Method and apparatus for user equipment-initiated beam management

Abstract

This method, of a user equipment, for user equipment-initiated beam management may include the steps of: determining whether a condition for transmitting a signal for triggering user equipment-initiated beam management is satisfied; when it is determined that the condition is satisfied, transmitting, to a base station, the signal for triggering user equipment-initiated beam management; receiving, from the base station, a channel state information (CSI)-related reference signal; and as a result of measuring the CSI-related reference signal, when a beam reporting event has occurred, transmitting, to the base station, a measurement report related to the beam reporting event.

Description

Terminal-driven beam management method and device

[0001] The present invention relates to beam management of a mobile communication system, and more particularly, to a terminal-driven beam management method and device.

[0002] Communication networks (e.g., 5G communication networks, 6G communication networks, etc.) are being developed to provide improved communication services compared to existing communication networks (e.g., long term evolution (LTE), advanced LTE-A (LTE-A), etc.). 5G communication networks (e.g., new radio (NR) communication networks) can support frequency bands above 6 GHz as well as frequency bands below 6 GHz. That is, 5G communication networks can support FR1 bands and / or FR2 bands. 5G communication networks can support various communication services and scenarios compared to LTE communication networks. For example, usage scenarios of 5G communication networks can include enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), etc.

[0003] Compared to 5G, 6G communication networks can support a wider range of communication services and scenarios. 6G communication networks can meet requirements for ultra-high performance, ultra-high bandwidth, ultra-high space, ultra-high precision, ultra-intelligence, and / or ultra-reliability. 6G communication networks can support diverse and wide frequency bands and be applied to various usage scenarios (e.g., terrestrial communications, non-terrestrial communications, sidelink communications, etc.).

[0004] Meanwhile, 3GPP (3 rdIn Release-19 of the 5GPP, standardization of user equipment-initiated / event-driven beam management is underway to resolve the problems of conventional network-driven beam management. Unlike conventional network-driven beam management, user equipment-initiated / event-driven beam management is a method in which the user equipment proactively performs beam management because it can recognize the current beam status and beam change trend relatively quickly compared to the base station. However, the method of switching from network-driven beam management to user equipment-initiated beam management and the signaling methods required for this have not yet been specified.

[0005] The purpose of the present disclosure to solve the above problems is to provide a method and device for performing terminal-led beam management.

[0006] According to one embodiment of the present disclosure for achieving the above object, a method of a terminal may include: a step of determining whether a condition for transmitting a terminal-led beam management triggering signal is satisfied; a step of transmitting the terminal-led beam management triggering signal to a base station when the condition is determined to be satisfied; a step of receiving a reference signal related to channel state information (CSI) from the base station; and a step of transmitting a measurement report related to a beam reporting event to the base station when a beam reporting event occurs as a result of measuring the CSI-related reference signal.

[0007] Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on whether a specific event has occurred in the terminal, and the specific event may be movement, rotation, or signal quality degradation of the terminal.

[0008] Whether the conditions for transmitting the above terminal-driven beam management triggering signal are met can be determined based on at least one of the measurement results of a CSI-RS (CSI-reference signal) or SSB (synchronization signal block) set by measurement configuration information received from the base station, the measurement results of a CSI-RS or SSB separately set for triggering terminal-driven beam management, or the measurement results for a separate pre-arranged signal or resource other than the CSI-RS or SSB.

[0009] The above terminal-driven beam management triggering signal may be transmitted via medium access control (MAC) control element (CE) and / or uplink control information (UCI).

[0010] The second container used for transmission of the measurement report may be determined according to the first container used for transmission of the terminal-led beam management triggering signal, and the first container may be a MAC CE or UCI, and the second container may be a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH).

[0011] The CSI-related reference signal may be transmitted after a first time offset from the time point at which the terminal-led beam management triggering signal is received from the terminal, and the measurement report may be received after a second time offset from the time point at which the terminal-led beam management triggering signal is received.

[0012] The terminal-led beam management triggering signal may include information requesting at least one of a transmission time of the CSI-related reference signal, a transmission period of the CSI-related reference signal, a number of transmissions of the CSI-related reference signal, and a transmission duration of the CSI-related reference signal.

[0013] The above measurement report may include information explicitly or implicitly indicating the beam that the terminal wishes to use.

[0014] The terminal-driven beam management may be performed based on at least one or a combination of two or more of a periodic CSI measurement reporting operation, an aperiodic CSI measurement reporting operation, or a semi-persistent CSI measurement reporting operation.

[0015] According to one embodiment of the present disclosure for achieving the above object, a method of a base station may include: receiving a terminal-driven beam management triggering signal from a terminal; transmitting a CSI (channel state information) related reference signal to the terminal in response to the terminal-driven beam management triggering signal; and receiving a measurement report related to a beam reporting event from the terminal, wherein the terminal may transmit the terminal-driven beam management triggering signal to the base station when a condition for transmitting the terminal-driven beam management triggering signal is satisfied, and may transmit the measurement report to the base station when the beam reporting event occurs as a result of measuring the CSI-related reference signal.

[0016] Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on whether a specific event has occurred in the terminal, and the specific event may be movement, rotation, or signal quality degradation of the terminal.

[0017] Whether the conditions for transmitting the above terminal-driven beam management triggering signal are met can be determined based on at least one of the measurement results of a CSI-RS (CSI-reference signal) or SSB (synchronization signal block) set by measurement configuration information transmitted by the base station to the terminal, the measurement results of a CSI-RS or SSB separately set for triggering terminal-driven beam management, or the measurement results for a separate pre-arranged signal or resource other than the CSI-RS or SSB.

[0018] The second container used for receiving the measurement report may be determined according to the first container used for receiving the terminal-led beam management triggering signal, and the first container may be MAC CE or UCI, and the second container may be PUCCH or PUSCH.

[0019] The terminal-led beam management triggering signal may include information requesting at least one of a transmission time of the CSI-related reference signal, a transmission period of the CSI-related reference signal, a number of transmissions of the CSI-related reference signal, and a transmission duration of the CSI-related reference signal.

[0020] The above measurement report may include information explicitly or implicitly indicating the beam that the terminal wishes to use.

[0021] In order to achieve the above object, one embodiment of the present disclosure includes a terminal including at least one processor, and the at least one processor may perform the following steps: determining whether a condition for transmitting a terminal-led beam management triggering signal is satisfied; if it is determined that the condition is satisfied, transmitting the terminal-led beam management triggering signal to a base station; receiving a reference signal related to CSI (channel state information) from the base station; and if a beam report event is generated as a result of measuring the CSI-related reference signal, transmitting a measurement report related to the beam report event to the base station.

[0022] Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on whether a specific event has occurred in the terminal, and the specific event may be movement, rotation, or signal quality degradation of the terminal.

[0023] Whether the conditions for transmitting the above terminal-driven beam management triggering signal are met can be determined based on at least one of the measurement results of a CSI-RS (CSI-reference signal) or SSB (synchronization signal block) set by measurement configuration information received from the base station, the measurement results of a CSI-RS or SSB separately set for triggering terminal-driven beam management, or the measurement results for a separate pre-arranged signal or resource other than the CSI-RS or SSB.

[0024] The terminal-led beam management triggering signal may include information requesting at least one of a transmission time of the CSI-related reference signal, a transmission period of the CSI-related reference signal, a number of transmissions of the CSI-related reference signal, and a transmission duration of the CSI-related reference signal.

[0025] The above measurement report may include information explicitly or implicitly indicating the beam that the terminal wishes to use.

[0026] When applying the embodiments of the present disclosure, a terminal can switch from performing existing base station-led beam management to terminal-led beam management without delay. Furthermore, when applying the embodiments of the present disclosure, the uplink signaling overhead for switching to terminal-led beam management can be minimized. Since the switch from performing base station-led beam management to terminal-led beam management is performed without increasing signaling overhead and delay time, the overall system performance can be improved, especially in high-frequency bands (e.g., FR2 bands) where rapid beam switching is essential.

[0027] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0028] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0029] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0030] Figure 4a is a block diagram illustrating a first embodiment of a transmission path.

[0031] Figure 4b is a block diagram illustrating a first embodiment of a receiving path.

[0032] Figure 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0033] Figure 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0034] Figure 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0035] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0036] Figure 9 is a flowchart illustrating the periodic CSI measurement reporting procedure.

[0037] Figure 10 is a flowchart illustrating an aperiodic CSI measurement reporting procedure.

[0038] Figure 11 is a flowchart illustrating a semi-persistent CSI measurement reporting procedure.

[0039] FIG. 12 is a flowchart illustrating a triggering method of terminal-led beam management according to one embodiment of the present invention.

[0040] FIG. 13 is a flowchart illustrating a triggering method of terminal-led beam management according to another embodiment of the present invention.

[0041] 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.

[0042] 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" may refer to a combination of multiple related items described herein or to any of multiple related items described herein.

[0043] In 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.” Additionally, in 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.”

[0044] In the present disclosure, (re)transmission may mean “transmission,” “retransmission,” or “transmission and retransmission,” (re)setting may mean “setting,” “resetting,” or “setting and resetting,” (re)connection may mean “connection,” “reconnection,” or “connection and reconnection,” and (re)connection may mean “connection,” “reconnection,” or “connection and reconnection.”

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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, the same reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted. In addition to the embodiments explicitly described in the present disclosure, operations may be performed according to combinations of embodiments, extensions of embodiments, and / or modifications of embodiments. The performance of some operations may be omitted, and the order of operation may be changed.

[0049] In an embodiment, even if a method (e.g., transmitting or receiving a signal) performed by a first communication node among communication nodes is described, a corresponding second communication node can perform a method (e.g., receiving or transmitting a signal) corresponding to the method performed by the first communication node. That is, if an operation of a UE (user equipment) is described, a corresponding base station can perform an operation corresponding to the operation of the UE. Conversely, if an operation of a base station is described, a corresponding UE can perform an operation corresponding to the operation of the base station.

[0050] A base station may be referred to as a NodeB, an evolved NodeB, a gNodeB (next generation node B), a gNB, a device, an apparatus, a node, a communication node, a BTS (base transceiver station), a RRH (radio remote head), a TRP (transmission reception point), a RU (radio unit), an RSU (road side unit), a radio transceiver, an access point, an access node, etc. A UE may be referred to as a terminal, a device, an apparatus, a node, a communication node, an end node, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, an OBU (on-broad unit), etc.

[0051] In the present disclosure, signaling may be at least one of upper layer signaling, MAC signaling, or PHY (physical) signaling. A message used for upper layer signaling may be referred to as an "upper layer message" or an "upper layer signaling message." A message used for MAC signaling may be referred to as a "MAC message" or a "MAC signaling message." A message used for PHY signaling may be referred to as a "PHY message" or a "PHY signaling message." Upper layer signaling may refer to a transmission and reception operation of system information (e.g., a master information block (MIB), a system information block (SIB)) and / or an RRC message. MAC signaling may refer to a transmission and reception operation of a MAC control element (CE). PHY signaling may refer to a transmission and reception operation of control information (e.g., downlink control information (DCI), uplink control information (UCI), sidelink control information (SCI)).

[0052] In the present disclosure, “an operation (e.g., a transmission operation) is set” may mean that “setting information for the operation (e.g., an information element, a parameter)” and / or “information instructing the performance of the operation” is signaled. “An information element (e.g., a parameter) is set” may mean that the information element is signaled. In the present disclosure, “a signal and / or a channel” may mean a signal, a channel, or “a signal and a channel,” and a signal may be used to mean “a signal and / or a channel.”

[0053] The communication networks to which the embodiments are applied are not limited to those described below, and the embodiments may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the term "communication network" may be used interchangeably with the term "communication system."

[0054] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0055] 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.

[0056] 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 have the following structure.

[0057] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0058] Referring to FIG. 2, a communication node (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 communication node (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the communication node (200) may be connected by a bus (270) and communicate with each other.

[0059] 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).

[0060] 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).

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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, sidelink communication (e.g., device to device communication (D2D), 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.

[0065] 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 sidelink communication 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 sidelink communication under the control of the second base station (110-2) and the third base station (110-3), respectively.

[0066] Meanwhile, communication nodes performing communication in a communication network may be configured as follows. The communication node illustrated in Fig. 3 may be a specific embodiment of the communication node illustrated in Fig. 2.

[0067] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0068] Referring to FIG. 3, each of the first communication node (300a) and the second communication node (300b) may be a base station or a UE. The first communication node (300a) may transmit a signal to the second communication node (300b). The transmission processor (311) included in the first communication node (300a) may receive data (e.g., a data unit) from a data source (310). The transmission processor (311) may receive control information from the controller (316). The control information may include at least one of system information, RRC configuration information (e.g., information configured by RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0069] The transmitting processor (311) may perform a processing operation on data (e.g., an encoding operation, a symbol mapping operation, etc.) to generate data symbol(s). The transmitting processor (311) may perform a processing operation on control information (e.g., an encoding operation, a symbol mapping operation, etc.) to generate control symbol(s). In addition, the transmitting processor (311) may generate synchronization / reference symbol(s) for a synchronization signal and / or a reference signal.

[0070] The Tx MIMO processor (312) may perform a spatial processing operation (e.g., a precoding operation) on data symbol(s), control symbol(s), and / or synchronization / reference symbol(s). The output (e.g., a symbol stream) of the Tx MIMO processor (312) may be provided to modulators (MODs) included in the transceivers (313a to 313t). The modulators (MODs) may perform a processing operation on the symbol stream to generate modulation symbols, and may perform an additional processing operation (e.g., an analog conversion operation, an amplification operation, a filtering operation, an upconversion operation) on the modulation symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (313a to 313t) may be transmitted via the antennas (314a to 314t).

[0071] Signals transmitted by the first communication node (300a) may be received by antennas (364a to 364r) of the second communication node (300b). Signals received by the antennas (364a to 364r) may be provided to demodulators (DEMODs) included in transceivers (363a to 363r). The demodulator (DEMOD) may perform a processing operation (e.g., a filtering operation, an amplification operation, a downconversion operation, a digital conversion operation) on the signal to obtain samples. The demodulator (DEMOD) may perform an additional processing operation on the samples to obtain symbols. The MIMO detector (362) may perform a MIMO detection operation on the symbols. The receiving processor (361) may perform a processing operation (e.g., a deinterleaving operation, a decoding operation) on the symbols. The output of the receiving processor (361) may be provided to a data sink (360) and a controller (366). For example, data may be provided to the data sink (360), and control information may be provided to the controller (366).

[0072] Meanwhile, the second communication node (300b) can transmit a signal to the first communication node (300a). The transmitting processor (368) included in the second communication node (300b) can receive data (e.g., data units) from a data source (367) and perform a processing operation on the data to generate data symbol(s). The transmitting processor (368) can receive control information from the controller (366) and perform a processing operation on the control information to generate control symbol(s). In addition, the transmitting processor (368) can perform a processing operation on a reference signal to generate reference symbol(s).

[0073] The Tx MIMO processor (369) may perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or reference symbol(s). The output (e.g., symbol stream) of the Tx MIMO processor (369) may be provided to modulators (MODs) included in the transceivers (363a to 363t). The modulators (MODs) may perform processing operations on the symbol streams to generate modulation symbols, and may perform additional processing operations (e.g., analog conversion operations, amplification operations, filtering operations, upconversion operations) on the modulation symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (363a to 363t) may be transmitted via the antennas (364a to 364t).

[0074] Signals transmitted by the second communication node (300b) may be received by the antennas (314a to 314r) of the first communication node (300a). The signals received by the antennas (314a to 314r) may be provided to demodulators (DEMODs) included in the transceivers (313a to 313r). The demodulator (DEMOD) may perform a processing operation (e.g., a filtering operation, an amplification operation, a downconversion operation, a digital conversion operation) on the signal to obtain samples. The demodulator (DEMOD) may perform an additional processing operation on the samples to obtain symbols. The MIMO detector (320) may perform a MIMO detection operation on the symbols. The receiving processor (319) may perform a processing operation (e.g., a deinterleaving operation, a decoding operation) on the symbols. The output of the receiving processor (319) may be provided to a data sink (318) and a controller (316). For example, data may be provided to the data sink (318) and control information may be provided to the controller (316).

[0075] Memories (315 and 365) can store data, control information, and / or program code. Scheduler (317) can perform scheduling operations for communication. The processors (311, 312, 319, 361, 368, 369) and controllers (316, 366) illustrated in FIG. 3 may be the processor (210) illustrated in FIG. 2 and may be used to perform the methods described in the present disclosure.

[0076] FIG. 4a is a block diagram illustrating a first embodiment of a transmission path, and FIG. 4b is a block diagram illustrating a first embodiment of a reception path.

[0077] Referring to FIGS. 4A and 4B, a transmission path (410) may be implemented in a communication node that transmits a signal, and a reception path (420) may be implemented in a communication node that receives a signal. The transmission path (410) may include a channel coding and modulation block (411), an S-to-P (serial-to-parallel) block (512), an N IFFT (Inverse Fast Fourier Transform) block (413), a P-to-S (parallel-to-serial) block (414), a CP (cyclic prefix) addition block (415), and an UC (up-converter) (UC) (416). The receiving path (420) may include a DC (down-converter) (421), a CP removal block (422), an S-to-P block (423), an N FFT block (424), a P-to-S block (425), and a channel decoding and demodulation block (426). Here, N may be a natural number.

[0078] In the transmission path (410), information bits may be input to a channel coding and modulation block (411). The channel coding and modulation block (411) may perform a coding operation (e.g., a low-density parity check (LDPC) coding operation, a polar coding operation, etc.) and a modulation operation (e.g., a quadrature phase shift keying (QPSK), a quadrature amplitude modulation (QAM), etc.) on the information bits. The output of the channel coding and modulation block (411) may be a sequence of modulation symbols.

[0079] The S-to-P block (412) can convert modulation symbols in the frequency domain into parallel symbol streams to generate N parallel symbol streams. N can be an IFFT size or an FFT size. The N IFFT block (413) can perform an IFFT operation on the N parallel symbol streams to generate signals in the time domain. The P-to-S block (414) can convert the output (e.g., parallel signals) of the N IFFT block (413) into a serial signal to generate a serial signal.

[0080] The CP addition block (415) can insert a CP into a signal. The UC (416) can up-convert the frequency of the output of the CP addition block (415) to an RF (radio frequency) frequency. Additionally, the output of the CP addition block (415) can be filtered at the baseband before up-conversion.

[0081] A signal transmitted from a transmission path (410) may be input to a reception path (420). An operation in the reception path (420) may be the reverse operation of the operation in the transmission path (410). A DC (421) may down-convert the frequency of the received signal to a baseband frequency. A CP removal block (422) may remove a CP from a signal. The output of the CP removal block (422) may be a serial signal. An S-to-P block (423) may convert the serial signal into parallel signals. An N FFT block (424) may perform an FFT algorithm to generate N parallel signals. A P-to-S block (425) may convert the parallel signals into a sequence of modulation symbols. A channel decoding and demodulation block (426) may perform a demodulation operation on the modulation symbols and perform a decoding operation on the result of the demodulation operation to restore data.

[0082] In FIGS. 4A and 4B , Discrete Fourier Transform (DFT) and Inverse DFT (IDFT) may be used instead of FFT and IFFT. Each of the blocks (e.g., components) in FIGS. 4A and 4B may be implemented by at least one of hardware, software, or firmware. For example, some of the blocks in FIGS. 4A and 4B may be implemented by software, and the remaining blocks may be implemented by hardware or a “combination of hardware and software.” In FIGS. 4A and 4B , a block may be subdivided into multiple blocks, multiple blocks may be integrated into a single block, some blocks may be omitted, and blocks supporting other functions may be added.

[0083] Figure 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0084] Referring to FIG. 5, time resources in a communication system can be divided into frame units. For example, system frames can be set consecutively in the time domain of the communication system. The length of a system frame can be 10 ms (milliseconds). The system frame number (SFN) can be set from #0 to #1023. In this case, 1024 system frames can be repeated in the time domain of the communication system. For example, the SFN of the system frame after system frame #1023 can be #0.

[0085] A system frame may include two half frames. A half frame may be 5 ms long. A half frame located at the beginning of the system frame may be referred to as "half frame #0," and a half frame located at the end of the system frame may be referred to as "half frame #1." A system frame may include 10 subframes. A subframe may be 1 ms long. The 10 subframes within a system frame may be referred to as "subframes #0-9."

[0086] Figure 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0087] Referring to FIG. 6, one subframe may include n slots, where n may be a natural number. Accordingly, one subframe may be composed of one or more slots.

[0088] Figure 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0089] Referring to Figure 7, a single slot may include one or more symbols. A single slot illustrated in Figure 7 may include 14 symbols. The length of a slot may vary depending on the number and length of symbols contained in the slot. Alternatively, the length of a slot may vary depending on the numerology.

[0090] In a communication system, the numerology applied to physical signals and channels may be variable. The numerology may be variable to meet various technical requirements of the communication system. In a communication system applying CP (cyclic prefix)-based OFDM waveform technology, the numerology may include subcarrier spacing and CP length (or CP type). Table 1 may be a first embodiment of a method for configuring a numerology for a CP-OFDM-based communication system. 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.

[0091] Subcarrier spacing 15kHz 30kHz 60kHz 120kHz 240kHz 480kHz OFDM symbol length (μs) 66.733.316.78.34.22.1 CP length (μs) 4.762.381.190.600.300.151 Number of OFDM symbols in ms 142856112224448

[0092]

[0093] When the subcarrier spacing is 15 kHz (e.g., μ=0), the slot length can be 1 ms. In this case, one system frame can contain 10 slots. When the subcarrier spacing is 30 kHz (e.g., μ=1), the slot length can be 0.5 ms. In this case, one system frame can contain 20 slots.

[0094] When the subcarrier spacing is 60 kHz (e.g., μ=2), the slot length can be 0.25 ms. In this case, one system frame can contain 40 slots. When the subcarrier spacing is 120 kHz (e.g., μ=3), the slot length can be 0.125 ms. In this case, one system frame can contain 80 slots. When the subcarrier spacing is 240 kHz (e.g., μ=4), the slot length can be 0.0625 ms. In this case, one system frame can contain 160 slots.

[0095] A symbol may be configured as a downlink (DL) symbol, a flexible (FL) symbol, or an uplink (UL) symbol. A slot consisting solely of DL symbols may be referred to as a "DL slot," a slot consisting solely of FL symbols may be referred to as an "FL slot," and a slot consisting solely of UL symbols may be referred to as a "UL slot."

[0096] The slot format can be semi-statically configured by higher layer signaling (e.g., RRC signaling). Information indicating the semi-static slot format can be included in the system information, and the semi-static slot format can be configured cell-specifically. In addition, the semi-static slot format can be additionally configured for each terminal through terminal-specific higher layer signaling (e.g., RRC signaling). The flexible symbol of the cell-specifically configured slot format can be overridden to 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 DCI). The semi-statically configured slot format can be overridden by a dynamically indicated slot format. For example, the semi-statically configured flexible symbol can be overridden to a downlink symbol or an uplink symbol by the SFI.

[0097] The reference signal may be a channel state information-reference signal (CSI-RS), a sounding reference signal (SRS), a demodulation-reference signal (DM-RS), a phase tracking-reference signal (PT-RS), etc. The channel may be a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), etc. In the present disclosure, a control channel may mean a PDCCH, a PUCCH, or a PSCCH, and a data channel may mean a PDSCH, a PUSCH, or a PSSCH.

[0098] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0099] Referring to FIG. 8, a resource consisting of one symbol (e.g., an OFDM symbol) in the time domain and one subcarrier in the frequency domain may be defined as a "RE (resource element)". Resources consisting of one OFDM symbol in the time domain and K subcarriers in the frequency domain may be defined as a "REG (resource element group)". A REG may include K REs. A REG may be used as a basic unit for resource allocation in the frequency domain. K may be a natural number. For example, K may be 12. N may be a natural number. In the slot illustrated in FIG. 7, N may be 14. N OFDM symbols may be used as a basic unit for resource allocation in the time domain.

[0100] In the present disclosure, RB may mean CRB (common RB). Alternatively, RB may mean PRB or VRB (virtual RB). In a communication system, CRB may mean RB that constitutes a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). Carriers and / or bandwidth portions may be arranged on the common RB grid. That is, the carrier and / or bandwidth portions may be composed of CRB(s). RBs or CRBs that constitute the bandwidth portions may be referred to as PRBs, and within the bandwidth portions, the CRB index may be appropriately converted to the PRB index.

[0101] Downlink data can be transmitted via the PDSCH. The base station can transmit PDSCH configuration information (e.g., scheduling information) to the terminal via the PDCCH. The terminal can obtain the PDSCH configuration information by receiving the PDCCH (e.g., downlink control information (DCI)). For example, the PDSCH configuration information can include the MCS (modulation coding scheme) used for transmitting and receiving the PDSCH, time resource information of the PDSCH, frequency resource information of the PDSCH, feedback resource information for the PDSCH, etc. The PDSCH can refer to a radio resource through which downlink data is transmitted and received. Alternatively, the PDSCH can refer to the downlink data itself. The PDCCH can refer to a radio resource through which downlink control information (e.g., DCI) is transmitted and received. Alternatively, the PDCCH can refer to the downlink control information itself.

[0102] A terminal can perform a monitoring operation on the PDCCH to receive a PDSCH transmitted from a base station. The base station can inform the terminal of the configuration information for the PDCCH monitoring operation using a higher layer message (e.g., an RRC (radio resource control) message). The configuration information for the PDCCH monitoring operation can include CORESET (control resource set) information and search space information.

[0103] CORESET information may include PDCCH DMRS (demodulation reference signal) information, PDCCH precoding information, PDCCH occasion information, etc. The PDCCH DMRS may be a DMRS used to demodulate the PDCCH. The PDCCH occasion may be a region where the PDCCH can exist. That is, the PDCCH occasion may be a region where DCI can be transmitted. The PDCCH occasion may be referred to as a PDCCH candidate. The PDCCH occasion information may include time resource information and frequency resource information of the PDCCH occasion. In the time domain, the length of the PDCCH occasion may be indicated in symbol units. In the frequency domain, the size of the PDCCH occasion may be indicated in RB units (e.g., in PRB (physical resource block) units or CRB (common resource block) units).

[0104] The search space information may include a coreset identifier (ID) associated with the search space, a period of PDCCH monitoring, and / or an offset. The period and offset of PDCCH monitoring may each be indicated on a slot-by-slot basis. In addition, the search space information may further include an index of the symbol at which the PDCCH monitoring operation begins.

[0105] A base station can configure a bandwidth part (BWP) for downlink communication. The BWP can be configured differently for each terminal. The base station can inform the terminal of the BWP configuration information using higher layer signaling. The higher layer signaling can mean "transmission operation of system information" and / or "transmission operation of RRC (radio resource control) message." The number of BWPs configured for one terminal can be one or more. The terminal can receive BWP configuration information from the base station and check the BWP(s) configured by the base station based on the BWP configuration information. When multiple BWPs are configured for downlink communication, the base station can activate one or more BWPs among the multiple BWPs. The base station can transmit the configuration information of the activated BWP(s) to the terminal using at least one of higher layer signaling, a medium access control (MAC) control element (CE), or DCI. The base station can perform downlink communication using the activated BWP(s). The terminal can identify the activated BWP(s) by receiving configuration information of the activated BWP(s) from the base station, and perform a downlink reception operation in the activated BWP(s).

[0106]

[0107] The 3GPP Rel-19 NR MIMO WI (work item) is currently discussing ways to improve intra-cell and inter-cell beam management. These improvements primarily target the FR2 band and single TRP (sTRP) scenarios, aiming to leverage existing legacy CSI measurement and reporting configuration procedures while reducing overhead and latency. UE-initiated and event-driven beam management techniques could be utilized for this purpose.

[0108] The beam management defined up to the existing 3GPP Rel-18 was performed in a way that the network (i.e., the base station) led the beam management. In the existing network (or base station)-led beam management method, the base station can instruct the terminal to perform beam switching for downlink reception or uplink transmission. In this case, the base station determines the need for beam switching based on the measurement report received from the terminal and instructs the terminal to perform the beam switching, so it cannot determine the optimal beam until it receives the measurement report transmitted by the terminal.

[0109] However, terminal-driven and event-based beam management techniques refer to beam management operations initiated by the terminal side, which can first detect beam changes. Compared to network-driven beam management operations, this can reduce latency (e.g., the time required for the base station to instruct the terminal to perform measurement and measurement reports, and to receive the measurement reports from the terminal) and signaling overhead (e.g., the signaling overhead for the base station to configure measurement reports for the terminal and the signaling overhead due to frequent measurement reports).

[0110]

[0111] Specifically, the procedure by which a base station receives channel state information (CSI) for configured beam(s) from a terminal can be largely divided into two steps. First, a beam selection step may be performed in which the base station selects candidate beams to be used for communication. The beam selection may be performed based on reference signals (RSs) that are transmitted in specific beam directions. In this case, the reference signal may be a downlink CSI-RS transmitted by the base station or a sounding reference signal (SRS) transmitted by the terminal. The number of configured RS resources may vary depending on the number of candidate analog beams. Next, in the downlink, the terminal may perform beam measurement for the CSI-RS (or SSB) transmitted by the base station, and in the uplink, the base station may perform beam measurement for the SRS transmitted by the terminal. That is, in order to derive beam quality through beam measurement, the terminal can measure the received power of each RS (e.g., L1-RSRP (layer 1-reference signal received power)) and report it to the base station. At this time, the terminal can report a preferred DL RS ID (e.g., SSBRI, CRI) based on the measurement value for CSI-RS or SSB. In the above description, the CSI-RS or SSB can be configured to be transmitted periodically or aperiodically from the base station, and the terminal can report the measurement value to the base station based on the RS transmitted periodically or aperiodically.

[0112] All beam management procedures currently defined in the NR standard are base station-driven. That is, the beam management procedure defined in the current NR standard uses a method in which the base station requests the terminal to measure some (or specific) beams, and then the terminal reports the optimal beam to the base station. In addition, the base station can instruct the terminal to switch to some (or specific) beams for downlink reception and / or uplink transmission. This base station-driven beam management method can incur delay time and signaling overhead. This is because the terminal is always the first to know about beam changes and changes to the optimal beam, but the base station is not aware of the beam change until the terminal reports the measurement results.

[0113]

[0114] Therefore, using a terminal-driven and event-driven beam management approach, the terminal can trigger the reporting of beam measurement results when it determines that beam fluctuations are sufficiently large (i.e., when a specific event occurs). This allows the terminal to report beam measurement results only when necessary, significantly reducing uplink signaling overhead. Furthermore, since the terminal can report measurement results immediately whenever necessary, the delay for measurement reporting can be reduced.

[0115]

[0116] In the following description, terminal-initiated and event-based beam management may be collectively referred to as 'terminal-initiated beam management.' Furthermore, in the following description, network-initiated beam management may be used with the same meaning as base station-initiated beam management. Furthermore, in the following description, 'beam management' may be used with the same meaning as 'beam management procedure,' 'beam management operation,' 'beam management method,' and 'beam management method,' as the case may be.

[0117]

[0118] In NR communication systems, CSI-RS or SSB can be configured as aperiodic, aperiodic, or semi-persistent through upper layer signaling, and the terminal can perform beam measurement according to the configuration and report the measurement results to the base station. In other words, the CSI measurement reporting procedure of NR communication systems can be divided into periodic, aperiodic, and semi-persistent CSI measurement reporting procedures.

[0119] Figure 9 is a flowchart illustrating the periodic CSI measurement reporting procedure.

[0120] Referring to FIG. 9, a terminal (910) can receive CSI measurement report configuration information from a base station (920) through upper layer signaling (S910). Based on the CSI measurement report configuration information, the terminal (910) can receive and measure a CSI-related reference signal from the base station (920) at regular intervals (S920, S940). The terminal (910) can measure a CSI-related reference signal (e.g., CSI-RS or SSB) received at regular intervals and transmit a measurement report generated by the measurement to the base station (920) (S930, S950). For example, the measurement report can include L1 (layer 1)-RSRP (reference signal received power) of the CSI-related reference signals. In this case, the measurement report can also be transmitted at the same interval as the interval of the CSI-related reference signal.

[0121] Figure 10 is a flowchart illustrating an aperiodic CSI measurement reporting procedure.

[0122] Referring to FIG. 10, similarly to the periodic CSI measurement reporting procedure described with reference to FIG. 9, in the aperiodic CSI measurement reporting procedure, the terminal (1010) can receive CSI measurement report configuration information from the base station (1020) through upper layer signaling (S1010). When aperiodic CSI measurement reporting is required, the base station (1020) can transmit a CSI trigger signal to the terminal (1010) (S1020). In this case, the CSI trigger signal can be transmitted through a medium access control (MAC) control element (CE) or downlink control information (DCI). The terminal (1010) can receive and measure a CSI-related reference signal transmitted from the base station (1020) after a certain time offset (e.g., X slot(s), X=0 is also possible) from the time of receiving the CSI trigger signal (S1030). The terminal (1010) can transmit a measurement report including the measurement result to the base station (1020) after a certain time offset (e.g., Y slot(s)) from the time of receiving the CSI trigger signal (S1040).

[0123] Figure 11 is a flowchart illustrating a semi-persistent CSI measurement reporting procedure.

[0124] Referring to FIG. 11, similar to the periodic CSI measurement reporting procedure and the aperiodic CSI measurement reporting procedure described with reference to FIGS. 9 and 10, in the semi-persistent CSI measurement reporting procedure, the terminal (1110) can receive CSI measurement reporting configuration information from the base station (1120) through upper layer signaling (S1110).

[0125] The base station (1120) may send an activation instruction to the terminal (1110) to activate the semi-persistent CSI measurement reporting procedure. At this time, the activation instruction may be transmitted via MAC CE and / or DCI. The terminal (1110) that receives the activation instruction may receive and measure CSI-related signals from the base station (1120) according to the CSI measurement reporting configuration information from the base station (1120).

[0126] For example, if an activation indication is received in slot n, the terminal can transmit the first measurement report in slot n+Y. If the period is set to P slots (where P is a natural number greater than or equal to 1), the terminal can transmit the second measurement report in slot n+Y+P. That is, in the semi-persistent CSI measurement reporting procedure, the measurement report of the first cycle can be transmitted in a manner similar to the aperiodic CSI measurement reporting procedure, and the measurement reports after the second cycle can be transmitted periodically based on CSI-related reference signals that are transmitted periodically.

[0127]

[0128] In NR communication systems, CSI-RS or SSB can be set to a terminal at a predetermined period through higher-layer signaling, and the terminal can perform beam measurements based on the corresponding period and report the measurement results to the base station. However, beam management operations cannot be performed until the terminal receives the RS periodically (or aperiodically) transmitted by the base station and transmits the measurement results for the received RS as a measurement report to the base station. In other words, in existing beam management procedures, the base station must frequently configure periodic beam reports or frequently trigger aperiodic beam reports to obtain the optimal beam for data transmission. This can result in significant overhead due to frequent measurement reports or control signaling for triggering. On the other hand, setting a low beam reporting frequency can lengthen the interval between measurement reports, which can prevent the base station from always obtaining the optimal beam, degrading network performance. Considering that the terminal performs beam measurements and is more aware of changes in beam quality, if beam management is initiated by the terminal, it can provide benefits in terms of both reporting overhead and timely reporting. When a terminal identifies that its current beam quality is deteriorating, it can initiate a beam report, allowing the base station to recognize the beam quality without performing frequent beam reports. However, a method for switching from network-driven beam management to terminal-driven beam management, as well as the signaling methods required for this, have not yet been specified. Therefore, the present disclosure proposes a method for a terminal to trigger terminal-driven beam management.

[0129]

[0130] FIG. 12 is a flowchart illustrating a triggering method of terminal-led beam management according to one embodiment of the present invention.

[0131] Referring to FIG. 12, if a terminal (1210) determines that a specific condition is satisfied and terminal-led beam management is necessary, the terminal (1210) may transmit a terminal-led beam management triggering signal to the base station (1220) (S1210). Here, the terminal-led beam management triggering signal may be transmitted via MAC CE and / or UCI.

[0132] Here, a specific condition for transmitting a terminal-driven beam management triggering signal may be when a specific event (e.g., sudden signal quality degradation due to movement or rotation of the terminal, or surrounding obstacles) occurs at the terminal. Alternatively, the specific condition may be when a measurement result of a CSI-RS or SSB set by measurement configuration information for a conventional beam management method (i.e., base station-driven beam management), a measurement result of a CSI-RS or SSB separately set for triggering the terminal-driven beam management proposed in the present invention, or a measurement result for a separate pre-arranged signal or resource other than the CSI-RS or SSB satisfies a predetermined condition.

[0133] The base station (1220) can receive a terminal-driven beam management triggering signal from the terminal (1210) (S1220). The base station (1220), which has received the terminal-driven beam management triggering signal from the terminal (1210), can transmit a CSI-related reference signal (e.g., CSI-RS or SSB) after a specific time offset (e.g., X slot(s), X=0 is also possible) has elapsed from the time of receiving the terminal-driven beam management triggering signal, and the terminal (1210) can receive the corresponding CSI-related reference signal (S1220). The terminal (1210) can measure the received CSI-related reference signal and transmit a measurement report generated therefrom to the base station after a specific time offset (e.g., Y slots) from the time of transmitting the terminal-driven beam management triggering signal (S1230). In this case, X and / or Y may be set in advance between the base station and the terminal. Alternatively, the base station may set the X and / or Y values ​​according to specific conditions (e.g., the movement / rotation speed of the terminal, the degree of change in the signal measurement results mentioned above). For example, if the terminal has a rapid movement or the results of the terminal measuring CSI-RS, SSB, and / or pre-arranged signals / resources show a rapid change, X and / or Y may be set to a small value. The X and / or Y values ​​may be set by higher layer signaling (e.g., reportSlotOffsetList-UE).

[0134] At this time, the terminal (1210) may transmit information on CSI-related reference signals required to improve measurement accuracy and / or a request for CSI-related reference signals to be transmitted by the base station (1220) by including the information in the terminal-driven beam management triggering signal. For example, the beam management triggering signal may request at least one of a transmission start time of the CSI-related reference signal and / or a transmission end time of the CSI-related reference signal, a transmission period of the CSI-related reference signal, a number of transmissions of the CSI-related reference signal, a transmission duration of the CSI-related reference signal, or beam mapping information of the CSI-related reference signal. In this case, the terminal may report the result with the best performance to the base station.

[0135] Meanwhile, a terminal that has transmitted a terminal-driven beam management triggering signal to a base station can transmit measurement reports for a specific period of time or a specific number of times. If the terminal determines that terminal-driven beam management is no longer necessary based on whether a specific condition is met, the terminal can transmit a triggering signal to the base station for a deactivation instruction to stop terminal-driven beam management operation. The terminal can also transmit the deactivation instruction to the base station via MAC CE and / or UCI.

[0136] A base station that receives a triggering signal for the deactivation instruction may re-perform the conventional base station-led beam management procedure. Meanwhile, after a certain period of time has elapsed since the last measurement report based on terminal-led beam management was transmitted, the terminal may or may not transmit a subsequent measurement report based on terminal-led beam management.

[0137]

[0138] FIG. 13 is a flowchart illustrating a triggering method of terminal-led beam management according to another embodiment of the present invention.

[0139] Referring to FIG. 13, the terminal (1310) can transmit a terminal-led beam management triggering signal in conjunction with the measurement report at the time of transmitting the measurement report while performing conventional base station-led beam management.

[0140] When the terminal determines that terminal-initiated beam management is necessary based on satisfaction of the above-described specific conditions, the terminal may transmit a terminal-initiated beam management triggering signal to the base station (e.g., via MAC CE and / or DCI). The terminal-initiated beam management triggering signal may be transmitted as included in a measurement report that the terminal transmits to the base station, transmitted simultaneously with a measurement report that the terminal transmits to the base station, or transmitted after a predetermined offset (e.g., N slot(s)) from the time point of transmission of the measurement report that the terminal transmits to the base station or the time point of reception of the corresponding CSI-related reference signal. That is, the terminal-initiated beam management triggering signal may be transmitted with a predetermined time / frequency correlation with the measurement report that the terminal transmits to the base station.

[0141] A base station that receives a terminal-initiated beam management triggering signal may stop transmitting periodic CSI-related reference signals according to conventional base station-initiated beam management. Thereafter, the base station may transmit the CSI-related reference signals whenever it receives a terminal-initiated beam management triggering signal from a terminal, or may transmit the CSI-related reference signals according to a new period (not the existing period) indicated by the terminal-initiated beam management triggering signal. The new period may be transmitted as a higher layer signaling (e.g., reportSlotConfig-UE).

[0142] At this time, the terminal (1310) may transmit information on CSI-related reference signals required to improve measurement accuracy and / or a request for CSI-related reference signals to be transmitted by the base station (1320) by including the information in the terminal-driven beam management triggering signal. For example, the beam management triggering signal may request at least one of a transmission start time of the CSI-related reference signal and / or a transmission end time of the CSI-related reference signal, a transmission period of the CSI-related reference signal, a number of transmissions of the CSI-related reference signal, a transmission duration of the CSI-related reference signal, or beam mapping information of the CSI-related reference signal. In this case, the terminal may report the best-performing result to the base station.

[0143] Meanwhile, a terminal that has transmitted a terminal-driven beam management triggering signal to a base station can transmit measurement reports for a specific period of time or a specific number of times. If the terminal determines that terminal-driven beam management is no longer necessary based on whether a specific condition is met, the terminal can transmit a triggering signal to the base station for a deactivation instruction to stop terminal-driven beam management operation. The terminal can also transmit the deactivation instruction to the base station via MAC CE and / or UCI.

[0144] A base station that receives a triggering signal for the deactivation instruction may re-perform the conventional base station-led beam management procedure. Meanwhile, after a certain period of time has elapsed since the last measurement report based on terminal-led beam management was transmitted, the terminal may or may not transmit a subsequent measurement report based on terminal-led beam management.

[0145]

[0146] Meanwhile, unlike conventional measurement reports that include measurement values ​​for CSI-related reference signals, in terminal-driven beam management, a terminal can transmit a measurement report that explicitly or implicitly indicates to the base station a beam appropriate for the terminal. That is, in terminal-driven beam management, a measurement report transmitted by a terminal may include information that directly (implicitly) indicates the beam that the terminal wants to use, unlike conventional measurement reports, or may be composed of information other than measurement values ​​for CSI-related reference signals. In this case, a measurement report for terminal-driven beam management may be defined by a name other than a measurement report.

[0147] The terminal-driven beam management described above may be performed in combination with at least one or a combination of two or more of the periodic CSI measurement reporting operation, the aperiodic CSI measurement reporting operation, or the semi-persistent CSI measurement reporting operation described through FIGS. 9 to 11. For example, the terminal-driven beam management may be performed based on the semi-persistent CSI measurement reporting operation of FIG. 11.

[0148] In one embodiment, whether the terminal-driven beam management is performed periodically, aperiodic, or semi-persistently may be determined depending on whether the existing base station-driven beam management was being performed, and depending on how the existing base station-driven beam management was being performed (e.g., periodic CSI measurement reporting operation, aperiodic CSI measurement reporting operation, or semi-persistent CSI measurement reporting operation).

[0149]

[0150] Meanwhile, the container in which the measurement report is transmitted may be determined depending on which container (e.g., MAC CE or UCI) the terminal-initiated beam management triggering signal is transmitted. For example, if the terminal-initiated beam management triggering signal is transmitted via MAC CE, the measurement report may be transmitted via PUCCH (or PUSCH). If the terminal-initiated beam management triggering signal is transmitted via UCI, the measurement report may be transmitted via PUSCH (or PUCCH). Alternatively, the measurement report method for conventional base station-initiated beam management may be used in the same manner in terminal-initiated beam management.

[0151] When activating or deactivating terminal-initiated beam management is indicated through a terminal-initiated beam management triggering signal, the activation or deactivation indication may be performed through DCI, and specific DCI field(s) within the DCI (e.g., field(s) existing within DCI 0_1 or DCI_0_2 (e.g., CSI request, etc.)) may be utilized. Alternatively, a new field (e.g., a 1-bit indicator) may be defined to indicate activating or deactivating terminal-initiated beam management. For example, when the terminal-initiated beam management triggering signal is configured as a 1-bit indicator, the terminal-initiated beam management triggering signal set to a first value (e.g., 1) may indicate activating terminal-initiated beam management, and the terminal-initiated beam management triggering signal set to a second value (e.g., 0) may indicate activating terminal-initiated beam management.

[0152]

[0153] In one embodiment, whether to apply conventional base station-led beam management or terminal-led beam management according to the present disclosure may be determined based on which container (e.g., MAC CE or DCI) the activation indication and / or deactivation indication are transmitted in the non-persistent measurement reporting procedure. Alternatively, once it is determined whether to apply conventional base station-led beam management or terminal-led beam management according to the present disclosure, it may be determined which container (e.g., MAC CE or DCI) the activation indication and / or deactivation indication are transmitted in the non-persistent measurement reporting procedure. For example, if the activation indication and / or deactivation indication are transmitted via MAC CE, base station-led beam management (or terminal-led beam management) may be performed. If the activation indication and / or deactivation indication are transmitted via DCI, terminal-led beam management (or base station-led beam management) may be performed. Alternatively, when base station-led beam management (or terminal-led beam management) is performed, the activation instruction and / or deactivation instruction may be transmitted via MAC CE, and when terminal-led beam management (or base station-led beam management) is performed, the activation instruction and / or deactivation instruction may be transmitted via DCI.

[0154]

[0155] The terminal-initiated beam management triggering signal may be transmitted as included in a signal related to beam management transmitted from the terminal to the base station (e.g., a measurement report), transmitted simultaneously with a signal related to beam management transmitted from the terminal to the base station, or transmitted before or after the time at which the terminal transmits the signal related to beam management transmitted from the terminal to the base station. That is, the terminal-initiated beam management triggering signal may be transmitted with a predetermined time / frequency correlation with a signal related to beam management transmitted from the terminal to the base station. Alternatively, the terminal-initiated beam management triggering signal may be transmitted independently of other signals related to beam management transmitted from the terminal to the base station.

[0156] The terminal-driven beam management triggering signal (e.g., a 1-bit indicator) may be transmitted as part of a beam management-related signal or via uplink control information (UCI). Alternatively, the terminal-driven beam management triggering signal may be transmitted via higher layer signaling (e.g., medium access control (MAC)-control element (CE) or RRC signaling).

[0157] A base station that receives a terminal-driven beam management triggering signal may provide measurement configuration information (e.g., configuration of periodic or aperiodic CSI-RS or SSB) for terminal-driven beam management to the terminal, terminals including the terminal, terminal group, or terminal groups.

[0158]

[0159] Meanwhile, in the situation of FIG. 9 (i.e., a situation in which base station-led beam management based on periodic CSI reporting is being performed), a measurement report event (described later) may occur at the terminal due to terminal-led beam management. In this case, the terminal may decide to switch from base station-led beam management to terminal-led beam management. At this time, the method or container for transmitting the signaling indicating the switch to terminal-led beam management (i.e., terminal-led beam management triggering signal) may vary depending on when the event condition occurs.

[0160] For example, an event may occur before the transmission time of a CSI-related reference signal and measurement report according to measurement configuration information for base station-driven beam management established through higher layer signaling from the base station. In this case, since the terminal knows the transmission cycle of the CSI-related reference signal and the measurement report time through the received measurement configuration information, the terminal can perform a measurement report for the occurred event using the corresponding measurement report time. In this case, the terminal may first transmit a signal indicating terminal-driven beam management triggering to the base station using the measurement report transmission time (i.e., the embodiment of FIG. 13). However, if an event occurs within a short period of time after receiving the measurement configuration information through higher layer signaling and a considerable amount of time remains until the transmission time of the first CSI-related reference signal and measurement report, or if a considerable amount of time remains until the transmission time of the next CSI-related reference signal and measurement report, the terminal may request the base station to bring forward the transmission time of the first or the next measurement report. The request may be transmitted together with the time at which the terminal transmits a signal indicating terminal-driven beam management triggering to the base station. At this time, since the terminal knows the periodicity of the CSI-related reference signal and measurement report, it can transmit only the offset value to the base station via UCI or MAC-CE to accelerate the transmission time. Alternatively, the terminal can update the periodicity of the CSI-related reference signal and measurement report to perform one or more measurement report operations or for faster measurement reporting.

[0161] As another example, an event may occur at the time of transmission of a CSI-related reference signal and measurement report based on measurement configuration information for base station-driven beam management established through upper-layer signaling from the base station, or at a time immediately preceding that transmission time. In this case, the terminal may perform a measurement report utilizing the transmission time of the CSI-related reference signal and measurement report. In this case, the terminal may first transmit a signal indicating the triggering of the base station-driven beam management utilizing the measurement report transmission time.

[0162] The above operation can be similarly applied to the aperiodic CSI measurement reporting procedure illustrated in FIG. 10 or the semi-persistent CSI measurement reporting procedure illustrated in FIG. 11. In addition, regardless of whether the base station-initiated beam management is performed periodically, aperiodic, or semi-persistently, the terminal-initiated beam management can always perform beam reporting periodically (or aperiodic or semi-persistently). If the previously performed base station-initiated beam management operation was based on aperiodic CSI measurement reporting, the terminal can additionally request period value information. The request for the period value information can be transmitted from the terminal to the base station as included in the terminal-initiated beam management triggering signal, or transmitted together with the terminal-initiated beam management triggering signal at the time of transmitting the terminal-initiated beam management triggering signal. Alternatively, the terminal-initiated beam management can be performed in the same manner (periodic, aperiodic, or semi-persistent) as the base station-initiated beam management is performed.

[0163]

[0164] In the above description, performing terminal-driven beam management may mean that the terminal performs beam reporting to the base station when a beam reporting event occurs (i.e., event-based beam management). For terminal-driven and event-based beam reporting, trigger event detection conditions for beam reporting by the terminal, conditions for evaluating whether the beam reporting trigger conditions are met by the terminal monitoring the RS, and / or trigger conditions for declaring a beam reporting event, etc. must be defined.

[0165] The trigger events being discussed for terminal-driven and event-based beam reporting and the conditions (e.g., thresholds, etc.) for determining whether the event has occurred can be defined as follows.

[0166] - Event-1: When the quality of the current beam (e.g., L1-RSRP) is lower than a certain threshold.

[0167] - Event-2: When the quality of one or more new beams (such as L1-RSRP) is better than the current beam by a threshold.

[0168] - Event-3: The quality of the new beam is higher than a certain threshold.

[0169] - Event-4: The quality of the current beam is lower than threshold 1, and the quality of at least one new beam is higher than threshold 2.

[0170] - Event-5: The absolute value of the difference between the quality of the current beam and the quality of at least one new beam is less than the threshold.

[0171] - Event-6: Current beam is not included in the top K beams (not included in the set beams for measurement and reporting).

[0172] - Event-7a: The quality of at least one new beam improves by a threshold value compared to the worst quality RS in the enabled TCI state.

[0173] - Event-7b: The quality of at least one new beam improves by a threshold value greater than that of the RS with the highest quality in the enabled TCI state.

[0174] - Event-8: M > 1 The quality of the new beam is improved by a threshold value compared to the current beam.

[0175] - Event-9: The quality of at least one new beam improves by a threshold value above the established reference RS (SSB or CSI-RS).

[0176]

[0177] In the above description, the transmission of information via DCI may mean that the information is transmitted as control information via a physical channel. The transmission of information via DCI may also be extended to mean that the information is transmitted via UCI.

[0178]

[0179] In the above description, the operation for a specific period can be extended to mean operation based on a specific number of RSs. Assuming SSB transmission, this can be extended to mean operation based on the SSB transmission period unit, the section (e.g., half-frame) in which SSBs are actually transmitted within the SSB transmission period, or the maximum or specific number of SSBs within the SSB transmission period.

[0180]

[0181] In the above description, the operation of transmitting a measurement report from a terminal can be extended to an operation of requesting a base station for a CSI-related reference signal that is the target of the measurement result included in the measurement report.

[0182]

[0183] In the above description, the meaning that terminal-led beam management is performed can be interpreted to mean that the terminal transmits a signaling message (e.g., a 'terminal-led beam management triggering signal') instructing the base station to perform terminal-led beam management. In the above description, the meaning that the performance of terminal-led beam management is stopped can be interpreted to mean that the terminal transmits a signaling message instructing the base station to stop terminal-led beam management or switches to conventional base station-led beam management.

[0184]

[0185] The methods and devices proposed in this disclosure can be applied to intra-cell beam management and inter-cell beam management scenarios, and the methods and devices proposed in this disclosure can also be applied in mTRP operation with similar principles.

[0186]

[0187] The operations of the method according to 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.

[0188] 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.

[0189] 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.

[0190] 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 in the present disclosure. The field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described in the present disclosure. In general, the methods are preferably performed by some hardware device.

[0191] 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. By terminal method, A step of determining whether a condition for transmitting a terminal-driven beam management triggering signal is satisfied; If it is determined that the above condition is met, a step of transmitting the terminal-led beam management triggering signal to the base station; A step of receiving a reference signal related to CSI (channel state information) from the base station; and Including a step of transmitting a measurement report related to the beam report event to the base station when a beam report event occurs as a result of measuring the CSI-related reference signal. Terminal method.

2. In claim 1, Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on whether a specific event has occurred in the terminal, and the specific event is movement, rotation, or signal quality degradation of the terminal. Terminal method.

3. In claim 1, Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on at least one of the following: a measurement result of a CSI-RS (CSI-reference signal) or SSB (synchronization signal block) set by measurement configuration information received from the base station, a measurement result of a CSI-RS or SSB set separately for triggering terminal-led beam management, or a measurement result for a separate pre-arranged signal or resource other than the CSI-RS or SSB. Terminal method.

4. In claim 1, The above terminal-led beam management triggering signal is transmitted via MAC (medium access control) CE (control element) and / or UCI (uplink control information). Terminal method.

5. In claim 1, The second container used for transmission of the measurement report is determined according to the first container used for transmission of the terminal-led beam management triggering signal, the first container is MAC CE or UCI, and the second container is PUCCH (physical uplink control channel) or PUSCH (physical uplink shared channel). Terminal method.

6. In claim 1, The CSI-related reference signal is transmitted after a first time offset from the time point at which the terminal-led beam management triggering signal is received from the terminal, and the measurement report is received after a second time offset from the time point at which the terminal-led beam management triggering signal is received. Terminal method.

7. In claim 1, The terminal-led beam management triggering signal includes information requesting at least one of a transmission time of the CSI-related reference signal, a transmission period of the CSI-related reference signal, a number of transmissions of the CSI-related reference signal, and a transmission duration of the CSI-related reference signal. Terminal method.

8. In claim 1, The above measurement report includes information that explicitly or implicitly indicates the beam that the terminal wishes to use. Terminal method.

9. In claim 1, The above terminal-driven beam management is performed based on at least one or a combination of two or more of periodic CSI measurement reporting operations, aperiodic CSI measurement reporting operations, or semi-persistent CSI measurement reporting operations. Terminal method.

10. By the method of the base station, A step of receiving a terminal-driven beam management triggering signal from a terminal; In response to the terminal-led beam management triggering signal, a step of transmitting a reference signal related to CSI (channel state information) to the terminal; and A step of receiving a measurement report related to a beam report event from the terminal, The terminal transmits the terminal-led beam management triggering signal to the base station when a condition for transmitting the terminal-led beam management triggering signal is satisfied, and transmits the measurement report to the base station when the beam report event occurs as a result of measuring the CSI-related reference signal. Base station method.

11. In claim 10, Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on whether a specific event has occurred in the terminal, and the specific event is movement, rotation, or signal quality degradation of the terminal. Base station method.

12. In claim 10, Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on at least one of the following: a measurement result of a CSI-RS (CSI-reference signal) or SSB (synchronization signal block) set by measurement configuration information transmitted by the base station to the terminal, a measurement result of a CSI-RS or SSB set separately for triggering terminal-led beam management, or a measurement result for a separate pre-arranged signal or resource other than the CSI-RS or SSB. Base station method.

13. In claim 10, The second container used for receiving the measurement report is determined according to the first container used for receiving the terminal-led beam management triggering signal, the first container is MAC CE or UCI, and the second container is PUCCH or PUSCH. Base station method.

14. In claim 10, The terminal-led beam management triggering signal includes information requesting at least one of a transmission time of the CSI-related reference signal, a transmission period of the CSI-related reference signal, a number of transmissions of the CSI-related reference signal, and a transmission duration of the CSI-related reference signal. Base station method.

15. In claim 10, The above measurement report includes information that explicitly or implicitly indicates the beam that the terminal wishes to use. Base station method.

16. A terminal including at least one processor, At least one processor of the terminal: A step of determining whether a condition for transmitting a terminal-driven beam management triggering signal is satisfied; If it is determined that the above condition is met, a step of transmitting the terminal-led beam management triggering signal to the base station; A step of receiving a reference signal related to CSI (channel state information) from the base station; and When a beam report event occurs as a result of measuring the above CSI-related reference signal, a step of transmitting a measurement report related to the beam report event to the base station is performed. Terminal.

17. In claim 16, Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on whether a specific event has occurred in the terminal, and the specific event is movement, rotation, or signal quality degradation of the terminal. Terminal.

18. In claim 16, Whether the conditions for transmitting the above terminal-led beam management triggering signal are met is determined based on at least one of the following: a measurement result of a CSI-RS (CSI-reference signal) or SSB (synchronization signal block) set by measurement configuration information received from the base station, a measurement result of a CSI-RS or SSB set separately for triggering terminal-led beam management, or a measurement result for a separate pre-arranged signal or resource other than the CSI-RS or SSB. Terminal.

19. In claim 16, The terminal-led beam management triggering signal includes information requesting at least one of a transmission time of the CSI-related reference signal, a transmission period of the CSI-related reference signal, a number of transmissions of the CSI-related reference signal, and a transmission duration of the CSI-related reference signal. Terminal.

20. In claim 16, The above measurement report includes information that explicitly or implicitly indicates the beam that the terminal wishes to use. Terminal.

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