource block 0.

[0133] Figure 7 shows an example of a physical resource block in NR.

[0134] Referring to FIG. 7, a physical resource block (PRB) may be composed of different frequency resources and time resources depending on the subcarrier spacing.

[0135] Figure 8 illustrates the slot structure of an NR frame.

[0136] Referring to FIG. 8, a slot may include multiple symbols in the time domain. For example, in the case of a normal CP, one slot may include 14 symbols, but in the case of an extended CP, one slot may include 12 symbols. A carrier may include multiple subcarriers in the frequency domain. A Resource Block (RB) may be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) may be defined as multiple consecutive (P)RBs in the frequency domain, and may correspond to one numerology (e.g., SCS, CP length, etc.). A carrier may include up to N BWPs (e.g., 4 or 5). Data communication is performed through activated BWPs, and only one BWP may be activated for one terminal. In the resource grid, each element is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

[0137] As another example, in the time domain, a slot for a normal CP contains 7 symbols, but in the case of an extended CP, a slot contains 6 symbols. A carrier contains multiple subcarriers in the frequency domain. A Resource Block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) is defined as multiple consecutive (P)RBs in the frequency domain, and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can contain up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal. Each element in the resource grid is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

[0138] A PDCCH (physical downlink control channel) may be composed of one or more CCEs (control channel elements) as shown in Table 3 below.

[0139] [Table 3]

[0140]

[0141] For example, a PDCCH can be transmitted via a resource consisting of 1, 2, 4, 8, or 16 CCEs, where a CCE is composed of 6 resource element groups (REGs), and one REG is composed of one resource block in the frequency domain and one orthogonal frequency division multiplexing (OFDM) symbol in the time domain.

[0142] Monitoring refers to decoding each PDCCH candidate according to the DCI (downlink control information) format. The terminal monitors a set of PDCCH candidates in one or more core sets (CORESETs, described below) on the active DL BWP of each activated serving cell for which PDCCH monitoring is configured, according to the corresponding search space set.

[0143] In NR, a new unit called a control resource set (CORESET) can be introduced. A terminal can receive PDCCHs in a CORESET.

[0144] Figure 9 illustrates a core set.

[0145] Referring to Figure 9, the core set is N in the frequency domain. CORESET RB It consists of N resource blocks and is in the time domain. CORESET symb ∈ {1, 2, 3} symbols. N CORESET RB , N CORESET symb can be provided by the base station via upper layer signals. As illustrated in Fig. 9, a core set may include multiple CCEs (or REGs).

[0146] A terminal may attempt PDCCH detection in units of 1, 2, 4, 8, or 16 CCEs within a core set. One or more CCEs for which PDCCH detection can be attempted may be referred to as PDCCH candidates.

[0147] A terminal can be configured with multiple core sets.

[0148] In conventional wireless communication systems (e.g., LTE / LTE-A), the control domain spans the entire system bandwidth used by the base station. Except for some terminals that support only narrow bandwidths (e.g., eMTC / NB-IoT terminals), all terminals must be able to receive radio signals across the entire system bandwidth of the base station to properly receive / decode the control information transmitted by the base station.

[0149] In contrast, NR introduces the aforementioned core set. A core set is a radio resource for control information that a terminal must receive. It can utilize only a portion of the system bandwidth in the frequency domain, rather than the entire bandwidth. Furthermore, it can utilize only a portion of the symbols within a slot in the time domain. The base station can assign a core set to each terminal and transmit control information through the assigned core set. In NR, a terminal can receive control information from the base station without necessarily receiving the entire system bandwidth.

[0150] The core set may include a terminal-specific core set for transmitting terminal-specific control information and a common core set for transmitting control information common to all terminals.

[0151] Meanwhile, in NR, depending on the application field, high reliability may be required, and in such a situation, the target block error rate (BLER) for downlink control information (DCI) transmitted through a downlink control channel (e.g., physical downlink control channel: PDCCH) may be significantly lower than in the prior art. One example of a method for satisfying such a requirement requiring high reliability is to reduce the amount of content included in the DCI and / or increase the amount of resources used when transmitting the DCI. In this case, the resources may include at least one of time domain resources, frequency domain resources, code domain resources, and spatial domain resources.

[0152] The following technologies / features can be applied in NR:

[0153] Self-contained subframe structure

[0154] Figure 10 illustrates an example of a slot structure for a new wireless access technology.

[0155] In NR, a structure in which a control channel and a data channel are time-division multiplexed (TDM) within one TTI, as shown in Fig. 10, can be considered for the purpose of minimizing latency.

[0156] FIG. 10 illustrates an example in which a downlink control region is located at the front of the TTI and an uplink control region is located at the back of the TTI. The region between the downlink control region and the uplink control region can be used for downlink data (DL data) transmission or uplink data (UL data) transmission. A characteristic of this structure is that downlink (DL) reception and uplink (UL) transmission are sequentially performed within a single subframe / slot, so that DL data can be received and UL ACK / NACK (Acknowledgement / Not-acknowledgement) can be transmitted within a single subframe / slot. As a result, the time required for data retransmission when a data transmission error occurs is reduced, thereby minimizing the latency of the final data transmission.

[0157] In this way, in a structure where data and control domains are TDMed, a time gap is required for the base station and terminal to transition from transmission mode to reception mode, or from reception mode to transmission mode. To this end, some OFDM symbols at the transition point from DL to UL in a self-contained subframe structure can be designated as a guard period (GP).

[0158] Figure 11 illustrates the structure of a self-contained slot.

[0159] In an NR system, a single slot may contain a DL control channel, DL or UL data, and a UL control channel. For example, the first N symbols in a slot may be used to transmit a DL control channel (hereinafter, referred to as a DL control region), and the last M symbols in the slot may be used to transmit a UL control channel (hereinafter, referred to as a UL control region). N and M are each integers greater than or equal to 0. A resource region (hereinafter, referred to as a data region) between the DL control region and the UL control region may be used for DL ​​data transmission or UL data transmission. As an example, the following configuration may be considered. Each section is listed in chronological order.

[0160] 1. DL only configuration

[0161] 2. UL only configuration

[0162] 3. Mixed UL-DL configuration

[0163] - DL area + GP (Guard Period) + UL control area

[0164] - DL control area + GP + UL area

[0165] DL area: (i) DL data area, (ii) DL control area + DL data area

[0166] UL domain: (i) UL data domain, (ii) UL data domain + UL control domain

[0167] In the DL control region, a PDCCH can be transmitted, and in the DL data region, a PDSCH (physical downlink shared channel) can be transmitted. In the UL control region, a PUCCH (physical uplink control channel) can be transmitted, and in the UL data region, a PUSCH (physical uplink shared channel) can be transmitted. In the PDCCH, downlink control information (DCI), such as DL data scheduling information and UL data scheduling information, can be transmitted. In the PUCCH, uplink control information (UCI), such as ACK / NACK (Positive Acknowledgement / Negative Acknowledgement) information for DL ​​data, CSI (Channel State Information) information, and SR (Scheduling Request), can be transmitted. GP provides a time gap when a base station and a terminal switch from transmission mode to reception mode or from reception mode to transmission mode. Some symbols at the time of switching from DL to UL within a subframe can be set as GP.

[0168] System information of an NR system can be transmitted in a broadcasting manner. At this time, analog beams belonging to different antenna panels within one symbol can be transmitted simultaneously, and a method of introducing a beam reference signal (BRS), which is a reference signal (RS) transmitted by applying a single analog beam (corresponding to a specific antenna panel) to measure a channel for each analog beam, is being discussed. The BRS can be defined for multiple antenna ports, and each antenna port of the BRS can correspond to a single analog beam. At this time, unlike the BRS, a synchronization signal or xPBCH can be transmitted by applying all analog beams within an analog beam group so that any terminal can receive it well.

[0169] In NR, a synchronization signal block (SSB, or may be referred to as a synchronization signal and physical broadcast channel (SS / PBCH) in the time domain) may be composed of four OFDM symbols numbered in ascending order from 0 to 3 within the synchronization signal block, and a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a PBCH associated with a demodulation reference signal (DMRS) may be mapped to the symbols. As described above, the synchronization signal block may also be referred to as an SS / PBCH block.

[0170] In NR, multiple synchronization signal blocks can be transmitted at different times, and SSB can be used to perform initial access (IA), serving cell measurement, etc. Therefore, when the transmission time and resources overlap with other signals, it is desirable to transmit SSB preferentially. To achieve this, the network can broadcast SSB transmission time and resource information or indicate it through UE-specific RRC signaling.

[0171] NR can perform beam-based transmission and reception operations. If the reception performance of the current serving beam degrades, a process called beam failure recovery (BFR) can be used to find a new beam.

[0172] Since BFR is not a process for declaring an error / failure in the link between the network and the terminal, it can be assumed that the connection with the current serving cell is maintained even when the BFR process is performed. During the BFR process, measurements are performed on different beams set by the network (a beam can be expressed as a CSI-RS port or an SSB (synchronization signal block) index, etc.) and the best beam for the terminal is selected. The terminal can proceed with the BFR process by performing the RACH process associated with the beam with the best measurement result.

[0173] Now, we will describe the Transmission Configuration Indicator (TCI) state. The TCI state can be set for each core set of the control channel, and parameters for determining the terminal's receive (Rx) beam can be determined based on the TCI state.

[0174] For each downlink bandwidth portion (DL BWP) of a serving cell, a terminal may be configured with up to three core sets. Additionally, for each core set, the terminal may be provided with the following information:

[0175] 1) Coreset index p (e.g., one from 0 to 11, where the index of each coreset can be uniquely determined among the BWPs of a serving cell),

[0176] 2) PDCCH DM-RS scrambling sequence initialization value,

[0177] 3) Interval in the time domain of the core set (can be given in symbol units),

[0178] 4) A set of resource blocks,

[0179] 5) CCE-to-REG mapping parameters,

[0180] 6) Antenna port quasi co-location (QCL) information indicating quasi co-location (QCL) information of DM-RS antenna ports for PDCCH reception in each core set (from a set of antenna port quasi co-locations provided by a higher layer parameter called 'TCI-State');

[0181] 7) Indicating the presence or absence of a transmission configuration indication (TCI) field for a specific DCI format transmitted by PDCCH in the core set, etc.

[0182] Let's explain QCL. If the characteristics of the channel through which a symbol on one antenna port is transmitted can be inferred from the characteristics of the channel through which a symbol on another antenna port is transmitted, then the two antenna ports are said to be in quasi-co-location (QCL). For example, if two signals (A and B) are transmitted from the same transmit antenna array with identical / similar spatial filters applied, the two signals may experience identical / similar channel conditions. From the receiver's perspective, if one of the two signals is received, the channel characteristics of the received signal can be used to detect the other signal.

[0183] In this sense, the fact that A and B are QCL may mean that A and B experienced similar channel conditions, and thus, the channel information estimated to detect A is also useful for detecting B. Here, the channel conditions may be defined by, for example, Doppler shift, Doppler spread, average delay, delay spread, spatial reception parameters, etc.

[0184] The 'TCI-State' parameter associates one or two downlink reference signals with a corresponding QCL type (there are QCL types A, B, C, and D, see Table 4).

[0185] [Table 4]

[0186]

[0187] Each 'TCI-State' may include parameters for establishing a quasi-colocation (QCL) relationship between one or two downlink reference signals and a DM-RS port of a PDSCH (or PDCCH), or a CSI-RS port of a CSI-RS resource.

[0188] Meanwhile, in each DL BWP configured for a terminal in a serving cell, the terminal may be provided with up to 10 search space sets. For each search space set, the terminal may be provided with at least one of the following pieces of information.

[0189] 1) Search space set index s (0≤s<40), 2) Association between core set P and search space set s, 3) PDCCH monitoring period and PDCCH monitoring offset (slot unit), 4) PDCCH monitoring pattern within a slot (e.g., indicating the first symbol of the core set within a slot for PDCCH monitoring), 5) Number of slots in which search space set s exists, 6) Number of PDCCH candidates per CCE aggregation level, 7) Information indicating whether search space set s is CSS (common search space) or USS (UE-specific search space), etc.

[0190] In NR, core set #0 can be configured by PBCH (or terminal-specific signaling for handover, PSCell configuration, or BWP configuration). The search space (SS) set #0 configured by PBCH can have different monitoring offsets (e.g., slot offset, symbol offset) for each associated SSB. This may be necessary to minimize the search space occasions that the terminal must monitor. Alternatively, it may also be necessary to provide a beam sweeping control / data area that can transmit control / data for each beam so that communication with the terminal can be continuously performed in a situation where the best beam of the terminal dynamically changes.

[0191] Figure 12 illustrates physical channels and typical signal transmission.

[0192] Referring to Figure 12, in a wireless communication system, a terminal receives information from a base station via the downlink (DL), and the terminal transmits information to the base station via the uplink (UL). The information transmitted and received between the base station and the terminal includes data and various control information, and various physical channels exist depending on the type and purpose of the information they transmit and receive.

[0193] When a terminal is powered on again from a powered-off state or newly enters a cell, it performs an initial cell search operation, such as synchronizing with the base station (S11). To this end, the terminal receives the PSCH (Primary Synchronization Channel) and SSCH (Secondary Synchronization Channel) from the base station to synchronize with the base station and obtain information such as the cell ID (cell identity). In addition, the terminal can obtain broadcast information within the cell by receiving the PBCH (Physical Broadcast Channel) from the base station. In addition, the terminal can receive the DL RS (Downlink Reference Signal) during the initial cell search phase to check the downlink channel status.

[0194] (Initial) cell search can be defined as a procedure in which a terminal acquires time and frequency synchronization with a cell and detects the cell ID of the cell. Cell search can be based on the primary synchronization signal and secondary synchronization signal of the cell, and the PBCH DMRS.

[0195] A terminal that has completed initial cell search can obtain more specific system information by receiving a PDCCH (Physical Downlink Control Channel) and a corresponding PDSCH (Physical Downlink Control Channel) (S12).

[0196] Thereafter, the terminal can perform a random access procedure (Random Access Procedure) to complete connection to the base station (S13-S16). Specifically, the terminal can transmit a preamble through a Physical Random Access Channel (PRACH) (S13) and receive a Random Access Response (RAR) for the preamble through a PDCCH and a corresponding PDSCH (S14). Thereafter, the terminal can transmit a Physical Uplink Shared Channel (PUSCH) using scheduling information in the RAR (S15) and perform a contention resolution procedure (Contention Resolution Procedure) such as a PDCCH and a corresponding PDSCH (which can be considered a process of receiving a contention resolution message) (S16).

[0197] When accessing a base station for the first time or when there is no radio resource for signal transmission, a terminal may perform a random access procedure (RACH) for the base station. At this time, a 4-step contention-based or type-1 random access may include a first step in which the terminal transmits a random access preamble (or Msg1) to the base station, a second step in which the terminal receives a random access response (RAR) (or Msg2) from the base station, a third step in which the terminal transmits an uplink message (or Msg3) to the base station, and a fourth step in which the terminal receives a contention resolution message (or Msg4) from the base station. Alternatively, a 2-step contention-based or type-2 random access may include a step A in which the terminal transmits a random access preamble and an uplink message to the base station, and a step B in which the terminal receives a random access response and a contention resolution message from the base station. A contention-free random access procedure may only include steps 1 and 2 of a contention-based access procedure, and steps 3 and 4 are not required because no contention occurs between terminals.

[0198] The terminal can transmit a random access preamble or PRACH to the base station based on the random access opportunity (RO), preamble transmission power, etc. provided through SIB1 or dedicated RRC signaling. Here, the terminal can select an optimal SSB or CSI-RS (Channel Status Information-Reference Signal) and determine an RO and / or preamble index group associated with the selected SSB or CSI-RS. The terminal can select an optimal SSB and a corresponding reception beam from among a plurality of SSBs corresponding to the multi-beam sweeping of the base station during the initial access process. Meanwhile, after the initial access, the terminal can perform transmission beam and / or reception beam selection or change through a CSI measurement and reporting process based on the CSI-RS from the base station in an RRC connection state.

[0199] After the terminal transmits the preamble, the terminal can monitor RAR reception for a predetermined period of time. For example, the terminal can monitor the PDCCH scrambled with RA-RNTI and receive the RAR through the PDSCH transmitted in the resource scheduled by the DCI in the PDCCH. The RAR may include a Random Access Preamble Identifier (RAPID), an uplink grant (UL Grant) for Msg3 scheduling, a temporary cell identifier (Temporary C(Cell)-RNTI), and a Timing Advance Command (TAC) determined based on the preamble reception timing.

[0200] If the terminal fails to successfully receive the RAR, the preamble can be retransmitted by applying power ramping, etc.

[0201] If the terminal successfully receives the RAR, it can transmit Msg3 based on the UL grant within the RAR. Once Msg3 is transmitted, the terminal can start the contention resolution timer (CR timer) and perform PDCCH monitoring based on the C-RNTI for Msg4 reception. If Msg4 is received while the CR timer is running, the terminal can determine that contention resolution has been successfully completed.

[0202] A terminal that has performed the above-described procedure can then perform PDCCH / PDSCH reception (S17) and PUSCH / PUCCH (Physical Uplink Control Channel) transmission (S18) as general uplink / downlink signal transmission procedures. Control information that the terminal transmits to the base station is referred to as UCI (Uplink Control Information). UCI includes HARQ ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CSI (Channel State Information), etc. CSI includes CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indication), etc. UCI is generally transmitted through PUCCH, but can be transmitted through PUSCH when control information and data must be transmitted simultaneously. In addition, the terminal can aperiodically transmit UCI through PUSCH according to a request / instruction of the network. UCI can be repeatedly transmitted over PUCCH.

[0203] Meanwhile, the control information that the terminal transmits to the base station via the uplink (or that the terminal receives from the base station) may include downlink / uplink ACK / NACK signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Index), RI (Rank Indicator), etc. For example, in the case of a 3GPP LTE system, the terminal may transmit the above-described control information such as CQI / PMI / RI via PUSCH and / or PUCCH.

[0204] The table below shows an example of the DCI format.

[0205] [Table 5]

[0206]

[0207] Referring to Table 5 above, DCI formats 0_0, 0_1, and 0_2 may include resource information related to scheduling of PUSCH (e.g., UL / SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), transport block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information (e.g., PUSCH power control, etc.), and the control information included in each DCI format may be predefined.

[0208] DCI format 0_0 is used for scheduling PUSCH in a single cell. The information contained in DCI format 0_0 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0209] DCI format 0_1 ​​is used to schedule one or more PUSCHs in a single cell, or to indicate configured grant (CG) downlink feedback information to the UE. The information contained in DCI format 0_1 ​​is CRC-scrambled and transmitted using the C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI.

[0210] DCI format 0_2 is used for scheduling PUSCH in a single cell. The information contained in DCI format 0_2 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, SP-CSI-RNTI, or MCS-C-RNTI.

[0211] Next, DCI formats 1_0, 1_1, and 1_2 may include resource information related to scheduling of PDSCH (e.g., frequency resource allocation, time resource allocation, VRB-PRB mapping, etc.), transport block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., antenna port, TCI, SRS request, etc.), PUCCH related information (e.g., PUCCH power control, PUCCH resource indicator, etc.), and control information included in each DCI format may be predefined.

[0212] DCI format 1_0 is used for scheduling PDSCH in a DL cell. The information contained in DCI format 1_0 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0213] DCI format 1_1 is used for scheduling PDSCH in a single cell. Information included in DCI format 1_1 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0214] DCI format 1_2 is used for scheduling PDSCH in a single cell. The information contained in DCI format 1_2 is CRC-scrambled and transmitted using C-RNTI, CS-RNTI, or MCS-C-RNTI.

[0215] Now, let's talk about LTM (L1 / L2 Triggered Mobility).

[0216] LTM is a procedure in which the gNB receives an L1 measurement report from the UE and, based on this, changes the UE's serving cell through a cell switch command signaled via MAC CE. The cell switch command indicates an LTM candidate configuration prepared in advance by the gNB and provided to the UE via RRC signaling. The UE then switches to the target configuration according to the cell switch command. The LTM procedure can be used to reduce mobility latency.

[0217] If configured by the network, the TCI states of one or more cells other than the current serving cell can be activated. For example, the TCI state of an LTM candidate cell can be activated before that cell becomes the serving cell. This allows the UE to perform downlink synchronization with that cell and, when a cell switch is triggered, to switch to one of the cells more quickly. All activated TCI states, except those received in the cell switch command, are deactivated when the LTM cell switch is executed.

[0218] In this way, in wireless communication systems, mobility has been continuously developed for handover of terminals to base stations. For example, the conventional 3GPP (3 rdIn the NR Release-18 of the NR Generation Partnership Project, handover for low latency was designed through LTM. However, in the LTM of Release 18, CSI (channel state information) reports were performed using only SSB (synchronization signal / physical broadcast channel (SS / PBCH) block).

[0219] In contrast, the LTM performing method according to the present disclosure can utilize a channel state information-reference signal (CSI-RS) for more accurate beam reporting. Furthermore, future standards (e.g., 3GPP NR Release 19) may allow for LTM design using CSI-RS.

[0220] The most significant difference between SSB and CSI-RS is that CSI-RS uses sharper beams than SSB. While CSI-RS offers the advantage of sharper beams, enabling more accurate beamforming for terminals, the downside is a lower overall cell quality and cell access reliability.

[0221] Accordingly, even if a good beam quality is reported based on CSI-RS, the cell quality may be poor. In this case, when the terminal changes the beam for some reason, it may frequently move to another cell due to poor cell quality, which may result in a ping-pong phenomenon. In LTM operation, not only beam quality but also reliable cell quality values ​​are important factors. Since conventional LTM uses SSB, the conventional LTM method cannot be directly applied to LTM using CSI-RS.

[0222] Existing LTM is SSB-based, and can be configured with a value of maxNrofLTM-CSI-ReportConfigurations = 48. However, when implementing CSI-RS-based LTM, additional report configurations may be required because the number of CSI-RSs is greater than that of SSB. In this case, the probability of collisions with other CSI reports or those of other candidate cells increases, and it is necessary to select the signal to be transmitted in the event of a collision through priority.

[0223] This disclosure describes priority rules for cases where a collision occurs during the processing of an LTM CSI report with another CSI report or a CSI report of another candidate cell.

[0224] Looking at the CSI-RS-ResourceConfigMobility and LTM-CSI-ResourceConfig IEs in existing standard specifications documents (e.g., 3GPP NR 38.331), we can see how the resource sets are configured for RRM and LTM, respectively. Table 6 shows an example of the CSI-RS-ResourceConfigMobility IE (information element). The CSI-RS-ResourceConfigMobility IE is used to configure CSI-RS-based RRM measurements.

[0225] [Table 6]

[0226]

[0227]

[0228] In Table 6, csi-rs-ResourceList-Mobility is a list of CSI-RS resources for mobility. csi-RS-CellList-Mobility is a list of cells for CSI-RS-based RRM measurement. refServCellIndex indicates a serving cell that provides a timing reference for CSI-RS resources without associated SSB. associatedSSB, if this field exists, allows the UE to base the timing of the CSI-RS resources indicated in CSI-RS-Resource-Mobility on the timing of the cell indicated by the cellId in CSI-RS-CellMobility. csi-RS-Index is a CSI-RS resource index associated with the CSI-RS resource to be measured (and used for reporting). firstOFDMSymbolInTimeDomain is a time domain allocation within a physical resource block. This field indicates the first OFDM symbol of the PRB used for CSI-RS. frequencyDomainAllocation is a frequency domain allocation within a physical resource block.

[0229] Table 7 is an example of an LTM-CSI-ResourceConfig IE. The LTM-CSI-ResourceConfig IE defines one or more CSI resource groups for one or more LTM candidate configurations.

[0230] [Table 7]

[0231]

[0232] In Table 7, ltm-CandidateIdList represents the LTM candidate cell IDs associated with the SSBs in ltm-CSI-SSB-ResourceList. This list can have the same number of entries as ltm-CSI-SSB-ResourceList. The first entry in this list is linked to the first entry in ltm-CSI-SSB-ResourceList, the second entry is linked to the second entry in ltm-CSI-SSB-ResourceList, and so on.

[0233] ltm-CSI-SSB-ResourceList is used to indicate SS / PBCH block resources of one or more LTM candidate cells.

[0234] The contents of Table 6, B are summarized as follows.

[0235] 1) RRM: One candidate cell ID is set for each CSI-RS-CellMobility of IE CSI-RS-ResourceConfigMobility, and multiple CSI-RS-Resource-Mobility are set. In addition, the associated SSB is set within the CSI-RS-Resource-Mobility.

[0236] 2) LTM: The resource set configured for CMR (channel measurement) is configured regardless of the candidate cell ID. That is, the SSBs of multiple candidate cells are configured in one resource set.

[0237] Table 8 is an example of a CSI-ReportConfig IE. The CSI-ReportConfig IE is used to configure periodic or semi-persistent reports transmitted on the PUCCH of the cell containing the CSI-ReportConfig, or to configure semi-persistent or aperiodic reports transmitted on the PUSCH triggered by DCI received from the cell containing the CSI-ReportConfig.

[0238] [Table 8]

[0239]

[0240]

[0241]

[0242]

[0243]

[0244]

[0245] In Table 8, csi-ReportingBand represents a subset of contiguous or non-contiguous subbands in the bandwidth portion for which CSI should be reported. csi-ReportSubConfigToAddModList is a list of CSI-ReportSubConfigurations to be added or modified in the CSI report configuration. nrofReportedGroups is the number of resource groups reported per CSI report. nrofReportedRS is the number of measured RS resources reported per report configuration in non-group-based reports. resourcesForChannelMeasurement represents resources for channel measurements.

[0246] Table 9 is an example of the LTM-CSI-ReportConfig IE. The LTM-CSI-ReportConfig IE is used to configure reports for cells containing LTM-CSI-ReportConfig.

[0247] [Table 9]

[0248]

[0249]

[0250] In Table 9, ltm-ReportContent defines the content of the LTM L1 measurement report. reportSlotConfig indicates the periodicity and slot offset, and nrOfReportedCells defines the number of cells reported within a single L1 measurement report instance. nrOfReportedRS-PerCell defines the number of RSs per cell reported within a single L1 measurement report instance. spCellInclusion indicates whether the UE includes L1 measurement reports related to the current SpCell. This field can be set only when the current SpCell is configured as an LTM candidate cell.

[0251] Table 10 illustrates a CandidateTCI-State IE. The CandidateTCI-State IE can define a TCI state configuration that associates one or more reference signals with the corresponding quasi-colocation (QCL) type.

[0252] [Table 10]

[0253]

[0254] In Table 10, pathlossReferenceRS-Id represents the PathlossReferenceRS of the LTM candidate containing CandidateTCI-State. qcl-Type1 and qcl-Type2 are QCL information for the TCI state. tci-StateId is the ID number of the TCI state.

[0255] Figure 13 illustrates the signaling process for LTM.

[0256] Referring to Figure 13, the LTM procedure can be performed as follows.

[0257] The terminal is in RRC_CONNECTED state (S131).

[0258] 1. The terminal transmits a measurement report (e.g., MeasurementReport) message to the base station (S132). The base station determines the LTM settings and begins LTM preparation (S133).

[0259] 2. The base station transmits an RRC reset message (e.g., RRCReconfiguration) including LTM candidate settings to the terminal (S134).

[0260] 3. The terminal stores the LTM candidate settings and transmits an RRC reconfiguration complete message (e.g., RRCReconfigurationComplete) to the base station (S135).

[0261] 4a. The terminal performs downlink (DL) synchronization with the LTM candidate cell before receiving the cell switch command (S136). The terminal can activate and deactivate the TCI state of the LTM candidate cell according to a trigger from the base station.

[0262] 4b. Before receiving a cell switch command, the UE can perform UL synchronization with the LTM candidate cell by using terminal-based TA measurement (if configured) or by transmitting a preamble to the candidate cell according to a trigger from the base station (S137). If terminal-based TA measurement is configured, the UE acquires the TA value of the candidate cell through the measurement. Before receiving the cell switch command, the UE can perform early TA acquisition for the candidate cell at the request of the network. This is performed through a CFRA triggered by a PDCCH command of the source cell, after which the UE transmits a preamble toward the designated candidate cell. To minimize data interruption of the source cell due to the CFRA toward the candidate cell, the UE does not receive a random access response from the network for TA value acquisition, and the TA value of the candidate cell can be indicated in the cell switch command. The UE does not maintain a TA timer for the candidate cell, and the validity of the TA can be guaranteed depending on the network implementation.

[0263] 5. The terminal performs L1 measurements on the configured LTM candidate cells and transmits an L1 measurement report to the base station (S138-1). L1 measurements may be required as long as RRC reconfiguration (step 2) is applied.

[0264] 6. The base station decides to execute a cell switch to the target cell (S138-2) and transmits an LTM cell switch command MAC CE that triggers the cell switch, which includes a target configuration ID indicating a candidate configuration index of the target cell, beam(s) indicated by DL and UL TCI states, and a timing advance command for the target cell (if available) (S138-3). The terminal detaches from the source cell, switches to the target cell, and applies the candidate configuration indicated by the target configuration ID (S138-4).

[0265] 7. If the terminal does not have a valid TA of the target cell, it performs a random access procedure for the target cell (S138-5).

[0266] 8. The terminal completes the LTM cell switching procedure by transmitting an RRC reconfiguration complete message (e.g., RRCReconfigurationComplete) to the target cell (S139).

[0267] If the terminal performs the RA procedure in step 7, the LTM cell transition execution can be considered to have been successfully completed if the random access procedure is successfully completed.

[0268] For LTM without RACH, the terminal can consider the LTM cell switch execution to be completed successfully when the network determines that the first UL data has been successfully received.

[0269] Steps 4 to 8 described above can be performed multiple times in subsequent LTM cell switch executions using the LTM candidate settings provided in step 2.

[0270] The procedure on the wireless interface described in FIG. 13 can be applied to both intra-gNB-DU LTM and inter-gNB-DU LTM.

[0271] The cell switch command is carried over the MAC CE, which contains the information required to perform the LTM cell switching.

[0272] The initial synchronization, LTM cell switch execution, and LTM cell switch completion steps can be repeated without disabling other LTM candidate settings after each LTM cell switch is completed.

[0273] <CSI 리포트에 대한 우선 순위 규칙(Priority rules for CSI reports)>

[0274] For two overlapping PUSCHs, if i) the UE is not configured with sTx-2Panel or ii) the UE is configured by the upper layer parameter PDCCH-Config containing two different coresetPoolIndex values ​​in different ControlResourceSets of the active DL BWP and the UE is configured with sTx-2Panel and the two overlapping PUSCHs are associated / related with the same coresetPoolIndex value, the following priority rules may be applied to the physical channels with the same priority index.

[0275] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·y+N cells ·M s ·k+M s ·Related / associated with c+s.

[0276] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0277] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0278] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0279] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0280] Related Pri of the first CSI report iCSI (y,k,c,s) values ​​are associated with the Pri in the second CSI report iCSI If the value of (y,k,c,s) is lower than that of the first CSI report, it can be said that the first CSI report has a higher priority (or has priority) than the second CSI report. That is, the associated priority value (Pri) of the CSI report iCSI The lower the (y,k,c,s) value, the higher the priority of the CSI report.

[0281] Two CSI reports are said to collide when the physical channel time occupancy reserved for transmitting (carrying) the CSI reports overlaps by at least one OFDM symbol and is transmitted on the same carrier. When a terminal is configured to transmit two conflicting CSI reports,

[0282] If the y values ​​between the two CSI reports above are different, the higher Pri iCSI Do not send CSI reports with (y,k,c,s) values, except when one of the y values ​​is 2 and the other is 3.

[0283] Otherwise, the two CSI reports are multiplexed or one of the two CSI reports is dropped depending on the priority values.

[0284] If the CSI report set with LTM-CSI-ReportConfig conflicts with the CSI report set with CSI-ReportConfig, Pri iCSI Regardless of the (y,k,c,s) values, it has higher priority than all CSI reports set with CSI-ReportConfig.

[0285] A semi-persistent CSI report to be transmitted via PUSCH overlaps temporally with a PUSCH data transmission in one or more symbols of the same carrier, and the earliest symbol of such PUSCH channel is N2+d after the last symbol of the DCI scheduling the PUSCH. 2,1 If it does not start earlier than the symbol (here d 2,1 d associated with the PUSCH that transmits the semi-persistent CSI report and the PUSCH that includes data transmission 2,1 ), the terminal does not transmit a CSI report. Otherwise, if the time line requirement is not met, this is an error case.

[0286] In a case where a terminal intends to transmit a first PUSCH including a semi-persistent CSI report and a second PUSCH including an UL-SCH on the same carrier, if the first PUSCH transmission temporally overlaps with the second PUSCH transmission, the terminal transmits the second PUSCH without transmitting the first PUSCH. The terminal expects that the first and second PUSCH transmissions will satisfy the timing conditions for the temporally overlapping PUSCH transmissions when at least one of the first PUSCH transmission or the second PUSCH transmission is a response to the detection of a DCI format of the terminal.

[0287] According to the priority rules mentioned above, CSI reports configured via LTM-CSI-ReportConfig take precedence over all other CSI reports.

[0288] Hereinafter, the priority rules mentioned in the present disclosure may be applied i) only between LTM CSI reports, 2) additionally to CSI reports configured for CSI acquisition during LTM or handover, or iii) to all CSI reports.

[0289] The priority value Pri mentioned above iCSI According to the formula of (y,k,c,s), the serving cell index value (c), 'LTM-CSI-ReportConfigID' (s), 'maxNrofLTM-CSI-ReportConfigurations' (M s ) will be a consideration for the priority of CSI reports according to the current LTM.

[0290] However, information importance may need to be prioritized. Therefore, the introduction of new information, rather than existing formulas, can be proposed. The importance of this information could be L1-SINR, L1-RSRP, or path loss, which correspond to the contents of the CSI report.

[0291] The priority rules described below can be set on a report-by-report basis. If a report contains reports on multiple resources and multiple priority values ​​are generated using the method below, a representative priority value for each report can be generated using a specific method.

[0292] The above-mentioned specific method can determine the report priority based on the lowest value generated in the report resource or the average value. Priority among LTM CSI reports can be determined based on all or part of the priority rules described below.

[0293] There are two types of LTM CSI reports. The first is a "gNB-instructed LTM CSI report," which is triggered by the gNB. The second is an "event-triggered LTM CSI report," which is triggered when the UE satisfies a certain event. In the case of an event-triggered LTM CSI report, the report can be reported / transmitted via the MAC CE (medium access control element).

[0294] Below, we describe specific methods for determining priorities when reporting CSI. These priorities can also be applied to L1 measurement reports during the LTM process.

[0295] Method 1. Method based on the order of measured RSRP / SINR.

[0296] Method 1 prioritizes CSI-RS measurements. When measuring CSI-RS in LTM, measurement values ​​can include, for example, L1-RSRP and L1-SINR. Each measures the signal strength of the CSI-RS received by the UE relative to the CSI-RS transmitted by the base station. A stronger signal is likely to result in better quality transmission. Considering that the purpose of LTM is UE mobility, transmitting high-quality CSI-RS information first would be advantageous for the UE's behavior.

[0297] A single report instance may contain multiple measurement results, in which case the report's priority can be determined based on the measurement result (RSRP or SINR). The following examples may be considered.

[0298] If the base station cannot predict which RS will have the highest RSRP / SINR and thus must perform unnecessary blind decoding, the base station can use the header via MAC-CE to learn which report information the terminal selectively sends based on the corresponding rule. In this case, event-triggered LTM CSI reporting may be applicable.

[0299] Priority rules can be calculated based on the largest measurement value among all resources within a single report instance (moment).

[0300] This would be the most common ordering scheme. After measuring all CSI-RSs, the terminal determines the largest measurement value. The terminal defines this measurement value as the reference value, and the priority of the CSI report can be determined based on this reference value.

[0301] At this time, the parameters reflected in the priority formula can be, for example, predefined priority values ​​according to the range of measurement values. The terminal can be predefined for each range and represented as values ​​such as q and q'. For example, if the maximum value of the range is defined as q and the minimum value of the range is defined as q', when a certain measurement value is q > measurement value > q', the priority value can be determined according to the value mapped to the corresponding range, and this value can be substituted into any variable of the priority formula to calculate the priority of the corresponding report.

[0302] For example, the range for each measured value can be defined from minofMeasuredValue to maxofMeasuredValue, and a priority value table for each range can be created. In this case, if the maximum value that can occur is maxofMeasuredValue, the priority of the measured value (r) and maxofMeasuredValue(M r ) can be set to perform the following examples.

[0303] For example, the CSI report has a priority value Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0304] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0305] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0306] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0307] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0308] r is the priority of the measured value and M r is the value of the upper layer parameter maxofMeasuredValue. For CSI reports set with LTM-CSI-ReportConfig, r is the priority of the measurements and M r is the value of the upper layer parameter maxofMeasuredValue.

[0309] If a conflict arises between two reports with the same priority value, the priority can be determined by comparing the reference values ​​of each report. The advantage of this method is that it allows the terminal to transmit CSI report information from a candidate cell favorable for handover with a higher priority.

[0310] Method 2. How to determine priority based on the type of measurement resource.

[0311] When a base station performs CSI-RS-based LTM, the terminal will require cell quality. However, because CSI-RS uses sharp beams, the reliability of cell quality assessment may be reduced. Therefore, the base station may also configure LTM via SSB for the terminal. In this case, the terminal can determine the priority order based on the resource type associated with the report.

[0312] In case of a conflict between LTM CSI reports, the SSB-based report has higher priority than the CSI-RS-based report.

[0313] SSB-based measurements are relatively more reliable than CSI-RS-based measurements in determining cell quality. Therefore, prioritizing SSB-based reports can improve their reliability. In this situation, the base station can prioritize cell quality by transmitting SSB first, followed by CSI-RS for sharp beams. In this case, SSB has a priority value of 1, and CSI-RS has a priority value of 2.

[0314] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0315] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0316] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0317] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0318] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0319] For CSI reports set to LTM-CSI-ReportConfig, r is 1 if SSB is set as an LTM resource, and r is 2 if CSI-RS is set as an LTM resource.

[0320] In case of a conflict between LTM CSI reports, the CSI-RS based report has higher priority than the SSB based report.

[0321] CSI-RS-based measurements are relatively more reliable than SSB-based measurements in determining beam quality. Therefore, CSI-RS-based reports are more important in determining beam quality after a terminal handover. Therefore, CSI-RS-based reports can be given priority, thereby increasing report reliability.

[0322] In this situation, the base station may prioritize beam scale mobility and transmit the CSI-RS first, followed by the SSB. In this case, the CSI-RS has a priority value of 1, and the SSB has a priority value of 2.

[0323] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0324] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0325] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0326] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0327] s is reportConfigID, and M sis the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0328] For CSI reports set to LTM-CSI-ReportConfig, r is 1 if CSI-RS is set as an LTM resource, and r is 2 if SSB is set as an LTM resource.

[0329] Depending on the embodiment, there may be no priority difference between SSB-based reports and CSI-RS-based reports.

[0330] In these situations, a new factor is needed to compare SSB and CSI-RS. Since ordering the measured values ​​can prioritize results that differ from actual channel quality due to power offsets in SSB / CSI-RS, path loss can be considered as a new criterion for judgment.

[0331] To calculate path loss, the signal's transmit and receive power must be known. For example, when measuring receive power at a terminal, the base station must inform the terminal of the transmit power via RRC parameters. This allows the terminal to calculate path loss and determine priority.

[0332] For SSB, the base station can receive ss-PBCH-BlockPower-r18 via the LTM-Candidate IE. This parameter allows the terminal to know the transmission power from the base station and the reception power at the terminal for SSB, which can be used to calculate path loss.

[0333] For CSI-RS, there is no parameter that directly indicates from the base station, but the power offset of CSI-RS compared to SSB can be indicated. The parameter that indicates this can be powercontroloffsetSS, and through the above-mentioned ss-PBCH-BlockPower-r18, the terminal can know the transmission power of the base station per RE of the CSI-RS, and by calculating this together with the CSI-RS BWP, the total transmission power of the CSI-RS at the base station and the reception power at the terminal can be known, and this can be used to calculate the path loss.

[0334] For example, if the maximum value of the range is defined as q and the minimum value of the range is defined as q', when a path loss value is q > path loss value > q', the priority value can be determined based on the value mapped to the range, and this value can be assigned to any variable of the priority formula to calculate the priority of the report.

[0335] For example, the range for each path loss value can be defined as minofpathlossValue to maxofpathlossValue, and a priority value table for each range can be created. In this case, if the maximum value that can occur is maxofpathlossValue, the priority of the path loss value and maxofMeasuredValue(M r ) can be set to determine the priority for CSI reports as follows.

[0336] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0337] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0338] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0339] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0340] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0341] For CSI reports set with LTM-CSI-ReportConfig, r is the priority of the path loss value of the SSB or CSI-RS resource, and M r is the value of the upper layer parameter maxofpathlossValue.

[0342] Method 3. A method to determine priority based on the index of the TCI state ID.

[0343] The TCI state ID is a factor that can be mentioned in the relationship between SSB and CSI-RS. Since the base station transmits the TCI state ID of each SSB and CSI-RS to the UE for each RS (reference signal), the UE can also sort RSs using the TCI state ID. Furthermore, for each SSB, one or more CSI-RSs may have the same TCI state ID, which may indicate that some QCL types are the same.

[0344] Therefore, the TCI state ID can be used as an element to group RSs of similar states, and this allows the terminal to sort CSI reports. The TCI state ID can be found in the CandidateTCI-State IE, and the index information of the RS corresponding to each ID is stored in LTM-TCI-Info. However, since a single report instance is composed of multiple resources, multiple priority values ​​can be calculated by the TCI state ID. Therefore, the terminal can determine the TCI state ID with the lowest or highest index among multiple TCI state IDs as the representative TCI state ID for the corresponding report. The terminal can determine the priority of the corresponding report based on the representative TCI state ID for each report. For example, the priority of a CSI report can be determined as follows.

[0345] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0346] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0347] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0348] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0349] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0350] For CSI reports set with LTM-CSI-ReportConfig, r is the TCI state ID of the SSB or CSI-RS resources, and M r is the value of the upper layer parameter maxNrofCandidateTCI-State.

[0351] A UE can also determine TCI state-based priorities using only the activated TCI state. NR Release 18 mobility introduced the ability to activate / deactivate TCI states for candidate cells. Once a UE receives the TCI state activation of a candidate cell, it can only receive cell switch commands to the candidate cell whose TCI state ID has been activated through the LTM process. In other words, a handover can only be performed to a candidate cell with an activated TCI state ID.

[0352] Accordingly, considering the utility of the terminal, CSI reports can be transmitted with priority given to the activated TCI state via MAC-CE. The priority of the CSI report can be determined as follows.

[0353] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0354] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0355] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0356] c is the serving cell index, and N cellsis the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0357] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0358] For CSI reports set with LTM-CSI-ReportConfig, r is the enabled TCI state ID of the SSB or CSI-RS resource, and M r is the value of the upper layer parameter maxNrofCandidateTCI-State.

[0359] Depending on the embodiment, the terminal may determine the priority based on the number of activated TCI state IDs. During the LTM process, if the terminal receives TCI activation for a candidate cell, it can receive cell switch commands with MAC-CE only for candidate cells with TCI activation. Therefore, a report containing a large number of activated TCI state IDs can be said to be a measurement report for cells for which the terminal is expected to perform a handover soon, and thus has high importance. In this case, the number of activated TCI states may be considered only within the same candidate cell or across all reports. If considered only within the same candidate cell, each report can derive the candidate cell with the highest possibility of handover within the corresponding report.

[0360] In this case, if information about multiple candidate cells is contained within a single report instance, the priority value (r) may be the inverse of the number of activated TCI state IDs of the candidate cell with the most activated TCI states. For example, the inverse of the number of activated TCI state IDs within all reports may also be the priority value (r).

[0361] That is, when a conflict occurs between LTM CSI reports, the terminal gives priority to reporting reports with a larger number of activated TCI state IDs and drops reports with a smaller number of activated TCI state IDs.

[0362] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0363] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0364] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0365] c is the serving cell index, and N cellsis the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0366] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0367] For CSI reports set to LTM-CSI-ReportConfig, r is 1 / (number of enabled TCI state IDs in candidate cells / CSI reports), and M r is the value of the upper layer parameter maxNrofCondCells / maxNrofCandidateTCI-State.

[0368] Method 4. A method to determine priority based on the index of the resource / resource set ID.

[0369] When performing a measurement report in LTM operation of NR Release 18, if the CSI-RS / SSB resource ID is obtained without referencing the TCI state ID, the TCI state ID cannot be used in the priority rule.

[0370] In this case, the priority rule can be determined based on the CSI-RS / SSB resource ID (starting with the lowest or highest CSI-RS / SSB resource ID) instead of the TCI state ID. Information about each resource can be found in the LTM-CSI-ReportConfig IE, and the ID of each resource is stored in LTM-CSI-ResourceConfigId. If there are multiple resource IDs, the terminal can determine the priority of the report through a special rule in the report (for example, the highest resource ID or the lowest resource ID).

[0371] Alternatively, if multiple resource sets are configured in a single report instance, the priority rule can be determined through the resource set ID. In NR Release 18 LTM operation, the resource set ID is not configured in the LTM-CSI-ResourceConfig IE, so the definition of a higher layer parameter such as ltm-CSI-ResourceSetConfigId in LTM-CSI-ResourceConfig may be required. Even in the case of resource set ID, if there are multiple resource set IDs in a single report instance, the terminal can determine the priority of the report through a special rule in the report (for example, the largest resource set ID or the smallest resource set ID).

[0372] The priority rules for resource ID or resource set ID can be applied as follows.

[0373] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0374] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0375] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0376] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0377] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0378] For CSI reports set with LTM-CSI-ReportConfig, r is the resource (set) ID, and M r is the value of the upper layer parameter maxNrofresource(set)ID.

[0379] Method 5. A method for determining priority based on the index of the candidate cell ID.

[0380] Most of the methods described above report information on cell quality or beam quality. However, the reliability of such information is not high at all times, and if it exceeds the complexity that the terminal can accept, one of the simplest methods is to determine the priority based on the candidate cell ID corresponding to the reported resource. The candidate cell ID is included in the configuration information of each resource. For example, in the case of SSB, the candidate cell ID can be identified as ltm-CandidateIdList in ltm-CSI-SSB-ResourceSet in the LTM-CSI-ResourceConfig IE. In the existing standard, CSI-RS does not define RRC parameters for LTM. On the other hand, in the embodiment of the present disclosure, it can be defined as shown in Table 11 below. In this case, ltm-CSI-RS-ResourceSet is defined in the LTM-CSI-ResourceConfig IE.

[0381] [Table 11]

[0382]

[0383] In cases like the above, the priority of the CSI report can be determined as follows.

[0384] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=2·N cells ·M s ·M r ·y+N cells ·M s · M r ·k+M s ·M r ·c+ M r ·Can be associated / related with s+r.

[0385] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0386] For CSI reports carrying L1-RSRP or L1-SINR, k=0, and for CSI reports not carrying L1-RSRP or L1-SINR, k=1.

[0387] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0388] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0389] For CSI reports set to LTM-CSI-ReportConfig, r is the candidate cell index, and M r is the value of the upper layer parameter maxNrofCondCells.

[0390] If priority is given based solely on candidate cell IDs, there is a risk of giving higher priority to distant cells. Therefore, a method can be considered that prioritizes reports on, for example, adjacent cell IDs that are advantageous for UE handover. However, since NR does not include a function to provide a list of adjacent cells, this function can be performed by activating / deactivating the TCI state. If the UE has activated the TCI state ID through the TCI state, the UE can send reports for the cell IDs in the list first. Alternatively, the base station can broadcast information in advance, either in the form of a TCI state ID or a cell ID list, regarding which cell IDs are beams / cells advantageous for UE handover for the activated TCI state ID. Accordingly, the UE can prioritize reports based on the activated TCI state information.

[0391] Method 5-1. A method for determining priority when a conflict occurs between a CSI report indicated by the gNB and a terminal event-triggered CSI report.

[0392] For the two methods of performing CSI reporting, there may be instances where both the gNB and the UE are triggered to perform CSI reporting simultaneously. In this case, multiple methods can be applied simultaneously, as they operate independently of the other methods. If a conflict arises between a CSI report indicated by the gNB and a CSI report triggered by a UE event, the CSI report indicated by the gNB may take precedence.

[0393] If the terminal needs additional information that can be received when the gNB instructs a CSI report, such as information on candidate cells favorable for handover of the terminal, the terminal may perform the gNB's instruction with priority over the terminal's event.

[0394] Alternatively, the terminal may prioritize terminal event triggers. For example, if the report includes terminal-generated information such as RSRP / SINR / path loss for priority calculation, the terminal may transmit the terminal's event-triggered CSI report with priority over the gNB's instructions.

[0395] Method 6. How to determine priority based on whether SpCell is included.

[0396] When a conflict occurs between LTM CSI reports, the terminal can determine the priority based on whether or not SpCell is included. SpCell is composed of PCell and PSCell, and the terminal can determine whether the L1 measurement report currently includes information about SpCell. If SpCell is included, the terminal transmits a report containing information about SpCell with priority over all of the above methods. This information can be found in spCellInclusion included in LTM-ReportContent of LTM-CSI-ReportConfig IE without any separate standard specification modification. When transmitting a report containing SpCell, it can be specified as follows.

[0397] CSI reports set with LTM-CSI-ReportConfig have priority value Pri if they conflict with CSI reports(s) set with CSI-ReportConfig. iCSI Regardless of (y,k,c,s), it has higher priority than all CSI reports set with CSI-ReportConfig.

[0398] When spCellInclusion-r18 is set to 'true', the CSI report set with LTM-CSI-ReportConfig will take precedence over the CSI report(s) set with CSI-ReportConfig if there is a conflict. iCSIRegardless of (y,k,c,s), it has higher priority than all CSI reports set with CSI-ReportConfig.

[0399] Method 7. Acquiring CSI for LTM or handover.

[0400] The terminal can perform CSI-RS measurement / report to obtain CSI before handover for fast data transmission and reception after handover in the target cell, as well as RSRP / SINR during LTM or handover process.

[0401] Reports for CSI acquisition, like RSRP / SINR measurements, may have multiple resources set by multiple candidate cells, and thus may conflict with CSI reports for the same / different purposes.

[0402] If a conflict occurs with a CSI report intended for another purpose, the CSI report may be for LTM or another purpose. If a CSI report intended for CSI acquisition conflicts with a CSI report intended for LTM, the terminal may transmit the report with LTM as the priority.

[0403] If a CSI report for CSI acquisition conflicts with a CSI report for the serving cell, the terminal can report the CSI report for CSI acquisition as a priority.

[0404] Here, a CSI report for LTM means a case where the content of the CSI report measures the power / quality of CSI, such as L1-RSRP / L1-SINR, and a CSI report for CSI acquisition means a case where the content of the CSI report is CQI / RI / PMI / LI, etc.

[0405] In case of conflict with CSI reports for the same purpose, all or part of the above-mentioned methods 1 to 6 may be additionally applied.

[0406] The expression of the formula for this purpose is, for example, as follows.

[0407] CSI reports have priority values ​​Pri iCSI (y,k,c,s)=3·N cells ·M s ·y+N cells ·M s ·k+M s ·c+ can be associated / related with s.

[0408] For aperiodic CSI reports to be transmitted on PUSCH, y=0, for semi-persistent CSI reports to be transmitted on PUSCH, y=1, for semi-persistent CSI reports to be transmitted on PUCCH, y=2, and for periodic CSI reports to be transmitted on PUCCH, y=3.

[0409] For CSI reports carrying L1-RSRP or L1-SINR, k=0, for CSI reports carrying CQI / RI / PMI / LI for candidate cells, k=1, and for CSI reports not carrying L1-RSRP, L1-SINR, or CQI / RI / PMI / LI for candidate cells, k=2.

[0410] c is the serving cell index, and N cells is the value of the upper layer parameter maxNrofServingCells. For CSI reports configured with LTM-CSI-ReportConfig, c is the serving cell index value for which the report configuration is configured.

[0411] s is reportConfigID, and M s is the value of the upper layer parameter maxNrofCSI-ReportConfigurations. For CSI reports set to LTM-CSI-ReportConfig, s is LTM-CSI-ReportConfigID, and M s is the value of the upper layer parameter maxNrofLTM-CSI-ReportConfigurations.

[0412] CSI reports set with LTM-CSI-ReportConfig have priority value Pri if they conflict with CSI reports(s) set with CSI-ReportConfig. iCSI Regardless of (y,k,c,s), it has higher priority than all CSI reports set with CSI-ReportConfig.

[0413] Figure 14 illustrates a method for performing LTM on a terminal.

[0414] Referring to FIG. 14, a user equipment (UE) transmits a specific CSI report among multiple CSI reports to a base station based on a priority related to a CSI (channel state information) report, and a parameter related to a type of measurement resource that the UE must measure is included among the parameters that determine the priority (S141).

[0415] For example, a terminal may be in an RRC connected state (RRC_CONNECTED state) with a base station that manages a serving cell and neighboring cells. In this case, the terminal may receive LTM candidate settings for LTM candidate cells from the base station. For example, at least one of the neighboring cells may be an LTM candidate cell, and the terminal may receive LTM candidate settings for the LTM candidate cell from the base station.

[0416] The LTM candidate configuration may include information necessary for access and communication with a candidate cell that can be switched via LTM. For example, the LTM candidate configuration may include at least one of identification information of the candidate cell (cell ID, frequency, etc. of the candidate cell), physical layer configuration information (e.g., SSB or CSI-RS related information (information necessary for measurement such as period, location, etc.)), TCI status (TCI status necessary for communication with a specific beam of the candidate cell), MAC CE related information (information indicating how to operate when an LTM cell switch command is received), and RACH related information (whether to perform a RACH procedure when switching cells, and required RACH parameters if performed).

[0417] The terminal performs L1 measurements and transmits an L1 measurement report to the base station. The L1 measurement report is related to a CSI report. When the terminal transmits an L1 measurement report, a specific CSI report among multiple CSI reports is transmitted to the base station as the L1 measurement report based on the priority associated with the CSI report. In this process, parameters related to the type of measurement resource to be measured by the terminal are included among the parameters determining the priority.

[0418] This has been described in detail in 'Method 2. Method for determining priority according to the type of measurement resource'. For example, according to the above priority, if a conflict occurs between the first CSI report, in which the measurement resource that the terminal must measure is SSB (Synchronization Signal Block), and the second CSI report, in which the measurement resource that the terminal must measure is CSI-RS (channel state information reference signal), the first CSI report can be transmitted with priority.

[0419] In an embodiment, according to the above priority, if a conflict occurs between a first CSI report in which the measurement resource to be measured by the terminal is a SSB (Synchronization Signal Block) and a second CSI report in which the measurement resource to be measured by the terminal is a CSI-RS (channel state information reference signal), the second CSI report may be transmitted with priority.

[0420] Depending on the embodiment, the priority may be determined by additionally applying the 'Method 5-1. Priority determination method when a conflict occurs between a CSI report indicated by a gNB and a terminal event-triggered CSI report' described above.

[0421] In this case, according to the above priority, if a conflict occurs between the first CSI report indicated by the base station and the second CSI report triggered by an event of the terminal, the first report can be transmitted with priority.

[0422] Alternatively, according to the above priority, if a conflict occurs between the first CSI report indicated by the base station and the second CSI report triggered by an event of the terminal, the second report may be transmitted with priority.

[0423] In an embodiment, according to the above priority, if a conflict occurs between a first CSI report for CSI acquisition for a target cell and a second CSI report for CSI reporting for LTM, the second CSI report may be transmitted with priority.

[0424] The terminal receives an LTM (L1 / L2 triggered mobility) cell switch command from the base station via MAC CE (S142). For example, the base station makes an LTM decision by referring to the terminal's L1 measurement report (the above-described specific CSI report), and then transmits an LTM cell switch command to the terminal via MAC CE, if necessary.

[0425] The above MAC CE is shorter and simpler than the RRC message and may include the following key information. For example, the LTM cell switch command may include target configuration ID (identifier) ​​information related to the index of the candidate configuration of the target cell. In other words, the LTM cell switch command may include information indicating a specific candidate configuration of a specific target cell among the candidate configurations of candidate cells provided by the LTM candidate configuration.

[0426] Depending on the embodiment, the LTM cell switch command may further include a TCI state directing the beam, a timing advance (TA) command, etc.

[0427] The terminal performs a handover procedure for the target cell based on the MAC CE (S143). For example, the terminal may perform a RACH procedure with the target cell using a candidate configuration corresponding to the target configuration ID indicated by the LTM cell switch command included in the MAC CE. Depending on the embodiment, the terminal may also perform a handover without a random access procedure.

[0428] LTM is crucial for reducing mobility latency. In conventional handover procedures, the UE receives target cell information via an RRC message only after receiving a handover command, and cell switching operations are initiated based on this information, which consumes significant time. Furthermore, conventional LTM operates based on SSB measurement / reporting, and the prioritization of CSI reporting does not take into account the fact that LTM can also operate based on CSI-RS measurement / reporting.

[0429] On the other hand, in the LTM according to the present disclosure, the base station pre-configures information about several candidate cells to the terminal through LTM candidate configuration, and the terminal stores this information. Thereafter, when an LTM cell switch command (MAC CE) is received, the cell switch operation can be quickly performed based on the stored LTM candidate configuration. This shortens the time required for RRC signaling and minimizes mobility delay. In addition, considering that LTM can operate based on CSI-RS measurement / reporting, a priority is determined when CSI reporting. Therefore, when there are multiple CSI reports, it is possible to clearly specify which CSI report to transmit, and LTM operation can also be performed more efficiently.

[0430] Figure 15 illustrates a signaling process and operation method between a base station and a terminal.

[0431] Referring to FIG. 15, the base station provides the terminal with LTM candidate settings through an RRC reset (S151). The LTM candidate settings may include settings for at least one candidate cell related to LTM.

[0432] The terminal transmits an RRC reset completion message to the base station (S152).

[0433] The terminal performs L1 measurements (S153). For example, the terminal may perform L1 measurements based on the SSB / CSI-RS of the serving cell and L1 measurements based on the SSB / CSI-RS of at least one neighboring cell based on the LTM candidate configuration.

[0434] The terminal transmits a specific CSI report among multiple CSI reports to the base station based on priority (S154). The priority determination method has been described above in Methods 1 through 7.

[0435] For example, based on the priority associated with a CSI report, a specific CSI report among multiple CSI reports is transmitted to the base station as an L1 measurement report. In this process, parameters related to the type of measurement resource to be measured by the terminal are included among the parameters determining the priority.

[0436] This has been described in detail in 'Method 2. Method for determining priority according to the type of measurement resource'. For example, according to the above priority, if a conflict occurs between the first CSI report, in which the measurement resource that the terminal must measure is SSB (Synchronization Signal Block), and the second CSI report, in which the measurement resource that the terminal must measure is CSI-RS (channel state information reference signal), the first CSI report can be transmitted with priority.

[0437] In an embodiment, according to the above priority, if a conflict occurs between a first CSI report in which the measurement resource to be measured by the terminal is a SSB (Synchronization Signal Block) and a second CSI report in which the measurement resource to be measured by the terminal is a CSI-RS (channel state information reference signal), the second CSI report may be transmitted with priority.

[0438] Depending on the embodiment, the priority may be determined by additionally applying the 'Method 5-1. Priority determination method when a conflict occurs between a CSI report indicated by a gNB and a terminal event-triggered CSI report' described above.

[0439] In this case, according to the above priority, if a conflict occurs between the first CSI report indicated by the base station and the second CSI report triggered by an event of the terminal, the first report can be transmitted with priority.

[0440] Alternatively, according to the above priority, if a conflict occurs between the first CSI report indicated by the base station and the second CSI report triggered by an event of the terminal, the second report may be transmitted with priority.

[0441] In an embodiment, according to the above priority, if a conflict occurs between a first CSI report for CSI acquisition for a target cell and a second CSI report for CSI reporting for LTM, the second CSI report may be transmitted with priority.

[0442] The base station transmits a MAC CE including a cell switch command to the terminal (S155). The LTM cell switch command may include target configuration ID (identifier) ​​information related to the index of the candidate configuration of the target cell to be switched by the LTM cell switch command. In other words, the LTM cell switch command may include information indicating a specific candidate configuration of a specific target cell among the candidate configurations of the candidate cells provided by the LTM candidate configuration.

[0443] The terminal performs a handover procedure with the target cell determined based on the LTM cell switch command (S156). For example, the terminal may perform a RACH procedure with the target cell using a candidate configuration corresponding to the target configuration ID indicated by the LTM cell switch command. Thereafter, the terminal may complete the LTM cell switch procedure by transmitting an RRC reconfiguration complete message to the target cell. Depending on the embodiment, the terminal may also perform a handover without a random access procedure.

[0444] Figure 16 illustrates a wireless device applicable to the present specification.

[0445] Referring to FIG. 16, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR).

[0446] A first wireless device (100) includes at least one processor (102) and at least one memory (104), and may further include at least one transceiver (106) and / or at least one antenna (108). The at least one processor (102, hereinafter simply referred to as a processor) controls at least one memory (104, hereinafter simply referred to as a memory) and / or at least one transceiver (106, hereinafter simply referred to as a transceiver or a transceiver), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal through the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive a wireless signal through one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit.In this specification, wireless device may also mean a communication modem / circuit / chip.

[0447] A processor (102) may be included in a terminal. The processor (102) transmits a specific CSI report among a plurality of CSI reports to a base station based on a priority related to a CSI (channel state information) report, receives an LTM (L1 / L2 triggered mobility) cell switch command from the base station through a MAC CE, and performs a random access procedure for a target cell based on the MAC CE, wherein a parameter related to a type of measurement resource that the terminal should measure is included among the parameters that determine the priority. The specific operation has been described with reference to FIGS. 13 to 15.

[0448] A second wireless device (200) includes at least one processor (202), at least one memory (204), and may further include at least one transceiver (206) and / or at least one antenna (208). The processor (202) controls the memory (204) and / or the transceiver (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signal, and then transmit a wireless signal including the third information / signal via the transceiver (206). In addition, the processor (202) may receive a wireless signal including fourth information / signal via the transceiver (206), and then store information obtained from signal processing of the fourth information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In this specification, a wireless device may also mean a communication modem / circuit / chip.

[0449] The processor (202) may be included in a base station. The processor (202) receives a specific CSI report from among a plurality of CSI reports based on a priority related to the CSI report from the terminal, transmits an LTM (L1 / L2 triggered mobility) cell switch command to the terminal through a MAC CE, and performs a random access procedure for the terminal and a target cell based on the MAC CE, wherein a parameter related to a type of measurement resource that the terminal should measure is included among the parameters that determine the priority. The specific operation has been described with reference to FIGS. 13 to 15.

[0450] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0451] The one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The one or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors (102, 202). The one or more processors (102, 202) may also be implemented by at least one computer-readable medium (CRM) containing instructions based on which at least one processor is executed.

[0452] For example, at least one computer readable medium (CRM) including instructions based on being executed by at least one processor performs the following operations: transmitting a specific CSI report among a plurality of CSI reports to a base station based on a priority associated with the CSI report, receiving an LTM (L1 / L2 triggered mobility) cell switch command from the base station through a MAC CE, and performing a random access procedure for a target cell based on the MAC CE. At this time, it is characterized in that a parameter related to a type of measurement resource that the terminal should measure is included among the parameters that determine the priority. The specific operations have been described with reference to FIGS. 13 to 15.

[0453] The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions. The firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be included in one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0454] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0455] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0456] Figure 17 illustrates another example of a wireless device.

[0457] According to FIG. 17, the wireless device may include at least one processor (102, 202), at least one memory (104, 204), at least one transceiver (106, 206), and one or more antennas (108, 208).

[0458] The difference between the example of the wireless device described in FIG. 16 and the example of the wireless device in FIG. 17 is that in FIG. 16, the processor (102, 202) and the memory (104, 204) are separated, whereas in the example of FIG. 17, the memory (104, 204) is included in the processor (102, 202). For example, the processor and the memory may constitute a single chipset.

[0459] Fig. 18 illustrates an example of a signal processing module structure. Here, signal processing may be performed in the processor (102, 202) of Fig. 16.

[0460] Referring to FIG. 18, a transmission device (e.g., a processor, a processor and a memory, or a processor and a transceiver) within a terminal or a base station may include a scrambler (301), a modulator (302), a layer mapper (303), an antenna port mapper (304), a resource block mapper (305), and a signal generator (306).

[0461] A transmitting device can transmit one or more codewords. The coded bits within each codeword are scrambled by a scrambler (301) and transmitted over a physical channel. A codeword may also be referred to as a data string and may be equivalent to a transport block, which is a data block provided by the MAC layer.

[0462] The scrambled bits are modulated into complex-valued modulation symbols by a modulator (302). The modulator (302) can modulate the scrambled bits according to a modulation scheme and arrange them into complex-valued modulation symbols that represent positions on a signal constellation. There is no limitation on the modulation scheme, and m-PSK (m-Phase Shift Keying) or m-QAM (m-Quadrature Amplitude Modulation) can be used to modulate the encoded data. The modulator may be referred to as a modulation mapper.

[0463] The complex modulation symbols may be mapped to one or more transmission layers by a layer mapper (303). The complex modulation symbols on each layer may be mapped by an antenna port mapper (304) for transmission on an antenna port.

[0464] The resource block mapper (305) can map the complex modulation symbol for each antenna port to an appropriate resource element within a virtual resource block (VRB) allocated for transmission. The resource block mapper can map the VRB to a physical resource block (PRB) according to an appropriate mapping scheme. The resource block mapper (305) can assign the complex modulation symbol for each antenna port to an appropriate subcarrier and multiplex it according to the user.

[0465] The signal generator (306) can generate a complex-valued time domain OFDM symbol signal by modulating a complex modulation symbol, for example, an antenna-specific symbol, for each antenna port, with a specific modulation method, for example, an Orthogonal Frequency Division Multiplexing (OFDM) method. The signal generator can perform an Inverse Fast Fourier Transform (IFFT) on the antenna-specific symbol, and a Cyclic Prefix (CP) can be inserted into the time domain symbol on which the IFFT is performed. The OFDM symbol is transmitted to a receiving device through each transmitting antenna through digital-to-analog conversion, frequency uplink conversion, etc. The signal generator can include an IFFT module, a CP inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0466] Fig. 19 illustrates another example of the signal processing module structure within a transmission device. Here, signal processing may be performed in a processor of a terminal / base station, such as the processor (102, 202) of Fig. 16.

[0467] Referring to FIG. 19, a transmission device (e.g., a processor, a processor and a memory, or a processor and a transceiver) in a terminal or a base station may include a scrambler (401), a modulator (402), a layer mapper (403), a precoder (404), a resource block mapper (405), and a signal generator (406).

[0468] The transmitting device can transmit coded bits within a codeword through a physical channel after scrambling the coded bits within the codeword by a scrambler (401).

[0469] The scrambled bits are modulated into complex modulation symbols by a modulator (402). The modulator can modulate the scrambled bits according to a predetermined modulation scheme and arrange them into complex modulation symbols representing positions on a signal constellation. There is no limitation on the modulation scheme, and pi / 2-BPSK (pi / 2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying), or m-QAM (m-Quadrature Amplitude Modulation) can be used to modulate the encoded data.

[0470] The above complex modulation symbol can be mapped to one or more transmission layers by the layer mapper (403).

[0471] The complex modulation symbols on each layer can be precoded by the precoder (404) for transmission on the antenna ports. Here, the precoder may perform precoding after performing transform precoding on the complex modulation symbols. Alternatively, the precoder may perform precoding without performing transform precoding. The precoder (404) may process the complex modulation symbols in a MIMO manner according to multiple transmission antennas to output antenna-specific symbols and distribute the antenna-specific symbols to the corresponding resource block mapper (405). The output z of the precoder (404) can be obtained by multiplying the output y of the layer mapper (403) by the precoding matrix W of NХM. Here, N is the number of antenna ports and M is the number of layers.

[0472] The resource block mapper (405) maps the demodulation modulation symbol for each antenna port to the appropriate resource element within the virtual resource block allocated for transmission.

[0473] The resource block mapper (405) can assign complex modulation symbols to appropriate subcarriers and multiplex them according to the user.

[0474] The signal generator (406) can generate a complex-valued time domain OFDM (Orthogonal Frequency Division Multiplexing) symbol signal by modulating a complex modulation symbol with a specific modulation method, for example, OFDM. The signal generator (406) can perform an Inverse Fast Fourier Transform (IFFT) on an antenna-specific symbol, and a Cyclic Prefix (CP) can be inserted into the time domain symbol on which the IFFT has been performed. The OFDM symbol is transmitted to a receiving device through each transmitting antenna after going through digital-to-analog conversion, frequency upconversion, etc. The signal generator (406) can include an IFFT module, a CP inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0475] The signal processing process of the receiving device may be configured in reverse order of the signal processing process of the transmitter. Specifically, the processor of the receiving device performs decoding and demodulation on a wireless signal received externally through the antenna port(s) of the transceiver. The receiving device may include a plurality of multiple receiving antennas, and each signal received through the receiving antenna is restored to a baseband signal and then multiplexed and MIMO demodulated to be restored to a data sequence originally intended to be transmitted by the transmitting device. The receiving device (1820) may include a signal restorer for restoring the received signal to a baseband signal, a multiplexer for combining and multiplexing the received and processed signals, and a channel demodulator for demodulating the multiplexed signal sequence into a corresponding codeword. The signal restorer, the multiplexer, and the channel demodulator may be configured as an integrated module performing their functions or as individual modules. More specifically, the signal restorer may include an analog-to-digital converter (ADC) that converts an analog signal into a digital signal, a CP remover that removes a CP from the digital signal, an FFT module that applies an FFT (fast Fourier transform) to a signal from which the CP has been removed to output a frequency domain symbol, and a resource element demapper / equalizer that restores the frequency domain symbol to an antenna-specific symbol. The antenna-specific symbol is restored to a transmission layer by a multiplexer, and the transmission layer is restored to a codeword that the transmitter intended to transmit by a channel demodulator.

[0476] FIG. 20 illustrates an example of a wireless communication device according to an implementation example of the present disclosure.

[0477] Referring to FIG. 20, a wireless communication device, for example, a terminal, may include at least one of a processor (2310) such as a digital signal processor (DSP) or a microprocessor, a transceiver (2335), a power management module (2305), an antenna (2340), a battery (2355), a display (2315), a keypad (2320), a global positioning system (GPS) chip (2360), a sensor (2365), a memory (2330), a subscriber identification module (SIM) card (2325), a speaker (2345), and a microphone (2350). There may be a plurality of antennas and processors.

[0478] The processor (2310) can implement the functions, procedures, and methods described in this specification. The processor (2310) of FIG. 20 may be the processor (102, 202) of FIG. 16.

[0479] Memory (2330) is connected to the processor (2310) and stores information related to the processor's operation. The memory may be located internally or externally to the processor and may be connected to the processor via various technologies, such as wired or wireless connections. The memory (2330) of FIG. 20 may be the memory (104, 204) of FIG. 16.

[0480] A user may input various types of information, such as a phone number, using various techniques, such as pressing buttons on a keypad (2320) or activating sound using a microphone (2350). The processor (2310) may receive and process the user's information and perform an appropriate function, such as dialing the entered phone number. In some scenarios, data may be retrieved from a SIM card (2325) or memory (2330) to perform the appropriate function. In some scenarios, the processor (2310) may display various types of information and data on a display (2315) for the user's convenience.

[0481] A transceiver (2335) is coupled to a processor (2310) and transmits and / or receives wireless signals, such as radio frequency (RF) signals. The processor may control the transceiver to initiate communication or transmit wireless signals containing various types of information or data, such as voice communication data. The transceiver includes a transmitter and a receiver for transmitting and receiving wireless signals. An antenna (2340) may facilitate the transmission and reception of wireless signals. In some implementations, upon receiving a wireless signal, the transceiver may forward and convert the signal to a baseband frequency for processing by the processor. The processed signal may be processed by various techniques, such as being converted into audible or readable information for output through a speaker (2345). The transceiver of FIG. 20 may be the transceiver (106, 206) of FIG. 16.

[0482] Although not shown in FIG. 20, various components, such as a camera and a Universal Serial Bus (USB) port, may be additionally included in the terminal. For example, the camera may be connected to the processor (2310).

[0483] Fig. 20 is only one implementation example for a terminal, and the implementation examples are not limited thereto. The terminal does not necessarily have to include all the elements of Fig. 20. For example, some components, such as a keypad (2320), a Global Positioning System (GPS) chip (2360), a sensor (2365), and a SIM card (2325), may not be essential elements, and in such cases, may not be included in the terminal.

[0484] Fig. 21 illustrates a communication system (1) applied to this specification.

[0485] Referring to FIG. 21, a communication system (1) applied to the present specification includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0486] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0487] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or, D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present specification.

[0488] Meanwhile, NR supports multiple numerologies (or subcarrier spacing (SCS)) to support various 5G services. For example, an SCS of 15 kHz supports a wide area in traditional cellular bands; an SCS of 30 kHz / 60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth; and an SCS of 60 kHz or higher supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0489] The NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges can be changed, and for example, the frequency ranges of the two types (FR1, FR2) can be as shown in Table 12 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0490] [Table 12]

[0491]

[0492] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 13 below. For example, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicular communications (e.g., autonomous driving).

[0493] [Table 13]

[0494]

[0495] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

1. In the method, The user equipment (UE) transmits a specific CSI report among multiple CSI reports to the base station based on the priority related to the CSI (channel state information) report. The terminal receives an LTM (L1 / L2 triggered mobility) cell switch command from the base station through MAC CE, and The above terminal performs a handover procedure for the target cell based on the MAC CE. A method characterized in that among the parameters determining the above priority, a parameter related to the type of measurement resource that the terminal must measure is included.

2. A method characterized in that, in the first paragraph, when a collision occurs between a first CSI report in which the measurement resource to be measured by the terminal is a SSB (Synchronization Signal Block) and a second CSI report in which the measurement resource to be measured by the terminal is a CSI-RS (channel state information reference signal), the first CSI report is transmitted with priority.

3. A method characterized in that, in the first paragraph, when a collision occurs between a first CSI report in which the measurement resource to be measured by the terminal is a SSB (Synchronization Signal Block) and a second CSI report in which the measurement resource to be measured by the terminal is a CSI-RS (channel state information reference signal), the second CSI report is transmitted with priority.

4. A method characterized in that, in the first paragraph, when a conflict occurs between the first CSI report indicated by the base station and the second CSI report triggered by an event of the terminal, the first report is transmitted with priority.

5. A method characterized in that, in the first paragraph, when a conflict occurs between the first CSI report indicated by the base station and the second CSI report triggered by an event of the terminal, the second report is transmitted with priority.

6. A method characterized in that, in the first paragraph, when a conflict occurs between the first CSI report for CSI acquisition for the target cell and the second CSI report for CSI reporting for LTM, the second CSI report is transmitted with priority.

7. A method according to claim 1, characterized in that the terminal receives LTM candidate settings for LTM candidate cells from the base station.

8. A method according to claim 7, characterized in that the LTM cell switch command includes target setting ID (identifier) ​​information related to the index of the candidate setting of the target cell.

9. The terminal (user equipment: UE) is At least one transceiver; At least one memory; and At least one processor operably coupled with said at least one memory and said at least one transceiver, wherein said at least one memory comprises instructions that are executed by said at least one processor to perform operations, The above actions are, Based on the priority related to the CSI (channel state information) report, a specific CSI report among multiple CSI reports is transmitted to the base station, Receives an LTM (L1 / L2 triggered mobility) cell switch command from the base station via MAC CE, and Perform a handover procedure for the target cell based on the above MAC CE, A terminal characterized in that among the parameters determining the above priority, a parameter related to the type of measurement resource that the terminal must measure is included.

10. In the 9th paragraph, when a collision occurs between a first CSI report in which the measurement resource to be measured by the terminal is a SSB (Synchronization Signal Block) and a second CSI report in which the measurement resource to be measured by the terminal is a CSI-RS (channel state information reference signal), the terminal is characterized in that the first CSI report is transmitted with priority.

11. In the 9th paragraph, when a collision occurs between a first CSI report in which the measurement resource to be measured by the terminal is a SSB (Synchronization Signal Block) and a second CSI report in which the measurement resource to be measured by the terminal is a CSI-RS (channel state information reference signal), the terminal is characterized in that the second CSI report is transmitted with priority.

12. A terminal characterized in that, in the 9th paragraph, when a conflict occurs between the first CSI report indicated by the base station and the second CSI report triggered by an event of the terminal, the first report is transmitted with priority.

13. A terminal characterized in that, in the 9th paragraph, when a conflict occurs between the first CSI report indicated by the base station and the second CSI report triggered by an event of the terminal, the second report is transmitted with priority.

14. A terminal characterized in that, in the 9th paragraph, when a conflict occurs between the first CSI report for CSI acquisition for the target cell and the second CSI report for CSI report for LTM, the second CSI report is transmitted with priority.

15. A terminal according to claim 9, characterized in that the terminal receives LTM candidate settings for LTM candidate cells from the base station.

16. A terminal according to claim 15, wherein the LTM cell switch command includes target setting ID (identifier) ​​information related to an index of a candidate setting of the target cell.

17. The device, At least one memory; and At least one processor operably coupled to at least one memory, wherein said at least one memory comprises instructions that are executed by said at least one processor to perform operations, The above actions are, Based on the priority related to the CSI (channel state information) report, a specific CSI report among multiple CSI reports is transmitted to the base station, Receives an LTM (L1 / L2 triggered mobility) cell switch command from the base station via MAC CE, and Perform a handover procedure for the target cell based on the above MAC CE, A device characterized in that among the parameters determining the above priority, a parameter related to the type of measurement resource that the terminal must measure is included.

18. At least one computer readable medium (CRM) containing instructions based on being executed by at least one processor, An operation of transmitting a specific CSI report among multiple CSI reports to a base station based on a priority related to the CSI (channel state information) report. An operation of receiving an LTM (L1 / L2 triggered mobility) cell switch command from the base station via MAC CE, and An operation is performed to perform a handover procedure for a target cell based on the above MAC CE, A CRM characterized in that among the parameters determining the above priorities, a parameter related to the type of measurement resource that the terminal must measure is included.

19. In the method, The base station receives a specific CSI report among multiple CSI reports based on the priority related to the CSI (channel state information) report from the user equipment (UE). The base station transmits an LTM (L1 / L2 triggered mobility) cell switch command to the terminal through MAC CE, and The base station performs a handover procedure for the terminal and the target cell based on the MAC CE. A method characterized in that among the parameters determining the above priority, a parameter related to the type of measurement resource that the terminal must measure is included.

20. The base station, At least one transceiver; At least one memory; and At least one processor operably coupled with said at least one memory and said at least one transceiver, wherein said at least one memory comprises instructions that are executed by said at least one processor to perform operations, The above actions are, Receives a specific CSI report among multiple CSI reports based on a priority related to a CSI (channel state information) report from a user equipment (UE), Transmitting an LTM (L1 / L2 triggered mobility) cell switch command to the above terminal through MAC CE, and Perform a handover procedure for the terminal and the target cell based on the above MAC CE, A base station characterized in that among the parameters determining the above priority, a parameter related to the type of measurement resource that the terminal must measure is included.

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