Reference signal configuration method for user-equipment initiated beam management operation, and apparatus using same

Abstract

This method, of a user equipment (UE), for a UE-initiated (UEI) / event-driven (ED) beam reporting operation may comprise the steps of: receiving, from a base station, a TCI state indicating the current beam for determining the occurrence of an event; determining whether only a TRS is configured as the QCL RS of the TCI state; identifying an RS associated with the TRS if it is determined that only the TRS is configured as the QCL RS of the TCI state; and identifying a separate RS associated with the TRS if it is identified that the TRS is associated with only an SSB, measuring the quality of the current beam on the basis of at least the separate RS, and determining the occurrence of the event on the basis of the measured quality of the current beam.

Description

Method for setting reference signals for terminal-led beam management operation and device using the same

[0001] The present disclosure relates to a method and device for beam management in a mobile communication system, and more particularly, to a method and device for terminal-driven beam management operation.

[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 rd In Release-19 of the 5GPP, standardization is underway for user equipment-initiated (UEI) / event-driven (ED) beam management to address the challenges of conventional network-driven beam management. Unlike conventional network-driven beam management, UE-initiated / event-driven beam management is a method in which UEs proactively perform beam management, as they can recognize the current beam status and beam change trends relatively quickly compared to base stations.

[0005] The purpose of the present disclosure to solve the above problems is to provide a method and device for UE-initiated (UEI) / event-driven (ED) beam reporting operation.

[0006] According to embodiments of the present disclosure for achieving the above object, a method of a terminal may include: receiving a transmission configuration indicator (TCI) state indicating a current beam for determining the occurrence of an event from a base station; determining whether only a tracking reference signal (TRS) is set as a quasi-co-location (QCL) reference signal (RS) of the TCI state; when it is determined that only a TRS is set as the QCL RS of the TCI state, identifying an RS associated with the TRS; and when it is determined that the TRS is associated only with a synchronization signal block (SSB), identifying a separate RS associated with the TRS, measuring a quality of the current beam based at least on the separate RS, and determining the occurrence of the event based on the measured quality of the current beam.

[0007] The above separate RS may be a CSI-RS (channel state information-reference signal) for beam management.

[0008] The above separate RS may have a specific QCL Type or a specific QCL Type combination.

[0009] When the above separate RS has a QCL Type combination, an indicator indicating a specific QCL Type to be used to measure the quality of the current beam in the QCL Type combination can be received from the base station.

[0010] The above separate RS can be set by parameters included in TRS-Info set in the above TRS.

[0011] The above separate RS can be changed by MAC (medium access control) CE (control element).

[0012] The method may further include: when the TRS is confirmed to be linked to a CSI-RS, a step of measuring a quality of the current beam based on at least the CSI-RS, and determining the occurrence of the event based on the measured quality of the current beam.

[0013] The method may further include: when it is determined that the event has occurred, a step of transmitting a first uplink (UL) channel notifying the occurrence of the event to the base station.

[0014] The above event may include at least Event-2.

[0015] According to embodiments of the present disclosure for achieving the above object, a method of a base station includes: transmitting a transmission configuration indicator (TCI) state indicating a current beam for determining the occurrence of an event to a terminal; and receiving a first uplink (UL) channel for notifying the occurrence of the event detected based on a quality of the current beam measured based on a quasi-co-location (QCL) reference signal (RS) of the TCI state from the terminal, wherein the quality of the current beam can be measured based on a separate RS linked to a tracking reference signal (TRS) when only a TRS is set as the QCL-RS of the TCI state and the TRS is linked only to a synchronization signal block (SSB).

[0016] The above separate RS may be a CSI-RS (channel state information-reference signal) for beam management.

[0017] The above separate RS may have a specific QCL Type or a specific QCL Type combination.

[0018] When the above separate RS has a QCL Type combination, an indicator indicating a specific QCL Type to be used to measure the quality of the current beam in the QCL Type combination may be transmitted to the terminal.

[0019] The above separate RS can be set by parameters included in TRS-Info set in the above TRS.

[0020] The above separate RS can be changed by MAC (medium access control) CE (control element).

[0021] The above event may include at least Event-2.

[0022] According to embodiments of the present disclosure for achieving the above object, a terminal may include at least one processor, and the at least one processor may perform the steps of: receiving a transmission configuration indicator (TCI) state indicating a current beam for determining the occurrence of an event from a base station; determining whether only a tracking reference signal (TRS) is set as a quasi-co-location (QCL) reference signal (RS) of the TCI state; if it is determined that only a TRS is set as the QCL RS of the TCI state, identifying an RS associated with the TRS; and if it is determined that the TRS is associated only with a synchronization signal block (SSB), identifying a separate RS associated with the TRS, measuring a quality of the current beam based at least on the separate RS, and determining the occurrence of the event based on the measured quality of the current beam.

[0023] The above separate RS may be a CSI-RS (channel state information-reference signal) for beam management.

[0024] The above separate RS may have a specific QCL Type or a specific QCL Type combination.

[0025] The at least one processor may further perform a step of transmitting a first uplink (UL) channel notifying the occurrence of the event to the base station when the terminal determines that the event has occurred.

[0026] When utilizing embodiments of the present disclosure, a reference signal (RS) capable of measuring the quality of the current beam can be appropriately configured in UE-initiated (UEI) / event-driven (ED) beam reporting operations. Therefore, the quality of the current beam can be measured more accurately, enabling accurate event detection and improving the accuracy of beam reporting. Consequently, this can lead to improved overall system performance.

[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 for explaining Mode A operation to which embodiments of the present invention are applied.

[0037] Figure 10 is a flowchart for explaining Mode B operation to which embodiments of the present invention are applied.

[0038] FIG. 11 is a flowchart illustrating a terminal operation method for terminal-driven / event-based beam reporting according to an embodiment of the present invention.

[0039] 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.

[0040] 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.

[0041] 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.”

[0042] 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.”

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

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

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

[0046] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding in describing the present disclosure, 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.

[0047] 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.

[0048] 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.

[0049] 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)).

[0050] 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.”

[0051] The communication network to which the embodiment is applied is not limited to what is described below, and the embodiment may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the communication network may be used in the same sense as the communication system.

[0052] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0053] 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.

[0054] A plurality of communication nodes (110 to 130) can support a communication protocol (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) specified in the 3GPP (3rd generation partnership project) standard. 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.

[0055] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0056] 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.

[0057] 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).

[0058] 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).

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0066] 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).

[0067] 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.

[0068] 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).

[0069] 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).

[0070] 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).

[0071] 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).

[0072] 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).

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] Figure 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0082] 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.

[0083] 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."

[0084] Figure 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0085] 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.

[0086] Figure 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0087] 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.

[0088] 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.

[0089] Subcarrier spacing 15kHz 30kHz 60kHz 120kHz 240kHz 480kHz OFDM symbol length (㎲) 66.733.316.78.34.22.1 CP length (㎲) 4.762.381.190.600.300.151 Number of OFDM symbols in ㎳ 142856112224448

[0090]

[0091] 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.

[0092] 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.

[0093] 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."

[0094] 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.

[0095] 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.

[0096] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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).

[0102] The search space information may include a coreset identifier (ID) associated with the search space, a period of PDCCH monitoring, and / or an offset. Each of the PDCCH monitoring period and offset may 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.

[0103] 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).

[0104]

[0105] Discussions are underway to improve intra-cell and inter-cell beam management, based on the work item description (WID) for 3GPP Rel-19 NR MIMO discussions. These improvements primarily target FR2 bands and single transmission / reception point (sTRP) scenarios, leveraging existing legacy CSI measurement and reporting configuration procedures while reducing overhead and latency.

[0106] To this end, UE-initiated (UEI) / event-driven (ED) beam management procedures are being discussed. The beam management methods defined up to Rel-18 were network-based. In other words, in network-initiated beam management, the network (i.e., the base station) can instruct the terminal to switch to a specific beam for DL ​​reception or UL transmission. In this case, the base station receives a measurement report from the terminal and issues an instruction based on the measurement report, so the base station cannot determine the optimal beam until it receives the measurement report transmitted by the terminal.

[0107] If beam management operations are initiated from the terminal side, which can first detect beam changes, delay time (e.g., time required for a base station to instruct a terminal to perform a measurement report and for a terminal to receive a measurement report based on the instruction) and signal overhead (e.g., overhead of a signal from a network to instruct a terminal to perform a measurement report) can be reduced compared to network-based beam management operations.

[0108]

[0109] Meanwhile, at the 3GPP RAN 1 meetings (RAN #116 and RAN #116-bis), outline beam report transmission procedures for UEI / ED beam reporting were approved.

[0110] First, the beam report transmission procedure is largely divided into Mode A and Mode B, and the outline of the procedure for each mode is as follows.

[0111] First, Mode A is a method of dynamically scheduling uplink control information (UCI) for beam reporting by the base station, and can be performed in the following three steps.

[0112] Step 1: The terminal may transmit the first UL channel requesting resources for the second UL channel for transmitting the beam report. The first UL channel consists of a PUCCH (i.e., the first PUCCH) containing single-bit information or multi-bit information, and the PUCCH may follow the existing SR (scheduling request terminal st) type or a new UCI type.

[0113] Step 2: The terminal can detect the DCI format indicating the resources of the second UL channel. In this case, no new DCI format is introduced.

[0114] Step 3: The terminal can transmit a beam report on a second UL channel. In this case, the second UL channel can be PUCCH, PUSCH, or both.

[0115] Mode A is a basic function of the terminal, and all terminals that support UEI / ED beam reporting must support this function.

[0116] Meanwhile, Mode B is a method of transmitting UCI on pre-configured resources for the second UL channel, and can be performed in the following two-step operation.

[0117] Step 1: The UE may transmit a first UL channel notifying that a beam report will be transmitted on a second UL channel. The first UL channel may consist of a PUCCH (i.e., the first PUCCH) containing single-bit information or multi-bit information, and the PUCCH may follow the existing SR (scheduling request terminal st) type or a new UCI type.

[0118] Step 2: The terminal can transmit a beam report on a second UL channel. As in Mode A, the second UL channel can be PUCCH, PUSCH, or both.

[0119] In Mode B, the notification in step 1 and the beam report in step 2 are transmitted as separate reporting instances, and it is not determined whether the terminal receives confirmation information in response to each step in Mode A and Mode B.

[0120] Additionally, cross-CC (component carrier) beam reporting can be supported in both Mode A and Mode B in the above procedures.

[0121]

[0122] Meanwhile, the following events are being discussed as events that trigger the above-described UEI / ED beam report.

[0123] -Event-1: The quality of the current beam (e.g. L1-RSRP, etc.) falls below a certain threshold.

[0124] -Event-2: The quality of at least one new beam is improved by a threshold amount compared to the current beam.

[0125] -Event-3: The quality of the new beam exceeds a certain threshold.

[0126] -Event-4: The quality of the current beam becomes lower than threshold 1, and the quality of at least one new beam becomes higher than threshold 2.

[0127] -Event-5: The absolute value of the difference between the quality of the current beam and the quality of at least one new beam becomes less than a certain threshold.

[0128] -Event-6: The current beam is not included in the top K(>1) beams configured for measurement and reporting.

[0129] -Event-7a: The quality of at least one new beam (e.g. L1-RSRP) improves by a certain threshold compared to the quality derived from the lowest quality RS among the active TCI states.

[0130] -Event-7b: The quality of at least one new beam (e.g. L1-RSRP) improves by a certain threshold compared to the quality derived from the highest quality RS among the active TCI states.

[0131] -Event-8: The quality of M(>1) new beams (e.g. L1-RSRP) is improved by a certain threshold compared to the current beam.

[0132] -Event-9: The quality of at least one new beam (e.g. L1-RSRP) is improved by a certain threshold compared to the configured reference RS (possibly SSB or CSI-RS).

[0133]

[0134] As described above, for UEI / ED beam reporting operation, a process of transmitting information from the terminal to the base station (Step 1) is required in all modes. In Mode A, where resources for beam reporting are not pre-allocated, the terminal can request resources for beam reporting from the base station. In Mode B, where resources for beam reporting are pre-allocated, the terminal can notify the base station that it will use the pre-allocated resources for beam reporting. In Step 1, the terminal can transmit the information to the base station via the PUCCH, and the information can be composed of 1-bit information or multi-bit information. If the information is composed of 1 bit, the information can be simply information requesting resources from the base station or information notifying that pre-allocated resources will be used. On the other hand, if the information is composed of multi-bit information, the information can be utilized for various purposes in addition to information requesting resources or information notifying that pre-allocated resources will be used.

[0135]

[0136] Figure 9 is a flowchart for explaining Mode A operation to which embodiments of the present invention are applied.

[0137] Referring to FIG. 9, a terminal may detect at least one event (S910). In this case, the terminal may detect at least one event among the previously described event(s) (e.g., Event-1 to Event-9). If at least one event is detected, the terminal requests resources for beam reporting through a first UL channel (i.e., first PUCCH) (S920), and a base station that receives the first UL channel may indicate resources of a second UL channel to be used by the terminal to transmit the beam report through DCI (S930). Thereafter, the terminal may transmit the second UL channel including the beam report by utilizing the corresponding resources (S940).

[0138] Figure 10 is a flowchart for explaining Mode B operation to which embodiments of the present invention are applied.

[0139] Referring to FIG. 10, a terminal may detect at least one event (S1010). In this case, the terminal may detect at least one event among the event(s) described above (e.g., Event-1 to Event-9). If at least one event is detected, the terminal may notify the base station that it will transmit second UL channel(s) using preset resources through the first UL channel (i.e., the first PUCCH) (S1020). Thereafter, the terminal may transmit second UL channel(s) including beam reports to the base station using the preset resources (S1040). In this case, the terminal may transmit the second UL channel after receiving a message from the base station indicating that the first PUCCH has been received (e.g., an ACK message consisting of a 1-bit indicator) (i.e., a notification message indicated by a dotted line in FIG. 10). Alternatively, the terminal may transmit the second UL channel in a slot or symbol after a preset offset from the slot or symbol in which the first PUCCH is transmitted without receiving an acknowledgement message for the first PUCCH from the base station.

[0140]

[0141] Looking at the triggering conditions of the events described above, the terminal can perform a UEI / ED beam reporting operation by transmitting the first UL channel (i.e., the first PUCCH) to the base station when a (predefined) event condition is satisfied based on the quality of the current beam or the quality of the new beam, or based on a comparison of the quality of the current beam and the quality of the new beam.

[0142] In order to measure the quality of the current beam or the new beam, it was defined for Event-2 which reference signal (RS) quality to measure (i.e. how to set the RS for measurement).

[0143]

[0144] For example, the following was agreed upon at the 3GPP RAN1 WG 116bis meeting:

[0145] With respect to event detection for UEI / ED beam reporting operations, at least Event-2 (when there is one or more new beams with a quality better than the current beam by a threshold (e.g., L1-RSRP)) is supported. In addition, at least L1-RSRP is supported as a quality metric used for triggering Event-2 (although other quality metrics (e.g., L1-SINR) are not excluded). However, it was agreed that further discussion will be conducted on how the trigger event is determined using L1-RSRP (e.g., timers, counters, filter coefficients) and whether the network has control over how the trigger event is determined using L1-RSRP.

[0146] First, with regard to RS measurements for the new beam for triggering Event-2, it was agreed that one or more of the following options would be selected:

[0147] Option-3a (Explicit): The RS for the new beam is explicitly configured via RRC signaling (e.g., by reusing existing RS measurement configurations or within the TCI-State) or via MAC-CE.

[0148] Option-3b (implicit): The RS for the new beam is implicitly derived from the quasi-co-location (QCL) RS of the activated TCI state.

[0149] Option-3c (implicit): The RS for the new beam is implicitly derived from the QCL RS of the configured TCI state.

[0150] In the above implicit methods, when two QCL RSs are set within one TCI state, the measurement RS for the new beam is derived from the QCL RS according to QCL-TypeD.

[0151] Next, it was agreed that the current beam for triggering Event-2 is defined as the beam corresponding to the indicated TCI state, and the implicit method of Option-2a below is applied with respect to RS measurements for the current beam.

[0152] Option-2a (implicit): The RS for the current beam is implicitly derived from the QCL RS of the indicated TCI state.

[0153] Meanwhile, the RS for the current beam may be a QCL RS within the indicated TCI state, or may be a SSB (synchronization signal block) having a QCL relationship with the QCL RS.

[0154] However, it was agreed that the explicit method below will also be discussed further in the future.

[0155] Option-2c (Explicit): The measurement RS for the current beam is explicitly configured via RRC or MAC-CE signaling. In this case, SSB or CSI-RS can be configured as the measurement RS for the current beam.

[0156]

[0157] Additionally, the following was agreed upon at the 3GPP RAN1 WG 117 meeting regarding RS measurements for triggering Event-2:

[0158] For the implicit method (Option-2a) with respect to RS measurements for the current beam for triggering Event-2, both methods are supported as follows:

[0159] Scheme-1: The RS for the current beam is the QCL RS within the indicated TCI state, and further discussion is needed on whether and how to handle the case where only one TRS (tracking reference signal) is set within the indicated TCI state.

[0160] Scheme-2: The RS for the current beam is an SSB having a QCL relationship with the QCL RS within the indicated TCI state.

[0161] Activation of either Scheme-1 or Scheme-2 is selected by the network, and further discussion is needed as to whether the selection of either Scheme-1 or Scheme-2 is made explicitly through RRC parameters or implicitly (e.g., activating Scheme-1 if the RS of the new beam is CSI-RS, otherwise activating Scheme-2). However, it is assumed that the same RS type is used for RS measurements of the current beam and the new beam regardless of whether Scheme-1 or Scheme-2 is activated. If two QCL RSs are configured in the indicated TCI state, the QCL RS according to QCL-TypeD is used as the RS for measuring the quality of the current beam.

[0162] Regarding RS measurements for the current beam, for Option-2a, in addition to Scheme-1 and Scheme-2, we further discuss the following to handle the case where only one TRS is configured within the indicated TCI state.

[0163] Option-1: Introduction of an additional method: The RS for the current beam can be a CSI-RS (channel state information-reference signal) for beam management derived from the QCL RS within the indicated TCI state.

[0164] Option-2: Add support for TRS as a measurement RS for estimating L1-RSRP of the current beam.

[0165] Option-3: Introducing an additional scheme: Currently, the RS for a beam is explicitly configured by RRC or MAC-CE signaling (this corresponds to Option-2c in the RAN1 WG 116b agreement).

[0166] Option-4: No further improvement (i.e., use Scheme-2 in this case)

[0167] Regarding RS measurements for the new beam of Event-2, at least Option-3a is supported.

[0168] It was agreed that at least Option-3a (explicit mode) is supported for RS measurements on new beams for triggering Event-2, and that additional support of Option-3b / 3c below is for further discussion.

[0169] Option-3b: The RS for the new beam is implicitly derived from the QCL RS of the activated TCI state.

[0170] Option-3c: The RS for the new beam is implicitly derived from the QCL RS of the TCI states included in the subset configured within the TCI state list set by legacy RRC signaling.

[0171] Meanwhile, with regard to the explicit RS setting for new beam measurements for triggering Event-2, it was agreed that one of the following options should be selected:

[0172] Option 1: The RS for the new beam is explicitly configured within a single RS resource set associated with the CSI report configuration. In this case, whether the RS within the RS resource set can be updated via MAC-CE requires further discussion.

[0173] Option-2: An RS list for measuring a new beam can be set by RRC signaling, and a subset of that list can be activated for measuring a new beam by MAC-CE.

[0174] Option-3: A list of RS resources for new beam measurements can be configured by RRC signaling, and a subset of RS resources in the list can be provided for new beam measurements via the indicated TCI state.

[0175]

[0176] As previously explained, the RS used to measure the quality of the current beam for triggering Event-2 may be the QCL RS of the indicated TCI state. Alternatively, the RS used to measure the quality of the current beam for triggering Event-2 may be the QCL RS and the QCL-SSB of the indicated TCI state. However, further discussion is still needed on how to determine the RS for measuring the quality of the current beam when only one TRS is set to the QCL-RS in the indicated TCI state.

[0177] Accordingly, the present invention proposes a method for determining an RS for measuring the quality of a current beam when only one TRS is set to QCL-RS in a directed TCI state, as follows.

[0178]

[0179] In one method, if only one TRS (i.e., a CSI-RS with trs-Info set) is set as the QCL RS of the indicated TCI state, that TRS can be used as the RS for measuring the quality of the current beam. In another method, if only one TRS (i.e., a CSI-RS with trs-Info set) is set as the QCL-RS of the indicated TCI state, the SSB QCLed with that TRS can be used as the RS for measuring the quality of the current beam.

[0180] In a typical beam management operation, CSI-RS resources configured for beam management may be set based on the SSB with the best quality among the SSBs measured at the terminal (e.g., among 8 SSBs). Therefore, when the SSB with the best quality at the terminal changes, it may be necessary to update the QCL RS of the CSI-RS (i.e., TRS) with trs-Info set at the terminal. In addition, in the present disclosure, the CSI-RS may be interpreted as a CSI-RS with trs-Info set (i.e., TRS) or a periodic CSI-RS.

[0181] At this time, depending on which RS the QCL RS of the indicated TCI state is, there may be cases where the QCL RS cannot be used for beam measurement. For example, it can be assumed that the QCL chain is set as follows. First, if the QCL RS of the indicated TCI state is a CSI-RS for beam management, the CSI-RS can be linked with SSB. Alternatively, if the QCL RS of the indicated TCI state is a CSI-RS for beam management, the CSI-RS can be linked with TRS and SSB. If the QCL RS of the indicated TCI state is a TRS, the TRS can be linked with SSB or a CSI-RS for beam management. Alternatively, if the QCL reference signal of the indicated TCI state is a TRS, the TRS can be linked with a CSI-RS and SSB for beam management.

[0182] As described above, if a specific QCL chain is configured (e.g., if the QCL RS in the indicated TCI state is a TRS and the TRS is only associated with SSB), accurate measurements of the current beam may not be possible according to the current agreement. In such a situation, additional configuration of the RS for measuring the quality of the current beam may be required. That is, if the QCL RS in the indicated TCI state is a TRS and the TRS is only associated with SSB, separate configuration of the RS for measuring the quality of the current beam may be required.

[0183]

[0184] FIG. 11 is a flowchart illustrating a terminal operation method for terminal-driven / event-based beam reporting according to an embodiment of the present invention.

[0185] Referring to FIG. 11, the terminal may receive a transmission configuration indicator (TCI) state indicating a current beam for determining the occurrence of an event from the base station (S1110). In this case, the TCI state may be indicated by a TCI field included in the most recently received PDCCH (e.g., DCI format 1_1 / 1_0, etc.). Here, the event may include at least Event-2, but events among the previously defined events that require measurement of the quality of the current beam are not excluded.

[0186] Basically, the terminal can measure the quality of the current beam using the RS derived from the QCL RS within the indicated TCI state. That is, the RS for measuring the quality of the current beam may be the QCL RS itself within the indicated TCI state, or may be an SSB and / or beam management CSI-RS having a QCL relationship with the QCL-RS.

[0187] As previously explained, if only TRS is set to QCL RS within the TCI state and only TRS and SSB are linked, it may be difficult to measure the quality of the current beam using the SSB. Therefore, the terminal can check whether only TRS is set to QCL RS within the indicated TCI state (S1120).

[0188] As a result of the judgment in step (S1120), if not only TRS but also CSI-RS or SSB is set as QCL RS within the TCI state, the terminal can measure the quality of the current beam using the CSI-RS or SSB and determine the occurrence of an event based on the measured quality of the current beam (S1130).

[0189] As a result of the judgment in step (S1120), if only TRS is set as QCL RS within the TCI state, the terminal can check whether the RS linked to the TRS is CSI-RS or SSB (S1140).

[0190] As a result of the verification in step (S1140), if it is confirmed that the TRS is linked to the CSI-RS, the terminal can measure the quality of the current beam at least based on the CSI-RS, and determine the occurrence of an event based on the measured quality of the current beam (S1150).

[0191] As a result of the verification in step (S1140), if it is confirmed that the TRS is only linked to SSB, the terminal can check a separate RS linked to the TRS, measure the quality of the current beam based on at least the separate RS, and determine the occurrence of the event based on the measured quality of the current beam (S1160).

[0192] In one embodiment, the base station may explicitly configure a separate RS for measuring the quality of the current beam using higher layer signaling (e.g., MAC-CE or RRC signaling). In this case, a specific parameter of the RRC signaling may be utilized to configure the RS for measuring the quality of the current beam. For example, when configuring (NZP-)CSI-RS, if the corresponding CSI-RS resource set is TRS (i.e., trs-Info is set to TRUE), a parameter indicating the RS for measuring the quality of the current beam may be utilized. For this purpose, the parameter may be added to the existing trs-Info or a new separate parameter may be defined and used. In this case, a TRS for which the parameter is not configured (i.e., a separate RS for measuring the quality of the current beam is not indicated) may not be configured as a QCL RS of the TCI state. That is, the terminal can expect that a TRS for which the corresponding parameter is not set (i.e., a separate RS for measuring the quality of the current beam is not indicated) will not be set as a QCL RS in the TCI state.

[0193] Meanwhile, the separate RS can be changed or updated by MAC CE. That is, when a change or update of the separate RS is required, the base station can transmit a MAC CE instructing the terminal to change or update the separate RS. Alternatively, the separate RS can be changed or updated by DCI. That is, when a change or update of the separate RS is required, the base station can transmit a DCI instructing the terminal to change or update the separate RS.

[0194] Finally, if it is determined that an event has occurred based on the quality of the current beam, the terminal may transmit a first uplink (UL) channel to the base station to notify the occurrence of the event (S1170). Here, the first UL channel may be the first PUCCH of the Mode A or Mode B beam reporting operation described with reference to FIGS. 9 and 10.

[0195]

[0196] A separate RS linked to the above TRS may have a specific QCL Type (e.g., QCL Type A or QCL Type D) or a specific QCL Type combination (e.g., QCL Type A and QCL Type D). In this case, if the linked RS has a combination of QCL Types (e.g., QCL Type A and QCL Type D), only a specific QCL Type (e.g., QCL Type D) among the combinations of QCL Types may be set to be used. Alternatively, a 1-bit indicator may be set to clearly designate the QCL type to be used (e.g., if the indicator is set to 0, QCL Type A may be used, and if the indicator is set to 1, QCL Type D may be used). For example, the indicator may be included in signaling for setting the separate RS and received from the base station.

[0197] As another example, in UEI / ED beam management operation, an NZP-CSI-RS-ResourceSet (configured recursively or non-repetitively) with a higher layer parameter trs-Info set may be configured to include only CSI-RS resources with a specific QCL Type (e.g., QCL-Type D). That is, the NZP-CSI-RS-ResourceSet with trs-Info set may not include CSI-RS resources that only have other QCL Types (e.g., QCL-Type A, etc.). That is, the UE may expect that the NZP-CSI-RS-ResourceSet with trs-Info set does not include CSI-RS resources that only have other QCL Types (e.g., QCL-Type A, etc.).

[0198]

[0199] In the above description, with respect to the explicit configuration of RS for new beam measurements for at least Event-2, the RS for the new beam may be explicitly configured in one RS resource set associated with the CSI reporting configuration. In this case, a parameter indicating the maximum number of RSs that can be configured in the RS resource set may be introduced. Additionally, the RSs within the RS resource set may be updated via MAC-CE.

[0200] In the above description, when Event-1 and / or Event-7a are supported among the events for UEI / ED beam reporting operation, the M value in the operation of Event-7a may be selected from a specific value (e.g., 1) or one or more values ​​(e.g., 1 or 2) or may be set via RRC signaling.

[0201] The information transmitted in the above description (e.g., a decision on which RS to set) or the action may be determined or selected by the network (or gNB).

[0202]

[0203] The information(s) described in this disclosure may be applied not only to Mode A and Mode B described in this disclosure, but also to Mode(s) to be defined later. The information(s) described in this disclosure may be applied differently depending on the Mode.

[0204] The first PUCCH described above may have an SR type or a new UCI type, or may have an SR type, a BSR type, or another format.

[0205] The information(s) described above may be transmitted via MAC-CE signaling, UCI, and / or RRC signaling (and / or another channel).

[0206] In the present disclosure, performing a terminal-driven / event-based beam management operation can be extended to mean that the terminal transmits signaling to the base station instructing it to perform a terminal-driven / event-based beam management operation.

[0207] In the present disclosure, the term "terminal-driven / event-based beam management operation being stopped" can be extended to mean that the terminal transmits signaling to the base station indicating that it does not perform the terminal-driven / event-based beam management operation, or that it performs the existing base station-driven beam management operation.

[0208] The methods proposed in this disclosure can be applied to additionally defined events in addition to the currently defined events. The methods proposed in this disclosure can be applied to intra-cell beam management and inter-cell beam management. The methods proposed in this disclosure can also be similarly applied to multi-TRP (mTRP) operations.

[0209]

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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. A terminal method for UE-initiated (UEI) / event-driven (ED) beam reporting operation. A step of receiving a transmission configuration indicator (TCI) state indicating a current beam for determining the occurrence of an event from a base station; A step of determining whether only the TRS (tracking reference signal) is set to the QCL (quasi-co-location) RS (reference signal) of the above TCI state; When it is determined that only the TRS is set as the QCL RS of the above TCI state, a step of checking the RS linked to the TRS; and If the TRS is confirmed to be linked only with a synchronization signal block (SSB), a step of checking a separate RS linked to the TRS, measuring the quality of the current beam based at least on the separate RS, and determining the occurrence of the event based on the measured quality of the current beam is included. Terminal method.

2. In claim 1, The above separate RS is a CSI-RS (channel state information-reference signal) for beam management. Terminal method.

3. In claim 1, The above separate RS has a specific QCL Type or a specific QCL Type combination, Terminal method.

4. In claim 1, When the above separate RS has a QCL Type combination, an indicator indicating a specific QCL Type to be used to measure the quality of the current beam in the QCL Type combination is received from the base station. Terminal method.

5. In claim 1, The above separate RS is set by the parameters included in the TRS-Info set in the above TRS. Terminal method.

6. In claim 1, The above separate RS is changed by MAC (medium access control) CE (control element). Terminal method.

7. In claim 1, If the TRS is confirmed to be linked to the CSI-RS, the method further comprises the step of measuring the quality of the current beam based on at least the CSI-RS, and determining the occurrence of the event based on the measured quality of the current beam. Terminal method.

8. In claim 1, If it is determined that the above event has occurred, the method further comprises the step of transmitting a first uplink (UL) channel notifying the occurrence of the event to the base station. Terminal method.

9. In claim 1, The above event includes at least event-2, Terminal method.

10. A method of a base station for UE-initiated (UEI) / event-driven (ED) beam reporting operation, A step of transmitting a TCI (transmission configuration indicator) state indicating a current beam to determine the occurrence of an event to the terminal; and A step of receiving a first uplink (UL) channel that notifies the occurrence of the event detected based on the quality of the current beam measured based on the QCL (quasi-co-location) RS (reference signal) of the TCI state from the terminal, The quality of the current beam is measured based on a separate RS linked to the TRS when only the TRS (tracking reference signal) is set to the QCL-RS of the TCI state and the TRS is linked only to the SSB (synchronization signal block). Base station method.

11. In claim 10, The above separate RS is a CSI-RS (channel state information-reference signal) for beam management. Base station method.

12. In claim 10, The above separate RS has a specific QCL Type or a specific QCL Type combination, Base station method.

13. In claim 10, When the above separate RS has a QCL Type combination, an indicator indicating a specific QCL Type to be used to measure the quality of the current beam in the QCL Type combination is transmitted to the terminal. Base station method.

14. In claim 10, The above separate RS is set by the parameters included in the TRS-Info set in the above TRS. Base station method.

15. In claim 10, The above separate RS is changed by MAC (medium access control) CE (control element). Base station method.

16. In claim 10, The above event includes at least event-2, Base station method.

17. A terminal including at least one processor, wherein the at least one processor: A step of receiving a transmission configuration indicator (TCI) state indicating a current beam for determining the occurrence of an event from a base station; A step of determining whether only the TRS (tracking reference signal) is set to the QCL (quasi-co-location) RS (reference signal) of the above TCI state; When it is determined that only the TRS is set as the QCL RS of the above TCI state, a step of checking the RS linked to the TRS; and If the TRS is confirmed to be linked only with a synchronization signal block (SSB), a step of checking a separate RS linked to the TRS, measuring the quality of the current beam based on at least the separate RS, and determining the occurrence of the event based on the measured quality of the current beam is performed. Terminal.

18. In claim 17, The above separate RS is a CSI-RS (channel state information-reference signal) for beam management. Terminal.

19. In claim 17, The above separate RS has a specific QCL Type or a specific QCL Type combination, Terminal.

20. In claim 17, At least one processor of the terminal: If it is determined that the above event has occurred, an additional step is performed to transmit a first uplink (UL) channel notifying the occurrence of the event to the base station. Terminal.

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