Beam management method and device

Abstract

A method performed by a base station comprises the steps of: receiving, from a terminal, capability information indicating whether beam squint-based beam sweeping of the terminal is supported; determining a target area including points at which beams formed through the beam squint-based beam sweeping reach; determining beam widths of the beams; determining, on the basis of at least one of the target area or the beam widths, the number of one or more time resources used for the beam squint-based beam sweeping; and transmitting the beams to the terminal in the one or more time resources on the basis of the beam squint-based beam sweeping for the target area.

Description

Beam management method and device

[0001] The present disclosure relates to improved communication technology, and more specifically to beam management technology.

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

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

[0004] Existing communication technologies (e.g., beam management) may presuppose that communication between a terminal and a base station takes place in the far-field. However, 6G communication networks can utilize high-frequency bands to address the depletion of frequency resources. Consequently, communication between a terminal and a base station in the far-field can be transitioned to communication in the near-field. Beam management between terminals and base stations in the near-field can be performed based on beam sweeping. Conventional beam sweeping can be performed by varying only the beam's angle domain. However, beam sweeping between a terminal and a base station in the near-field can be performed by varying not only the beam's angle domain but also the distance domain. The procedure for searching for the optimal beam may involve searching in the distance domain as well as the angle domain. An increase in the domains being searched can lead to an increase in computational complexity when performing beam management. A method may be required to address the aforementioned problems.

[0005] The objective of the present disclosure to solve the above-mentioned problems is to provide a beam management method and apparatus using a beam squint in a communication system that supports a high frequency band.

[0006] A method of a base station according to embodiments of the present disclosure for achieving the above objective comprises: receiving capability information from a terminal indicating whether the terminal supports beam squint-based beam sweeping; determining a target area including points to which beams formed through beam squint-based beam sweeping reach; determining the beam width of the beams; determining the number of one or more time resources used for beam squint-based beam sweeping based on at least one of the target area or the beam width; and transmitting the beams from the one or more time resources to the terminal based on beam squint-based beam sweeping for the target area.

[0007] The capability information may include at least one of a parameter indicating the capability of a terminal to support the beam squint-based beam sweeping or a parameter indicating the state of a terminal having the capability, and the state of the terminal may be a state indicating whether the beam squint-based beam sweeping can be supported.

[0008] The above target area may be located on a distance domain based on a base station and an angle domain based on a base station, and the above target area may be determined based on maximum distance information / minimum distance information belonging to the distance domain and maximum angle information / minimum angle information belonging to the angle domain.

[0009] The above target area may include a point where the beam associated with the largest measurement value among the measurements reported by the terminal during the initial beam establishment procedure between the base station and the terminal reaches.

[0010] The method of the base station described above may further include the step of receiving mobility information of a terminal from a terminal before determining a target area, and the step of determining the target area based on at least one of the mobility information or the resource usage status of the base station.

[0011] The above beam width may be determined based on at least one of the base station's resource usage status, the purpose for which beam squint-based beam sweeping is performed, or the terminal's delay requirements.

[0012] The beam width can be determined based on the angle between one or more points where the power decreases by a preset value relative to the maximum power of each main lobe of the beams.

[0013] The method of the base station described above may further include the step of determining a target area and then determining the maximum and minimum frequencies of the subcarriers to which the beams are transmitted, such that the area formed by the beams includes the target area.

[0014] The above maximum frequency and minimum frequency may be determined to satisfy the first inequality and the second inequality, and the first inequality and the second inequality may be based on at least one of the maximum distance information / minimum distance information on which the target area is based, one or more time delay (TD) parameters used to adjust the phase of the elements of the true time delayer (TTD) used by the base station, one or more phase shift (PS) parameters used to adjust the phase of the elements of the phase shifter used by the base station, the center frequency of the bandwidth in which the beams are transmitted, or the spacing between the antenna elements forming the beams.

[0015] The method of the base station may further include the steps of setting a first PS parameter used to adjust the phase of elements of a phase shifter used to form beams based on a beam width before determining the number of one or more time resources, and determining the number of one or more time resources to satisfy a third inequality, wherein the first PS parameter may be set so that the regions formed by each of the beams correspond to each of the points belonging to the target region, and the third inequality may be based on at least one of the beam width of the beam corresponding to the maximum frequency or the first PS parameter.

[0016] The method of the base station may further include the step of determining the number of one or more time resources and then mapping the beams to the resources based on at least one of the maximum frequency, the minimum frequency, or the number of time resources.

[0017] The method of the base station may further include the step of transmitting a beam index corresponding to each of the beams, wherein the beam index may correspond to at least one of a point, a time resource, or a subcarrier frequency associated with each of the beams, and the point may belong to the target area.

[0018] The method of the base station may further include the steps of receiving a report from a terminal containing measurement values ​​of each of the beams, determining an optimal beam to be used for communication with the terminal based on the report, and performing communication with the terminal based on the optimal beam, and the report may further include information indicating a correspondence relationship between each of the measurement values ​​and the beam index.

[0019] A method of user equipment (UE) according to embodiments of the present disclosure for achieving the above objective comprises the steps of: transmitting capability information to a base station indicating whether the terminal supports beam squint-based beam sweeping; receiving beams formed by beam squint-based beam sweeping performed by the base station; determining measurement values ​​for each beam through measurement of the beams; and transmitting a report including the measurement values ​​to the base station.

[0020] The capability information may include at least one of a parameter indicating the capability of a terminal to support the beam squint-based beam sweeping or a parameter indicating the state of a terminal having the capability, and the state of the terminal may be a state indicating whether the beam squint-based beam sweeping can be supported.

[0021] The above method of the UE may further include the step of communicating with a base station through a beam selected by the base station based on the above report.

[0022] The above report may further include information indicating the correspondence between each of the above measurement values ​​and the beam index.

[0023] A base station according to embodiments of the present disclosure for achieving the above objective comprises at least one processor, wherein the at least one processor receives capability information from a terminal indicating whether the base station supports beam squint-based beam sweeping of the terminal, determines a target area including points to which beams formed through beam squint-based beam sweeping reach, determines the beam width of the beams, determines the number of one or more time resources used for beam squint-based beam sweeping based on at least one of the target area or the beam width, and causes the terminal to transmit the beams from the one or more time resources based on beam squint-based beam sweeping for the target area.

[0024] The above at least one processor may further cause the base station to determine the maximum and minimum frequencies of the subcarriers to which the beams are transmitted, such that the area formed by the beams includes the target area after the base station has determined the target area.

[0025] The above at least one processor may further cause the base station to set a first PS parameter used to adjust the phase of the phase shifter elements used to form the beams based on the beam width before determining the number of the one or more time resources, and the first PS parameter may be set such that the regions formed by each of the beams correspond to each of the points belonging to the target region, and the number of the one or more time resources may be determined to satisfy a third inequality, and the third inequality may be based on at least one of the beam width of the beam corresponding to the maximum frequency or the first PS parameter.

[0026] According to the present disclosure, beam squint-based beam sweeping may be presented. A base station may determine whether a terminal is a terminal that supports beam squint-based beam sweeping based on the capability information of a received terminal. The base station may determine a target area where beam squint-based beam sweeping is performed or the width of the beams used for beam squint-based beam sweeping. The base station may determine the number of time resources (e.g., symbols) used for beam squint-based beam sweeping based on at least one of the area of ​​the target area or the width of the beams. Based on the number of time resources, the base station may determine the resources to which reference signals transmitted through beam squint-based beam sweeping are mapped. The base station may perform beam squint-based beam sweeping on the resources. A terminal may transmit measurement values ​​for the beams received through beam squint-based beam sweeping to the base station. Based on the measurement values, the base station may determine the optimal beam used for communication with the terminal. Through the above procedures, the base station can consume fewer time resources to find the optimal beam, and the computational complexity at the base station can be reduced.

[0027] FIG. 1 is a conceptual diagram illustrating embodiments of a communication system.

[0028] FIG. 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0029] FIG. 3 is a block diagram illustrating embodiments of communication nodes performing communication.

[0030] FIG. 4a is a block diagram illustrating embodiments of a transmission path.

[0031] FIG. 4b is a block diagram illustrating embodiments of a receiving path.

[0032] FIG. 5 is a conceptual diagram illustrating embodiments of a system frame in a communication system.

[0033] FIG. 6 is a conceptual diagram illustrating embodiments of subframes in a communication system.

[0034] FIG. 7 is a conceptual diagram illustrating embodiments of slots in a communication system.

[0035] FIG. 8 is a conceptual diagram illustrating embodiments of time-frequency resources in a communication system.

[0036] FIG. 9 is a conceptual diagram illustrating embodiments of beams formed by a beam squint.

[0037] FIG. 10 is a conceptual diagram illustrating embodiments of target areas where beam sweeping is performed.

[0038] FIG. 11 is a conceptual diagram illustrating embodiments of beams having different beam widths.

[0039] FIG. 12 is a conceptual diagram illustrating embodiments of target areas where beam squint-based beam sweeping is performed.

[0040] FIG. 13 is a flowchart illustrating embodiments of a beam squint-based beam sweeping procedure.

[0041] The present disclosure is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present disclosure to specific embodiments and should be understood to include all modifications, equivalents, and substitutions that fall within the spirit and scope of the present disclosure.

[0042] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present disclosure, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" may mean a combination of a plurality of related described items or any of a plurality of related described items.

[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 one or more combinations 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 one or more combinations 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 it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0046] The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit this disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0047] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which this disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this disclosure.

[0048] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. To facilitate an overall understanding of the present disclosure, the same reference numerals are used for identical components in the drawings, and redundant descriptions of identical components are omitted. Operations according to combinations of embodiments, extensions of embodiments, and / or modifications of embodiments may be performed, as well as the embodiments explicitly described in the present disclosure. The performance of some operations may be omitted, and the order of operations may be changed.

[0049] In the embodiments, even when a method performed at a first communication node among the communication nodes (e.g., transmission or reception of a signal) is described, the corresponding second communication node may perform a method corresponding to the method performed at the first communication node (e.g., reception or transmission of a signal). That is, when the operation of a UE (user equipment) is described, the corresponding base station may perform an operation corresponding to the operation of the UE. Conversely, when the operation of a base station is described, the corresponding UE may perform an operation corresponding to the operation of the base station.

[0050] A base station may be referred to as Node B, evolved Node B, gNode B (next generation node B), gNB, device, apparatus, node, communication node, BTS (base transceiver station), RRH (radio remote head), TRP (transmission reception point), RU (radio unit), RSU (road side unit), radio transceiver, access point, access node, etc. A UE may be referred to as terminal, device, apparatus, node, communication node, end node, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, 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 the transmission and reception operations of system information (e.g., MIB (master information block), SIB (system information block)) and / or RRC (radio resource control) messages. MAC signaling may refer to the transmission and reception operations of MAC CE (control element). PHY signaling may refer to the transmission and reception operations of control information (e.g., DCI (downlink control information), UCI (uplink control information), SCI (sidelink control information)).

[0052] In the present disclosure, "setting an operation (e.g., a transmission operation)" may mean that "setting information for said operation (e.g., an information element, a parameter)" and / or "information directing the performance of said operation" is signaled. "Setting an information element (e.g., a parameter)" may mean that said information element is signaled. In the present disclosure, "signal and / or channel" may mean a signal, a channel, or "signal and channel," and "signal" may be used to mean "signal and / or channel." In the present disclosure, "time" and "time point" may be used interchangeably. "Time" may be interpreted as a time or a time point depending on the context, and "time point" may be interpreted as a time point or a time depending on the context.

[0053] In the present disclosure, a phrase containing "~ case (e.g., when ~)" may be expressed as a phrase containing "~ based on (e.g., based on ~)" or a phrase containing "~ in response to (e.g., in response to ~)". In other words, a phrase containing "~ case" may be interpreted as identical or similar to a phrase containing "~ based on" or a phrase containing "~ in response to".

[0054] 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 "communication system."

[0055] FIG. 1 is a conceptual diagram illustrating embodiments of a communication system.

[0056] 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). Additionally, the communication system (100) may further include a core network (e.g., S-GW (serving-gateway), P-GW (PDN (packet data network)-gateway), MME (mobility management entity)). 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.

[0057] Multiple communication nodes (110 to 130) can support communication protocols defined in 3GPP (3rd generation partnership project) standards (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.). Multiple communication nodes (110 to 130) can 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 multiple communication nodes may have the following structure.

[0058] FIG. 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0059] Referring to FIG. 2, the communication node (200) may include at least one processor (210), a memory (220), and a transceiver (230) that is connected to a network to perform communication. Additionally, 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) to communicate with one another.

[0060] The processor (210) can execute a program command stored in at least one of the memory (220) and the storage device (260). The processor (210) may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the methods according to embodiments of the present disclosure are performed. Each of the memory (220) and the storage device (260) may be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be composed of at least one of read-only memory (ROM) and random access memory (RAM).

[0061] 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 located 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 located 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 located within the cell coverage of the third base station (110-3). The first terminal (130-1) may be located within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be located within the cell coverage of the fifth base station (120-2).

[0062] Here, each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as NB (NodeB), eNB (evolved NodeB), gNB, ABS (advanced base station), HR-BS (high reliability-base station), BTS (base transceiver station), radio base station, radio transceiver, access point, access node, RAS (radio access station), MMR-BS (mobile multihop relay-base station), RS (relay station), ARS (advanced relay station), HR-RS (high reliability-relay station), HNB (home NodeB), HeNB (home eNodeB), RSU (road side unit), RRH (radio remote head), TP (transmission point), TRP (transmission and reception point), etc.

[0063] Each of the multiple terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as UE (user equipment), TE (terminal equipment), AMS (advanced mobile station), HR-MS (high reliability-mobile station), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, OBU (on board unit), etc.

[0064] Meanwhile, each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in different frequency bands or in the same frequency band. Each of the multiple 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 an ideal backhaul link or a non-ideal backhaul link. Each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to a core network via an ideal backhaul link or a non-ideal backhaul link. Each of the multiple 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.

[0065] In addition, each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) can support MIMO transmission (e.g., SU (single user)-MIMO, MU (multi user)-MIMO, massive MIMO, etc.), CoMP (coordinated multipoint) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, sidelink communication (e.g., D2D (device to device communication), ProSe (proximity services)), IoT (Internet of Things) 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 method, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) based on the SU-MIMO method. Alternatively, the second base station (110-2) can transmit a signal 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 a signal from the second base station (110-2) by the MU-MIMO method.

[0066] 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 method, 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) by the CoMP method. Each of the multiple base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive signals based on the CA method with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its cell coverage area. 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 by controlling each of the second base station (110-2) and the third base station (110-3).

[0067] Meanwhile, communication nodes performing communication in a communication network may be configured as follows. The communication node shown in FIG. 3 may be a specific embodiment of the communication node shown in FIG. 2.

[0068] FIG. 3 is a block diagram illustrating embodiments of communication nodes performing communication.

[0069] Referring to FIG. 3, the first communication node (300a) and the second communication node (300b) may each be a base station or a UE. The first communication node (300a) may transmit a signal to the second communication node (300b). A 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 a controller (316). The control information may include at least one of system information, RRC setting information (e.g., information set by RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0070] The transmitting processor (311) can generate data symbol(s) by performing processing operations on data (e.g., encoding operations, symbol mapping operations, etc.). The transmitting processor (311) can generate control symbol(s) by performing processing operations on control information (e.g., encoding operations, symbol mapping operations, etc.). Additionally, the transmitting processor (311) can generate synchronization / reference symbol(s) for synchronization signals and / or reference signals.

[0071] The Tx MIMO processor (312) can perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or synchronization / reference symbol(s). The output of the Tx MIMO processor (312) (e.g., a symbol stream) can be provided to modulators (MODs) included in transceivers (313a to 313t). The modulators (MODs) can perform processing operations on the symbol stream to generate modulated symbols and perform additional processing operations on the modulated symbols (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations) to generate signals. The signals generated by the modulators (MODs) of the transceivers (313a to 313t) can be transmitted through antennas (314a to 314t).

[0072] Signals transmitted by the first communication node (300a) can be received at the antennas (364a to 364r) of the second communication node (300b). Signals received at the antennas (364a to 364r) can be provided to demodulators (DEMODs) included in the transceivers (363a to 363r). The demodulators (DEMODs) can obtain samples by performing processing operations on the signals (e.g., filtering, amplification, down-conversion, digital conversion). The demodulators (DEMODs) can obtain symbols by performing additional processing operations on the samples. The MIMO detector (362) can perform MIMO detection operations on the symbols. The receiving processor (361) can perform processing operations on the symbols (e.g., deinterleaving, decoding). The output of the receiving processor (361) can be provided to the data sink (360) and the controller (366). For example, data can be provided to the data sink (360), and control information can be provided to the controller (366).

[0073] Meanwhile, the second communication node (300b) can transmit a signal to the first communication node (300a). The transmission processor (368) included in the second communication node (300b) can receive data (e.g., a data unit) from the data source (367) and can generate data symbol(s) by performing a processing operation on the data. The transmission processor (368) can receive control information from the controller (366) and can generate control symbol(s) by performing a processing operation on the control information. Additionally, the transmission processor (368) can generate reference symbol(s) by performing a processing operation on a reference signal.

[0074] The Tx MIMO processor (369) can perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or reference symbol(s). The output of the Tx MIMO processor (369) (e.g., a symbol stream) can be provided to modulators (MODs) included in transceivers (363a to 363t). The modulators (MODs) can perform processing operations on the symbol stream to generate modulated symbols and perform additional processing operations on the modulated symbols (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations) to generate signals. The signals generated by the modulators (MODs) of the transceivers (363a to 363t) can be transmitted through antennas (364a to 364t).

[0075] Signals transmitted by the second communication node (300b) can be received at the antennas (314a to 314r) of the first communication node (300a). Signals received at the antennas (314a to 314r) can be provided to demodulators (DEMODs) included in the transceivers (313a to 313r). The demodulators (DEMODs) can obtain samples by performing processing operations on the signals (e.g., filtering operation, amplification operation, down-conversion operation, digital conversion operation). The demodulators (DEMODs) can obtain symbols by performing additional processing operations on the samples. The MIMO detector (320) can perform MIMO detection operations on the symbols. The receiving processor (319) can perform processing operations on the symbols (e.g., deinterleaving operation, decoding operation). The output of the receiving processor (319) can be provided to the data sink (318) and the controller (316). For example, data can be provided to the data sink (318), and control information can be provided to the controller (316).

[0076] The memories (315 and 365) may store data, control information, and / or program code. The scheduler (317) may perform scheduling operations for communication. The processors (311, 312, 319, 361, 368, 369) and controllers (316, 366) shown in FIG. 3 may be the processor (210) shown in FIG. 2 and may be used to perform the methods described in this disclosure.

[0077] FIG. 4a is a block diagram illustrating embodiments of a transmission path, and FIG. 4b is a block diagram illustrating embodiments of a reception path.

[0078] Referring to FIGS. 4a and 4b, a transmission path (410) may be implemented at a communication node that transmits a signal, and a reception path (420) may be implemented at 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 reception 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 can be a natural number.

[0079] Information bits in the transmission path (410) can be input to the channel coding and modulation block (411). The channel coding and modulation block (411) can perform coding operations (e.g., LDPC (low-density parity check) (LDPC) coding operations, polar coding operations, etc.) and modulation operations (e.g., QPSK (Quadrature Phase Shift Keying), QAM (Quadrature Amplitude Modulation), etc.) on the information bits. The output of the channel coding and modulation block (411) may be a sequence of modulation symbols.

[0080] The S-to-P block (412) can convert modulated symbols in the frequency domain into parallel symbol streams to generate N parallel symbol streams. N can be the IFFT size or the FFT size. The N IFFT block (413) can generate signals in the time domain by performing an IFFT operation on the N parallel symbol streams. The P-to-S block (414) can convert the output of the N IFFT block (413) (e.g., parallel signals) into a serial signal to generate a serial signal.

[0081] The CP addition block (415) can insert CP into the 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 in the baseband before up-conversion.

[0082] A signal transmitted from the transmission path (410) can be input to the reception path (420). The operation in the reception path (420) may be the inverse operation of the operation in the transmission path (410). The DC (421) may down-convert the frequency of the received signal to a baseband frequency. The CP removal block (422) may remove CP from the signal. The output of the CP removal block (422) may be a serial signal. The S-to-P block (423) may convert the serial signal into parallel signals. The N FFT block (424) may generate N parallel signals by performing an FFT algorithm. The P-to-S block (425) may convert the parallel signals into a sequence of modulation symbols. The 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 the data.

[0083] In FIGS. 4a and 4b, Discrete Fourier Transform (DFT) and Inverse DFT (IDFT) may be used instead of FFT and IFFT. In FIGS. 4a and 4b, each of the blocks (e.g., components) may be implemented by at least one of hardware, software, or firmware. For example, in FIGS. 4a and 4b, some blocks 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, one block may be subdivided into multiple blocks, multiple blocks may be integrated into one block, some blocks may be omitted, and blocks supporting other functions may be added.

[0084] FIG. 5 is a conceptual diagram illustrating embodiments of a system frame in a communication system.

[0085] Referring to FIG. 5, time resources in a communication system can be divided into frames. 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 (millisecond). 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 a system frame after system frame #1023 can be #0.

[0086] A single system frame may contain two half frames. The length of a single half frame may be 5ms. 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 contain 10 subframes. The length of a single subframe may be 1ms. Within a single system frame, the 10 subframes may be referred to as "Subframe #0-9".

[0087] FIG. 6 is a conceptual diagram illustrating embodiments of subframes in a communication system.

[0088] Referring to FIG. 6, one subframe may include n slots, where n is a natural number. Thus, one subframe may consist of one or more slots.

[0089] FIG. 7 is a conceptual diagram illustrating embodiments of slots in a communication system.

[0090] Referring to FIG. 7, a slot may contain one or more symbols. A slot illustrated in FIG. 7 may contain 14 symbols. The length of the slot may vary depending on the number of symbols included in the slot and the length of the symbols. Alternatively, the length of the slot may vary depending on the numerology.

[0091] Numerals applied to physical signals and channels in a communication system may be variable. Numerals may be variable to meet various technical requirements of the communication system. In a communication system where CP (cyclic prefix) based OFDM waveform technology is applied, numerals may include subcarrier spacing and CP length (or CP type). Table 1 may be a first embodiment of a method for configuring numerals for a CP-OFDM based communication system. Depending on the frequency band in which the communication system operates, at least some of the numerals in Table 1 may be supported. Additionally, numerals not listed in Table 1 may be further supported in the communication system.

[0092]

[0093]

[0094] When the subcarrier spacing is 15 kHz (e.g., μ=0), the slot length may be 1 ms. In this case, one system frame may contain 10 slots. When the subcarrier spacing is 30 kHz (e.g., μ=1), the slot length may be 0.5 ms. In this case, one system frame may contain 20 slots.

[0095] When the subcarrier spacing is 60 kHz (e.g., μ=2), the slot length may be 0.25 ms. In this case, one system frame may contain 40 slots. When the subcarrier spacing is 120 kHz (e.g., μ=3), the slot length may be 0.125 ms. In this case, one system frame may contain 80 slots. When the subcarrier spacing is 240 kHz (e.g., μ=4), the slot length may be 0.0625 ms. In this case, one system frame may contain 160 slots.

[0096] The symbol can be set as a downlink (DL) symbol, a flexible (FL) symbol, or an uplink (UL) symbol. A slot consisting only of a DL symbol may be referred to as a "DL slot," a slot consisting only of an FL symbol may be referred to as an "FL slot," and a slot consisting only of a UL symbol may be referred to as an "UL slot."

[0097] The slot format can be semi-fixed by upper-layer signaling (e.g., RRC signaling). Information indicating the semi-fixed slot format may be included in system information, and the semi-fixed slot format can be set cell-specifically. Additionally, the semi-fixed slot format can be additionally set per terminal through terminal-specific upper-layer signaling (e.g., RRC signaling). The flexible symbols of the cell-specific slot format can be overridden as downlink symbols or uplink symbols by the terminal-specific upper-layer signaling. Furthermore, the slot format can be dynamically indicated by physical layer signaling (e.g., the SFI (slot format indicator) included in the DCI). The semi-fixed slot format can be overridden by the dynamically indicated slot format. For example, the semi-fixed flexible symbols can be overridden as downlink symbols or uplink symbols by the SFI.

[0098] The reference signal may be a CSI-RS (channel state information-reference signal), SRS (sounding reference signal), DM-RS (demodulation-reference signal), PT-RS (phase tracking-reference signal), etc. The channel may be a PBCH (physical broadcast channel), PDCCH (physical downlink control channel), PDSCH (physical downlink shared channel), PUCCH (physical uplink control channel), PUSCH (physical uplink shared channel), PSCCH (physical sidelink control channel), PSSCH (physical sidelink shared channel), etc. In the present disclosure, the control channel may mean PDCCH, PUCCH, or PSCCH, and the data channel may mean PDSCH, PUSCH, or PSSCH.

[0099] FIG. 8 is a conceptual diagram illustrating embodiments of time-frequency resources in a communication system.

[0100] 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 can be defined as a "RE (resource element)." A resource consisting of one OFDM symbol in the time domain and K subcarriers in the frequency domain can be defined as a "REG (resource element group)." A REG can include K REs. A REG can be used as the basic unit of resource allocation in the frequency domain. K can be a natural number. For example, K can be 12. N can be a natural number. In the slot illustrated in FIG. 7, N can be 14. N OFDM symbols can be used as the basic unit of resource allocation in the time domain.

[0101] In the present disclosure, RB may mean a common RB (CRB). Alternatively, RB may mean a PRB or a virtual RB (VRB). In a communication system, a CRB may mean an RB that constitutes a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). A carrier and / or bandwidth portion may be placed on the common RB grid. That is, the carrier and / or bandwidth portion may be composed of CRB(s). An RB or CRB constituting the bandwidth portion may be referred to as a PRB, and within the bandwidth portion, a CRB index may be appropriately converted to a PRB index.

[0102] Downlink data may be transmitted via PDSCH. A base station may transmit configuration information of the PDSCH (e.g., scheduling information) to a terminal via PDCCH. A terminal may obtain the configuration information of the PDSCH by receiving the PDCCH (e.g., downlink control information (DCI)). For example, the configuration information of the PDSCH may include a modulation coding scheme (MCS) 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. PDSCH may refer to a radio resource where downlink data is transmitted and received. Alternatively, PDSCH may refer to the downlink data itself. PDCCH may refer to a radio resource where downlink control information (e.g., DCI) is transmitted and received. Alternatively, PDCCH may refer to the downlink control information itself.

[0103] The terminal may perform a monitoring operation for the PDCCH to receive the PDSCH transmitted from the base station. The base station may notify the terminal of configuration information for the monitoring operation of the PDCCH using a higher-layer message (e.g., a radio resource control (RRC) message). The configuration information for the monitoring operation of the PDCCH may include CORESET (control resource set) information and search space information.

[0104] 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. A PDCCH occasion may be an area where the PDCCH can exist. That is, a PDCCH occasion may be an area where DCI can be transmitted. A PDCCH occasion may be referred to as a PDCCH candidate. 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., PRB (physical resource block) units or CRB (common resource block) units).

[0105] The search space information may include a CORESET ID (identifier) ​​associated with the search space, the period of PDCCH monitoring, and / or an offset. The period and offset of PDCCH monitoring may each be specified in slots. Additionally, the search space information may further include the index of the symbol at which the PDCCH monitoring operation begins.

[0106] A base station may configure a Bandwidth Part (BWP) for downlink communication. BWPs may be configured differently for each terminal. The base station may notify the terminal of the BWP configuration information using upper-layer signaling. Upper-layer signaling may refer to "transmission operations of system information" and / or "transmission operations of Radio Resource Control (RRC) messages." One or more BWPs may be configured for a single terminal. The terminal may receive BWP configuration information from the base station and identify the BWP(s) configured by the base station based on the BWP configuration information. If multiple BWPs are configured for downlink communication, the base station may activate one or more of the multiple BWPs. The base station may transmit the configuration information of the activated BWP(s) to the terminal using at least one of upper-layer signaling, a Medium Access Control (MAC) Control Element (CE), or a DCI. The base station may 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 can perform a downlink reception operation on the activated BWP(s).

[0107] A terminal may be located within the region where signals radiated from base station antennas propagate (hereinafter referred to as the 'electromagnetic field'). The types of electromagnetic fields can be classified into near fields or far fields. The types of electromagnetic fields can be classified based on the Rayleigh distance. If the distance between the terminal and the base station is shorter than the Rayleigh distance, the terminal may be in the near field. If the distance between the terminal and the base station is longer than the Rayleigh distance, the terminal may be in the far field. The Rayleigh distance can be expressed as shown in Equation 1 below.

[0108]

[0109]

[0110] In mathematical formula 1, R can represent the Rayleigh distance. ≡ can be the maximum length of an antenna array belonging to a transmitter (e.g., a base station), and 0 can be the maximum length of the antenna array belonging to the receiver (e.g., a unit). ε₀ can refer to the wavelength of the signal used for communication between the base station and the terminal. Referring to Equation 1, the Rayleigh distance can increase as the length of the antenna array belonging to the base station or the terminal increases. The Rayleigh distance can increase as the wavelength of the signal used for communication between the terminal and the base station becomes shorter. Since frequency and wavelength are inversely proportional to each other, the Rayleigh distance can increase as the frequency of the signal used for communication between the terminal and the base station increases.

[0111] 5G communication (e.g., NR (new radio)) can support communication using FR (frequency range) 1 or FR 2. NR can support beamforming to prevent path attenuation in FR 2 and MIMO (multiple input multiple output) systems to increase data transmission rates. Future 6G communication is expected to use frequency bands higher than FR 2 (e.g., the terahertz band). Since 6G communication uses the terahertz band higher than FR 2, signals with frequencies higher than those used in NR may be used for communication between terminals and base stations in 6G. 6G communication may introduce XL-MIMO (extra-large multiple input multiple output) systems to compensate for path attenuation caused by the increase in frequency bands. If XL-MIMO systems are introduced, the size of antenna arrays belonging to the nodes participating in the communication may increase. Due to the aforementioned characteristics of 6G communication (e.g., terahertz band or XL-MIMO), the Rayleigh distance in NR can be extended in 6G. Therefore, an electromagnetic field considered as a far-field in NR can be considered as a near-field in 6G.

[0112] Communication technologies used in NR (e.g., initial access, codebook design, handover, beam management, etc.) may assume that the terminal belongs to the far field. The frequency band used in 6G communication networks may be higher, and the number of antennas may be increased. A terminal previously determined to belong to the far field may be determined to belong to the near field in a 6G communication network. It may be difficult to apply existing communication technologies in the same way to communication between a terminal belonging to the near field and a base station. In the following, when the terminal belongs to the near field, it may be referred to as a near-field communication environment. In the following, when the terminal belongs to the far field, it may be referred to as a far-field communication environment.

[0113] Signals radiated from base station antennas may be spherical waves in the near field. Signals radiated from base station antennas can be considered planar waves in the far field. A terminal in the far field may regard the signals transmitted from the base station antennas as planar waves. The assumption by a terminal in the far field that received signals are planar waves may be referred to as the planar wave assumption.

[0114] If the plane wave assumption holds, the phase of the electromagnetic wave observed at an antenna can be expressed as a linear function of the antenna index. Therefore, the calculation of the beamforming vector can be simple. However, if the terminal is located in the near field, the difference between the phases of the electromagnetic waves observed at two different antennas can be significant. If the difference between the phases of the electromagnetic waves observed at two different antennas is large, channel modeling based on the plane wave assumption may become impossible. Since the shape of the wavefronts of the transmitted and received electromagnetic waves may not be planar when the terminal is in the near field, existing communication technologies may be difficult to apply. Therefore, communication technologies designed for the case where the terminal is in the near field may be required.

[0115] In NR, beam management procedures may include an initial beam establishment procedure, a beam adjustment procedure, and a beam failure recovery procedure. The initial beam establishment procedure and the beam adjustment procedure may be a procedure for determining the transmit-receive beam combination that has the largest RSRP (reference signal received power) value among transmit-receive beam combinations through beam sweeping. The beam failure recovery procedure may be a procedure for determining a new beam when the previously used beam can no longer be used due to the influence of the surrounding environment, etc.

[0116] When performing beam sweeping in 6G communication networks, the beam distance domain can be additionally considered in addition to the beam angle domain. For beam sweeping with terminals in the far field, the beam can be formed by specifying the direction in which the beam is directed. For beam sweeping with terminals in the near field, the beam can be formed by specifying a specific location where the beam arrives (e.g., a location determined by the direction the beam is directed and the distance it arrives at) rather than the direction in which it is directed. Therefore, when performing beam sweeping, terminals and base stations can consider the beam distance domain as well as the beam angle domain. Both dimensions (e.g., angle dimension and distance dimension) can be considered to search for the optimal beam. Increasing the number of dimensions considered by one can increase complexity (e.g., computational complexity at the base station or waste of time resources). In 6G communication networks, a beam management method with low computational complexity may be required.

[0117] FIG. 9 is a conceptual diagram illustrating embodiments of beams formed by a beam squint.

[0118] 6G communication networks can have a wider and higher bandwidth than the bandwidth in existing NR communication networks, specifically in the terahertz band used in NR communication networks. When an antenna array operates in the terahertz band, the following phenomenon may occur. When an antenna array forms a beam at the center frequency, beams directed in different directions may be formed depending on the subcarrier frequency. The further a beam is associated with a subcarrier frequency from the center frequency, the more it may be steered in a direction different from the direction of the beam associated with the center frequency. The aforementioned phenomenon may be referred to as beam squint.

[0119] If beam squint is not prevented, even if the antenna array forms a beam in a single direction, the formed beams may be steered in multiple directions depending on the subcarrier frequency. Beam squint can act as a problem in steering the beam in the intended direction.

[0120] Referring to FIG. 9, the center frequency of the bandwidth used for communication between the terminal and the base station (or A frequency can be formed in ). The formed beam can be a desired beam. can be the frequency of the subcarrier corresponding to the target beam. However, the frequency of a different subcarrier (e.g., , , , The direction of beams formed in ) may differ from the direction of the target beam. Beams formed in different directions due to beam squinting can cause a reduction in transmission rate. However, the beam squinting phenomenon can be utilized to reduce the complexity of beam management procedures.

[0121] In NR communication, the following procedures can be performed to search for five candidate directions. The phases of antennas belonging to the base station can be set to form a beam directed toward one of the five candidate directions. Therefore, five antenna settings can be performed to search for the five candidate directions. The phases of antennas that form beams directed toward different directions may differ from each other.

[0122] However, by utilizing beam squint, a single antenna setup can be performed to search for five candidate directions. Once the antenna phase is set to form the target beam and the target beam is formed, beam squint can cause beams to be formed toward the candidate directions. In other words, a new antenna phase setup procedure may not be required every time to search for different candidate directions. Once the antenna phase is set to form a beam (e.g., the target beam) directed toward one direction at the center frequency of the bandwidth, beams toward other candidate directions can be formed. To perform beam sweeping using beam squint, the spacing between subcarrier frequencies can be set significantly. As the spacing between subcarrier frequencies increases, broadband communication can be achieved.

[0123] The present disclosure may present a method for performing beam management processes with limited time resources by utilizing beam squinting, in which beams are spatially shifted in the high-frequency band. In a near-field communication environment, beams may not be radiated into a specific angular domain. In a near-field communication environment, beams may reach a single point. The present disclosure may present a method for performing beam management with low computational complexity through beam squinting in a near-field communication environment.

[0124] FIG. 10 is a conceptual diagram illustrating embodiments of target areas where beam sweeping is performed.

[0125] Referring to FIG. 10, beams can reach points on the ground by being spatially shifted due to beam squinting. In a far-field communication environment, beams can be shifted in the angle domain due to beam squinting. In a near-field communication environment, beams can be shifted in the distance domain as well as the angle domain due to beam squinting. Each of the points shown in FIG. 10 can indicate a point reached by beams formed at different subcarrier frequencies.

[0126] The subcarrier frequency is m can satisfy the following mathematical equation 2. ... may be the maximum number of beams formed by beam sweeping. can be the lowest subcarrier frequency among the subcarrier frequencies used for beam sweeping. can be the highest subcarrier frequency among the subcarrier frequencies used for beam sweeping. FIG. 10 may be an example when M=55. It can be determined based on mathematical formula 3. θ can be the center frequency of the bandwidth used for beam sweeping. B can be the bandwidth.

[0127]

[0128]

[0129]

[0130]

[0131] Referring to FIG. 10, beam sweeping can be performed using 55 subcarrier frequencies. The base station uses 55 subcarriers An attempt can be made to transmit a single beam to a point corresponding to [the point]. However, due to beam squinting, 55 beams may be formed. The formed beams may be shifted in space due to beam squinting. The shifted beams may reach each of the points shown in Fig. 10. The square area shown in Fig. 10 may be a target region. The target region may be an area where the base station intends to perform beam sweeping. The hatched area within the target region may be an area where at least one beam has reached. The unhatched area within the target region may be an area where no beam has reached. To have a beam reach the unhatched area, the base station may reset the phase of the antennas (e.g., antenna elements) belonging to the base station and then form the beams again.

[0132] - CSI (channel state information) - RS (reference signal) antenna port

[0133] In the beam adjustment procedure, the base station may select some of the antenna ports to transmit CSI-RS. The antenna port number to which CSI-RS is transmitted may be referred to as p. p can be determined based on Equation 4 below. s may be a sequence index. L may satisfy Equation 5 below. L may be the code division multiplexing (CDM) group size. N may be the number of antenna ports to which CSI-RS is transmitted.

[0134]

[0135]

[0136]

[0137]

[0138] For example, referring to Equation 6, when N is 8 and L is 2, the antenna port numbers through which CSI-RS are transmitted may include numbers 3000 to 3007. The number of CSI-RS antenna ports in NR may be up to 32. When the number of antenna panels is 2, up to 16 CSI-RS antenna ports may be assigned per panel. Referring to Equation 7, when the number of antenna panels is 4, up to 8 CSI-RS antenna ports may be assigned per panel.

[0139]

[0140]

[0141]

[0142]

[0143] The present disclosure may propose a beam management procedure based on beam squinting to reduce the high computational complexity and waste of time resources that occur when a base station performs beam sweeping in a near-field communication environment. The base station may set the phases of antennas (e.g., antenna elements) so that a beam reaches a specific point. After setting the phases of the antenna elements, the base station may perform beam sweeping using broadband frequency resources. The beams formed by beam sweeping can reach all points within a target area due to beam squinting. Thanks to beam squinting, the base station may not need to set phases corresponding to all points belonging to the target area on the antenna elements so that the beam reaches all points within the target area. In other words, the base station can perform beam sweeping for the target area with a single phase setting for the antenna elements. Therefore, the computational complexity and the amount of time resources used by the base station can be reduced. Due to the reduction in time resources consumed for beam management, the base station can perform beam management for terminals requiring low latency.

[0144] The present disclosure may propose a procedure for transmitting a pilot signal for a low-complexity beam management procedure. The pilot signal may be a CSI-RS or a synchronization signal block (SSB). The present disclosure may be described below on the premise that the pilot signal is a CSI-RS. However, a new reference signal may be proposed for 6G communication. The beam squint-based beam management procedure presented in the present disclosure may be performed using the newly proposed reference signal.

[0145] A beam squint-based beam management procedure (e.g., a beam adjustment procedure) according to the present disclosure may be distinguished into three procedures. The first procedure may be a procedure for determining whether a terminal is capable of supporting beam sweeping utilizing beam squint (hereinafter "beam squint-based beam sweeping"). Terminals may be distinguished into terminals capable of supporting beam squint-based beam sweeping and legacy terminals that do not possess this capability. Even if a terminal has the capability to support beam squint-based beam sweeping, the terminal may not be able to support beam squint-based beam sweeping. Whether beam squint-based beam sweeping is supported may depend on the state of the terminal, regardless of the terminal's capability. If the terminal does not have the capability to support beam squint-based beam sweeping or is not in a state capable of supporting beam squint-based beam sweeping, an existing legacy beam adjustment procedure may be performed.

[0146] The second procedure may be a procedure for determining the number of one or more time resources (e.g., orthogonal frequency division multiplexing (OFDM) symbols) used to perform beam squint-based beam sweeping. Hereinafter, OFDM may be referred to as symbols. Beams formed through beam squint-based beam sweeping may be transmitted from the one or more symbols. The base station may transmit CSI-RS to terminal(s) using the beams formed through beam squint-based beam sweeping. The base station may determine the number of one or more time resources (e.g., symbols) required to transmit CSI-RS based on beam width and / or target area (or area of ​​the target area). The number of one or more time resources may be determined as a minimum number. Once the number of one or more time resources is determined, the base station may map CSI-RS to resources (e.g., resource elements (REs).

[0147] The third procedure may be a procedure in which beam squint-based beam sweeping is performed on resources mapped to CSI-RSs. The base station can form beams through beam squint-based beam sweeping. The base station can transmit CSI-RSs to terminal(s) using the formed beams. The terminal can perform measurements on the received beams. The terminal can transmit a report containing the measurements obtained through the measurements to the base station. The base station can determine the optimal beam based on the report. The base station can communicate with the terminal through the optimal beam.

[0148] - Initiation of beam adjustment procedure

[0149] To perform beam adjustment using beam squint proposed in this disclosure (hereinafter "beam squint-based beam adjustment"), it may be necessary to verify the capabilities of the terminal. A base station may verify whether the terminal has the capability to support beam squint-based beam sweeping. A base station may verify whether a terminal capable of supporting beam squint-based beam sweeping is in a state capable of supporting beam squint-based beam sweeping. A terminal that does not have the capability to support beam squint-based beam sweeping may be a legacy terminal.

[0150] The base station may receive capability information from the terminal. The capability information may include a parameter indicating whether the terminal has the capability to support beam squint-based beam sweeping. The capability information may include a parameter indicating whether a terminal capable of supporting beam squint-based beam sweeping is in a state capable of supporting beam squint-based beam sweeping. In Table 2 below, the parameter indicating whether the terminal has the capability to support beam squint-based beam sweeping may be NFBS_based_BM. The parameter indicating whether a terminal capable of supporting beam squint-based beam sweeping is in a state capable of supporting beam squint-based beam sweeping may be NFBS_based_BM_status. Legacy beam coordination may be beam coordination performed in existing NR. In other examples, NFBS_based_BM_status may be transmitted to the base station by UE auxiliary information, UE capability information, or other radio resource control (RRC) signaling independently of NFBS_based_BM.

[0151] The base station can determine whether a terminal has the capability to support beam squint-based beam sweeping based on the NFBS_based_BM included in the received capability information. If the terminal has the capability to support beam squint-based beam sweeping, the base station can determine whether the terminal is in a state to support beam squint-based beam sweeping based on the NFBS_based_BM_status.

[0152] If a base station is identified as a legacy terminal, it may perform beam coordination with that terminal using a beam coordination method performed in NR (hereinafter referred to as the "NR beam coordination method"). Even if a terminal is identified as a terminal capable of supporting beam squint-based beam sweeping, if the base station determines that the terminal is not in a state capable of supporting beam squint-based beam sweeping, it may perform beam coordination with that terminal using the NR beam coordination method. If the base station determines that a terminal capable of supporting beam squint-based beam sweeping is in a state capable of supporting beam squint-based beam sweeping, it may perform beam coordination with that terminal using the beam squint-based beam coordination method.

[0153]

[0154]

[0155] Based on the received capability information, the base station can determine whether the terminal is a legacy terminal or a terminal in a state where it cannot support beam squint-based beam sweeping. The base station can perform beam sweeping for points within the target area. The base station can form a beam reaching a single point by setting the phases for antenna elements. The base station can receive measurement values ​​for that beam from the terminal that received the formed beam. The base station can reset the phases for antenna elements belonging to the base station to form a beam reaching another point. The base station can form a beam reaching another point by resetting the phases for antenna elements. The terminal can receive the beam reaching another point and perform measurements on that beam. The terminal can report the measurement values ​​obtained through the measurement to the base station. As described above, if beam squint-based beam sweeping is not performed, the base station may perform multiple phase settings to perform beam sweeping for points within the target area. Multiple phase settings may cause the consumption of time resources.

[0156] - Overview of Determining the Number of Time Resources

[0157] The number of pilot signal transmissions may refer to the number of time resources (e.g., symbols) required for a base station to form beams that reach points within a target area. In this disclosure, since the pilot signal is a CSI-RS, the number of pilot signal transmissions may refer to the number of symbols required for a base station to transmit CSI-RSs when performing beam adjustment.

[0158] In conventional NR, the number of symbols required may be equal to the number of points belonging to the target area. However, in a near-field communication environment, if a base station utilizes beam squint, it can form beams within a single symbol that cover areas defined by the angle domain and distance domain. Therefore, fewer symbols may be required compared to conventional NR. However, even if the base station uses beam squint-based beam sweeping, it cannot transmit all beams within a single symbol. Therefore, the base station can determine the minimum number of symbols required to perform beam squint-based beam sweeping based on the beam width and / or the area of ​​the target region. In other words, the base station can determine the minimum number of symbols required to transmit CSI-RS based on the beam width and / or the area of ​​the target region.

[0159] - Determine target area

[0160] The target area may be an area where the base station intends to perform beam squint-based beam sweeping. The target area may include one or more points. Each beam formed by the base station may reach each of the one or more points. In a short-range communication environment, the base station may perform beam sweeping in the distance domain as well as the angle domain. The target area may be defined in the angle domain and the distance domain. Referring to Table 3, the factors required to define the target area may be maximum angle information / minimum angle information in the angle domain and maximum distance information / minimum distance information in the distance domain. The reference for the angle domain may be the base station. The reference for the distance domain may be the base station. The distance defined in the distance domain may be the distance from the base station.

[0161]

[0162]

[0163] The maximum angle information / minimum angle information can be an angle value. Alternatively, the maximum angle information / minimum angle information can be a function value of the angle value. For example, if the angle in the angle domain is defined in radians, the angle information can be determined by a sine function as shown in Equation 8. The maximum distance information / minimum distance information can be a distance value. Alternatively, the maximum distance information / minimum distance information can be a function value of the distance. For example, as shown in Equation 9, the maximum distance information / minimum distance information can be a function value of the distance value from the base station and the angle value relative to the base station. In Equation 9, r can be the distance from the base station, and It can be an angle based on the base station.

[0164]

[0165]

[0166]

[0167]

[0168] Since the beam squint-based beam sweeping proposed in this disclosure is an operation for beam adjustment, a base station can determine a target area centered on the point where the reference signal received power (RSRP) of the SSB is highest during the initial beam establishment procedure between the terminal and the base station. In other words, the base station can determine a target area such that the target area includes the point where the RSRP of the SSB is highest during the initial beam establishment procedure between the terminal and the base station. The center of the target area may be the point where the RSRP of the SSB is highest during the initial beam establishment procedure between the terminal and the base station, or it may be close to the point where the RSRP of the SSB is highest. The RSRP used to determine the target area may be an RSRP obtained through beam squint-based beam sweeping. Alternatively, the RSRP used to determine the target area may be an RSRP obtained through beam sweeping used in conventional NR.

[0169] The settings for the target area are , , , and It can mean settings for. , , , and Once the configuration for [the target area] is completed, the location of the target area and the area of ​​the target area may be determined. In the present disclosure, the determination of the target area may mean the determination of the location of the target area or the determination of the area of ​​the target area. The base station may determine the target area by considering at least one of the terminal's mobility or the base station's current resource usage status. The terminal's mobility may include at least one of the terminal's speed, the terminal's direction of movement, the terminal's trajectory, the terminal's location, the terminal's Doppler shift, or the terminal's Doppler spread. The base station may receive information regarding the terminal's mobility from the terminal before determining the target area. For example, the base station may determine the target area such that the target area includes the terminal's location (e.g., the terminal's latest location).

[0170] FIG. 11 is a conceptual diagram illustrating embodiments of beams having different beam widths.

[0171] Referring to FIG. 11, beams with different beam widths depending on the antenna gain can be identified. Beam width will be described below. When a base station forms a beam, main lobes and side lobes may be formed. Beam width can be defined as the width of the main lobe. Beam width can be defined as the angle between two points where the maximum power of the main lobe drops below a preset value (dB). For example, if the beam width is 3 dB, the beam width may be the angle between two points where the maximum power of the main lobe of the beam drops by 3 dB. For example, a 1 dB beam width may be smaller than a 2 dB beam width.

[0172] - Determining beam width

[0173] If the beam width is wide, the base station can quickly find the optimal beam through beam sweeping. However, since the beam directivity is reduced, the match between the beam and the channel may decrease. For example, the antenna gain (numerical) in Table 3 can indicate the similarity (e.g., cosine similarity) between the beamforming vector and the channel (e.g., channel matrix, channel vector). The closer the antenna gain (numerical) is to 1, the higher the match between the beam formed by the beamforming vector and the channel may be. A wide beam width may make it slower to find the optimal beam through beam sweeping. However, since the beam width is narrow, the match between the beam and the channel may be high. High accuracy between the beam and the channel can correspond to improved communication performance. In other words, there may be a trade-off relationship between beam search speed and the match between the beam and the channel. The base station can adjust the aforementioned trade-off relationship through the beam width.

[0174] A base station may determine the beam width based on at least one of the purpose of performing beam sweeping (e.g., initial beam establishment, beam adjustment), the quality of service (QoS) profile set on the terminal (e.g., latency requirements), or the terminal's mobility (e.g., terminal speed). For example, since it is important to quickly locate the terminal during the initial beam establishment procedure, the base station may set the beam width wide when performing the initial beam establishment procedure. Since precise beam management is required during beam adjustment, the base station may set the beam width narrow. In another example, the base station may set the beam width wide if the terminal's latency requirements are low. In another example, the base station may set the beam width narrow if the terminal's latency requirements are high. In another example, the base station may set the beam width wide if the terminal's speed is fast. In another example, the base station may set the beam width narrow if the terminal's speed is slow.

[0175]

[0176]

[0177] The antenna gain (dB) indicating the beam width and the antenna gain (numerical) may have a relationship based on Equations 10 and 11 below. The antenna gain (dB) may be x, and the antenna gain (numerical) may be y. The base station may determine the beam width using the antenna gain (dB) and then convert the determined antenna gain (dB) into the antenna gain (numerical) based on Equation 10. Based on the antenna gain (numerical), the base station may determine the number of one or more time resources used to transmit CSI-RS via beam squint-based beam sweeping.

[0178]

[0179]

[0180]

[0181]

[0182] - Determining subcarrier maximum / minimum frequency

[0183] The base station can determine the subcarrier frequencies for performing beam squint-based beam sweeping in the target area based on the information elements according to Table 2. In other words, the base station can determine the maximum / minimum frequencies of the subcarriers used for beam squint-based beam sweeping so that beams formed by beam squint-based beam sweeping reach all points within the target area. After determining the maximum / minimum frequencies of the subcarriers, the base station can determine the number of one or more time resources (e.g., symbols) used for beam squint-based beam sweeping based on the maximum / minimum frequencies of the subcarriers.

[0184] The base station can determine the maximum / minimum frequency of the subcarrier frequency based on Equations 12 and 13. The base station can determine the maximum / minimum frequency of the subcarrier that satisfies the inequalities according to Equations 12 and 13. The maximum and minimum subcarrier frequencies can be pre-set in the base station. The base station can adjust the pre-set maximum / minimum subcarrier frequencies to satisfy Equations 12 and 13. If the minimum subcarrier frequency does not satisfy the inequalities according to Equations 12 and 13, the base station can lower the minimum subcarrier frequency. If the maximum subcarrier wavenumber does not satisfy the inequalities according to Equations 12 and 13, the base station can increase the maximum subcarrier wavenumber.

[0185] The variables included in Equations 12 and 13 will be explained below. can be the center frequency of the bandwidth used for beam squint-based beam sweeping. It can be the subcarrier minimum frequency. is the maximum subcarrier frequency. may be a factor used to adjust the phase of each of the units (or elements) of the TTD (true time delayer) that the base station uses for beamforming. ε₀ may be a factor used to adjust the phase of each unit (or element) of the phase shifter used by the base station for beamforming. d may be the spacing between antennas (e.g., antenna elements) belonging to the base station. q may be determined based on Equation 14. In Equation 14 It can be a function that returns an integer value by discarding the decimal part of x.

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192] The factors used to adjust the phase of the TTD and the phase shifter will be explained below. The base station can determine the phase of the nth unit of the TTD based on Equation 15. The base station or The phase of the nth unit of the TTD can be determined by setting at least one of the factors. In Equation 15 can be the wavenumber of the m-th subcarrier and can be determined based on Equation 17. can be the frequency of the m-th subcarrier. can be the number of antenna elements. The base station can determine the phase of the nth unit of the phase shifter based on Equation 16. The base station or The phase of the nth unit of the phase shifter can be determined by setting at least one of the factors. In Equation 16 can be the wavenumber at the center frequency of the bandwidth. Unlike TTD, the phase shifter can perform phase setting that is not dependent on the frequency of the subcarrier.

[0193] The base station When setting this, the antenna gain (numerical) according to Table 3 can be considered. The area in the distance domain reachable by a single beam may vary depending on the beam width. If the beam width is large, the area in the distance domain reachable by a single beam may increase. If the beam width is small, the area in the distance domain reachable by a single beam may decrease. If the beam does not reach a specific area in the angle domain, a coverage hole may occur. If two or more beams reach a specific area in the angle domain, ambiguity may occur. Therefore, the base station ensures that all points belonging to the target area are covered by a single beam having a specific beam width (e.g., 3dB beam width). You can set it. In other words, It can be dynamically set according to the beam width.

[0194]

[0195]

[0196]

[0197]

[0198]

[0199]

[0200]

[0201]

[0202] - Determine the minimum number of symbols

[0203] The base station can determine the number of one or more time resources (e.g., symbols) used to perform beam squint-based beam sweeping by selecting the smallest integer K among the integers K satisfying the inequality according to Equation 19. The variables included in Equation 19 will be explained below. can mean the maximum range for which coverage by the beam is required in the distance domain. represents the beam width at the subcarrier maximum frequency and can be determined based on Equation 20. p can be determined based on Equation 21. It can be 1.318 when the beam width is 3dB. can be a parameter representing the degree of beam diffusion, and it can be a value that increases proportionally as the beam width increases. If the beam width changes It can change. If it changes can change. K is Since it is an integer satisfying the inequality containing, K can vary depending on the beam width. Referring to Table 5, the base station can determine K to be 2 based on Equation 19.

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210]

[0211]

[0212] - Resource allocation for CSI-RS transmission

[0213] After determining the minimum number of symbols and the subcarrier maximum / minimum frequencies, the base station can map CSI-RS to resources (e.g., REs). In other words, the base station can map the resources used to perform beam squint-based beam sweeping to the CSI-RS. One CSI-RS can be mapped to one RE. Referring to Table 5, the base station [uses] a symbol index (or identifier) at from CSI-RS can be transmitted via 55 subcarriers and corresponding REs. In other words, the base station transmits CSI-RS using symbol indices at from It can be mapped to the 55 subcarriers and their corresponding REs. Since a subcarrier frequency can correspond to a single subcarrier, the subcarrier frequency can be a subcarrier index (or identifier). The base station is the symbol index at from CSI-RS can be transmitted through 49 subcarriers and their corresponding REs. In other words, the base station transmits CSI-RS via symbol index at from It can be mapped to 49 subcarriers and corresponding REs.

[0214]

[0215]

[0216] FIG. 12 is a conceptual diagram illustrating embodiments of target areas where beam squint-based beam sweeping is performed.

[0217] Referring to Fig. 12, the base station can perform beam squint-based beam sweeping based on resource allocation after completing the resource allocation procedure according to Table 5. The base station can transmit CSI-RS to each of all points belonging to the target area through beam squint-based beam sweeping. The points marked with circles in Fig. 10 are These may be the points reached by the beams transmitted from the symbol. The points marked with an X in Fig. 10 are These can be the points reached by the beams transmitted from the symbol. 55 CSI-RS can be transmitted in the symbol. 49 CSI-RS can be transmitted in the symbol.

[0218] - Optimal beam determination

[0219] A procedure for determining the optimal beam among the beams formed through beam squint-based beam sweeping will be presented below. After completing resource allocation according to Table 6, the base station can transmit CSI-RS to points within the target area through beam squint-based beam sweeping. In other words, after completing resource allocation according to Table 6, the base station can transmit CSI-RS to the terminal through beam squint-based beam sweeping. The terminal can perform measurements on the received CSI-RS. The terminal can transmit a report containing measurement values ​​(e.g., RSRP) for the CSI-RS to the base station. The base station can determine the optimal beam based on the RSRP values ​​included in the report. The base station can determine information regarding the point where the optimal beam reaches. The information regarding the point where the optimal beam reaches may include distance information in the distance domain and angle information in the angle domain. The base station can form the optimal beam and perform communication with the terminal. The beam squint-based beam sweeping proposed in this disclosure can also be applied to initial beam establishment. CSI-RS transmitted by a base station can be received by multiple terminals as well as a single terminal. The beam squint-based beam sweeping proposed in this disclosure can also be used for beam coordination between multiple users and a single base station.

[0220] The base station can transmit CSI-RS to the terminal via beam squint-based beam sweeping. Each CSI-RS may be associated with an index (or identifier) ​​that identifies the CSI-RS. Each CSI-RS transmitted by the base station may include a CSI-RS index. The size of the CSI-RS index (e.g., bits) is It can be determined according to. can be the number of transmitted beams. ceil can be the ceiling function.

[0221] The CSI-RS index can be transmitted to the terminal via DCI (downlink control information), MAC (media access control)-CE (control element), or RRC reset messages. When the terminal receives CSI-RS, it can determine which beam the received CSI-RS was transmitted through based on the CSI-RS index.

[0222] The base station may transmit a CSI report request to the terminal in beam squint-based beam coordination. Alternatively, the base station may transmit a request to stop CSI reporting in beam squint-based beam coordination to the terminal. A beam squint-based CSI-RS resource set enable / disable MAC-CE used to transmit the CSI report request or the CSI report stop request may be defined. The base station may transmit a CSI report request for beams transmitted via beam squint-based beam sweeping to the terminal through the beam squint-based CSI-RS resource set enable / disable MAC-CE.

[0223] The CSI-RS index can correspond to information about the point where the CSI-RS arrives (e.g., distance information in the distance domain and angle information in the angle domain). The CSI-RS index can correspond to the symbol index of the symbol to which the CSI-RS is transmitted. The CSI-RS index can correspond to the subcarrier index of the subcarrier to which the CSI-RS is transmitted.

[0224] A base station may transmit first information to a terminal indicating a first correspondence relationship between a CSI-RS index and information regarding the point where the CSI-RS arrives. A base station may transmit second information to a terminal indicating a second correspondence relationship between a CSI-RS index and the symbol index of the symbol to which the CSI-RS is transmitted. A base station may transmit third information to a terminal indicating a third correspondence relationship between a CSI-RS index and the subcarrier frequency of the subcarrier to which the CSI-RS is transmitted. The CSI-RS transmitted by the base station may include at least one of the first information, the second information, or the third information. Alternatively, the base station may transmit at least one of the first information, the second information, or the third information to the terminal after transmitting the CSI-RS. Alternatively, the CSI-RS transmitted by the base station may include at least one of the first information, the second information, or the third information. Alternatively, at least one of the first correspondence relationship, the second correspondence relationship, or the third correspondence relationship may be set in advance on the terminal and / or the base station.

[0225] If at least one of the 1st correspondence, 2nd correspondence, or 3rd correspondence is configured in advance at the terminal and / or base station, the base station may transmit CSI-RS and then transmit CSI report requests and CSI-RS index information to the terminal via DCI. The base station may trigger CSI measurement and CSI reporting by transmitting CSI report requests and CSI-RS index information to the terminal via DCI.

[0226] Referring to Table 7, the 104 points may be points according to the embodiments illustrated in FIG. 12. Table 7 may be applied to the embodiments illustrated in FIG. 12. The base station may perform beam sweeping for a total of 104 points in 2 symbols.

[0227]

[0228]

[0229] The terminal can perform measurements on the CSI-RS received from the base station. Through these measurements, the terminal can determine a measurement value (e.g., RSRP) for each of the CSI-RS. The terminal can transmit a report containing the RSRP values ​​to the base station via uplink control information (UCI). The report may include fourth information indicating a fourth correspondence relationship between the RSRP value and the CSI-RS index. The report by the terminal may be performed in response to a UE information request transmitted by the base station. The base station may transmit instructions for performance reporting on candidate beams via SIB or new RRC signaling. Referring to Tables 8 and 9, the base station receiving the report may determine the distance information in the distance domain and the angle information in the angle domain for the beam with the CSI-RS index of 1000111 based on the fact that the beam with the CSI-RS index of 1000111 has the largest RSRP value. The base station may form an optimal beam based on the distance information in the distance domain and the angle information in the angle domain. The base station can communicate with the terminal through the optimal beam.

[0230]

[0231]

[0232]

[0233]

[0234] - Generation of beamforming vectors for optimal beamforming

[0235] The base station can generate a beamforming vector based on angle information in the angle domain and distance information in the distance domain of the optimal beam. If the number of antenna elements is odd, the base station can generate a beamforming vector based on Equation 22. If the number of antenna elements is even, the base station can generate a beamforming vector based on Equation 23. In Equations 22 and 23, N can be determined based on Equation 24. The phase of the base station's antenna elements can be determined through each component belonging to the beamforming vector. The base station can form an optimal beam through the beamforming vector.

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242] FIG. 13 is a flowchart illustrating embodiments of a beam squint-based beam sweeping procedure.

[0243] Referring to FIG. 13, the base station can receive capability information from the terminal (S1310). The base station can determine through the capability information whether the terminal is capable of supporting beam squint-based beam sweeping. The same can be applied to determining the type of the terminal as described in the beam adjustment procedure initiation section above.

[0244] The base station may determine the target area based on whether the terminal supports beam squint-based beam sweeping. The same applies to the target area determination described in the aforementioned target area determination section. The base station may determine the beam width. The same applies to the beam width determination described in the aforementioned beam width determination section. The order in which the beam width determination and the target area determination are performed may be reversed.

[0245] The base station can determine the maximum / minimum frequency of the subcarrier used for beam squint-based beam sweeping. The same content described in the section on determining the maximum / minimum frequency of the subcarrier above may be applied to the determination of the maximum / minimum frequency of the subcarrier. The base station that has determined the maximum / minimum frequency of the subcarrier can determine the minimum number of symbols used for beam squint-based beam sweeping (S1320). The same content described in the section on determining the minimum number of symbols above may be applied to the determination of the minimum number of symbols.

[0246] A base station that has determined the minimum number of symbols can perform resource allocation for transmitting CSI-RS (S1330). The same content described in the resource allocation for CSI-RS transmission section above may be applied to the resource allocation for transmitting CSI-RS. A base station that has completed resource allocation can transmit CSI-RS to a terminal via beam squint-based beam sweeping (S1340). The same content according to the embodiments illustrated in FIG. 12 may be applied to the transmission of CSI-RS via beam squint-based beam sweeping. The terminal can perform measurements on the received CSI-RS. Through the measurements, the terminal can transmit a report containing the measured values ​​(S1350). The base station can determine the optimal beam based on the report (S1360). The same content described in the optimal beam determination section above may be applied to the measurement / reporting by the terminal and the optimal beam determination by the base station above.

[0247] The base station can determine the optimal beam and form the optimal beam. The same applies to the optimal beam forming described in the section on generating beamforming vectors for optimal beam forming mentioned above. The base station can communicate with the terminal through optimal beam forming.

[0248] Simple combinations, partial combinations, and / or extended combinations of two or more of the embodiments described above (e.g., methods, ways) may be possible. Some of the embodiments described above may be omitted. In other words, some embodiments may be performed optionally.

[0249] The operation 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 in which information that can be read by a computer system is stored. Additionally, a computer-readable recording medium may be distributed across networked computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0250] In addition, computer-readable recording media may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Program instructions may include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

[0251] Some aspects of the present disclosure have been described in the context of a device, but may also be described according to 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 according to 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 of the most important method steps may be performed by such a device.

[0252] 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 this disclosure. A field-programmable gate array may operate with a microprocessor to perform one of the methods described in this disclosure. Generally, it is preferable that the methods be performed by some hardware device.

[0253] Although the present disclosure has been described with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the following claims.

Claims

1. As a method of base stations, A step of receiving capability information from a terminal indicating whether the terminal supports beam squint-based beam sweeping; A step of determining a target region including points reached by beams formed through beam squint-based beam sweeping; A step of determining the beam widths of the above beams; A step of determining the number of one or more time resources used for beam squint-based beam sweeping based on at least one of the target area or the beam width; and A step comprising transmitting the beams from the one or more time resources to the terminal based on the beam squint-based beam sweeping for the target area. Base station method.

2. In Claim 1, The above capability information includes at least one of a parameter indicating the capability of the terminal to support the beam squint-based beam sweeping or a parameter indicating the state of the terminal having the capability, and the state of the terminal is a state indicating whether the beam squint-based beam sweeping can be supported. Base station method.

3. In Claim 1, The above target area is located on a distance domain based on the base station and an angle domain based on the base station, and the above target area is determined based on maximum distance information / minimum distance information belonging to the distance domain and maximum angle information / minimum angle information belonging to the angle domain. Base station method.

4. In Claim 1, The above target area includes a point where the beam associated with the largest measurement value among the measurements reported by the terminal in the initial beam establishment procedure between the base station and the terminal reaches. Base station method.

5. In Claim 1, Before determining the above target area, the method further includes the step of receiving mobility information of the terminal from the terminal, and The above target area is determined based on at least one of the above mobility information or the resource usage status of the above base station, Base station method.

6. In Claim 1, The beam width is determined based on at least one of the resource usage status of the base station, the purpose for which the beam squint-based beam sweeping is performed, or the delay requirements of the terminal, Base station method.

7. In Claim 1, The beam width is determined based on the angle between one or more points where the power decreases by a preset value relative to the maximum power of each of the main lobes of the beams, Base station method.

8. In Claim 1, The method further includes the step of determining the maximum and minimum frequencies of subcarriers to which the beams are transmitted, such that the region formed by the beams includes the target region, after determining the target region. Base station method.

9. In Claim 8, The above maximum frequency and minimum frequency are determined to satisfy the first inequality and the second inequality, and the first inequality and the second inequality are based on at least one of the maximum distance information / minimum distance information on which the target area is based, one or more time delay (TD) parameters used to adjust the phase of the elements of a true time delayer (TTD) used by the base station, one or more phase shift (PS) parameters used to adjust the phase of the elements of a phase shifter used by the base station, the center frequency of the bandwidth in which the beams are transmitted, or the spacing between the antenna elements forming the beams. Base station method.

10. In claim 8, The method further includes the step of setting a first PS parameter used to adjust the phase of the phase shifter elements used to form the beams based on the beam width before determining the number of the one or more time resources mentioned above, and The first PS parameter is set such that the regions formed by each of the beams correspond to each of the points belonging to the target region, and the number of the one or more time resources is determined to satisfy the third inequality, and the third inequality is based on at least one of the beam width of the beam corresponding to the maximum frequency or the first PS parameter. Base station method.

11. In Claim 8, After determining the number of the above one or more time resources, the method further includes the step of mapping the beams to the resources based on at least one of the maximum frequency, the minimum frequency, or the number of time resources. Base station method.

12. In Claim 1, The method further includes the step of transmitting a beam index corresponding to each of the above beams, and The beam index corresponds to at least one of a point, time resource, or subcarrier frequency associated with each of the beams, and the point belongs to the target region. Base station method.

13. In Claim 12, A step of receiving a report from the terminal containing measurement values ​​of each of the beams; A step of determining an optimal beam used for communication with the terminal based on the above report; and The method further includes the step of communicating with the terminal based on the optimal beam. The above report further includes information indicating the correspondence relationship between each of the above measurement values ​​and the beam index, Base station method.

14. As a method of UE (user equipment), A step of transmitting capability information to a base station indicating whether the terminal supports beam squint-based beam sweeping; A step of receiving beams formed by beam squint-based beam sweeping performed by the base station; A step of determining measurement values ​​for each of the beams through measurements of the beams; and A step comprising transmitting a report containing the above measurement values ​​to the base station, UE's method.

15. In Claim 14, The above capability information includes at least one of a parameter indicating the capability of the terminal to support the beam squint-based beam sweeping or a parameter indicating the state of the terminal having the capability, and the state of the terminal is a state indicating whether the beam squint-based beam sweeping can be supported. UE's method.

16. In Claim 14, A step further comprising communicating with the base station through a beam selected by the base station based on the above report, UE's method.

17. In Claim 14, The above report further includes information indicating the correspondence relationship between each of the above measurement values ​​and the beam index, UE's method.

18. As a base station, It includes at least one processor, The above at least one processor is the base station, Receiving capability information from a terminal indicating whether the terminal supports beam squint-based beam sweeping; Determining a target area including points reached by beams formed through beam squint-based beam sweeping; Determine the beam widths of the above beams; Determining the number of one or more time resources used for beam squint-based beam sweeping based on at least one of the above target area or the above beam width; and Causing the terminal to transmit the beams from the one or more time resources based on the beam squint-based beam sweeping for the target area, Base station.

19. In Claim 18, The above at least one processor further causes the base station to determine the maximum and minimum frequencies of the subcarriers to which the beams are transmitted, such that the region formed by the beams includes the target region after the base station has determined the target region. Base station.

20. In Claim 19, The above at least one processor further causes the base station to set a first PS parameter used to adjust the phase of the phase shifter elements used to form the beams based on the beam width before determining the number of the one or more time resources, and The first PS parameter is set such that the regions formed by each of the beams correspond to each of the points belonging to the target region, and the number of the one or more time resources is determined to satisfy the third inequality, and the third inequality is based on at least one of the beam width of the beam corresponding to the maximum frequency or the first PS parameter. Base station.

Images