Method and apparatus for beam quality reporting in communication system

Abstract

Disclosed are a method and an apparatus for beam quality reporting in a communication system. The method for a terminal comprises the steps of: receiving configuration information of a periodic downlink resource from a base station; performing a beam measurement operation for a first signal received in the periodic downlink resource; on the basis of the result of the beam measurement operation, determining that an event has occurred; if the event has occurred, generating beam reporting information; and performing a reporting operation on the beam reporting information on the basis of the event.

Description

Method and device for beam quality reporting in a communication system

[0001] The present disclosure relates to a beam quality reporting technique, and more particularly, to a beam quality reporting technique initiated by a terminal.

[0002] The development of next-generation communication systems (e.g., new radio (NR) communication systems, sixth generation (6G) communication systems, etc.) is becoming increasingly important as the infrastructure for the proliferation of various future convergence services. Next-generation communication systems can support not only conventional mobile communication frequency bands, but also millimeter wave bands, terahertz bands, and upper-mid bands. Next-generation communication systems can support a wider range of performance indicators and scenarios than conventional communication systems (e.g., long term evolution (LTE) communication systems). In high-frequency band communications, technology for stably managing terminal beams is required to support beamforming-based transmission, and ongoing research is needed to optimize the overhead required for beam management and beam switching delay time.

[0003] Beam reporting operations may be necessary in communication systems. Conventional beam reporting operations can be triggered by the base station. In this case, the signaling overhead for beam reporting operations can be significant, and the delay required for beam switching can also be long. Consequently, resource efficiency and / or link stability may be low in communication systems. To address the aforementioned issues, an improved beam reporting operation is needed.

[0004] The purpose of the present disclosure to solve the above problems is to provide a method and device for beam quality reporting initiated by a terminal in a communication system.

[0005] According to embodiments of the present disclosure for achieving the above object, a method of a terminal includes the steps of: receiving configuration information of a periodic downlink resource from a base station; performing a beam measurement operation on a first signal received from the periodic downlink resource; determining that an event has occurred based on a result of the beam measurement operation; generating beam report information when the event has occurred; and performing a reporting operation on the beam report information based on the event, wherein the beam measurement operation includes an operation of deriving a beam quality value of the first signal N times, and the beam report information includes at least an index of the periodic downlink resource.

[0006] The step of determining that the above event has occurred may include the step of comparing the beam quality values ​​derived N times with a reference value; and the step of determining that the event has occurred based on the comparison result between the beam quality values ​​derived N times and the reference value.

[0007] The above periodic downlink resource may correspond to a first TCI belonging to a TCI list set in the terminal, and the first TCI may be an activated TCI.

[0008] The above beam quality value may be RSRP, and the reference value may be a beam quality value of a periodic downlink resource corresponding to the current beam of the terminal.

[0009] The reference value may not change during the section in which the above beam measurement operation is performed.

[0010] The first signal may be received within a preset time interval, and the preset time interval may include one or more periods for the periodic downlink resource.

[0011] The above reporting operation may be an operation that notifies the base station that “the terminal transmits SR in the first uplink resource and transmits PUSCH in the second uplink resource.”

[0012] The above PUSCH may include the beam report information.

[0013] The second uplink resource may be interrelated with the first uplink resource, and the period of the second uplink resource may coincide with the period of the first uplink resource.

[0014] According to embodiments of the present disclosure for achieving the above object, a method of a base station includes the steps of: transmitting configuration information of periodic downlink resources to a terminal; transmitting a first signal for a beam measurement operation of the terminal to the terminal through the periodic downlink resources; and, when an event occurs based on a result of the beam measurement operation, receiving a report on beam report information from the terminal, wherein the beam measurement operation includes an operation of deriving a beam quality value of the first signal N times, and the beam report information includes at least an index of the periodic downlink resources.

[0015] The above periodic downlink resource may correspond to a first TCI belonging to a TCI list set in the terminal, and the first TCI may be an activated TCI.

[0016] The first signal may be transmitted within a preset time interval, and the preset time interval may include one or more periods for the periodic downlink resource.

[0017] The above report may include information informing the base station that “the terminal transmits SR on the first uplink resource and transmits PUSCH on the second uplink resource.”

[0018] The above PUSCH may include the beam report information.

[0019] The second uplink resource may be interrelated with the first uplink resource, and the period of the second uplink resource may coincide with the period of the first uplink resource.

[0020] According to embodiments of the present disclosure for achieving the above object, a terminal includes at least one processor, wherein the at least one processor causes the terminal to receive configuration information of a periodic downlink resource from a base station; perform a beam measurement operation on a first signal received from the periodic downlink resource; determine that an event has occurred based on a result of the beam measurement operation; generate beam report information when the event has occurred; and perform a reporting operation on the beam report information based on the event, wherein the beam measurement operation includes an operation of deriving a beam quality value of the first signal N times, and the beam report information includes at least an index of the periodic downlink resource.

[0021] When it is determined that the above event has occurred, the at least one processor may cause the terminal to compare the beam quality values ​​derived N times with a reference value; and determine that the event has occurred based on the comparison result between the beam quality values ​​derived N times and the reference value.

[0022] The above periodic downlink resource may correspond to a first TCI belonging to a TCI list set in the terminal, and the first TCI may be an activated TCI.

[0023] The above reporting operation may be an operation that notifies the base station that “the terminal transmits SR in the first uplink resource and transmits PUSCH in the second uplink resource.”

[0024] The PUSCH may include the beam reporting information, the second uplink resource may be interrelated with the first uplink resource, and the period of the second uplink resource may coincide with the period of the first uplink resource.

[0025] According to the present disclosure, a terminal can perform a beam measurement operation on a signal received from a base station, and transmit beam report information to the base station based on the result of the beam measurement operation. The terminal can transmit the beam report information to the base station when an event occurs without triggering the base station. Since the beam report information transmission operation is performed without triggering the base station, the signaling overhead for the beam report operation can be reduced, and the delay time required for beam switching can be reduced. In addition, resource efficiency and / or link stability can be improved in a communication system.

[0026] Figure 1 is a conceptual diagram illustrating embodiments of a communication system.

[0027] Figure 2 is a block diagram illustrating embodiments of the device.

[0028] Figure 3 is a conceptual diagram illustrating a first embodiment of a TCI instruction method by DCI.

[0029] FIG. 4 is a conceptual diagram illustrating a first embodiment of a method for setting a candidate beam set for downlink TCI.

[0030] FIG. 5 is a conceptual diagram illustrating a first embodiment of a method for setting a candidate beam set for uplink TCI.

[0031] FIG. 6 is a conceptual diagram illustrating a second embodiment of a method for setting a candidate beam set for downlink TCI.

[0032] FIG. 7 is a conceptual diagram illustrating a second embodiment of a method for setting a candidate beam set for uplink TCI.

[0033] Figure 8 is a conceptual diagram illustrating a first embodiment of a beam reporting method by (method 300).

[0034] Figure 9 is a conceptual diagram illustrating a first embodiment of a beam reporting method by (method 310).

[0035] FIG. 10 is a conceptual diagram illustrating a first embodiment of a beam reporting method based on repeated PUCCH resources.

[0036] FIG. 11 is a conceptual diagram illustrating a second embodiment of a beam reporting method based on repeated PUCCH resources.

[0037] FIG. 12 is a conceptual diagram illustrating a third embodiment of a beam reporting method based on repeated PUCCH resources.

[0038] Figure 13 is a conceptual diagram illustrating a first embodiment of a beam switching method without intervention of a base station.

[0039] Fig. 14 is a conceptual diagram illustrating a first embodiment of a beam switching method by intervention of a base station.

[0040] This disclosure may be subject to various modifications and various embodiments. Specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the disclosure.

[0041] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component." The term "and / or" encompasses any combination of multiple related items or any one of multiple related items.

[0042] In embodiments of the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Furthermore, in embodiments of the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.”

[0043] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0044] The terminology used in this disclosure is only used to describe specific embodiments and is not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0045] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0046] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding in describing the present disclosure, identical reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted.

[0047] A communication system to which embodiments according to the present disclosure are applied will be described. The communication system may be a 4G communication system (e.g., a long-term evolution (LTE) communication system, LTE-A communication system), a 5G communication system (e.g., a new radio (NR) communication system), a 6G communication system, etc. The 4G communication system can support communication in a frequency band below 6 GHz, and the 5G communication system can support communication in a frequency band above 6 GHz as well as a frequency band below 6 GHz. The communication system to which embodiments according to the present disclosure are applied is not limited to the contents described below, and the embodiments according to the present disclosure can be applied to various communication systems. Here, the communication system may be used with the same meaning as a communication network, and “LTE” may indicate a “4G communication system,” an “LTE communication system,” or an “LTE-A communication system,” and “NR” may indicate a “5G communication system” or an “NR communication system.”

[0048] In an embodiment, “an operation (e.g., a transmission operation) is set to a communication node” may mean that “setting information for the operation (e.g., an information element, a parameter)” and / or “information instructing performance of the operation” are signaled to the communication node. In other words, “an operation (e.g., a transmission operation) is set to a communication node” may mean that the communication node receives “setting information for the operation (e.g., an information element, a parameter)” and / or “information instructing performance of the operation.” “An information element (e.g., a parameter) is set to a communication node” may mean “the information element is signaled to the communication node (e.g., the communication node receives the information element).” The signaling may be at least one of SI (system information) signaling (e.g., transmission of a system information block (SIB) and / or a master information block (MIB)), RRC signaling (e.g., transmission of RRC parameters and / or upper layer parameters), MAC CE (control element) signaling, or PHY signaling (e.g., transmission of DCI (downlink control information), UCI (uplink control information), and / or SCI (sidelink control information)).

[0049] In this disclosure, "time" may refer to a time point, and "time point" may refer to time. "Time" and "point point" may be used interchangeably. The reception time of a signal or channel may refer to the start time of reception or the end time of reception. The transmission time of a signal or channel may refer to the start time of transmission or the end time of transmission.

[0050] Figure 1 is a conceptual diagram illustrating embodiments of a communication system.

[0051] Referring to FIG. 1, the communication system (100) may include a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). In addition, the communication system (100) may further include a core network (e.g., a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), a mobility management entity (MME)). If the communication system (100) is a 5G communication system (e.g., a new radio (NR) system), the core network may include an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc.

[0052] A plurality of communication nodes (110 to 130) can support a communication protocol specified in the 3rd generation partnership project (3GPP) standard (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.). The plurality of communication nodes (110 to 130) may support CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (non-orthogonal multiple access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (space division multiple access) technology, etc. Each of the plurality of communication nodes may mean an apparatus or a device. The embodiments may be performed by a device or apparatus. The structure of the apparatus (e.g., device) may be as follows.

[0053] Figure 2 is a block diagram illustrating embodiments of the device.

[0054] Referring to FIG. 2, the device (200) may include at least one processor (210), a memory (220), and a transmission / reception device (230) that is connected to a network and performs communication. In addition, the device (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the device (200) may be connected by a bus (270) and communicate with each other.

[0055] The processor (210) can execute program commands stored in at least one of the memory (220) and the storage device (260). The processor (210) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which the methods according to embodiments of the present disclosure are performed. Each of the memory (220) and the storage device (260) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0056] Referring again to FIG. 1, the communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) may form a macro cell. Each of the fourth base station (120-1) and the fifth base station (120-2) may form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) may be within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) may be within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be within the cell coverage of the third base station (110-3). The first terminal (130-1) may be within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be within the cell coverage of the fifth base station (120-2).

[0057] Here, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as a NodeB (NB), an evolved NodeB (eNB), a gNB, an advanced base station (ABS), a high reliability-base station (HR-BS), a base transceiver station (BTS), a radio base station, a radio transceiver, an access point, an access node, a radio access station (RAS), a mobile multihop relay-base station (MMR-BS), a relay station (RS), an advanced relay station (ARS), a high reliability-relay station (HR-RS), a home NodeB (HNB), a home eNodeB (HeNB), a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), etc.

[0058] Each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), high reliability-mobile station (HR-MS), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, on board unit (OBU), etc.

[0059] Meanwhile, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in a different frequency band or may operate in the same frequency band. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to each other via an ideal backhaul link or a non-ideal backhaul link, and may exchange information with each other via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to the core network via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0060] Additionally, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may support MIMO transmission (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, device to device communication (D2D) (or, proximity services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can perform an operation corresponding to the base station (110-1, 110-2, 110-3, 120-1, 120-2) and an operation supported by the base station (110-1, 110-2, 110-3, 120-1, 120-2). For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO scheme, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) by the SU-MIMO scheme. Alternatively, the second base station (110-2) can transmit signals to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO method, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive signals from the second base station (110-2) based on the MU-MIMO method.

[0061] Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can transmit a signal to the fourth terminal (130-4) based on the CoMP scheme, and the fourth terminal (130-4) can receive a signal from the first base station (110-1), the second base station (110-2), and the third base station (110-3) based on the CoMP scheme. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive a signal with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its cell coverage based on the CA scheme. Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can control D2D between the fourth terminal (130-4) and the fifth terminal (130-5), and each of the fourth terminal (130-4) and the fifth terminal (130-5) can perform D2D under the control of the second base station (110-2) and the third base station (110-3).

[0062] The present disclosure may relate to a technology for transmitting and receiving signals in a communication system. More specifically, the present disclosure relates to a technology and device for performing signal transmission and beam management based on multiple transmission points in a communication system. The embodiments described below may be applied to a NR communication system, and may also be applied to other communication systems (e.g., an LTE communication system, a 5G (fifth generation) communication system, a 6G (sixth generation) communication system, etc.) in addition to the NR communication system.

[0063] In a communication system (e.g., NR communication system, 6G communication system), the numerology applied to the physical signal and channel can be variable. The numerology can be variable to meet various technical requirements of the communication system. In a communication system to which CP (cyclic prefix)-based OFDM waveform technology is applied, the numerology can include subcarrier spacing and CP length (or CP type). Table 1 may be a first embodiment of a numerology configuration for a CP-OFDM-based communication system. Adjacent subcarrier spacings can have a relationship of exponentiation of 2 with each other, and the CP length can be scaled at the same rate as the OFDM symbol length. At least some of the numerologies in Table 1 may be supported depending on the frequency band in which the communication system operates. In addition, the communication system may additionally support numerologies not listed in Table 1. Additional CP types (e.g., extended CP) not listed in Table 1 may be supported for specific subcarrier spacing (e.g., 60 kHz).

[0064]

[0065] Below, the frame structure of a communication system will be described. In the time domain, elements (e.g., resource elements) that constitute the frame structure may include subframes, slots, mini-slots, and symbols. A subframe may be used as a unit for transmission, measurement, etc., and the length of a subframe may have a fixed value (e.g., 1 ms) regardless of the subcarrier spacing. A slot may include consecutive symbols (e.g., 14 OFDM symbols). The length of a slot may be variable, unlike the length of a subframe. For example, the length of a slot may be inversely proportional to the subcarrier spacing.

[0066] A slot can be used as a unit for transmission, measurement, scheduling, resource configuration, timing (e.g., scheduling timing, hybrid automatic repeat request (HARQ) timing, channel state information (CSI) measurement and reporting timing, etc.). The length of the actual time resource used for transmission, measurement, scheduling, resource configuration, etc. may or may not match the length of the slot. A minislot can include consecutive symbol(s), and the length of a minislot can be shorter than the length of a slot. A minislot can be used as a unit for transmission, measurement, scheduling, resource configuration, timing, etc. A minislot (e.g., minislot length, minislot boundary, etc.) can be predefined in a technical specification. Alternatively, a minislot (e.g., minislot length, minislot boundary, etc.) can be configured (or instructed) to a terminal. It can be configured (or instructed) to a terminal that a minislot is used when a specific condition is satisfied.

[0067] A base station can schedule a data channel (e.g., a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), a physical sidelink shared channel (PSSCH)) using some or all of the symbols constituting a slot. In particular, a data channel can be transmitted using a part of a slot for Ultra Reliable Low Latency Communication (URLLC) transmission, unlicensed band transmission, transmission in a situation where NR communication systems and LTE communication systems coexist, analog beamforming-based multi-user scheduling, etc. In addition, the base station can schedule a data channel using a plurality of slots. In addition, the base station can schedule a data channel using at least one mini-slot.

[0068] In the frequency domain, elements that constitute a frame structure may include resource blocks (RBs), subcarriers, etc. One RB may include consecutive subcarriers (e.g., 12 subcarriers). The number of subcarriers constituting one RB may be constant regardless of the numerology. In this case, the bandwidth occupied by one RB may be proportional to the subcarrier spacing of the numerology. An RB may be used as a transmission and resource allocation unit for data channels, control channels, etc. Resource allocation for a data channel may be performed in units of RBs or RB groups (e.g., resource block groups (RBGs)). One RBG may include one or more consecutive RBs. Resource allocation for a control channel may be performed in units of control channel elements (CCEs). In the frequency domain, one CCE may include one or more RBs.

[0069] In a communication system (e.g., an NR communication system), the unit time resource (hereinafter referred to as a "slot") described above may be composed of a combination of one or more of a downlink (DL) interval, a flexible interval (or an unknown interval), and an uplink (UL) interval. Each of the downlink interval, the flexible interval, and the uplink interval may be composed of one or more consecutive symbols. The flexible interval may be located between a downlink interval and an uplink interval, between a first downlink interval and a second downlink interval, between a first uplink interval and a second uplink interval, etc. When a flexible interval is inserted between a downlink interval and an uplink interval, the flexible interval may be used as a guard interval.

[0070] A slot may include one or more flexible periods. Alternatively, a slot may not include a flexible period. A terminal may perform a predefined operation in a flexible period. Alternatively, the terminal may perform an operation that is semi-statically or periodically configured by a base station in the flexible period. For example, an operation that is periodically configured by a base station may include a physical downlink control channel (PDCCH) monitoring operation, a synchronization signal block (SSB) reception and measurement operation, a CSI-RS (reference signal) reception and measurement operation, a downlink SPS (semi-persistent scheduling) PDSCH reception operation, a sounding reference signal (SRS) transmission operation, a physical random access channel (PRACH) transmission operation, a periodically configured PUCCH transmission operation, a PUSCH transmission operation according to a configured grant (CG), etc. A flexible symbol may be overridden by a downlink symbol or an uplink symbol. When a flexible symbol is overridden by a downlink or uplink symbol, the terminal may perform a new operation instead of the existing operation on the flexible symbol (e.g., the overridden flexible symbol).

[0071] In the present disclosure, SSB may refer to a set of signals including a synchronization signal and / or a broadcast channel. The synchronization signal may include PSS, SSS, etc., and the broadcast channel may include a physical broadcast channel (PBCH). The SSB may further include a reference signal. The reference signal (e.g., a reference signal included in the SSB) may refer to a demodulation reference signal (DM-RS), a CSI-RS, a tracking reference signal (TRS), a positioning reference signal (PRS), a phase tracking reference signal (PT-RS), etc. for decoding the PBCH. In an NR communication system, the SSB may refer to a synchronization signal / physical broadcast channel (SS / PBCH) block. The SSB may be transmitted periodically, and one or more SSB(s) may be repeatedly transmitted in one period.

[0072] The format of a unit time resource (hereinafter referred to as "slot format") can be semi-statically set by higher layer signaling (e.g., radio resource control (RRC) signaling). Information indicating a semi-static slot format can be included in system information, and the semi-static slot format can be set cell-specifically. In addition, the semi-static slot format can be additionally set for each terminal through terminal-specific higher layer signaling (e.g., RRC signaling). The flexible symbol of the cell-specifically set slot format can be overridden with a downlink symbol or an uplink symbol by terminal-specific higher layer signaling. In addition, the slot format can be dynamically indicated by physical layer signaling (e.g., a slot format indicator (SFI) included in downlink control information (DCI)). The semi-statically set slot format can be overridden by a dynamically indicated slot format. For example, a flexible symbol that is set to semi-static can be overridden by SFI as a downlink symbol or an uplink symbol.

[0073] A terminal can perform downlink operations, uplink operations, sidelink operations, etc. in a bandwidth part. A bandwidth part can be defined as a set of consecutive RBs (e.g., physical resource blocks (PRBs)) in a frequency domain having a specific numerology. One numerology can be used for signal transmission (e.g., transmission of a control channel or a data channel) in one bandwidth part. In the present disclosure, "signal" may mean any physical signal and channel when used in a broad sense. A terminal performing an initial access procedure can obtain configuration information of an initial bandwidth part from a base station through system information. A terminal operating in an RRC connected state can obtain configuration information of a bandwidth part from a base station through terminal-specific upper layer signaling.

[0074] The configuration information of the bandwidth portion may include information about the numerology and / or RB set applied to the bandwidth portion. At least one of the bandwidth portion(s) configured for the terminal may be activated. For example, one uplink bandwidth portion and one downlink bandwidth portion may each be activated within one carrier. In a time division duplex (TDD)-based communication system, a pair of uplink bandwidth portions and downlink bandwidth portions may be activated. The base station may configure multiple bandwidth portions for the terminal within one carrier and switch the active bandwidth portion of the terminal.

[0075] In embodiments, "a frequency band (e.g., a carrier, a bandwidth portion, a set of RBs, a listen before talk (LBT) subband, a guard band, etc.) is activated" may mean "a base station or a terminal is in a state where it can transmit and receive signals using the frequency band." In addition, "a frequency band is activated" may mean "a state where an RF (radio frequency) filter (e.g., a band-pass filter) of a transceiver is operating including the frequency band."

[0076] In embodiments, RB may mean CRB (common RB). Alternatively, RB may mean PRB or VRB (virtual RB). In a communication system (e.g., NR communication system), CRB may mean RB that constitutes a set of consecutive RBs (e.g., common RB grid) based on a reference frequency (e.g., point A). Carriers, bandwidth portions, etc. may be arranged on the common RB grid. In other words, carriers, bandwidth portions, etc. may be configured as CRB(s). RBs or CRBs that constitute bandwidth portions may be referred to as PRBs, and within bandwidth portions, CRB indices may be appropriately converted to PRB indices. In embodiments, RB may mean IRB (interlace RB).

[0077] The PDCCH can be used to transmit DCI or DCI formats to a terminal. The minimum resource unit constituting the PDCCH can be a resource element group (REG). For example, an REG can be composed of one RB in the frequency domain and one OFDM symbol in the time domain. DM-RS for decoding the PDCCH can be mapped to some of the REs constituting the REG, and control information (e.g., modulated DCI) can be mapped to the remaining REs. A PDCCH candidate can be composed of one CCE or aggregated CCEs. A CCE can be composed of multiple REGs. In an NR communication system, CCE aggregation levels 1, 2, 4, 8, and 16 can be supported, and a CCE can be composed of six REGs.

[0078] A CORESET (control resource set) may be a resource region in which a terminal performs blind decoding of a PDCCH. A CORESET may be composed of multiple REGs. A CORESET may be composed of one or more RBs in the frequency domain and one or more symbols (e.g., OFDM symbols) in the time domain. The symbols constituting a CORESET may be consecutive in the time domain. The RBs constituting a CORESET may be consecutive or non-contiguous in the frequency domain. One DCI (e.g., one DCI format, one PDCCH) may be transmitted within a CORESET. Multiple CORESETs may be configured from a cell perspective or a terminal perspective, and the time-frequency resource regions to which the multiple CORESETs are mapped may or may not overlap with each other.

[0079] A CORESET may be set in a terminal during the initial access procedure. For example, a CORESET may be set in a terminal by an initial access signal (e.g., PBCH or system information transmitted via PBCH). The ID (identifier) ​​of the CORESET set by the initial access signal may be 0. The CORESET set by the initial access signal may be referred to as CORESET 0. A terminal operating in an RRC idle state may perform a monitoring operation in CORESET 0 to receive the first PDCCH in the initial access procedure. Not only a terminal operating in an RRC idle state but also a terminal operating in an RRC connected state may perform a monitoring operation in CORESET 0. In addition to system information transmitted via an initial access signal (e.g., PBCH), a CORESET may be set in a terminal by other system information (e.g., SIB1 (system information block type 1)). For example, a terminal may receive SIB1 containing configuration information of CORESET for receiving a random access response (e.g., Msg2). CORESET may be configured in the terminal by terminal-specific higher layer signaling (e.g., RRC signaling).

[0080] A search space may refer to a set of candidate resource regions where PDCCHs can be transmitted. The UE may perform blind decoding on each PDCCH candidate within a predefined search space or a search space established by the base station. The UE may determine whether the PDCCH has been transmitted to itself by performing a cyclic redundancy check (CRC) on the blind decoding results. If the PDCCH is determined to be intended for the UE, the UE may receive the PDCCH.

[0081] One or more search spaces may constitute a search space set. The search spaces may be defined / configured for each CCE aggregation level, and the search space set may refer to a search space for each CCE aggregation level or a sum of search spaces for all CCE aggregation levels. For each CCE aggregation level, the PDCCH candidate may be composed of CCE(s) selected by a predefined hash function within a CORESET or a search space occasion. In an embodiment, the "search space set" may refer to a "search space."

[0082] A search space set can be logically associated (e.g., combined) with one CORESET. One CORESET can be logically associated with one or more search space sets. A common search space set configured via PBCH can be used to monitor a DCI scheduling a PDSCH for transmitting SIB1. The ID of the common search space set configured via PBCH can be set to 0. In other words, the common search space set configured via PBCH can be defined as a type 0 PDCCH common search space set or search space set #0. Search space set #0 can be logically associated with CORESET 0.

[0083] The search space set can be divided into a common search space set and a UE-specific search space set depending on the purpose or terminal operation. In the common search space set, common DCI or UE-specific DCI (e.g., UE-specific DCI) can be transmitted, and in the UE-specific search space set (e.g., UE-specific search space set), UE-specific DCI can be transmitted. For example, the common DCI can include resource allocation information of the PDSCH including system information, paging messages, etc., power control commands, slot format indicators (SFIs), and / or preemption indicators. The UE-specific DCI can include resource allocation information of the PDSCH and / or resource allocation information of the PUSCH. Depending on the purpose, multiple DCI formats can be defined, and the multiple DCI formats can be distinguished at the terminal by the DCI payload, DCI fields, DCI sizes, and / or radio network temporary identifiers (RNTIs).

[0084] In the present disclosure, a common search space may be referred to as a CSS (common search space), and a set of common search spaces may be referred to as a CSS set. A terminal-specific search space may be referred to as a USS (UE-specific search space), and a set of terminal-specific search spaces may be referred to as a USS set.

[0085] The terminal can assume that the PDCCH DM-RS has a QCL (quasi co-location) relationship with a certain signal (e.g., SSB, CSI-RS, PDSCH DM-RS, PDCCH DM-RS, etc.). The PDCCH DM-RS can refer to a DM-RS used for modulation and / or demodulation of the PDCCH. The PDSCH DM-RS can refer to a DM-RS used for modulation and / or demodulation of the PDSCH. Since the PDCCH has the same antenna port as the PDCCH DM-RS, the PDCCH and the PDCCH DM-RS can have a QCL relationship with each other. Through the QCL assumption, the terminal can obtain information about the large-scale propagation characteristics of the wireless channel experienced by the PDCCH and PDCCH DM-RS, and can utilize the large-scale propagation characteristics of the wireless channel for channel estimation, reception beamforming, etc. The QCL parameter may include at least one of a delay spread, a Doppler spread, a Doppler shift, an average gain, an average delay, or a spatial Rx parameter. The spatial Rx parameter may correspond to at least one characteristic of a receive beam, a receive channel spatial correlation, or a transmit / receive beam pair. The spatial Rx parameter may be referred to as "spatial QCL." The PDCCH may be used to mean including a PDCCH DM-RS. That the PDCCH has a QCL relationship with a certain signal may mean that the DM-RS of the PDCCH has a QCL relationship with the certain signal. A signal having a QCL relationship with the PDCCH or a resource of the signal may be referred to as a QCL source, a QCL source signal, a QCL source resource, etc.

[0086] PDCCHs transmitted in the same CORESET (e.g., a search space set corresponding to the same CORESET, a PDCCH monitoring occasion, etc.) may have the same QCL relationship. In other words, a unit of a set in which a UE assumes the same QCL may be a CORESET, and the QCL assumptions may be independent for each CORESET. In an embodiment, each of a QCL and a QCL source of a CORESET may mean the QCL and a QCL source of a PDCCH received through the corresponding CORESET. Exceptionally, different QCL assumptions may be applied to search space sets corresponding to a single CORESET. For example, a search space set for monitoring RA (random access)-RNTI (e.g., a type 1 CSS set) and a search space set other than the search space set may have different QCL relationships.

[0087] The QCL relationship or QCL assumption (e.g., QCL source, QCL type, etc.) of a CORESET can be determined by a predefined method. For example, a UE can assume that a PDCCH DM-RS received through a certain CORESET or a certain search space set has a QCL relationship with respect to an SSB and / or CSI-RS selected during an initial access or random access procedure and a predefined QCL type. A QCL type can mean a set of one or more QCL parameters. The QCL relationship or QCL assumption (e.g., QCL source, QCL type, etc.) of a CORESET can be signaled from a base station to a UE (e.g., RRC signaling, MAC (medium access control) CE (control element) signaling, DCI signaling, a combination of the above signaling, etc.). In other words, the base station can set a transmission configuration information (TCI) state for a CORESET to the UE. In general, a TCI state may include at least one of an ID of a signal having a QCL relationship with a DM-RS of a physical channel to which the TCI is applied (e.g., a PDCCH DM-RS) (e.g., a QCL source of the PDCCH DM-RS, a QCL source resource) or a QCL type for the signal. For example, a base station may configure one or more TCI state candidates for each CORESET to a terminal via RRC signaling, and may indicate (e.g., configure) one TCI state used for CORESET monitoring of the terminal among the one or more TCI state candidates via MAC signaling (or DCI signaling). If there is only one TCI state candidate configured by RRC signaling, the MAC signaling procedure (or DCI signaling procedure) may be omitted.The terminal can perform PDCCH monitoring and reception operations for the corresponding CORESET based on TCI state setting information received from the base station.

[0088] In the present disclosure, the TCI state may be conveniently referred to as TCI. While TCI may generally refer to a broad concept including a beam or signaling information corresponding to a beam, it may be conveniently used in the present disclosure in a meaning corresponding to a beam. A downlink TCI or a TCI for receiving a downlink signal may correspond to a reception beam, and an uplink TCI or a TCI for transmitting an uplink signal may correspond to a transmission beam. A transmission beam may refer to spatial relation information, a transmission spatial filter, etc.

[0089] Meanwhile, in communication systems, beam operation in high-frequency and low-frequency bands can differ. In low-frequency bands (e.g., bands below 6 GHz), signal path loss due to the channel is relatively small, so signals can be transmitted and received using beams with wide beamwidths. Control channel transmission can cover the entire cell (or sector) with a single beam. In high-frequency bands (e.g., bands above 6 GHz) where signal path loss is high, beamforming using large antennas can be used to extend signal reach. Beamforming can be applied not only to data channels but also to common signal and control channels. A communication node (e.g., a base station) can form a beam with a narrow beamwidth through multiple antennas and transmit and receive signals multiple times using multiple beams with different directivity in different directions to cover the entire spatial area of ​​a cell (or sector). This operation of repeatedly transmitting signals using multiple beams across multiple time resources can be referred to as beam sweeping. A system that transmits signals using multiple beams with narrow beamwidths may be referred to as a multi-beam system.

[0090] A multi-beam system can operate based on beam management. A terminal can measure beam quality for a received signal (e.g., SSB, CSI-RS, etc.) and report the beam quality measurement result to a base station. For example, the terminal can calculate beam quality measurements such as reference signal received power (RSRP) (e.g., L1-RSRP) and signal-to-interference-plus-noise ratio (SINR) for each beam (e.g., each signal, each resource), and report optimal beam(s) and / or measurement value(s) corresponding to the optimal beam(s) to the base station. The terminal can report beam index(es) corresponding to the measurement value(s) to the base station. The beam index can mean information about SSB resources, CSI-RS resources, etc. (e.g., SSB resource indicator, CSI-RS resource indicator, etc.). Information on beam indexes may be included in CSI, and the CSI may be transmitted through an uplink channel such as PUCCH, PUSCH, etc. The base station may determine a transmission beam for the terminal based on beam index(es) and / or beam quality measurement information (e.g., beam quality measurement value(s)) reported from the terminal. The base station may set a TCI state for reception of physical signals and channels (e.g., PDCCH, PDSCH, CSI-RS, PUCCH, PUSCH, SRS, PRACH, etc.) of the terminal based on beam index(es) and / or beam quality measurement information (e.g., beam quality measurement value(s)) reported from the terminal.

[0091] A multi-beam can be formed by a plurality of TRPs and / or panels. In the present disclosure, TRPs and panels may be collectively referred to as TRPs. TRPs may be arranged based on different spatial locations, antenna shapes, boresights, etc. Different beams (e.g., a transmit beam, a receive beam, a transmit / receive beam pair) may be formed on each channel formed between TRPs and a terminal. A base station may perform multi-beam transmission using multiple TRPs. Transmission reliability may be improved by beam selection gain or beam diversity gain. A multi-TRP transmission scheme may be referred to as coordinated multipoint (CoMP). TRPs participating in multi-TRP transmission may belong to the same base station or the same serving cell. Alternatively, TRPs participating in multi-TRP transmission may belong to multiple base stations or multiple serving cells. Ideal backhaul and non-ideal backhaul may be considered as backhaul environments between TRPs. Joint scheduling may be difficult to apply between TRPs connected by non-ideal backhauls.

[0092] The PDCCH reception beam (e.g., TCI) and the PDSCH reception beam (e.g., TCI) of the terminal can be individually managed by the base station. The TCI of the PDCCH can be set for the CORESET corresponding to the PDCCH. The terminal can perform PDCCH monitoring and reception operations in the search space set, PDCCH candidates, etc. corresponding to the CORESET based on the TCI state included in the configuration information of the CORESET. In the present disclosure, the signal reception operation based on the TCI can include operations such as determining and applying a reception beam, and estimating a channel. The TCI of the PDSCH can be set (e.g., indicated) separately from the TCI of the PDCCH. The TCI of the PDSCH can be included in the DCI for scheduling the PDSCH, and the DCI can be transmitted to the terminal. In other words, the DCI of the PDSCH can be dynamically indicated to the terminal. The base station can select one TCI from among the candidate TCI(s) of the PDSCH set to the terminal (e.g., candidate TCI(s) of the activated PDSCH) through upper layer signaling, and can indicate the selected TCI to the terminal through scheduling DCI. In multiple TRP transmission, the DCI can include multiple TCIs, and the terminal can receive the PDSCH using the indicated multiple TCIs. The TCI of other downlink signals (e.g., CSI-RS, TRS, PRS) can be determined independently from the TCI of the PDCCH or PDSCH.

[0093] In the uplink, the PUCCH transmission beam (e.g., TCI) and the PUSCH transmission beam (e.g., TCI) of the terminal can be managed separately. The TCI (e.g., transmission spatial filter or spatial relationship information) of the PUCCH can be semi-statically configured for the terminal. The TCI (e.g., transmission spatial filter or spatial relationship information) of the PUSCH can be semi-statically configured. Alternatively, the TCI of the PUSCH can be included in scheduling DCI, and the scheduling TCI can be transmitted to the terminal. In other words, the TCI of the PUSCH can be dynamically indicated to the terminal. The TCI of the PUSCH can be indirectly indicated by SRS resource indication information, and the terminal can transmit the PUSCH by applying the same TCI (e.g., transmission spatial filter or spatial relationship information) set for the indicated SRS resource to the PUSCH. The TCI of other uplink signals (e.g., SRS, PRACH) can be determined independently from the TCI of PUCCH or PUSCH.

[0094] The above-described method allows for individual beam management for each transmission signal or channel, thereby achieving a high degree of freedom and flexibility. However, if beams are to be changed simultaneously for all signals, separate signaling procedures are required for each signal, potentially resulting in significant signaling overhead and increased beam management delays.

[0095] To address the above issues, a method of indicating TCIs of multiple signals (e.g., physical signals and / or physical channels) to a terminal with a single signaling may be considered. In the downlink, the terminal may receive an indication of a downlink TCI via DCI, and the indicated downlink TCI may be applied to both the PDCCH and the PDSCH. The indicated downlink TCI may be applied to downlink signals other than the PDCCH and the PDSCH (e.g., CSI-RS, TRS, PRS). In the uplink, the terminal may receive an indication of an uplink TCI via DCI, and the indicated uplink TCI may be applied to both the PUCCH and the PUSCH. The indicated uplink TCI may be applied to uplink signals other than the PUCCH and the PUSCH (e.g., SRS, PRACH). The downlink TCI and the uplink TCI may be individually indicated via different DCIs. Alternatively, the downlink TCI and the uplink TCI may be indicated together via the same DCI. Downlink TCI and uplink TCI may be identical. In this case, the TCI may be referred to as a joint TCI. The joint TCI may be indicated to the terminal via DCI. The joint TCI may be applied to both the above-described downlink signals (e.g., PDCCH, PDSCH, and the non-channel signal(s)) and the above-described uplink signals (e.g., PUCCH, PUSCH, and the non-channel signal(s)). Since the above-described TCI is applied equally to multiple signals (specifically, physical signals and / or physical channels), it may be referred to as a unified TCI, a single TCI, etc.

[0096] A signal to which the integrated TCI is applied may be a signal for transmitting terminal-specific information. For example, a PDSCH may include unicast data (e.g., a DL-SCH). A PDCCH may include DCI for scheduling a data channel (e.g., a PDSCH, a PUSCH, a PSSCH) containing unicast data or DCI containing terminal-specific control information. A PDCCH may be a PDCCH transmitted in a USS set and / or a specific CSS set (e.g., a Type 3 CSS set). CSI-RS, TRS, PRS, etc. may be configured terminal-specifically. In other words, CSI-RS, TRS, PRS, etc. may be signals transmitted terminal-specifically. For another example, a PUSCH may include unicast data (e.g., a UL-SCH). SRS, PRACH, etc. may be configured terminal-specifically. In other words, SRS, PRACH, etc. may be signals transmitted terminal-specifically. Terminal-specific signals can be configured in the terminal through terminal-specific RRC signaling procedures, MAC CE, DCI, etc.

[0097] The integrated TCI can be indicated by a scheduling DCI. The downlink DCI format (e.g., DCI format 1_1, 1_2) that schedules the PDSCH can be used to indicate the TCI (e.g., the integrated TCI).

[0098] Figure 3 is a conceptual diagram illustrating a first embodiment of a TCI instruction method by DCI.

[0099] Referring to FIG. 3, a base station can transmit a downlink DCI scheduling a PDSCH. A terminal can receive the downlink DCI scheduling a PDSCH. The terminal can check the indication of the TCI based on the downlink DCI. Generally, the DCI can schedule a PDSCH, but if certain field(s) of the DCI are set to a predefined value, the PDSCH may not be scheduled. In this case, the DCI may be used for other purposes. Even if the scheduling DCI is used for purposes other than scheduling a PDSCH, the terminal can check the indication of the TCI from the scheduling DCI. The terminal can report a HARQ-ACK (acknowledgement) to the base station as a response to receiving the PDSCH or the downlink DCI. The HARQ-ACK may be composed of an ACK or a NACK. Alternatively, the HARQ-ACK may be composed of only an ACK. The transmission resources (e.g., PUCCH resources) of HARQ-ACK can be determined based on the resource locations of PDSCH. Even when PDSCH is not transmitted, the transmission resources of HARQ-ACK can be determined based on the virtual PDSCH resources allocated by the DCI.

[0100] According to the above-described operation, the beam quality measurement and reporting operation of the terminal can be triggered by the base station. The terminal can perform the beam measurement operation based on a downlink signal (e.g., SSB, CSI-RS, etc.) set (e.g., indicated) by the base station, and can transmit the measurement result to the base station through an uplink resource (e.g., PUCCH, PUSCH, etc.) set (or indicated) by the base station. In the above-described operation, the entity that determines and manages the beam of the terminal can be the base station. The base station can determine and manage the most suitable transmit / receive beam for the terminal based on the beam report (e.g., measurement result) received from the terminal. If a beam change is required, the base station can indicate a new beam to the terminal through a beam-related signaling message (e.g., TCI, spatial relationship information, QCL, etc.).

[0101] The above-described method has the following problems in terms of signaling overhead and beam switching delay. In order to reduce beam switching delay, the period of uplink resources for beam reporting of terminals must be short, and the short period of uplink resources for beam reporting may increase signaling overhead. On the other hand, if the period of uplink resources for beam reporting is set long in order to reduce signaling overhead, the beam switching delay may increase, and as a result, link performance may deteriorate. In other words, signaling overhead and beam switching delay may have a trade-off relationship.

[0102] As a method for solving the above problem, a method of triggering the beam quality measurement and reporting operation of the terminal by the terminal itself may be considered. The terminal may arbitrarily trigger the beam reporting operation when it determines that a beam change is necessary. For example, the terminal may transmit beam reporting information to the base station using preset uplink resources (e.g., PUCCH resources, PUSCH resources, PRACH resources, SRS resources) only when beam reporting is necessary. Alternatively, the terminal may request a second uplink resource (e.g., PUCCH resources, PUSCH resources) for beam reporting using preset first uplink resources (e.g., PUCCH SR resources, PRACH resources, SRS resources), and transmit beam reporting information to the base station using the second uplink resources. The uplink resources may be optimally located based on the time when the terminal performs the beam quality measurement operation. According to the above operation, the delay time (e.g., beam switching delay time) from the time when the terminal determines that a beam change is necessary to the time when the beam is reported can be reduced, and the uplink resources required for beam reporting can also be minimized. Below, specific embodiments of a terminal-initiated beam reporting method and a beam switching method will be described.

[0103] [How to report a terminal-triggered beam]

[0104] The operation of the terminal to trigger a beam report can be performed in an event-driven manner. For example, a trigger condition for beam report may be when the quality of the currently applied beam does not satisfy a threshold value. In other words, when the quality of the currently applied beam does not satisfy a threshold value, the terminal can trigger a beam report operation. For example, the terminal can periodically measure a metric (e.g., L1-RSRP (layer1-reference signal received power), L1-SINR (layer1-signal-to-interference-plus-noise ratio), hypothetical SINR, etc.) for the CSI-RS or SSB, which are QCL source signals (e.g., source beams) of the currently applied integrated TCI, and can trigger a beam report operation for the purpose of changing the integrated TCI when the metric falls below a threshold value (e.g., when the beam quality is determined to be degraded). The measurement operation (e.g., beam measurement operation) can be performed on periodic downlink resource(s). The base station can transmit configuration information of periodic downlink resource(s) to the terminal, and the terminal can receive configuration information of the periodic downlink resource(s) from the base station. A beam measurement operation can be performed on the periodic downlink resource(s) indicated by the configuration information. The beam measurement operation can be performed N times on the periodic downlink resource(s). The results of the N beam measurement operations can be compared with a reference value. N can be a natural number. The beam measurement operation can be performed on a signal received within a preset time interval, and the preset time interval can include one or more downlink resource periods. The downlink resource can correspond to (e.g., be associated with) a first TCI (e.g., an activated TCI) belonging to a TCI list configured in the terminal. In other words, the first TCI can be applied to the downlink resource.The beam reporting information generated based on the result of the beam measurement operation may include at least an index of a downlink resource (e.g., a periodic downlink resource). The reference value may be a value quantified by the beam quality metric described above. The reference value may be a beam quality of a downlink resource corresponding to (e.g., associated with) a current beam of the terminal. The reference value may not change during the section in which the beam measurement operation is performed. The reference value may mean a beam quality value of the reference beam. For example, the reference beam may be a candidate beam to be described later, and the terminal may trigger a beam reporting operation when the beam quality of the current beam is worse than the beam quality of the candidate beam. The CSI-RS may be periodically transmitted to the terminal. The CSI-RS may be a channel measurement resource (CMR). Alternatively, when L1-RSRP is used as the beam measurement metric, the CSI-RS may include both a CMR and an interference measurement resource (IMR). In other words, the beam quality measurement operation can be performed based on multiple NZP (non-zero power) CSI-RS resources or ZP CSI-RS resources.

[0105] According to the above-described operation, the terminal can perform a beam quality measurement operation for the CSI-RS or SSB corresponding to the current beam. When the beam quality measurement operation is performed for the CSI-RS corresponding to the current beam, the CSI-RS for a specific purpose (e.g., beam management or tracking) can be set as a QCL source signal of the TCI, and the terminal can perform a beam quality measurement operation for the CSI-RS that is the QCL source signal of the current TCI. The terminal can measure L1-RSRP, etc. for one or more CSI-RS resource(s) for the CSI-RS. When the beam quality measurement operation is performed for the SSB corresponding to the current beam, the SSB can be set as a QCL source signal of the TCI, and the terminal can perform a beam quality measurement operation for the SSB that is the QCL source signal of the current TCI. Alternatively, the terminal can perform a beam quality measurement operation for the SSB that has a QCL relationship with the CSI-RS that is the QCL source signal of the TCI. The above SSB may be a CD-SSB (cell-defining SSB), and the CD-SSB may be configured in the terminal by an RRC message including at least one of MIB, SIB, or serving cell common configuration information. Alternatively, the SSB may be a NCD (non-CD)-SSB configured in an activated downlink bandwidth portion. If an NCD-SSB is configured in a downlink active bandwidth portion, the terminal may perform a beam quality measurement operation for the current beam or candidate beam using the NCD-SSB, and CD-SSB reception may be omitted.

[0106] The above measurement value may be a result value measured once for a downlink resource. Alternatively, the measurement value may be a result value (e.g., an average value) measured multiple times for multiple downlink resources. The beam quality degradation determination may be performed more than once. If the beam quality metric is measured to be below a reference value a predefined number of times M (e.g., the preset number of times M) for the same resource of the current beam, the terminal may finally determine that the beam quality is degraded and trigger a beam reporting operation. Simultaneously or separately from the above operation, if the beam quality metric is measured to meet the reference value a predefined number of times N (e.g., the preset number of times N) for the same resource of the candidate beam, the terminal may determine that a new beam to replace has been found and may also trigger a beam reporting operation. In an embodiment, N may be equal to M. Alternatively, N may be different from M. Each of N and M may be a natural number. The beam reporting trigger condition by the terminal may be associated with both the current beam measurement number M and the candidate beam measurement number N. In general, N can be defined or set to a value separate from M. The above-described operations may be referred to as filtering and may be performed at the physical layer of the terminal. In other words, signaling between the physical layer and the upper layer to obtain the measurement value may be unnecessary. The plurality of downlink resources may be resource occasions that are configured (e.g., transmitted) over multiple periods for the same CSI-RS resource or the same SSB resource. Alternatively, the plurality of downlink resources may be multiple different CSI-RS resources and / or SSB resources.

[0107] The reference value for the beam quality may be invariant for multiple measurement operations. In other words, multiple measurements for the current beam may all be compared with a single reference value (e.g., a beam quality measurement value of the candidate beam). Multiple measurements for the candidate beam may all be compared with a single reference value (e.g., a beam quality measurement value of the current beam). Meanwhile, while the terminal is performing quality measurement operations for multiple beams for the same resource (e.g., a resource of the current beam, a resource of the candidate beam), the reference value may be changed by a new measurement for the reference beam (e.g., a candidate beam, a current beam). In this case, the beam quality measurement operation may be stopped. Alternatively, the beam quality measurement operation may be restarted for the changed reference value. Alternatively, the terminal may apply the previous reference value as is to the remaining beam quality measurement operations.

[0108] Alternatively, the beam quality threshold may be changed while multiple measurement operations are being performed. For example, the terminal may perform a beam quality measurement operation on a first resource of the current beam. The measured value of the beam quality measurement operation on the first resource may be referred to as a first threshold value. Next, the terminal may perform a beam quality measurement operation on the first resource of the candidate beam, and if the measured value of the beam quality measurement operation is higher than the first threshold value, it may be determined for the first time that a new beam to be replaced has been found. Thereafter, the terminal may perform a beam quality measurement operation on a second resource of the current beam. The measured value of the beam quality measurement operation on the second resource may be referred to as a second threshold value, and the second threshold value may be different from the first threshold value. Next, the terminal may perform a beam quality measurement operation on the second resource of the candidate beam, and if the measured value of the beam quality measurement operation is higher than the second threshold value, it may be determined for the second time that a new beam to be replaced has been found. In other words, the reference value (e.g., beam quality reference value) can be updated by a new reference beam measurement while the above multiple measurement operations are being performed.

[0109] Alternatively, when multiple reference values ​​are generated while performing multiple measurement operations, the terminal may derive a representative reference value based on the multiple reference values, and determine a beam reporting trigger condition by commonly applying the representative reference value to the multiple measurement operations. For example, the representative reference value may be any one of the multiple reference values ​​(e.g., the largest value, the median value, or the smallest value). In another example, the representative reference value may be a new value derived from the multiple reference values ​​(e.g., the average value).

[0110] Alternatively, the subsequent operation of the terminal may be determined based on the relationship between the second reference value and the first reference value. For example, the second reference value may be no higher than the first reference value. In this case, the multiple beam measurement operations of the terminal may continue, and the event counting may be maintained. On the other hand, if the second reference value is higher than the first reference value, the events previously determined by the terminal may no longer be valid. In this case, the terminal may reset the event count to 0 and restart the beam measurement operation.

[0111] A trigger condition for a beam report may include that the terminal discovers a new candidate beam to replace a beam currently in use (e.g., the current beam). Since the application of the new candidate beam may be finally determined or confirmed by the base station, it may be appropriate to refer to it as a candidate beam. In the present disclosure, the terms new candidate beam, candidate beam, target beam, etc. may be used interchangeably. The terminal may measure beam quality (e.g., L1-RSRP, L1-SINR, hypothetical SINR, etc.) for beam(s) constituting a preset beam set, and may determine one or more beams among beam(s) whose beam quality satisfies a reference value as a new beam to replace the current beam. The new beam may be a different beam from the beam currently in use (e.g., the current beam). A beam set may mean a set of TCIs (or TCI states), and each beam constituting the beam set may mean a QCL source signal of a TCI (e.g., SSB, CSI-RS, SRS, etc.).

[0112] In embodiments, a QCL source signal (e.g., a source beam) of a TCI may be interpreted as a QCL source signal for a spatial reception parameter (e.g., QCL Type D). For example, a TCI in which the QCL source signal (e.g., a source beam) is an uplink signal (e.g., an uplink beam) may mean a TCI in which the spatial reception parameter or the source signal for QCL Type D is set as an uplink resource, a TCI in which the QCL source signal (e.g., a source beam) is a downlink signal (e.g., a downlink beam) may mean a TCI in which the spatial reception parameter or the source signal for QCL Type D is set as a downlink resource, and a TCI without a QCL source signal (e.g., a source beam) may mean a TCI in which the spatial reception parameter or the source signal for QCL Type D is not set. The above-described TCI may include source signals for other QCL parameters (e.g., delay spread, Doppler spread, Doppler shift, average gain, average delay, etc.) or other QCL types (e.g., QCL types A, B, C, etc.).

[0113] With the proposed method, a terminal can independently determine the transmission direction in which a new beam will be used. The terminal can distinguish the transmission direction of the beam and report the new beam to the base station. For example, the terminal can report information about the new beam and information about the transmission direction of the beam to the base station. Alternatively, the terminal can report beam information including information about the transmission direction of the beam to the base station. The above-described method(s) may be referred to as (method 100).

[0114] A terminal can perform beam management operations based on an integrated TCI framework. In an embodiment, the terminal can receive indications of downlink TCI (e.g., downlink integrated TCI) and uplink TCI (e.g., uplink integrated TCI) from a base station. The terminal can perform a downlink reception operation and / or an uplink transmission operation based on each of the indicated TCIs. The terminal can determine whether the above-described beam report trigger condition is satisfied for each of the downlink and uplink. If the beam report trigger condition is satisfied, the terminal can perform a beam report. For example, the terminal can determine that the beam quality of the currently applied downlink TCI has deteriorated, and can search for a new beam to replace the current downlink TCI. The terminal can determine a first beam that satisfies a criterion value as a new beam (e.g., a candidate beam that can be indicated by the downlink TCI). The new beam can be searched within a downlink TCI pool (e.g., downlink TCI status pool, downlink TCI list), and the first beam (e.g., downlink TCI corresponding to the first beam) can belong to the downlink TCI pool. The terminal can determine that the beam quality of the currently applied uplink TCI has deteriorated, and can search for a new beam to replace the current uplink TCI. The terminal can determine a second beam that satisfies a threshold value as a new beam (e.g., a candidate beam that can be indicated by the uplink TCI). The new beam can be searched within an uplink TCI pool (e.g., uplink TCI status pool, uplink TCI list), and the second beam (e.g., uplink TCI corresponding to the second beam) can belong to the uplink TCI pool. The threshold value can mean a value quantified by the above-described beam quality metric. The threshold value can mean a beam quality value of a reference beam.For example, the reference beam may be the currently applied beam, and the terminal may trigger a beam reporting operation if the beam quality of the candidate beam is better than the beam quality of the current beam.

[0115] FIG. 4 is a conceptual diagram illustrating a first embodiment of a method for setting a candidate beam set for downlink TCI.

[0116] Referring to FIG. 4, a downlink candidate beam set may be determined based on a downlink TCI pool (e.g., a downlink TCI list, a downlink TCI set). Specifically, the downlink candidate beam set may be a subset of the downlink TCI pool. In the present disclosure, set A being a subset of set B may include that set A matches set B. The downlink candidate beam set may include at least five TCIs having indices from 0 to 4, and each TCI may have an SSB resource or a CSI-RS resource as a QCL source signal. The downlink candidate beam set may be configured as a set of TCIs (or TCI indices). Alternatively, the downlink candidate beam set may include SSB resource A, SSB resource B, CSI-RS resource A, CSI-RS resource B, and CSI-RS resource C, which are source signals of the TCIs. A downlink candidate beam set can be configured as a set of downlink resources (e.g., downlink resource indices) corresponding to downlink TCIs. A method in which only CSI-RS is used as a QCL source signal can be applied. In this case, downlink (DL) TCI #0 and #1 described in FIG. 4 can be excluded from the downlink candidate beam set. The terminal can measure beam quality based on CSI-RS resource A, which is a QCL source signal of TCI #2, which is a current downlink beam, and can determine that the quality of TCI #2 has deteriorated based on the beam quality measurement result. In this case, the terminal can search for a new downlink beam in the downlink candidate beam set. Alternatively, the terminal can perform beam quality measurement of CSI-RS resource A, which is a current downlink beam, and beam quality measurement for candidate beams together.For example, if the beam quality measured based on CSI-RS resource B corresponding to TCI #3 (e.g., DL TCI #3) satisfies a reference value (e.g., if the beam quality of CSI-RS resource B is higher than the beam quality of CSI-RS resource A), the terminal may determine TCI #3 as a new downlink candidate beam and report TCI #3 to the base station as a new candidate beam for downlink TCI.

[0117] FIG. 5 is a conceptual diagram illustrating a first embodiment of a method for setting a candidate beam set for uplink TCI.

[0118] Referring to FIG. 5, an uplink candidate beam set may be determined based on an uplink TCI pool (e.g., an uplink TCI list, an uplink TCI set). Specifically, the uplink candidate beam set may be a subset of the uplink TCI pool. The uplink TCI pool and the uplink candidate beam set may be configured or determined independently from the downlink TCI pool and the downlink candidate beam set. In other words, the uplink TCI pool may be the same as or different from the downlink TCI pool, and the uplink candidate beam set may be the same as or different from the downlink candidate beam set. The uplink candidate beam set may include at least five TCIs having indices from 0 to 4, and each TCI may have an SSB resource, a CSI-RS resource, or an SRS resource as a QCL source signal. The uplink candidate beam set may be configured as a set of TCIs (e.g., TCI indices). Alternatively, the uplink candidate beam set may include SSB resource A, SSB resource B, CSI-RS resource A, CSI-RS resource B, and / or SRS resource A for the source signals of the TCIs. The uplink candidate beam set may be configured as a set of downlink / uplink resources (e.g., uplink / downlink resource indices) corresponding to the uplink TCIs. Alternatively, a method in which only CSI-RS and SRS are used as QCL source signals may be applied, in which case uplink (UL) TCI #0 and #1 may be excluded from the uplink candidate beam set. The terminal may measure beam quality based on CSI-RS resource A, which is a QCL source signal of the current uplink beam, TCI #2, and may determine that the quality of TCI #2 has deteriorated based on the beam quality measurement result. In this case, the terminal may search for a new uplink beam in the uplink candidate beam set. Alternatively, the terminal may perform beam quality measurement of CSI-RS resource A, which is the current uplink beam, and beam quality measurement for the candidate beam together.For example, if the beam quality measured based on SSB resource B corresponding to TCI #1 satisfies a reference value (e.g., if the beam quality of SSB resource B is higher than the beam quality of CSI-RS resource A), the terminal may determine TCI #1 as a new uplink candidate beam and report TCI #1 to the base station as a new candidate beam for uplink TCI.

[0119] In another embodiment, a terminal may receive an indication of a joint TCI (e.g., a joint integrated TCI) from a base station. The terminal may perform a downlink reception operation and / or an uplink transmission operation based on the indicated joint TCI. The terminal may determine the above-described beam report trigger condition for the joint TCI regardless of the transmission direction, and may perform beam reporting based on the determination result. For example, the terminal may determine that the beam quality of the currently applied joint TCI has deteriorated, and may search for a new beam to replace the current joint TCI. The terminal may determine a third beam that satisfies a threshold value as the new beam (e.g., a candidate beam that can be indicated by the joint TCI). The new beam may be searched within a joint TCI pool (e.g., a joint TCI status pool, a joint TCI list) or a downlink TCI pool (e.g., a downlink TCI status pool, a downlink TCI list). The third beam (e.g., a joint TCI corresponding to the third beam) may belong to a joint TCI pool or a downlink TCI pool.

[0120] Meanwhile, a beam reporting operation for a terminal that does not support integrated TCI or a beam reporting operation for a physical signal / channel to which integrated TCI is not applied may also be triggered by the terminal. In the present disclosure, a downlink TCI may be interpreted as a downlink beam (e.g., a reception beam, QCL, QCL type D) of a specific downlink physical signal / channel (e.g., a PDCCH, a PDSCH, a CSI-RS), an uplink TCI may be interpreted as an uplink beam (e.g., a transmission beam, spatial relationship information, QCL) of a specific uplink physical signal / channel (e.g., a PUCCH, a PUSCH, a SRS), and a joint TCI may be interpreted as a beam commonly applied to both a downlink signal / channel and an uplink signal / channel. Based on the above interpretation, beam measurement and reporting operations of the terminal may be performed in the same manner even when integrated TCI is not set.

[0121] The operation of measuring beam quality and the operation of determining event occurrence at the terminal can be performed for a beam set or a corresponding signal set. In the downlink, a downlink signal set composed of downlink signals (e.g., downlink physical signals and / or channels) (or a downlink beam set composed of QCL source beams corresponding to the downlink signal set) can be configured, and the terminal can determine that the downlink beam of the corresponding serving cell is degraded when the beam quality of all signals belonging to the downlink signal set (or the downlink beam set) is measured to be below a reference value. Alternatively, the operation of measuring downlink beam quality and the operation of determining event occurrence at the terminal can be performed for each downlink signal. For example, an event in which the quality of a QCL source beam of a PDCCH (e.g., CORESET) is degraded and an event in which the quality of a QCL source beam of a CSI-RS is degraded can be distinguished from each other, and a beam reporting operation can be triggered by at least one of the events. In other words, the beam reporting operation can be triggered even when only some of the downlink beams set or indicated to the terminal experience quality degradation. The above-described operation can be defined in the same way for the uplink. The downlink (or uplink) signal set or downlink (or uplink) beam set can be set to the terminal by the base station. A specific signal can be fixedly included in the signal set or beam set. For example, the reception beam of the downlink control channel (e.g., CORESET beams or CORESETs) can be included in the beam set by default. As another example, a signal set or beam set including both downlink signals / beams and uplink signals / beams can be set to the terminal, and the beam quality measurement operation or the event occurrence determination operation in the terminal can be performed for the signal set or the beam set.For example, if an event occurs in which all downlink beams and all uplink beams selected as beam sets by the base station are degraded, the terminal may trigger a beam reporting operation.

[0122] Referring to the above-described embodiments, a beam set in a terminal may include both a beam corresponding to the integrated TCI (hereinafter referred to as a first beam) and a beam of a signal that does not follow the integrated TCI (hereinafter referred to as a second beam). The number of second beams may be one or more depending on beam settings for downlink physical signals and channels. For example, the second beam may include a TCI activated in CORESET 0 and / or a TCI activated in a CORESET that is set not to follow the integrated TCI. The second beam may include a periodic CSI-RS or a QCL source beam of the periodic CSI-RS. In the uplink, the second beam may include a periodic SRS or a QCL source beam of the periodic SRS. Similarly, the number of first beams may be one or more depending on whether a multi-TRP transmission scheme is applied or not.

[0123] According to an embodiment, a beam reporting method triggered by a terminal may be applied to both a first beam and a second beam. In this case, beam quality measurement for a current beam may be performed for both the first beam and the second beam. The first beam and the second beam may be used as reference beams for a new beam. The terminal may trigger a beam reporting operation when the beam quality of at least one of the first beam and the second beam is degraded. Alternatively, the terminal may trigger a beam reporting operation when the beam qualities of both the first beam and the second beam are degraded. Alternatively, one of the former triggering operation and the latter triggering operation may be selectively performed depending on the configuration of the first beam and / or the second beam. For example, if the second beam includes at least a beam of CORESET (e.g., a TCI of CORESET 0), the terminal may trigger a beam reporting operation even when only the second beam is degraded. According to the above-described method, both the first beam and the second beam may be involved in the event of beam quality degradation, and information about the first beam and the second beam may belong to the same beam report (e.g., the same CSI report setting). The beam report information may include information that helps determine whether the first beam is degraded and / or whether the second beam is degraded, and the base station may appropriately update the beam of the terminal based on the information (e.g., beam report information).

[0124] In another embodiment, the beam reporting method triggered by the terminal may be applied only to the first beam. In other words, the beam quality value and / or beam quality degradation of the second beam may be reported to the base station by a separate beam reporting procedure (e.g., a legacy beam reporting procedure, a beam reporting procedure triggered by an instruction of the base station). In this case, the beam report of the first beam and the beam report of the second beam may be included in the same CSI reporting configuration, and the beam report of the first beam and the beam report of the second beam may be transmitted together through the same uplink resource. Alternatively, the beam report of the first beam and the beam report of the second beam may belong to different CSI reporting configurations. In this case, the uplink transmission including the beam report of the first beam and the uplink transmission including the beam report of the second beam may be different from each other. The uplink transmission including the beam report of the first beam and the uplink transmission including the beam report of the second beam may collide within the same reference unit time (e.g., the same slot, the same symbol(s)). For example, a first uplink resource (e.g., PUCCH, PUSCH) including beam report information of a first beam and a second uplink resource (e.g., PUCCH, PUSCH) including beam report information of a second beam may be mapped to the same slot.

[0125] In this case, the beam report information of the first beam and the beam report information of the second beam can be multiplexed. The beam report information of the first beam and the beam report information of the second beam can be transmitted to the base station via the first uplink resource, the second uplink resource, or an uplink resource other than the first uplink resource and the second uplink resource. The other uplink resource can be one of candidate resources preset in the terminal, and the other uplink resource can be determined based on a predefined rule. Alternatively, the terminal can select one of the first uplink resource and the second uplink resource based on a priority rule, and transmit the beam report information to the base station using the selected uplink resource, and the unselected uplink resource can be dropped. The priority can be defined between the beam report information of the first beam and the beam report information of the second beam. For example, since the first beam based on the integrated TCI is applied to most signals that are terminal-specific, the first beam can have a higher priority than the second beam. Alternatively, the second beam, which may include a beam of CORESET, may have a higher priority than the second beam corresponding to terminal-specific transmission. Alternatively, the second beam may be further subdivided to apply different priorities depending on the signal / channel type of the second beam. Alternatively, beam reporting information may be transmitted in both the first uplink resource and the second uplink resource. For example, the first uplink resource and the second uplink resource may be mapped to different symbol sets or different sub-slots within the same slot, and the terminal may transmit beam reporting information in both uplink resources. Transmission operations in the first uplink resource and the second uplink resource may be applied differently depending on the number of first beams and / or the number of second beams.

[0126] It is inefficient for a base station to transmit configuration information to a terminal to update a signal set or beam set whenever a beam of the terminal changes. A method may be considered in which a terminal updates a signal set or beam set by itself according to a predetermined rule whenever a beam of the terminal changes. For example, when N existing beam(s) are replaced by N new beam(s), a beam set may additionally include the existing beams and the N new beams. N may be a natural number. For another example, the N changed beam(s) may be added to the beam set, the N existing beam(s) may be excluded from the beam set, and the size of the beam set may be maintained. In an embodiment, N may be 1. The update operation of the beam set may be performed only when a new beam is included in the beam report information of the terminal. The update operation of the beam set may be performed after the beam report operation of the terminal. For example, the terminal can appropriately update the beam set after receiving a response message to a beam report (e.g., a confirmation message or beam indication information in response to a beam report) from the base station.

[0127] According to the above embodiments, the transmission direction in which a beam quality degradation event occurred and the transmission direction of the new candidate beam may be identical. As a method for expanding the range of candidate beams, the transmission direction constraint may be relaxed or removed. For example, the terminal may search for a beam to replace the downlink TCI with degraded quality from the uplink TCI pool. Alternatively, the terminal may search for a beam to replace the uplink TCI with degraded quality from the downlink TCI pool. The above operations may correspond to (method 200) described below.

[0128] The terminal may report information about the determined candidate beam (e.g., candidate beam information) to the base station. Information about the beam transmission direction may be included in the candidate beam information. Alternatively, information about the beam transmission direction may be reported to the base station together with the candidate beam information. In an embodiment, information about the beam transmission direction may be signaled to the base station in an explicit manner. For example, the terminal may report a candidate beam for a downlink TCI to the base station. The reporting operation of the candidate beam may include an operation of the terminal reporting to the base station an index of the downlink TCI (e.g., a TCI index assigned within a downlink TCI pool or a downlink TCI list), an index of a QCL source signal of the downlink TCI (e.g., an SSB resource index or a CSI-RS resource index), and / or a candidate beam or candidate resource index assigned within a downlink beam set. In the embodiment of FIG. 4, the terminal may transmit an index of downlink TCI #3 (e.g., 3) or an index of CSI-RS resource B to the base station as beam reporting information. The above action may correspond to the terminal notifying that the transmission direction to which the candidate beam is to be applied is downlink.

[0129] A terminal may report a candidate beam for an uplink TCI to a base station. The operation may include an operation in which the terminal reports to the base station an index of an uplink TCI (e.g., a TCI index assigned within an uplink TCI pool or an uplink TCI list), an index of a QCL source signal of the uplink TCI (e.g., an SSB resource index, a CSI-RS resource index, or an SRS resource index), and / or a candidate beam or candidate resource index assigned within an uplink beam set. In the embodiment of FIG. 5, the terminal may transmit an index of an uplink TCI #1 (e.g., 1) or an index of an SSB resource B to the base station as beam reporting information. The operation may correspond to the terminal notifying that the transmission direction to which the candidate beam is to be applied is uplink.

[0130] A terminal may report a candidate beam for a joint TCI to a base station. The operation may include an operation in which the terminal reports to the base station an index of a joint TCI (e.g., a TCI index assigned within a joint TCI pool or a joint TCI list), an index of a QCL source signal of the joint TCI (e.g., an SSB resource index, a CSI-RS resource index, or an SRS resource index), and / or a candidate beam or candidate resource index assigned within a joint candidate beam set. Alternatively, the operation (e.g., an operation in which the candidate beam is reported) may include an operation in which the terminal reports to the base station an index of a downlink TCI (e.g., a TCI index assigned within a downlink TCI pool or a downlink TCI list), an index of a QCL source signal of the downlink TCI (e.g., an SSB resource index or a CSI-RS resource index), and / or a candidate beam or candidate resource index assigned within a downlink candidate beam set. The operation may correspond to the terminal notifying that the transmission direction to which the candidate beam is to be applied is downlink and uplink.

[0131] Meanwhile, the beam report information may include information about a condition and / or event that triggered the beam report. Information about the beam transmission direction may be transmitted to the base station as part of information about the beam trigger condition (or event). Alternatively, information about the beam transmission direction may be derived at the base station by the reported beam trigger condition (or event). For example, the beam report of the terminal may be triggered at least by an event of beam quality degradation of a downlink beam (e.g., a downlink TCI, a beam of a downlink signal / channel), in which case the beam report information including the candidate beam and the event information may be encoded. Based on the event information, the base station may determine that the candidate beam is a candidate beam applicable to the downlink. The above operation may be equally applicable when the beam report operation is triggered by quality degradation of an uplink beam (e.g., an uplink TCI, a beam of an uplink signal / channel) and / or a joint beam (e.g., a joint TCI, a beam commonly applied to a downlink signal / channel and an uplink signal / channel).

[0132] The beam report information may include candidate beam information for downlink TCI or candidate beam information for uplink TCI. Alternatively, the beam report information may include only candidate beam information for downlink TCI, only candidate beam information for uplink TCI, or both candidate beam information for downlink TCI and candidate beam information for uplink TCI. To support this operation, information for distinguishing between downlink TCI and uplink TCI (e.g., a 1-bit indicator) may be included in the beam report information. Alternatively, the beam report information may always include candidate beam information for downlink TCI and candidate beam information for uplink TCI. In this case, separate information for distinguishing the transmission direction may not be included in the beam report, and the transmission direction may be interpreted based on the order in which the candidate beams are mapped. For example, in the payload of the beam report information, the downlink candidate beam information may be mapped first, and the uplink candidate beam information may be mapped after the downlink candidate beam information. The base station may interpret the candidate beam information that is earlier in the payload of the beam report information (e.g., the candidate beam information mapped closer to the most significant bit (MSB)) as being for the downlink TCI, and may interpret the candidate beam information that is later in the payload of the beam report information (or the candidate beam information mapped closer to the least significant bit (LSB)) as being for the uplink TCI. In this case, if there is no candidate beam for a specific transmission direction, the terminal may map information (e.g., a code point) indicating that there is no candidate beam to the corresponding bit (string).

[0133] The above-described candidate beam set can be configured from the base station to the terminal. For example, the candidate beam set can be semi-statically configured to the terminal based on an RRC signaling procedure. The candidate beam set can be dynamically configured to the terminal based on a MAC layer signaling procedure. Alternatively, the candidate beam set can be activated / deactivated in the terminal based on a MAC layer signaling procedure. The downlink candidate beam set and the uplink candidate beam set can be configured to the terminal based on individual signaling procedures (e.g., individual RRC messages, individual MAC CEs). Simultaneously with or separately from the above operations, the above-described candidate beam set can be determined based on a predefined rule. For example, the predefined rule can be a method of including a beam or TCI satisfying a predetermined condition in the candidate beam set. For example, a beam (e.g., TCI, QCL, etc.) configured for receiving a downlink control channel (e.g., CORESET, search space set) can be included in the candidate beam set.

[0134] Alternatively, a method of excluding beams, resources, or TCIs that satisfy a predetermined condition from the candidate beam set may be considered. In the present disclosure, excluding a beam (or resource, TCI) from the candidate beam set may mean not only that the beam is not included in the candidate beam set, but also that the beam is included in the candidate beam set but is excluded from the candidate beams. For example, the terminal may perform a beam quality measurement operation on the remaining beam(s) excluding the beam(s) even though the beam(s) is included in the candidate beam set, and select new candidate beam(s) based on the result of the measurement operation. As a first condition, the beam currently being applied (e.g., the current beam) may be excluded from the candidate beam set. Since a prerequisite for the terminal to search for a new candidate beam includes determining that the quality of the current beam is degraded, excluding the current beam from the candidate beam set may be appropriate. In other words, the current beam may mean a beam used as a criterion for triggering a beam reporting operation. The terminal can configure a candidate beam set by excluding each of the currently applied downlink TCI, uplink TCI, and / or joint TCI from the downlink candidate beam set, uplink candidate beam set, and / or joint candidate beam set.

[0135] FIG. 6 is a conceptual diagram illustrating a second embodiment of a method for setting a candidate beam set for downlink TCI, and FIG. 7 is a conceptual diagram illustrating a second embodiment of a method for setting a candidate beam set for uplink TCI.

[0136] Referring to FIG. 6, the downlink candidate beam set may be configured as a subset of the downlink TCI pool. The embodiment of FIG. 6 may be similar to the embodiment of FIG. 4. Referring to FIG. 7, the uplink candidate beam set may be configured as a subset of the uplink TCI pool. The embodiment of FIG. 7 may be similar to the embodiment of FIG. 5. Based on the first condition described above, the current beam, downlink TCI #2, may be excluded from the downlink candidate beam set. Based on the first condition described above, the current beam, uplink TCI #2, may be excluded from the uplink candidate beam set. The downlink TCI #2 may be a beam used as a reference for triggering a reporting operation of the downlink candidate beam, and the uplink TCI #2 may be a beam used as a reference for triggering a reporting operation of the uplink candidate beam. The downlink TCI #2 or the uplink TCI #2 may be used as a reference beam that provides a beam quality reference value for determining a new beam.

[0137] As a second condition for determining a beam or TCI to be excluded from the candidate beam set, a TCI whose QCL source signal (or source beam) is an uplink signal (or uplink beam) or a TCI whose QCL source signal (or source beam) is not set may be excluded from the candidate beam set. In other words, the candidate beam set may only include TCI(s) whose QCL source signal (or source beam) is a downlink signal (or downlink beam). The candidate beam set may not include an uplink resource (or uplink beam), and may only include downlink resource(s) (or downlink beam(s)). As described above, the QCL source signal (or source beam) may mean a source signal in terms of a spatial reception parameter or a QCL Type D. The beam quality measurement operation of the terminal may be performed based on the downlink reception operation, and when the QCL source signal is an uplink resource or when the QCL source signal does not exist, it may be difficult for the terminal to measure the beam quality of the TCI. The above TCI may not be suitable as a new candidate beam to be determined by the terminal, and it may be appropriate to configure the candidate beam set to be limited to TCIs or downlink resources having a downlink QCL source signal.

[0138] The above TCI may mean an uplink TCI, and the candidate beam set may mean an uplink candidate beam set. For example, the terminal may configure the candidate beam set by excluding an uplink TCI whose QCL source signal is an SRS resource (or whose source beam is an SRS beam), an uplink TCI without a QCL source signal, or an SRS resource from the uplink candidate beam set. Referring again to FIG. 7, the uplink TCI pool may include an uplink TCI #4, and the QCL source signal of the uplink TCI #4 may be an SRS resource (e.g., SRS resource A). Based on the second condition described above, the terminal may exclude the uplink TCI #4 from the uplink candidate beam set. Alternatively, the TCI may include not only an uplink TCI but also a downlink TCI or a joint TCI. For example, the terminal can configure a downlink candidate beam set by excluding a downlink TCI in which the QCL source signal is an SRS resource, a downlink TCI without the QCL source signal, and / or an SRS resource from the downlink candidate beam set. The terminal can configure a joint candidate beam set by excluding a joint TCI in which the QCL source signal is an SRS resource, a joint TCI without the QCL source signal, and / or an SRS resource from the joint candidate beam set.

[0139] In addition to the conditions described above, several conditions may be considered to determine which TCIs to exclude from the candidate beam set. For example, an outdated TCI or an outdated resource may be excluded from the candidate beam set. If there is no valid beam quality measurement result for a QCL source signal of a certain TCI or a certain resource (e.g., there is no valid measurement result for a CSI-RS or SSB, which is a QCL source of the TCI, within the last X ms or the last Y slots (or subframes) or within a predetermined time window), the TCI or the resource may be considered outdated. Each of X and Y may be a natural number. In an embodiment, the valid measurement result may include only measurements based on periodic or semi-persistent signals (e.g., CSI-RS, SSB), and measurements based on aperiodic signals (e.g., CSI-RS) may be considered invalid. For another example, if a QCL source signal of a certain TCI or a certain resource is not configured to be received by a terminal, the certain TCI or the certain resource may be excluded from the candidate beam set. If a certain CSI-RS resource is configured as a QCL source signal of a TCI, but a configuration regarding the certain CSI-RS resource and / or a CSI reporting configuration associated with the certain CSI-RS resource is not configured in the terminal, the certain CSI-RS resource or the TCI having the certain CSI-RS resource as a QCL source signal may be considered unsuitable as a new beam candidate and may be excluded from the candidate beam set.

[0140] For another example, a TCI or beam measurement resource may be transitioned to a deactivated state by a signaling procedure from a base station (e.g., MAC CE, RRC signaling), and the deactivated TCI or deactivated beam measurement resource may be excluded from the candidate beam set. In other words, the candidate beam set may include only activated TCIs or activated beam measurement resources. In the above embodiments, the TCIs included in the downlink candidate beam set and the uplink candidate beam set may be activated TCIs. The above-described downlink TCI state pool (or list) and uplink TCI state pool (or list) may be interpreted as a set composed of activated TCIs or activated resources corresponding to the activated TCIs.

[0141] For another example, a beam (or TCI, resource) having a QCL relationship with the current beam may be excluded from the candidate beams. As described above, the terminal may measure the beam quality for the SSB corresponding to the current beam and monitor for beam quality degradation events. The terminal reporting the beam having the QCL relationship with the SSB to the base station as a new candidate beam may not be helpful for updating the current SSB beam. When a beam belonging to the candidate beam set has a QCL relationship with the SSB, the terminal may exclude the beam from the candidate beams and may not select the beam as a new candidate beam. For example, the beam may be a CSI-RS resource or a TCI having the CSI-RS resource as a QCL source signal.

[0142] A candidate beam set can be configured in a terminal explicitly or implicitly. When a candidate beam set is configured in a terminal explicitly, the candidate beam set can include TCIs (e.g., TCI indices) or beam measurement resources (e.g., resource indices). Similar to the methods described in the above embodiments, the candidate beam set can be configured for each of the downlink and uplink, or can be configured comprehensively for the downlink and uplink.

[0143] When a candidate beam set is composed of beam measurement resources, whether the candidate beam set includes an SSB resource can be determined based on a current beam measurement operation of the terminal. When the terminal performs a measurement operation of the current beam based on a source signal of the currently applied TCI (e.g., a CSI-RS resource), the candidate beam set may not include an SSB resource. For example, the candidate beam set may include a CSI-RS resource, and the CSI-RS resource may be limited to a CSI-RS resource or a TRS for beam management. On the other hand, when the terminal performs a measurement operation of the current beam based on an SSB that has a QCL relationship with the currently applied TCI, the candidate beam set may include an SSB resource and / or a CSI-RS resource. When an SSB resource is reported as a new candidate beam, the base station may select a TCI that has a QCL relationship with the SSB resource, and instruct the terminal to apply the selected TCI. When multiple CSI-RS resources are QCL with one SSB, it may be difficult for the base station to select an appropriate TCI. If the terminal reports SSB as a new beam, it may be difficult for the terminal to arbitrarily perform an operation to update the current TCI. Even if the terminal performs a measurement operation of the current beam based on the SSB that has a QCL relationship with the currently applied TCI, the candidate beam set may only include CSI-RS resources, which are downlink resources, as described above. In the above-described method, only resources (e.g., CSI-RS resources, SRS resources) set as source signals of TCI set or activated in the terminal may be included in the candidate beam set. If a resource that is not set as a source signal of TCI is included in the candidate beam set, the terminal may omit the beam measurement operation for the resource and exclude the resource from the candidate beam. The two methods described above may be applied selectively.In other words, the terminal can receive information from the base station through signaling that instructs to apply either a method of measuring the source signal of the current TCI or a method of measuring an SSB having a QCL relationship with the source signal of the current TCI for event detection of beam quality degradation.

[0144] As described above, each candidate beam may match a source signal of a TCI configured / activated in the terminal, or each candidate beam may have at least the same QCL relationship with a source signal of a TCI configured / activated in the terminal. To support the above operation, each candidate beam may be correlated with one or more TCI(s) configured / activated in the terminal. For example, each candidate beam may be associated with a TCI index, and the TCI index associated with each candidate beam may be included in the candidate beam configuration information. The TCI associated with each candidate beam may be a joint TCI. Alternatively, the TCI associated with each candidate beam may be a downlink TCI or an uplink TCI. A candidate beam may be associated with either a downlink TCI or an uplink TCI. Alternatively, a candidate beam may be associated with multiple TCIs. For example, a candidate beam may be associated with at least one downlink TCI and at least one uplink TCI. According to the above-described method, the terminal can perform beam measurement operation based on the source signal of the TCI associated with each candidate beam without setting up a separate SSB or CSI-RS for beam measurement of the candidate beam. The signaling overhead for setting up the candidate beam can be reduced.

[0145] Alternatively, a method of separately configuring resources corresponding to candidate beams in a terminal may be considered. For example, a single CSI-RS resource set may be used for candidate beam configuration. The CSI-RS resource set may be distinguished from CSI-RS resource sets configured for other purposes (e.g., CSI reporting, legacy beam reporting, radio resource management (RRM) / radio link monitoring (RLM)). For example, information regarding the purpose of the CSI-RS resource set may be included in configuration information of the CSI-RS resource set, and the configuration information of the CSI-RS resource set may be transmitted to the terminal. The terminal may receive the configuration information of the CSI-RS resource set from the base station, and may perform a candidate beam measurement operation using the CSI-RS resource set based on the information regarding the purpose included in the configuration information of the CSI-RS resource set. Alternatively, a configuration message (e.g., a parameter) of the CSI-RS resource set may be defined to be distinct from a configuration message (e.g., a parameter) of a CSI-RS resource set for another purpose, and an operation of a terminal corresponding to the CSI-RS resource set (e.g., a configuration message of the CSI-RS resource set) may be distinguished from an operation of a terminal corresponding to the CSI-RS resource set for another purpose (e.g., a configuration message of the CSI-RS resource set for another purpose). Alternatively, the CSI-RS resource set may belong to a specific CSI-RS resource setting (e.g., a CSI-RS resource setting having a specific index, a CSI-RS resource setting separately defined by a specific parameter), and the terminal may use the CSI-RS resource set belonging to the specific CSI-RS resource setting for the purpose of candidate beam measurement. The CSI-RS resource set may include resource(s) corresponding to candidate beam(s), and the resource(s) may include SSB resources and / or CSI-RS resources.The above method may only be supported by some terminals, depending on their capabilities. Terminals that do not support the above method may perform beam measurement operations based on a separate procedure (e.g., a method utilizing the aforementioned TCI correlation).

[0146] Meanwhile, some candidate beams may not be associated with a TCI or may not match the source signal of some TCI. The candidate beam (e.g., some candidate beam) may be reported to the base station as a new beam. In this case, since the candidate beam is a beam determined to be a valid beam for downlink and / or uplink transmission, the TCI pool (e.g., TCI state pool) may need to be updated to include the candidate beam. The terminal may arbitrarily perform the operation of updating the TCI pool. In other words, if "the terminal reports the candidate beam to the base station" or "the terminal reports the candidate beam to the base station and receives a response message for the report of the candidate beam," the terminal may add the candidate beam to the corresponding TCI pool. The corresponding TCI pool may be a joint TCI pool, a downlink TCI pool, or an uplink TCI pool. The corresponding TCI pool may be a TCI pool to which a TCI associated with the candidate beam belongs. Alternatively, the corresponding TCI pool may be determined based on a beam failure determination event.

[0147] In a different method from (Method 100), the terminal may report a new candidate beam to the base station without distinguishing the transmission direction of the beam. In other words, the beam report information may not include information regarding the transmission direction of the reported beam. The above operation may be referred to as (Method 200).

[0148] (Method 200) may be implemented based on the integrated TCI framework described above. For example, the terminal may perform an operation of checking a trigger condition of a beam report based on the integrated TCI set by the base station in the same manner as described above. If it is determined that the beam quality of the current TCI or the SSB QCL with the current TCI does not satisfy a reference value, the terminal may search for a new beam from a candidate beam set. The candidate beam set may be determined within the union of the downlink TCI pool and the uplink TCI pool. For example, the candidate beam set may be defined to match the union of the downlink TCI pool and the uplink TCI pool. Alternatively, the candidate beam set may be defined as a subset of the union of the downlink TCI pool and the uplink TCI pool. In other words, the terminal can set beams of all TCIs (e.g., QCL source signals) or beams of some TCIs (e.g., QCL source signals) belonging to the downlink TCI pool and the uplink TCI pool as candidate beams, and report at least one beam among the candidate beams to the base station as a new candidate beam without distinction of transmission direction. Alternatively, the terminal can explicitly receive a configuration for one candidate beam set from the base station without distinction of transmission direction, and the candidate beam set can include at least one of a CSI-RS resource, an SRS resource, or an SSB resource.

[0149] Even without explicit information about the beam transmission direction reported from the terminal, the base station can determine the beam transmission direction based on the inclusion relationship between the reported beam and the TCI pool. For example, if the reported beam belongs to a downlink TCI or is a source signal of a downlink TCI, or if the reported event is an event regarding a downlink beam, the base station can consider the reported beam as a candidate beam for a downlink TCI (e.g., a downlink signal / channel). If the reported beam belongs to an uplink TCI or is a source signal of an uplink TCI, or if the reported event is an event regarding an uplink beam, the base station can consider the reported beam as a candidate beam for an uplink TCI (e.g., an uplink signal / channel). If the reported beam belongs to both downlink TCI and uplink TCI, if the reported beam is used for both source signals of downlink TCI and uplink TCI, if the reported event includes both events regarding downlink beam and events regarding uplink beam, or if the reported event is an event regarding downlink beam and uplink beam, the base station can determine that the reported beam is a candidate beam for both downlink TCI and uplink TCI (e.g., both downlink signal / channel and uplink signal / channel). In this case, the base station can specify the transmission direction of the reported beam based on a predefined rule.

[0150] Meanwhile, unlike the descriptions of the above embodiments, a new candidate beam (target beam) to replace a deteriorated beam may not be found for several reasons. For example, the beam quality of all target beam candidates belonging to the beam set may be measured as falling below a reference value. Alternatively, if the beam quality reference value is changed during the beam quality measurement operation of the candidate beam, it may be difficult to identify a new candidate beam. Alternatively, even if a beam satisfying the beam quality reference value is found, if the transmission direction of the beam does not match the transmission direction of the existing beam or if the beam is in an inactive state, the beam may be difficult to use as a target beam.

[0151] In this case, the beam report information of the terminal may not include information about a new beam (e.g., a target beam). The operations according to (method 100) and (method 200) assume the existence of a target beam, but even if the target beam is not found, the terminal can trigger a beam report operation by distinguishing the transmission direction of the beam, and transmit beam report information including information about the transmission direction of the beam to the base station. For example, the beam report information may include at least one event in which the beam transmission direction is distinguished. In other words, the terminal can report an event in which the quality of a downlink beam is deteriorated and / or an event in which the quality of an uplink beam is deteriorated to the base station through the beam report procedure.

[0152] Depending on whether the beam report information includes information on a target beam, the operation of the base station can be determined. If the beam report information includes information on a target beam, the base station can transmit a response message confirming that the target beam will be applied to the terminal. Alternatively, the base station can indicate the target beam to the terminal using a general beam indication procedure (e.g., integrated TCI indication). On the other hand, if the beam report information does not include information on a target beam, the base station can control the terminal to change the beam measurement operation. In other words, the base station can set a new beam measurement target signal to the terminal so that the terminal can find another effective target beam, and can transmit the measurement target signal to the terminal. The terminal can additionally perform a beam measurement operation for the new signal(s) (e.g., the new measurement target signal(s)). If a target beam satisfying the condition is found, the terminal can report information on the target beam back to the base station. The additional beam measurement operation and report should be completed quickly, and the additional beam measurement operation and report can be performed based on a dynamic signaling (e.g., DCI) procedure. For example, beam measurement and reporting of the terminal may be performed based on aperiodic CSI-RS and aperiodic CSI reporting indicated by DCI, respectively. The beam measurement operation may be performed by CSI-RS that is repeatedly transmitted. CSI-RS occasions that constitute repeated transmission may have the same QCL relationship, and the reception beam of the terminal may be refined through beam measurement and reporting based on the CSI-RS. Alternatively, CSI-RS occasions that constitute repeated transmission may have independent QCL sources, and the transmission beam of the base station may be refined through beam measurement and reporting based on the CSI-RS. The terminal may recommend to the base station a beam procedure that it prefers among the former procedure and the latter procedure.Information about the preferred beam procedure may be transmitted to the base station as assistance information, and information about the preferred beam procedure may be included in beam report information.

[0153] Both beam reporting operations including a target beam and beam reporting operations not including a target beam can be supported by the same beam reporting configuration (e.g., CSI reporting configuration). For example, beam reporting information including a target beam and beam reporting information not including a target beam can be transmitted in the first and second periods of the CSI reporting configuration, respectively. To support the above operation, “information indicating whether the beam reporting information includes a target beam” or “information indicating that the beam reporting information does not include a target beam” can be included in the beam reporting information. For example, the presence or absence of a target beam can be expressed by 1 bit, and information indicating the presence or absence of a target beam can be mapped to the payload of the beam reporting information. As another example, some code points of a field indicating a TCI index of a target beam can be used to notify the base station that there is no target beam. Specifically, some of the code points may not be mapped to any TCI index.

[0154] The beam report information may include beam quality measurements for the current beam. For example, the terminal may report L1-RSRP measurements for the current TCI and L1-RSRP measurements for one or more target beam(s) together to the base station. The measurements of the current TCI or the measurements of the target beams may be expressed as differential values. For example, the measurements of the current TCI (or SSB) may be expressed as a difference value between the measurements of the current TCI and the measurements of the target beam. Alternatively, the measurements of the target beam may be expressed as a difference value between the measurements of the target beam and the measurements of the current TCI (or SSB). Considering the possibility that multiple target beams may be included in one beam report, the latter representation method may be advantageous in terms of reducing signaling overhead.

[0155] After determining beam reporting information according to the above-described method, the terminal can trigger a beam reporting operation. The beam reporting operation of the terminal can be performed by at least two methods. The first method may be a method in which the terminal directly transmits beam reporting information on a given uplink resource. The first method may be referred to as (method 300). The second method may be a method in which the terminal requests another uplink resource (hereinafter referred to as a second uplink resource) to transmit beam reporting information by transmitting a signal on a given uplink resource (hereinafter referred to as a first uplink resource). The second method may be referred to as (method 310).

[0156] FIG. 8 is a conceptual diagram illustrating a first embodiment of a beam reporting method by (method 300), and FIG. 9 is a conceptual diagram illustrating a first embodiment of a beam reporting method by (method 310).

[0157] Referring to FIGS. 8 and 9, a terminal may perform a physical signal transmission and reception operation based on an integrated TCI. The terminal may perform a beam quality measurement operation for a current TCI based on a QCL source signal (e.g., a CSI-RS resource) of the currently applied TCI. The current TCI may be a downlink TCI, an uplink TCI, or a joint TCI. The terminal may perform a beam measurement operation based on the QCL source signal, and the time required for the terminal to determine whether the beam quality of the current TCI is degraded may be referred to as T1.

[0158] If the beam quality of the current TCI (e.g., the beam of a specific signal) is determined to be degraded (e.g., below a reference value, invalid), the terminal may trigger a beam reporting operation. The terminal may perform a preparatory operation for uplink transmission for beam reporting. The preparatory operation may include an operation of determining beam report information, an operation of encoding and / or modulating the beam report information, an operation of mapping the beam report information onto an uplink physical resource, an operation of determining an uplink physical resource to transmit the beam report information, etc. The time required for the preparatory operation may be referred to as T2. The values ​​corresponding to T1 and T2 may be predefined in the technical specification. Alternatively, the values ​​corresponding to T1 and T2 may be set in the terminal from the base station. T1 and T2 may not be defined individually, and a value corresponding to (T1+T2) may be defined in the technical specification. Alternatively, a value corresponding to (T1+T2) may be set in the terminal from the base station. The values ​​corresponding to T1, T2, or (T1+T2) can be expressed as the number of symbols, the number of slots, or the sum of the number of symbols and the number of slots. T1 may further include the time for performing other operations in addition to the beam measurement operation and deterioration determination operation of the terminal described above. T2 may further include the time for performing other operations in addition to the uplink transmission preparation operation described above.

[0159] According to the embodiment of FIG. 8, the terminal can determine an uplink resource for transmitting beam report information, and perform a beam report operation based on the determined uplink resource. The uplink resource may be the earliest resource that appears after a time of (T1+T2) has elapsed from the CSI-RS resource among uplink resources set for beam reporting. The uplink resource may be a periodic PUCCH resource or a semi-persistent PUCCH resource. The uplink resource(s) may include a periodic PUCCH resource and a semi-persistent PUCCH resource, and the determined uplink resource may be a periodic PUCCH resource or a semi-persistent PUCCH resource that satisfies the above-described time relationship. The uplink resource may include an aperiodic PUCCH resource. For example, the terminal may select the earliest resource among PUCCH resources that satisfies the above-described time relationship regardless of the time domain characteristics of the PUCCH resource, and may report a new candidate beam using the selected earliest resource.

[0160] Valid uplink resources may include a PUSCH. Valid uplink resources may be used for transmitting beam reporting information. For example, the valid uplink resources may include a configured grant PUSCH, and the beam reporting information may be included in uplink control information (UCI) or configured grant-UCI (CG-UCI), and the UCI or the CG-UCI may be multiplexed with the configured grant PUSCH and transmitted to the base station. The valid uplink resources may include a dynamically scheduled PUSCH. Regardless of the scheduling type, the terminal may perform a beam reporting operation on the earliest resource among the PUSCH resources that satisfy the above-described time relationship. As a method for minimizing the beam reporting delay time, the terminal may perform a beam reporting operation on the earliest resource among the above-described PUCCH resources and PUSCH resources that satisfy the above-described time relationship. The earliest resource may be a PUCCH or a PUSCH. When a beam report is transmitted via PUCCH or PUSCH, the beam report information may be included in CSI (e.g., CSI payload). The PUCCH resource may be a PUCCH resource set at least for the purpose of transmitting CSI. The beam report information may be multiplexed with other CSI (e.g., information such as CQI, PMI, RI, LI, etc.), and the multiplexed beam report information and other CSI may be transmitted via PUCCH. When the beam report is transmitted via PUSCH, the beam report information may be defined as a MAC CE, the beam report information may be encoded into a TB, and the encoded TB (e.g., the encoded beam report information) may be mapped to a PUSCH resource. For example, a new MAC CE including beam report information triggered by a terminal may be defined, and the new MAC CE may be distinguished from a conventional MAC CE.

[0161] According to the embodiment of FIG. 9, the terminal may determine a first uplink resource and request another uplink resource (e.g., a second uplink resource) for transmitting beam report information through the determined first uplink resource. In the embodiment, the first uplink resource may be a PUCCH resource configured to transmit an SR (hereinafter referred to as a PUCCH SR resource), and the second uplink resource may be an uplink resource (e.g., a PUSCH or PUCCH) dynamically scheduled by DCI in response to the SR. The second uplink resource may be located on the same carrier as the first uplink resource. Alternatively, the second uplink resource may be located on a different carrier from the first uplink resource. The first uplink resource and the second uplink resource may be interrelated. The period of the second uplink resource may coincide with the period of the first uplink resource. Alternatively, the period of the second uplink resource may be different from the period of the first uplink resource. The first uplink resource may be the earliest resource that appears after a time equal to (T1+T2) from the CSI-RS resource among the valid uplink resources set for beam reporting. The valid uplink resources may include periodic PUCCH resources and / or semi-persistent PUCCH resources.

[0162] In the above embodiments, an uplink resource for transmitting beam report information or an uplink resource for requesting a resource for transmitting beam report information may be associated with a QCL source signal (e.g., a CSI-RS resource, an SSB resource) of a current TCI. An uplink resource for transmitting beam report information or an uplink resource for requesting a resource for transmitting beam report information may be configured as a dedicated resource for beam reporting triggered by a terminal. The uplink resource may be determined based on the QCL source signal (e.g., a CSI-RS resource). For example, a time resource (e.g., a slot, a symbol) of the uplink resource may be expressed as a resource shifted by a predetermined time offset from a time resource (e.g., a slot, a symbol) of the CSI-RS resource. The time offset may be transmitted to the terminal as configuration information for the uplink resource. According to an embodiment, the time offset may correspond to a time that is not shorter than (T1+T2). The periodicity of the above uplink resource may coincide with the periodicity of the CSI-RS resource. In this case, the periodicity value of the above uplink resource may not be separately signaled to the terminal. The periodicity value of the above uplink resource may be determined by the terminal based on the periodicity of the CSI-RS resource. The periodicity of the above uplink resource may be a divisor or a multiple of the periodicity of the CSI-RS resource.

[0163] In the above embodiment, the valid uplink resources may include PRACH resources and / or SRS resources. Since it is difficult to transmit a large amount of information on PRACH resources or SRS resources, PRACH resources or SRS resources may be used when the size of the beam report information is small (e.g., when the size of the beam report information is within several bits). Alternatively, PRACH resources or SRS resources may be used only for the purpose of the first uplink resource described above. In other words, PRACH resources or SRS resources may be used for the purpose of requesting other uplink resources.

[0164] Meanwhile, the uplink beam applied to the uplink resource for the above-described beam report may be degraded. For example, the uplink resource may be a resource to which an integrated TCI (e.g., an uplink integrated TCI or a joint integrated TCI) is applied, and the beam of the current integrated TCI (e.g., an uplink integrated TCI or a joint integrated TCI) may be instantaneously degraded or determined to be invalid. In this case, if the terminal reports a candidate beam based on the uplink resource and the degraded beam, the base station may not receive information on the candidate beam reported by the terminal.

[0165] As a method for solving the above problem, a method of configuring uplink resources for beam reporting in a form in which multiple resources are repeatedly arranged may be used. The multiple repeated resources may be distinguished in the time domain. In other words, the multiple repeated resources may be mapped to different symbol sets, and the multiple repeated resources may be arranged in the same slot or different slots. Each of the multiple resources may be interrelated with multiple uplink beams. The terminal may select one or more resources among the multiple resources, and perform an operation of requesting a beam reporting operation or another uplink resource on the selected resource(s) based on an uplink beam corresponding to the selected resource(s). At least an SR may be mapped to the selected resource(s). For example, the selected resource may be a PUCCH SR resource. Alternatively, at least a CSI (e.g., a CSI including beam reporting information) may be mapped to the selected resource(s). For example, the selected resource may be a PUCCH resource for CSI transmission.

[0166] In an embodiment, the uplink resource may be a PRACH resource, and the PRACH resource may include a plurality of repeated PRACH resources. According to another embodiment, the uplink resource may be an SRS resource, and the SRS resource may include a plurality of repeated SRS resources. The PRACH resource or the SRS resource may be configured in the terminal for a purpose other than beam reporting (e.g., contention-based random access, non-contention-based random access, uplink beam management, uplink CSI acquisition, etc.), and the terminal may reuse the PRACH resource or the SRS resource for the purpose of beam reporting. Based on the above operation, uplink resources may be saved since separate uplink resources are not required for beam reporting. Specific sequences or specific preambles of PRACH or SRS may be allocated as dedicated resources for beam reporting, and information regarding the number, set, etc. of the specific sequences or the specific preambles may be configured in the terminal from the base station. In other words, transmissions for beam reporting purposes and transmissions for other purposes can be distinguished by sequences or preambles.

[0167] The uplink beam to be applied to the above-described multiple repeated PRACH resources may be arbitrarily determined by the terminal. Alternatively, the beam of the PRACH resources may be formed based on the reception beam of the SSB resource(s) that are interrelated. The reception beam of the SSB resource may have little correlation with the integrated TCI (e.g., uplink integrated TCI, joint integrated TCI). An uplink beam (e.g., TCI, spatial relationship information) may be configured for the SRS resources. The configured uplink beam may be a beam allocated for a purpose other than beam reporting. The configured uplink beam may have little correlation with the integrated TCI (e.g., uplink integrated TCI, joint integrated TCI). In order to perform the proposed integrated TCI-based beam reporting procedure, it may be necessary to define a mapping relationship between PRACH resources and uplink beams (e.g., TCIs) or between SRS resources and uplink beams (e.g., TCIs). The mapping relationship will be described later.

[0168] As a method for further improving uplink resource efficiency, PUCCH resources can be used as the uplink resources. PUCCH resources can include PUCCH resources (or PUCCH repeated transmissions, PUCCH instances) that are repeated L times in the time domain. A mapping relationship between the repeated PUCCH resources and uplink beams (e.g., TCIs) can be defined. When the number of uplink beams (e.g., TCIs) is N, the mapping relationship can generally be established between L PUCCH resources and N uplink beams (e.g., TCIs). Each of L and N can be a natural number.

[0169] As described above, an uplink beam may correspond to an integrated TCI. The N uplink beams may be TCIs belonging to an integrated TCI pool (e.g., an integrated TCI list). According to the above-described condition, the N uplink beams may include only activated TCIs. For example, N TCIs may be selected from M activated uplink or joint integrated TCIs, and the selected N TCIs may be mapped to the L PUCCH resources or a portion of the L PUCCH resources. M may be greater than or equal to N. More specific details will be described through the embodiments below.

[0170] FIG. 10 is a conceptual diagram illustrating a first embodiment of a beam reporting method based on repeated PUCCH resources.

[0171] Referring to FIG. 10, a terminal may receive from a base station a configuration of PUCCH resources that are repeated four times in the time domain for the above-described beam reporting operation. The terminal may receive indications (e.g., configurations) of four activated uplink TCIs from the base station. In other words, L may be 4 and N may be 4. The four activated uplink TCIs may be sequentially mapped to the four PUCCH resources. In other words, the first to fourth activated uplink TCIs may be interrelated with the first to fourth PUCCH resources, respectively. For example, an activated TCI having a low index (or a high index) may be mapped to an earlier PUCCH resource (or a later PUCCH resource).

[0172] The terminal may select one resource (e.g., a second PUCCH resource) from among four PUCCH resources to be used for beam reporting. The terminal may report CSI (e.g., CSI including beam reporting information) to the base station based on the second activated uplink TCI corresponding to the second PUCCH resource in the second PUCCH resource or transmit an SR requesting uplink resources.

[0173] In the above embodiment, M and N may be 4. In other words, all activated uplink TCIs may be mapped one-to-one to PUCCH resources. Alternatively, M may be greater than N, and N may be 4. In this case, the terminal may select N TCIs from the M activated uplink TCIs, and map the selected N uplink TCIs to the PUCCH resources. The N uplink TCIs may be selected according to a predetermined rule. For example, the N uplink TCIs may be selected in order of low TCI index (or high TCI index). For another example, the N uplink TCIs may be selected in order of uplink TCI activation first (or last activation first). Alternatively, the N uplink TCIs may be appropriately determined by the base station, and information about the determined N uplink TCIs may be transmitted from the base station to the terminal. The terminal can identify N uplink TCIs based on the above information and map the identified N uplink TCIs to the PUCCH resources. If M is greater than N, and there is no valid beam among the TCIs (e.g., uplink TCIs) mapped to the PUCCH resources, the terminal may not perform a beam reporting operation using the PUCCH resources.

[0174] In the above embodiment, the terminal may not expect the number of uplink resources (e.g., L) to be set to a value smaller than the number of activated uplink TCIs (e.g., M or N). The terminal may always expect the setting of L>=M or L>=N. If L>=M or L>=N is not set, the terminal may consider the setting as an error. If the setting is considered an error, the terminal may not perform a beam reporting operation using the uplink resources.

[0175] FIG. 11 is a conceptual diagram illustrating a second embodiment of a beam reporting method based on repeated PUCCH resources.

[0176] Referring to FIG. 11, two activated uplink TCIs may be mapped to four repeated PUCCH resources. In other words, N may be 4, and N may be 2. All activated uplink TCIs may be mapped to the PUCCH resources. In other words, M and N may be 2. Alternatively, the two uplink TCIs may be uplink TCIs selected by the base station or by a predetermined rule from among the M activated uplink TCIs. In other words, M may be greater than N, and N may be 2. In this case, the remaining (LN) PUCCH resources (e.g., the third PUCCH resource and the fourth PUCCH resource) to which no uplink TCIs are mapped may not be used at least for beam reporting purposes. The terminal may transmit other uplink signals and channels on the third PUCCH resource and the fourth PUCCH resource. The above other uplink signals and channels may be dynamically allocated by the base station. Alternatively, the above other uplink signals and channels may be semi-statically set resources that overlap with the third PUCCH resource or the fourth PUCCH resource.

[0177] Alternatively, the terminal may not expect the number of uplink resources (e.g., L) to be set to a value greater than the number of activated uplink TCIs (e.g., M or N). The terminal may always expect L<=M or L<=N. If L<=M or L<=N is not set, the terminal may consider the setting as an error. If the setting is considered an error, the terminal may not perform a beam reporting operation using the uplink resources. Alternatively, based on a combination with the above-described method, the terminal may always expect L=M or L=N to be set. If L=M or L=N is not set, the terminal may consider the setting as an error.

[0178] In another embodiment, the number of uplink resources may be limited to 2. In other words, L may be 2.

[0179] FIG. 12 is a conceptual diagram illustrating a third embodiment of a beam reporting method based on repeated PUCCH resources.

[0180] Referring to FIG. 12, two PUCCH resources may be configured in a terminal for a beam reporting operation initiated by the terminal. The first PUCCH resource and the second PUCCH resource may be recurring PUCCH resources. The first PUCCH resource and the second PUCCH resource may be independently configured resources, and configuration information such as resource format, location, and size may be different between the first PUCCH resource and the second PUCCH resource. An uplink beam mapping method different from the method applied to the above embodiment may be applied to the embodiment of FIG. 12. For example, the first PUCCH resource may be correlated with a currently used (activated) uplink TCI or a joint TCI. The second PUCCH resource may be correlated with a current TCI and any other (activated) TCI. The other TCI may refer to a TCI corresponding to a backup beam, a default beam, etc. The above other TCI may be any one of the uplink TCIs or the activated joint TCIs activated by a predefined rule. Alternatively, the above other TCI may be dynamically or semi-statically configured for the terminal by the base station. When the current TCI of the terminal and / or the above other TCI are updated by the TCI instruction, the TCI(s) mapped to the PUCCH resource(s) may also be updated with a corresponding beam.

[0181] The method applied to the above embodiments can be equally applied to beam reporting operations based on PRACH resources and SRS resources. In other words, in the above embodiments, the PUCCH resources repeated L times can correspond to the PRACH resources repeated L times or the SRS resources repeated L times, and the TCI mapping method described above can be equally applied to the PRACH resources repeated L times and the SRS resources repeated L times.

[0182] Multiple uplink resource sets may be configured for beam reporting. For example, a first uplink resource set consisting of a single PUCCH resource (or, PRACH resource, SRS resource, etc.) and / or a second uplink resource set consisting of repeated PUCCH resources (or, PRACH resource, SRS resource, etc.) may be configured for the terminal. The terminal may select one of the first uplink resource set and the second uplink resource set based on a predetermined condition, and may perform the above-described beam reporting operation based on the selected resource set. For example, if the currently applied uplink TCI is valid, beam reporting may be performed based on the first uplink resource set. Conversely, if the current uplink TCI is invalid, beam reporting may be performed based on the second uplink resource set. The first uplink resource set and the second uplink resource set may overlap. In an embodiment, the first uplink resource set may be a subset of the second uplink resource set. In other words, the PUCCH resources (or PRACH resources, SRS resources, etc.) constituting the second uplink resource set may include the PUCCH resources (or PRACH resources, SRS resources, etc.) of the first uplink resource set.

[0183] Uplink resources for transmitting beam report information and / or uplink resources for requesting resources for beam report information may be allocated to a serving cell different from the serving cell where the terminal measured the downlink resources. In other words, the above-described beam measurement operation and the above-described beam reporting operation may be performed in different serving cells. The new candidate beam reported by the terminal may be applied not only to the serving cell where the terminal performed the beam measurement (e.g., the first serving cell) but also to a serving cell different from the serving cell where the terminal performed the beam measurement (e.g., the second serving cell). A QCL relationship may be established between the first serving cell and the second serving cell. For example, at least one downlink signal or at least one uplink signal transmitted from the second serving cell may be configured to have a QCL relationship with the SSB of the first serving cell. The second serving cell may be the same as or different from the serving cell to which the uplink resource is allocated.

[0184] The integrated TCI of a terminal may be updated while a beam reporting operation or a preparation operation for beam reporting is being performed. In other words, the terminal may receive information (e.g., TCI indication information) indicating to apply a new TCI (e.g., a second TCI) that is different from the currently applied TCI (e.g., a first TCI). Specifically, the terminal may receive DCI including the TCI indication information, and may complete a decoding operation for the DCI between a first time point and a second time point. A time point (e.g., a slot or a symbol) for applying the TCI indicated by the DCI may be located between the first time point and the second time point. For example, the first time point may be a time point (e.g., a slot or a symbol) at which the terminal determines beam quality degradation of the current TCI. Alternatively, the first time point may be a resource (e.g., a slot or a symbol) at which the terminal receives a QCL source signal (e.g., a CSI-RS resource or an SSB resource) of the current TCI. The second time point may be the uplink resource (e.g., slot, symbol) used for beam reporting. Alternatively, the second time point may refer to a time point or resource (e.g., slot, symbol) that is (T1+T2) after the above-described reference resource (e.g., CSI-RS resource, SSB resource).

[0185] In the above-described embodiment, the terminal may stop a beam reporting operation triggered by the current TCI (e.g., the first TCI). In other words, the terminal may skip an uplink transmission operation being prepared for beam reporting. If the beam quality of the newly indicated TCI (e.g., the second TCI) is determined to be degraded or invalid, the terminal may trigger a new beam reporting operation based on the TCI (e.g., the second TCI). The time point at which the terminal determines the beam quality of the TCI may be independent of the reception resources of the DCI indicating the TCI. For example, "the time point (e.g., slot, symbol) at which the terminal receives a QCL source signal corresponding to the indicated new TCI and performs a beam measurement operation" may be earlier than, the same as, or later than the reception resources (e.g., slot, symbol) of the DCI. The beam reporting operation triggered by the terminal may be performed at most once at a time point. In other words, the beam reporting operation of the terminal may be performed by at most one triggering. Alternatively, in the above-described embodiment, the terminal may continue to perform the beam reporting operation triggered by the current TCI (e.g., the first TCI) and may perform the uplink transmission being prepared as is. In this case, if the beam quality of the newly indicated TCI (e.g., the second TCI) is determined to be degraded or invalid, the terminal may not initiate a new beam reporting operation based on the second TCI until the beam reporting operation is completed (e.g., until an uplink signal including beam reporting information is transmitted). Alternatively, the beam reporting operation based on the first TCI and the beam reporting operation based on the second TCI may be performed in parallel and simultaneously. In this case, the terminal may expect that the uplink resources corresponding to the first TCI and the uplink resources corresponding to the second TCI do not overlap with each other.For example, the uplink resource corresponding to the second TCI may be allocated to a later resource than the uplink resource corresponding to the first TCI.

[0186] In the above embodiments, one or more new candidate beams may be reported. The terminal may select multiple candidate beams from the candidate beam set and transmit information about the multiple selected candidate beams on one uplink resource. The multiple candidate beams may be included in one beam report or one CSI report. In this case, the terminal may sequentially map the multiple candidate beams to the CSI payload in order of high (or low) beam quality. The base station may determine a priority among the multiple candidate beams based on the above rule. Alternatively, beam quality measurements (e.g., L1-RSRP, L1-SINR, hypothetical SINR, etc.) corresponding to the new candidate beam(s) may be explicitly included in the beam report or CSI report together with the new candidate beam(s).

[0187] The beam report information or CSI report information may include information about a cell ID (e.g., a physical layer cell identifier (PCI)). For example, the cell ID of a serving cell where an event occurred may be included in the beam report information together with information about the event. As another example, the cell ID of a serving cell where the beam quality of a candidate beam is measured (e.g., a serving cell where a QCL source signal of a TCI is received) may be included in the beam report information together with information about the candidate beam. Alternatively, the cell ID may indicate the ID of a target serving cell to which a new beam is to be applied. The target serving cell may be arbitrarily determined by the terminal. Alternatively, one or more of the cell IDs in the above embodiments may be included in the beam report information. The information about the cell ID may include a cell ID value. Alternatively, the information about the cell ID may include a separate index for indicating cell ID(s) set in the terminal. For example, the separate index can be indexed from 0 to ((the number of cell IDs set in the terminal) - 1). By the above-described method, the proposed beam reporting method may not be limited to operations within a serving cell, but may be extended to beam measurement, discovery, and reporting operations between serving cells. For example, the terminal may update the beam of the second serving cell using the optimal beam found in the first serving cell.

[0188] According to the above-described terminal-triggered beam reporting method, the signaling overhead for beam reporting can be reduced, and the delay time required for beam switching can be shortened. Therefore, resource efficiency and link stability can be improved compared to the conventional beam reporting method triggered by the base station. Since the terminal determines the transmission direction of the candidate beam and reports the related information (explicitly or implicitly), the base station may not perform a separate procedure for determining the transmission direction of the beam. The above operation may be advantageous for the high-speed beam switching operation described later. According to the above embodiment, the beam quality value of the candidate beam can be excluded from the beam reporting information (or, CSI reporting information), and thus the UCI overhead can be reduced, and the range of selection of uplink resources for transmitting UCI can be expanded.

[0189] Some configurations of the above-described method can be equally applied to the beam failure recovery procedure of the terminal. For example, when a beam failure occurs, the terminal can search for a beam to replace the beam in which the beam failure occurred from the above-described beam set (e.g., a beam set configured based on the TCI pool), and can transmit one or more beams (e.g., information on one or more beams) that satisfy the beam quality criterion q1 to the base station via the PRACH or PUSCH. The same beam set can be commonly used for the beam reporting procedure and the beam recovery procedure of the terminal. Alternatively, an inclusion relationship can be established between the beam set used for the beam reporting procedure and the beam set used for the beam recovery procedure.

[0190] [Beam switching method]

[0191] The beam of the terminal can be dynamically controlled by the base station. The base station can determine a downlink beam and / or an uplink beam suitable for the terminal based on beam report information received from the terminal, and can indicate the determined beam to the terminal. The beam indication operation can be performed based on the integrated TCI framework. Alternatively, the beam indication operation can be performed by individual signaling procedures for each physical signal and channel. The beam indication information can be transmitted to the terminal by terminal-specific DCI including scheduling information of a data channel. The transmission resource of the DCI (e.g., a PDCCH search space set) can be set independently from the uplink resource for beam reporting. In an NR communication system, the DCI can include DCI format 1_0, DCI format 1_1, DCI format 1_2, DCI format 1_3, DCI format 0_0, DCI format 0_1, DCI format 0_2, DCI format 0_3, etc. Scheduling DCIs can have relatively large payload sizes, and can be mapped to a wide resource area (e.g., multiple CCEs) for high-reliability transmission. When updating a terminal's beam using the above method, signaling overhead can be significant, and the delay time until beam updates can increase depending on the monitoring cycle of the DCI format.

[0192] A method may be considered in which, in conjunction with the beam report of the terminal, the terminal switches the beam to the candidate beam reported to the base station on its own. Alternatively, a method may be considered in which, with minimal intervention by the base station, the base station may transmit a confirm message or simplified beam indication information to the terminal based on the beam report of the terminal, and the terminal switches the beam based on reception of the confirm message or the received simplified beam indication information. If the candidate beam is a downlink beam, the terminal may switch the downlink beam to the candidate beam. If the candidate beam is an uplink beam, the terminal may switch the uplink beam to the candidate beam. If the candidate beam is a beam for both uplink and downlink, the terminal may switch the uplink beam and the downlink beam to the candidate beam. The above-described method may be referred to as (method 400).

[0193] Figure 13 is a conceptual diagram illustrating a first embodiment of a beam switching method without intervention of a base station.

[0194] Referring to FIG. 13, a terminal may report a new beam to a base station based on an uplink resource determined by the above-described method. The new beam may be an integrated TCI, and the new beam may be a different beam from the current TCI. The current TCI may be interpreted as a previous TCI from a beam switching perspective. The terminal may determine when to apply the reported beam based on the resource for which the beam is reported. The beam may be applied from a specific slot or symbol determined in consideration of the time (e.g., T3) required for the base station to decode the uplink resource. For example, the specific slot may be determined as a slot that is K1 times later than a slot to which the uplink resource is mapped. The specific symbol may be determined as a symbol that is K2 times later than the last symbol of the uplink resource. Alternatively, the specific slot may be determined as the first slot that appears after a symbol that is K3 times later than the uplink resource (e.g., the last symbol of the uplink resource). Each of K1, K2, and K3 can be a natural number.

[0195] Fig. 14 is a conceptual diagram illustrating a first embodiment of a beam switching method by intervention of a base station.

[0196] Referring to FIG. 14, a terminal may report a new beam to a base station based on uplink resources determined by the above-described method. The new beam may be an integrated TCI, or may be a beam different from the current TCI. The base station may receive the beam report, and transmit a confirmation message or beam indication information to the terminal as a response to the beam report. The confirmation message or beam indication information may be transmitted via DCI. The terminal may receive the DCI (e.g., a DCI including the confirmation message or beam indication information) and determine when to apply the reported beam based on the resources on which the DCI is received. The beam may be applied from a specific slot or symbol determined in consideration of the time (e.g., T4) required for the terminal to decode the DCI. For example, the specific slot may be determined as a slot that is K4 times later than a slot to which the DCI is mapped. The specific symbol may be determined as a symbol that is K5 times later than the last symbol to which the DCI is mapped. Alternatively, the particular slot may be determined as the first slot that appears after K6 symbols later than the resource to which the DCI is mapped (e.g., the last symbol to which the DCI is mapped). Each of K4, K5, and K6 may be a natural number.

[0197] According to the above-described method, a terminal can report multiple candidate beams to a base station. For example, the terminal can report multiple candidate beams to the base station for one transmission direction (e.g., downlink or uplink). In this case, the terminal can determine one of the multiple reported candidate beams as a new TCI and switch the beam for the corresponding transmission direction with the determined TCI. For example, the terminal can determine the beam with the highest beam quality among the multiple candidate beams as the new TCI.

[0198] The above beam report information may include both a downlink candidate beam and an uplink candidate beam. In this case, the time point at which the downlink beam is switched to the downlink candidate beam and the time point at which the uplink beam is switched to the uplink candidate beam may coincide. The base station may generate a common confirmation message for the downlink candidate beam and the uplink candidate beam, and transmit the common confirmation message to the terminal through the same DCI. The terminal may receive the DCI from the base station, and confirm the common confirmation message for the downlink candidate beam and the uplink candidate beam included in the DCI.

[0199] According to an embodiment, a terminal may report a first TCI belonging to a downlink TCI pool to a base station as a new candidate beam for a downlink TCI. Based on the above-described method, the terminal may switch the downlink TCI to the first TCI. The first TCI may be included not only in the downlink TCI pool but also in the uplink TCI pool (e.g., a set of activated uplink TCIs). In this case, even though the terminal has not performed a beam reporting operation for the uplink TCI, the terminal may switch the uplink TCI to the first TCI based on the downlink beam reporting. The time point of switching the uplink TCI may coincide with the time point of switching the downlink TCI.

[0200] The above embodiment can be equally applied even when the transmission direction is reversed. For example, the terminal can report the second TCI belonging to the uplink TCI pool to the base station as a new candidate beam for the uplink TCI. Based on the above-described method, the terminal can switch the uplink TCI to the second TCI. The second TCI can be included not only in the uplink TCI pool but also in the downlink TCI pool (e.g., a set of activated downlink TCIs). In this case, even though the terminal has not performed a beam reporting operation for the downlink TCI, the terminal can switch the downlink TCI to the second TCI based on the uplink beam reporting.

[0201] According to (method 200), the transmission direction of the reported candidate beam may not be distinguished. Even though the transmission direction of the reported candidate beam is not distinguished, the base station can determine the transmission direction of the candidate beam based on the inclusion relationship between the candidate beam and the TCI pool. The terminal can update the downlink beam and / or the uplink beam based on the inclusion relationship between the reported candidate beam and the TCI pool. If the reported candidate beam belongs to a downlink TCI (e.g., a set of activated downlink TCIs), the terminal can replace the downlink TCI with the candidate beam based on the method described above. If the reported candidate beam belongs to an uplink TCI (e.g., a set of activated uplink TCIs), the terminal can replace the uplink TCI with the candidate beam based on the method described above. If the reported candidate beam belongs to both a downlink TCI (e.g., a set of activated downlink TCIs) and an uplink TCI (e.g., a set of activated uplink TCIs), the terminal may replace the downlink TCI and the uplink TCI with the candidate beam.

[0202] The operations of the method according to the embodiments of the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores information readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0203] Additionally, the computer-readable recording medium may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. The program instructions may include not only machine language codes produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0204] While some aspects of the present disclosure have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one or more of the most significant method steps may be performed by such a device.

[0205] In embodiments, a programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described herein. In embodiments, the field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. In general, the methods are preferably performed by some hardware device.

[0206] Although the present disclosure has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the claims below.

Claims

1. As a terminal method, A step of receiving setting information of periodic downlink resources from a base station; A step of performing a beam measurement operation for a first signal received from the above periodic downlink resource; A step of determining that an event has occurred based on the result of the above beam measurement operation; When the above event occurs, a step of generating beam report information; and A step of performing a reporting operation on the beam report information based on the above event, The beam measuring operation includes an operation of deriving a beam quality value of the first signal N times, and the beam reporting information includes at least an index of the periodic downlink resource. Terminal method.

2. In claim 1, The steps for determining that the above event has occurred are: A step of comparing the beam quality values ​​derived N times with the reference value; and Including a step of determining that the event has occurred based on the comparison result between the beam quality values ​​derived N times and the reference value. Terminal method.

3. In claim 1, The above periodic downlink resource corresponds to a first TCI (transmission configuration information) belonging to a list of TCIs set in the terminal, and the first TCI is an activated TCI. Terminal method.

4. In claim 1, The above beam quality value is RSRP (reference signal received power), and the reference value is a beam quality value of a periodic downlink resource corresponding to the current beam of the terminal. Terminal method.

5. In claim 1, In the section where the above beam measurement operation is performed, the reference value does not change. Terminal method.

6. In claim 1, The first signal is received within a preset time interval, wherein the preset time interval includes one or more periods for the periodic downlink resource. Terminal method.

7. In claim 1, The above reporting operation is an operation to notify the base station that "the terminal transmits an SR (scheduling request) in the first uplink resource and transmits a PUSCH (physical uplink shared channel) in the second uplink resource." Terminal method.

8. In claim 7, The above PUSCH includes the beam reporting information, Terminal method.

9. In claim 7, The second uplink resource is interrelated with the first uplink resource, and the period of the second uplink resource is identical to the period of the first uplink resource. Terminal method.

10. As a method of base station, A step of transmitting configuration information of periodic downlink resources to a terminal; A step of transmitting a first signal for beam measurement operation of the terminal to the terminal from the periodic downlink resource; and A step of receiving a report on beam report information from the terminal when an event occurs based on the result of the above beam measurement operation, The beam measuring operation includes an operation of deriving a beam quality value of the first signal N times, and the beam reporting information includes at least an index of the periodic downlink resource. Method of base station.

11. In claim 10, The above periodic downlink resource corresponds to a first TCI (transmission configuration information) belonging to a list of TCIs set in the terminal, and the first TCI is an activated TCI. Method of base station.

12. In claim 10, The first signal is transmitted within a preset time interval, wherein the preset time interval includes one or more periods for the periodic downlink resource. Method of base station.

13. In claim 10, The above report includes information that informs the base station that "the terminal transmits an SR (scheduling request) in the first uplink resource and transmits a PUSCH (physical uplink shared channel) in the second uplink resource." Method of base station.

14. In claim 13, The above PUSCH includes the beam reporting information, Method of base station.

15. In claim 13, The second uplink resource is interrelated with the first uplink resource, and the period of the second uplink resource is identical to the period of the first uplink resource. Method of base station.

16. As a terminal, Contains at least one processor, At least one processor of the terminal, Receive periodic downlink resource configuration information from a base station; Performing a beam measurement operation for a first signal received from the above periodic downlink resource; An event is determined to have occurred based on the result of the above beam measurement operation; When the above event occurs, generate beam report information; and Causes a reporting action to be performed on the beam reporting information based on the above event, The beam measuring operation includes an operation of deriving a beam quality value of the first signal N times, and the beam reporting information includes at least an index of the periodic downlink resource. Terminal.

17. In claim 16, When the above event is determined to have occurred, the at least one processor causes the terminal to: Compare the beam quality values ​​derived N times with the reference value; and Causing the event to be determined to have occurred based on the comparison result between the beam quality values ​​derived N times and the reference value. Terminal.

18. In claim 16, The above periodic downlink resource corresponds to a first TCI (transmission configuration information) belonging to a list of TCIs set in the terminal, and the first TCI is an activated TCI. Terminal.

19. In claim 16, The above reporting operation is an operation to notify the base station that "the terminal transmits an SR (scheduling request) in the first uplink resource and transmits a PUSCH (physical uplink shared channel) in the second uplink resource." Terminal.

20. In claim 16, The PUSCH includes the beam reporting information, the second uplink resource is interrelated with the first uplink resource, and the period of the second uplink resource is identical to the period of the first uplink resource. Terminal.

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