Method and apparatus for beam sweeping based on frequency-dependent beam

Abstract

Disclosed are a method and apparatus for beam sweeping based on a frequency-dependent beam. A method of a user equipment (UE) comprises the steps of: receiving, from a base station, configuration information for a beam sweeping procedure; determining the type of the beam sweeping procedure on the basis of the configuration information; and receiving a signal from the base station via the beam sweeping procedure according to the determined type.

Description

Method and apparatus for beam sweeping based on a frequency-dependent beam

[0001] The present disclosure relates to an improved communication technology, and more specifically, to a technology for beam sweeping based on a frequency-dependent beam.

[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] Meanwhile, in analog beamforming methods, transmitting a beam in a single direction at a specific moment can be considered. Recently, research on beamforming techniques that transmit beams to different directions (e.g., different directions in the far-field) and / or different locations (e.g., different locations in the near-field) depending on the frequency band at a specific moment has been actively conducted. The aforementioned beamforming technique can be useful for reducing time complexity in beam sweeping procedures. According to the aforementioned beamforming technique, it may be possible to perform multi-user beamforming, which was previously performed digitally, in an analog manner. A beam transmitted to different directions or different locations depending on the frequency band at a specific point in time can be defined as a frequency-dependent beam. Due to the aforementioned advantages, frequency-dependent beams are receiving attention as an important element in the design of next-generation communication systems. Frequency-dependent beams can be formed by the beam squint phenomenon and the Joint Phase-Time Array (JPTA).

[0005] The beam sequencing phenomenon can occur when performing broadband communication in the high-frequency band. Beam sequencing refers to a phenomenon where a beam designed to match the center frequency deviates in direction at frequency components other than the center frequency. JPTA can refer to a beamforming structure utilizing an analog phase shifter and a true-time delayer. When the aforementioned beamforming structure is utilized, if a portion of a given frequency band is defined as a sub-band, it becomes possible to form beams pointing in different directions within each sub-band. JPTA enables the implementation of frequency-dependent beams not only in limited communication environments, such as broadband communication utilizing the beam sequencing phenomenon in the terahertz band, but also in other communication environments. By utilizing JPTA, it is possible to intentionally adjust the beam spreading that occurs in the conventional beam sequencing phenomenon to be wider or narrower. By utilizing frequency-dependent beams, beams pointing in multiple directions at a specific moment can be implemented using an analog method. However, current communication systems do not support technology for frequency-dependent beams, and procedures and parameters are required to support technology for frequency-dependent beams.

[0006] The objective of the present disclosure to solve the above-mentioned problems is to provide a method and apparatus for beam sweeping based on a frequency-dependent beam.

[0007] A method of user equipment (UE) according to embodiments of the present disclosure for achieving the above objective comprises: receiving setting information for a beam sweeping procedure from a base station; determining a type of beam sweeping procedure based on the setting information; and receiving a signal from the base station through a beam sweeping procedure according to the determined type.

[0008] The types of the beam sweeping procedure described above can be classified into a fixed-beam transmission procedure, a fixed-time-frequency beam sweeping procedure, a fixed-frequency-time beam sweeping procedure, and a full 2D beam sweeping procedure. The fixed-beam transmission procedure may be a procedure without beam sweeping. In the fixed-time-frequency beam sweeping procedure, beam sweeping may be performed in units of frequency resources. In the fixed-time-frequency beam sweeping procedure, beam sweeping may be performed in units of time resources. In the full 2D beam sweeping procedure, beam sweeping may be performed in units of frequency resources and time resources.

[0009] The above frequency resource unit may be a resource block (RB) group or a resource element (RE) group, the RB group may include one or more RBs, and the RE group may include one or more REs, and the above time resource unit may be a slot group or a symbol group, the slot group may include one or more slots, and the symbol group may include one or more symbols.

[0010] Based on whether the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, the setting information may include parameters indicating whether to maintain the transmission period and start offset of the signal in the time domain.

[0011] Based on the fact that the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, and that the transmission period and start offset of the signal are not maintained in the time domain, the setting information may include a parameter indicating the transmission period and start offset of the signal in each of the frequency resources to which the beam sweeping is applied, and a parameter indicating the first symbol in which the signal is transmitted within the slot.

[0012] Based on whether the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, the setting information may include start RB information and RB count information for each of the frequency resources to which the beam sweeping is applied.

[0013] The above configuration information may include a repetition factor-frequency parameter indicating whether to perform repeated transmission in the frequency domain and a repetition factor-time parameter indicating whether to perform repeated transmission in the time domain, and the repetition factor-frequency parameter and the repetition factor-time parameter may be used to indicate the type of beam sweeping procedure.

[0014] The repetition factor-frequency parameter set to on and the repetition factor-time parameter set to on may indicate that the type of beam sweeping procedure is a beam fixed transmission procedure without beam sweeping, the repetition factor-frequency parameter set to off and the repetition factor-time parameter set to on may indicate that the type of beam sweeping procedure is a time fixed-frequency beam sweeping procedure in which beam sweeping is performed in frequency resource units, the repetition factor-frequency parameter set to on and the repetition factor-time parameter set to off may indicate that the type of beam sweeping procedure is a frequency fixed-time beam sweeping procedure in which beam sweeping is performed in time resource units, and the repetition factor-frequency parameter set to off and the repetition factor-time parameter set to off may indicate that the type of beam sweeping procedure is a full 2D beam sweeping procedure in which beam sweeping is performed in frequency resource units and time resource units.

[0015] The method of the above UE may further include the step of transmitting information to the base station indicating whether the UE supports the beam sweeping procedure in the frequency domain, and the setting information may be determined based on whether the UE supports the beam sweeping procedure in the frequency domain.

[0016] In the above frequency domain, the beam sweeping procedure may be an RB-level beam sweeping procedure or an RE-level beam sweeping procedure, the RB-level beam sweeping procedure may be performed in units of RB groups, and the RE-level beam sweeping procedure may be performed in units of RE groups.

[0017] A method of a base station according to embodiments of the present disclosure for achieving the above objective comprises: generating configuration information for a beam sweeping procedure; transmitting the configuration information for the beam sweeping procedure to a UE (user equipment); and transmitting a signal to the UE by performing a beam sweeping procedure according to a type indicated by the configuration information.

[0018] The types of the beam sweeping procedure described above can be classified into a fixed-beam transmission procedure, a fixed-time-frequency beam sweeping procedure, a fixed-frequency-time beam sweeping procedure, and a full 2D beam sweeping procedure. The fixed-beam transmission procedure may be a procedure without beam sweeping. In the fixed-time-frequency beam sweeping procedure, beam sweeping may be performed in units of frequency resources. In the fixed-time-frequency beam sweeping procedure, beam sweeping may be performed in units of time resources. In the full 2D beam sweeping procedure, beam sweeping may be performed in units of frequency resources and time resources.

[0019] The above frequency resource unit may be a resource block (RB) group or a resource element (RE) group, the RB group may include one or more RBs, and the RE group may include one or more REs, and the above time resource unit may be a slot group or a symbol group, the slot group may include one or more slots, and the symbol group may include one or more symbols.

[0020] Based on whether the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, the setting information may include parameters indicating whether to maintain the transmission period and start offset of the signal in the time domain.

[0021] Based on the fact that the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, and that the transmission period and start offset of the signal are not maintained in the time domain, the setting information may include a parameter indicating the transmission period and start offset of the signal in each of the frequency resources to which the beam sweeping is applied, and a parameter indicating the first symbol in which the signal is transmitted within the slot.

[0022] Based on whether the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, the setting information may include start RB information and RB count information for each of the frequency resources to which the beam sweeping is applied.

[0023] The above configuration information may include a repetition factor-frequency parameter indicating whether to perform repeated transmission in the frequency domain and a repetition factor-time parameter indicating whether to perform repeated transmission in the time domain, and the repetition factor-frequency parameter and the repetition factor-time parameter may be used to indicate the type of beam sweeping procedure.

[0024] The repetition factor-frequency parameter set to on and the repetition factor-time parameter set to on may indicate that the type of beam sweeping procedure is a beam fixed transmission procedure without beam sweeping, the repetition factor-frequency parameter set to off and the repetition factor-time parameter set to on may indicate that the type of beam sweeping procedure is a time fixed-frequency beam sweeping procedure in which beam sweeping is performed in frequency resource units, the repetition factor-frequency parameter set to on and the repetition factor-time parameter set to off may indicate that the type of beam sweeping procedure is a frequency fixed-time beam sweeping procedure in which beam sweeping is performed in time resource units, and the repetition factor-frequency parameter set to off and the repetition factor-time parameter set to off may indicate that the type of beam sweeping procedure is a full 2D beam sweeping procedure in which beam sweeping is performed in frequency resource units and time resource units.

[0025] The method of the base station may further include the step of receiving information from the UE indicating whether the UE supports the beam sweeping procedure in the frequency domain, and the setting information may be determined based on whether the UE supports the beam sweeping procedure in the frequency domain.

[0026] In the above frequency domain, the beam sweeping procedure may be an RB-level beam sweeping procedure or an RE-level beam sweeping procedure, the RB-level beam sweeping procedure may be performed in units of RB groups, and the RE-level beam sweeping procedure may be performed in units of RE groups.

[0027] According to the present disclosure, a beam sweeping procedure in the frequency domain and parameters required for said beam sweeping procedure can be proposed, and an existing beam sweeping procedure in the time domain can be extended to the frequency domain. Based on the proposal of the present disclosure, the high complexity and overhead of the beam sweeping procedure required in next-generation communication systems can be reduced. When the beam sweeping procedure is performed in the frequency domain, the transmission period and / or start offset of the signal / channel in the time domain for each frequency resource to which the beam sweeping procedure is applied can be set independently. According to the present disclosure, the overhead and computational burden caused by the beam sweeping procedure can be reduced. Different beams can be applied to each frequency resource (e.g., RB, RE), and the beam sweeping procedure can be performed efficiently in a communication system that considers frequency-dependent beams. Thus, the performance of the communication system can be improved.

[0028] FIG. 1 is a conceptual diagram illustrating embodiments of a communication system.

[0029] FIG. 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0030] FIG. 3 is a block diagram illustrating embodiments of communication nodes performing communication.

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

[0032] FIG. 4b is a block diagram illustrating embodiments of a receiving path.

[0033] FIG. 5 is a conceptual diagram illustrating embodiments of a system frame in a communication system.

[0034] FIG. 6 is a conceptual diagram illustrating embodiments of subframes in a communication system.

[0035] FIG. 7 is a conceptual diagram illustrating embodiments of slots in a communication system.

[0036] FIG. 8 is a conceptual diagram illustrating embodiments of time-frequency resources in a communication system.

[0037] Figure 9 is a conceptual diagram illustrating the beam fixed transmission procedure.

[0038] Figure 10 is a conceptual diagram illustrating a time-fixed-frequency beam sweeping procedure.

[0039] Figure 11 is a conceptual diagram illustrating a frequency-fixed-time beam sweeping procedure.

[0040] Figure 12 is a conceptual diagram illustrating a full 2D beam sweeping procedure.

[0041] Figure 13 is a flowchart illustrating a communication method based on a beam sweeping procedure.

[0042] 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.

[0043] 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.

[0044] 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".

[0045] 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".

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. To facilitate overall understanding in describing 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.

[0050] 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.

[0051] 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.

[0052] 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)).

[0053] 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.

[0054] 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".

[0055] 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."

[0056] FIG. 1 is a conceptual diagram illustrating embodiments of a communication system.

[0057] 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., an S-GW (serving-gateway), a P-GW (PDN (packet data network)-gateway), and an 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 AMF (access and mobility management function), a UPF (user plane function), an SMF (session management function), etc.

[0058] 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.

[0059] FIG. 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0060] 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.

[0061] 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).

[0062] 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).

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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).

[0068] 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.

[0069] FIG. 3 is a block diagram illustrating embodiments of communication nodes performing communication.

[0070] 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).

[0071] 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.

[0072] 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).

[0073] 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).

[0074] 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.

[0075] 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).

[0076] 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).

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] FIG. 5 is a conceptual diagram illustrating embodiments of a system frame in a communication system.

[0086] 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.

[0087] 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".

[0088] FIG. 6 is a conceptual diagram illustrating embodiments of subframes in a communication system.

[0089] 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.

[0090] FIG. 7 is a conceptual diagram illustrating embodiments of slots in a communication system.

[0091] 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.

[0092] 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.

[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 slot units. Additionally, the search space information may further include the index of the symbol where 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] Meanwhile, the base station can generate configuration information for NZP (non-zero power) CSI-RS resources and transmit the configuration information for NZP CSI-RS resources to a terminal via signaling. The terminal can receive the configuration information for NZP CSI-RS resources via the base station's signaling and can identify the NZP CSI-RS resources indicated by the configuration information. The base station can transmit NZP CSI-RS based on the above-described configuration information, and the terminal can receive NZP CSI-RS based on the above-described configuration information. The configuration information for NZP CSI-RS resources can be configured as shown in Table 2 below.

[0108]

[0109] The terminal can receive NZP CSI-RS for channel state estimation. CSI-RS power can be allocated to a resource element (RE). By measuring CSI-RS (e.g., NZP CSI-RS), the terminal can generate channel state information (e.g., channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI)) and transmit the channel state information to a base station (e.g., feedback).

[0110] The terminal can measure NZP CSI-RS to obtain channel estimation information (e.g., channel state information) and / or beamforming information. The base station can deploy NZP CSI-RS in the time-frequency domain by appropriately allocating time resources and frequency resources. The CSI-RS-ResourceMapping information elements (e.g., resourceMapping parameters) in Table 2 may include parameters related to resource allocation of NZP CSI-RS. The CSI-RS-ResourceMapping information elements may be configured as shown in Figure 3 below.

[0111]

[0112] The frequencyDomainAllocation and frequencyBand parameters in Table 3 may indicate information related to frequency resource allocation. The frequencyDomainAllocation parameter may indicate the RE(s) to which CSI-RS is allocated among the RE(s) (e.g., 12 RE(s)) within a resource block (RB). CSI-RS allocation within a resource block may be based on Tables 4 and 5 below. In other words, Tables 4 and 5 may be used to determine CSI-RS locations within a single slot.

[0113]

[0114]

[0115] CSI-RS allocation in RB units can be based on the freqBand parameter. In other words, CSI-RS allocation in RB units can be based on the startingRB parameter and the nrofRBs parameter. The startingRB parameter can indicate the starting RB to which CSI-RS is allocated. The nrofRBs parameter can indicate the number of RBs to which CSI-RS is allocated. Based on the startingRB parameter and the nrofRBs parameter, a situation may occur where CSI-RS is allocated from a frequency resource outside the BWP (bandwidth part). In the above situation, a truncated operation may be applied to the CSI-RS allocated from a frequency resource outside the BWP.

[0116] Conventional communication systems consider only beam sweeping operations in the time domain. In conventional communication systems, it may be possible to transmit different beams (e.g., different analog beams) at different time resources (e.g., slots or OFDM symbols), but it may not be considered to transmit different beams through different frequency resources (e.g., RBs or REs) within a single symbol. In the present disclosure, a beam may be interpreted as an analog beam and / or a digital beam depending on the context, beam transmission may mean the transmission of a signal / channel through a beam, beam reception may mean the reception of a signal / channel through a beam, parameter may mean information, symbol may be interpreted as an OFDM symbol depending on the context, and signal / channel may be interpreted as a signal, a channel, or "signal and channel" depending on the context. Alternatively, the term signal may be used to include a channel.

[0117] Next-generation communication systems can support frequency-dependent beamforming schemes utilizing beam squint phenomena and / or JPTA. In frequency-dependent beamforming schemes, different beams can be formed depending on the frequency resources. Based on frequency-dependent beamforming schemes, beam sweeping procedures (e.g., beam sweeping operations) in the frequency domain can be supported. Methods for supporting beam sweeping procedures in the frequency domain will be proposed in this disclosure.

[0118] In existing communication systems, CSI-RS resources can be allocated at the RB level based on the freqBand parameter included in the CSI-RS-ResourceMapping information elements. CSI-RS transmissions can be configured in specific REs within an RB based on the frequencyDomainAllocation parameter included in the CSI-RS-ResourceMapping information elements. The aforementioned CSI-RS configuration may be based on the assumption that the same beam (e.g., the same analog beam) is used within one or more RBs. To support transmissions based on different beams in different frequency resources, new parameters indicating that transmissions in different frequency resources are performed through different beams may be required, and methods for signaling these new parameters to terminals may be required. Since existing communication systems assume that a single beam exists within a single time resource (e.g., a slot or symbol), parameters indicating that transmissions in different frequency resources are performed through different beams do not exist in existing communication systems. In the present disclosure, beam sweeping procedures in the time domain can be extended to beam sweeping procedures in the time-frequency domain (e.g., 2D (dimensional) domain). Types of beam sweeping procedures in the 2D domain can be classified into (1) beam fixed transmission procedures, (2) time fixed-frequency beam sweeping procedures, (3) frequency fixed-time beam sweeping procedures, and (4) full 2D beam sweeping procedures.

[0119] CSI-RS can be assigned to multiple RBs, and CSI-RS transmissions at different RBs can be performed through different beams. Beam sweeping procedures will be described based on CSI-RS, but the embodiments proposed in this disclosure can be applied to the transmission and reception of other signals / channels as well as CSI-RS. For example, the embodiments proposed in this disclosure can be applied to the transmission and reception of a reference signal for channel measurement.

[0120] In a beam-fixed transmission procedure among beam-sweeping procedures in the 2D domain, a signal / channel can be transmitted through the same beam in both the time domain and the frequency domain. In other words, a beam-fixed transmission procedure may mean a procedure without beam sweeping. In a time-fixed-frequency beam-sweeping procedure among beam-sweeping procedures in the 2D domain, a signal / channel can be transmitted through the same beam in the time domain, and a signal / channel can be transmitted through different beams in the frequency domain. In a time-fixed-frequency beam-sweeping procedure, transmissions from different time resources (e.g., slots or symbols) within a single frequency resource (e.g., RB or RE) can be performed through a single beam, and transmissions from different frequency resources (e.g., RBs or REs) within a single time resource (e.g., slots or symbols) can be performed through different beams. When different beams are assigned from multiple RBs, methods may be needed to determine whether the beams set per frequency resource maintain the same transmission period and / or start offset in the time domain.

[0121] In existing communication systems, since a single beam is configured for the frequency domain, the methods described above may not be necessary. When utilizing frequency-dependent beams, different beams may be configured for each frequency resource (e.g., frequency band, RB, RE), and the transmission period and / or start offset in the time domain may be configured differently for said different beams. Therefore, methods to determine whether the beam configured for each frequency resource maintains the same transmission period and / or start offset in the time domain may be necessary. In a time-fixed-frequency beam sweeping procedure, the transmission period and / or start offset in the time domain for the beam configured for each frequency resource may or may not be maintained.

[0122] A frequency-fixed-time beam sweeping procedure may be similar to an existing beam sweeping procedure in the time domain. In a full 2D beam sweeping procedure, the beam sweeping procedure can be performed in both the time domain and the frequency domain. In a full 2D beam sweeping procedure, transmissions in different time resources (e.g., slots or symbols) may be based on different beams, and transmissions in different frequency resources (e.g., RBs or REs) may be based on different beams.

[0123] Parameters necessary for a beam sweeping procedure utilizing frequency-dependent beams will be proposed. A parameter indicating whether the terminal supports a beam sweeping procedure (e.g., frequency beam sweeping procedure) in units of frequency resources (e.g., RB or RE) may be set. In a frequency beam sweeping procedure, the terminal can simultaneously receive signals / channels through different beams and process said signals / channels. For the above-described operation, a high amount of computation may be required in the terminal. Operations for the frequency beam sweeping procedure may be limited depending on the processing capability of the terminal. Whether the terminal supports a frequency beam sweeping procedure may be indicated by the frequencyBandSweeping parameter. A frequencyBandSweeping parameter set to a first value (e.g., 0) may indicate that the terminal does not support a frequency beam sweeping procedure. A frequencyBandSweeping parameter set to a second value (e.g., 1) may indicate that the terminal supports a frequency beam sweeping procedure. The terminal can transmit frequencyBandSweeping parameters to the base station via signaling. The frequencyBandSweeping parameters may be included in the UE capability information transmitted by the terminal to the base station. The base station can receive frequencyBandSweeping parameters from the terminal and determine whether the terminal supports a frequency beam sweeping procedure based on the value of the frequencyBandSweeping parameters.

[0124] The frequency beam sweeping procedure may be performed in RB units (e.g., RB group units) or RE units (e.g., RE group units). An RB group may include one or more RBs. An RE group may include one or more REs. In the present disclosure, RB may be interpreted as an RB group depending on the context, and RE may be interpreted as an RE group depending on the context. In other words, an operation based on an RB unit may be interpreted as an operation based on an RB group unit, and an operation based on an RE unit may be interpreted as an operation based on an RE group unit. When the frequency beam sweeping procedure is performed in RB units, different beams may be used for each RB. When the frequency beam sweeping procedure is performed in RE units, different beams may be used for each RE. For the frequency beam sweeping procedure in RE units, a higher amount of computation may be required at the terminal.

[0125] Whether the terminal supports a frequency beam sweeping procedure in RE units can be indicated by the subcarrierSweeping parameter. A subcarrierSweeping parameter set to a first value (e.g., 0) may indicate that the terminal does not support a frequency beam sweeping procedure in RE units. In other words, a subcarrierSweeping parameter set to a first value (e.g., 0) may indicate that the terminal supports only a frequency beam sweeping procedure in RB units. A subcarrierSweeping parameter set to a second value (e.g., 1) may indicate that the terminal supports a frequency beam sweeping procedure in RE units. In other words, a subcarrierSweeping parameter set to a second value (e.g., 1) may indicate that the terminal supports both a frequency beam sweeping procedure in RB units and a frequency beam sweeping procedure in RE units. The terminal may transmit subcarrierSweeping parameters to the base station via signaling. The subcarrierSweeping parameters may be included in the UE capability information transmitted by the terminal to the base station. The base station may receive subcarrierSweeping parameters from the terminal and determine whether the terminal supports a frequency beam sweeping procedure at the RE unit level based on the value of the subcarrierSweeping parameters. A frequency beam sweeping procedure at the RB unit level or RB group level may be referred to as an RB-level beam sweeping procedure. A frequency beam sweeping procedure at the RE unit level or RE group level may be referred to as an RE-level beam sweeping procedure.

[0126] [Beam Fixed Transmission Procedure]

[0127] Figure 9 is a conceptual diagram illustrating the beam fixed transmission procedure.

[0128] Referring to FIG. 9, in a beam-fixed transmission procedure, a base station may transmit a signal / channel (e.g., CSI-RS) using the same beam (e.g., Beam #A) in both the time domain and the frequency domain. A terminal may receive the signal / channel through the same beam in both the time domain and the frequency domain. A may be a natural number. The base station may instruct the terminal to perform the beam-fixed transmission procedure using a repetition factor parameter. The repetition factor parameter may be used to indicate the type of beam sweeping procedure.

[0129] For example, the base station may transmit a repetition factor-frequency parameter and a repetition factor-time parameter, both set to 'on', to the terminal via signaling. Setting both the repetition factor-frequency parameter and the repetition factor-time parameter to 'on' may indicate that the beam sweeping procedure is not being performed. The repetition factor-frequency parameter and the repetition factor-time parameter may be set as shown in Table 6 below. The size of each of the repetition factor-frequency parameter and the repetition factor-time parameter may be 1 bit. A combination of the repetition factor-frequency parameter and the repetition factor-time parameter may be used to indicate the type of beam sweeping procedure.

[0130]

[0131] In Table 6, 'on' may mean enabled, and 'off' may mean disabled. The repetition factor-frequency parameter may be a new parameter introduced for the beam sweeping procedure in the frequency domain. The base station may use the repetition factor-frequency parameter to convey information regarding whether to perform the frequency beam sweeping procedure. The repetition factor-frequency parameter may be referred to as the repetition flag-frequency parameter. The repetition factor-time parameter may be a parameter to support the beam sweeping procedure in the time domain. The repetition factor-time parameter may be referred to as the repetition flag-time parameter.

[0132] A repetition factor-frequency parameter set to off (e.g., a first value (e.g., 0)) may indicate that repeat transmissions are not performed in the frequency domain. In other words, a repetition factor-frequency parameter set to off may imply that transmissions using different beams are performed in the frequency domain. A repetition factor-frequency parameter set to on (e.g., a second value (e.g., 1)) may indicate that repeat transmissions are performed using the same beam in the frequency domain.

[0133] A repetition factor-time parameter set to off (e.g., a first value (e.g., 0)) may indicate that no repetition transmissions are performed in the time domain. In other words, a repetition factor-time parameter set to off may imply that transmissions using different beams are performed in the time domain. A repetition factor-time parameter set to on (e.g., a second value (e.g., 1)) may indicate that repetition transmissions are performed using the same beam in the time domain.

[0134] A combination of a repetition factor-frequency parameter set to ON and a repetition factor-time parameter set to ON can indicate that a beam-fixed transmission procedure is performed. A terminal can receive the repetition factor-frequency parameter and the repetition factor-time parameter through the signaling of a base station and can determine whether a beam-fixed transmission procedure is performed based on the repetition factor-frequency parameter and the repetition factor-time parameter. If both the repetition factor-frequency parameter and the repetition factor-time parameter are set to ON, the terminal can determine that a beam-fixed transmission procedure is performed.

[0135] In a communication system, a repeat factor (e.g., a repeat flag) can be used to indicate repeated transmissions (e.g., repeated transmissions over a specific beam). When repeated transmissions are performed, the opportunity for beam measurement at the terminal may increase, and the terminal can accurately measure beam quality even in environments with poor channel conditions. When the repeat factor is set to ON, the base station can perform repeated transmissions using the same beam. When the repeat factor is set to OFF, the base station can perform transmissions using different beams. For example, the base station can perform transmissions using different beams for each time resource (e.g., slot or symbol).

[0136] The use of a fixed beam in the time domain and frequency domain may mean that the base station does not sweep the beam. In other words, the base station can perform transmissions (e.g., repetitive transmissions) using a fixed beam without beam sweeping.

[0137] [Time-Fixed-Frequency Beam Sweeping Procedure]

[0138] Figure 10 is a conceptual diagram illustrating a time-fixed-frequency beam sweeping procedure.

[0139] Referring to FIG. 10, in a time-fixed-frequency beam sweeping procedure, a base station may transmit a signal / channel (e.g., CSI-RS) using the same beam in the time domain of each frequency resource and transmit a signal / channel (e.g., CSI-RS) using different beams (e.g., beam #A, beam #B, beam #C) in the frequency domain. A terminal may receive a signal / channel through the same beam in the time domain of each frequency resource and receive a signal / channel through different beams in the frequency domain. A, B, and C may each be natural numbers.

[0140] For example, Beam #A may be used in frequency resource #1, Beam #B may be used in frequency resource #2, and Beam #C may be used in frequency resource #3. Communication between a base station and a terminal in the time domain of frequency resource #1 (e.g., different time resources) may be performed based on Beam #A. Communication between a base station and a terminal in the time domain of frequency resource #2 (e.g., different time resources) may be performed based on Beam #B. Communication between a base station and a terminal in the time domain of frequency resource #3 (e.g., different time resources) may be performed based on Beam #C. Each of frequency resources #1, #2, and #3 may include one or more REs or one or more RBs.

[0141] The beam for CSI-RS transmission in different time resources (e.g., slots or symbols) of each frequency resource can be considered the same beam. The beam for CSI-RS transmission in different frequency resources (e.g., RBs or REs) can be considered different beams. When a time-fixed-frequency beam sweeping procedure is performed, the repetition factor-frequency parameter and the repetition factor-time parameter can be set as shown in Table 7 below. In other words, the repetition factor-frequency parameter can be set to off, and the repetition factor-time parameter can be set to on.

[0142]

[0143] To perform a time-fixed-frequency beam sweeping procedure, the base station may set the repetition factor-frequency parameter to off and the repetition factor-time parameter to on, and transmit the repetition factor-frequency parameter set to off and the repetition factor-time parameter set to on to the terminal via signaling. The terminal may receive the repetition factor-frequency parameter and the repetition factor-time parameter via the base station's signaling. When the repetition factor-frequency parameter is set to off and the repetition factor-time parameter is set to on, the terminal may determine that the time-fixed-frequency beam sweeping procedure is being performed and may perform communication with the base station based on the time-fixed-frequency beam sweeping procedure.

[0144] When beams differ for each frequency resource (e.g., RB or RE) (e.g., when a beam sweeping procedure is performed in the frequency domain), the scenario may differ based on whether the transmission period and / or start offset (e.g., transmission start offset) of the signal / channel are maintained in the time domain. In a situation where the repetition factor-frequency parameter is set to off, the base station may additionally set the timeDomainEqualPattern parameter. In other words, the timeDomainEqualPattern parameter may be set only when the repetition factor-frequency parameter is set to off. The timeDomainEqualPattern parameter set to off (e.g., disabled, first value (e.g., 0)) may indicate that different transmission periods and / or different start offsets are applied in the time domain for the frequency resources to which the beam sweeping procedure is applied. The timeDomainEqualPattern parameter set to ON (e.g., Enable, a second value (e.g., 1)) may indicate that the same transmission period and / or the same start offset is applied in the time domain for frequency resources to which the beam sweeping procedure is applied. The embodiment of FIG. 10 may be an embodiment in which the timeDomainEqualPattern parameter is set to ON.

[0145] The base station may transmit the timeDomainEqualPattern parameter to the terminal via signaling. The terminal may check the timeDomainEqualPattern parameter via the base station's signaling and, based on the setting of the timeDomainEqualPattern parameter, determine whether the same transmission period and / or the same start offset is applied in the time domain for frequency resources to which the beam sweeping procedure is applied. The timeDomainEqualPattern parameter may be set to off as shown in Table 8 below. The size of the timeDomainEqualPattern parameter may be 1 bit.

[0146]

[0147] When the timeDomainEqualPattern parameter is set to off, the transmission period and / or start offset in the time domain for each frequency resource can be set to the terminal via the base station's signaling. In other words, the base station can transmit the parameters defined in Table 9 below to the terminal via signaling. The terminal can check the parameters defined in Table 9 below via the base station's signaling. When the timeDomainEqualPattern parameter is set to off, the transmission pattern (e.g., transmission period, start offset, start symbol) may differ for each frequency resource.

[0148]

[0149] The StartingRB-RB group n parameter and the nrofRBs-RB group n parameter may be configuration information for frequency resources. The StartingRB-RB group n parameter and the nrofRBs-RB group n parameter may be transmitted to the terminal by the base station's signaling regardless of the value of the timeDomainEqualPattern parameter. Alternatively, if the timeDomainEqualPattern parameter is set to off, the StartingRB-RB group n parameter and the nrofRBs-RB group n parameter may be transmitted to the terminal by the base station's signaling. The StartingRB-RB group n parameter may indicate the starting RB of RB group #n (e.g., starting RB index). The nrofRBs-RB group n parameter may indicate the number of RBs belonging to RB group #n. In other words, the nrofRBs-RB group n parameter can indicate the number of RBs to which the beam associated with RB group #n is applied. Instead of the StartingRB-RB group n parameter and the nrofRBs-RB group n parameter, an index indicating a frequency resource may be used.

[0150] The peridicityAndOffset-RB group n parameter can specify the transmission period and start offset in the time domain for RB group #n. The transmission period can specify how many slots the signal / channel transmission (e.g., CSI-RS transmission) is repeated in the time domain. The start offset can specify from which slot within the transmission period the signal / channel transmission (e.g., CSI-RS transmission) begins. If the peridicityAndOffset-RB group n parameter specifies sf5 and offset3, the signal / channel transmission can be performed every 5 slots, and in each transmission period, the signal / channel transmission can begin from the 3rd slot.

[0151] The firstOFDMSymbolInTimeDomain- RB group n parameter may indicate the first symbol (e.g., the first OFDM symbol within a slot) for which transmission of the signal / channel is performed in the time domain for RB group #n. n can be a natural number, and the range of n can be from 1 to N. In a time-fixed-frequency beam sweeping procedure, N may indicate the total number of available beams within a single time resource (e.g., slot, symbol). The parameters defined in Table 8 may be set in units of frequency resources (e.g., RB group or RE group).

[0152] The transmission pattern of a signal / channel (e.g., CSI-RS) in the time domain can be determined based on the periodicityAndOffset-RB group n-parameter and / or the firstOFDMSymbolInTimeDomain-RB group n-parameter. The transmission period and / or start offset indicated by the periodicityAndOffset-RB group n-parameter can be set on a slot-by-slot basis. The firstOFDMSymbolInTimeDomain-RB group n-parameter can be used to determine the start symbol to which the signal / channel (e.g., CSI-RS) is assigned within a single slot. Based on the parameters defined in Table 9, the transmission period and / or start offset in the time domain for each of the frequency resources in the embodiment of FIG. 10 can be set independently. For example, different transmission periods and / or different start offsets can be set for the frequency resources.

[0153] When the timeDomainEqualPattern parameter is set to ON, the transmission pattern (e.g., transmission period, start offset, start symbol) in the time domain for all frequency resources (e.g., frequency resources #1, #2, and #3 in the embodiment of FIG. 10) can be determined based on the periodicityAndOffset parameter and the firstOFDMSymbolInTimeDomain parameter defined in the existing communication system, instead of the parameters defined in Table 9 (e.g., periodicityAndOffset-RB group n parameter, firstOFDMSymbolInTimeDomain-RB group n parameter).

[0154] [Frequency Fixed-Time Beam Sweeping Procedure]

[0155] Figure 11 is a conceptual diagram illustrating a frequency-fixed-time beam sweeping procedure.

[0156] Referring to FIG. 11, in a frequency fixed-time beam sweeping procedure, a base station may transmit a signal / channel (e.g., CSI-RS) using the same beam in the frequency domain of each time resource and transmit a signal / channel (e.g., CSI-RS) using different beams (e.g., beam #A, beam #B, beam #C) in the time domain. A terminal may receive a signal / channel through the same beam in the frequency domain of each time resource and receive a signal / channel through different beams in the time domain. A, B, and C may each be natural numbers.

[0157] For example, Beam #A may be used in Time Resource #1, Beam #B may be used in Time Resource #2, and Beam #C may be used in Time Resource #3. Communication between a base station and a terminal in the frequency domain of Time Resource #1 (e.g., different frequency resources) may be performed based on Beam #A. Communication between a base station and a terminal in the frequency domain of Time Resource #2 (e.g., different frequency resources) may be performed based on Beam #B. Communication between a base station and a terminal in the frequency domain of Time Resource #3 (e.g., different frequency resources) may be performed based on Beam #C. Each of Time Resources #1, #2, and #3 may include one or more symbols or one or more slots.

[0158] The beam for CSI-RS transmission in different frequency resources (e.g., REs or RBs) of each time resource can be considered the same beam. The beam for CSI-RS transmission in different time resources (e.g., symbols or slots) can be considered different beams. When a frequency fixed-time beam sweeping procedure is performed, the repetition factor-frequency parameter and the repetition factor-time parameter can be set as shown in Table 10 below. In other words, the repetition factor-frequency parameter can be set to ON, and the repetition factor-time parameter can be set to OFF.

[0159]

[0160] To perform a frequency fixed-time beam sweeping procedure, the base station may set the repetition factor-frequency parameter to ON and the repetition factor-time parameter to OFF, and transmit the repetition factor-frequency parameter set to ON and the repetition factor-time parameter set to OFF to the terminal via signaling. The terminal may receive the repetition factor-frequency parameter and the repetition factor-time parameter via the base station's signaling. When the repetition factor-frequency parameter is set to ON and the repetition factor-time parameter is set to OFF, the terminal may determine that the frequency fixed-time beam sweeping procedure is being performed and may perform communication with the base station based on the frequency fixed-time beam sweeping procedure.

[0161] [Full 2D Beam Sweeping Procedure]

[0162] Figure 12 is a conceptual diagram illustrating a full 2D beam sweeping procedure.

[0163] Referring to FIG. 12, in a full 2D beam sweeping procedure, a base station can transmit a signal / channel (e.g., CSI-RS) using different beams (e.g., beam #A, beam #B, beam #C, beam #D, beam #E, beam #F, beam #G, beam #H, beam #I) in a time-frequency domain (e.g., 2D domain). A terminal can receive a signal / channel through different beams (e.g., beam #A, beam #B, beam #C, beam #D, beam #E, beam #F, beam #G, beam #H, beam #I) in a time-frequency domain. Each of A, B, C, D, E, F, G, H, and I can be a natural number.

[0164] For example, Beam #A can be used in Time Resource #1 and Frequency Resource #1, Beam #B can be used in Time Resource #1 and Frequency Resource #2, and Beam #C can be used in Time Resource #1 and Frequency Resource #3. Beam #D can be used in Time Resource #2 and Frequency Resource #1, Beam #E can be used in Time Resource #2 and Frequency Resource #2, and Beam #F can be used in Time Resource #2 and Frequency Resource #3. Beam #G can be used in Time Resource #3 and Frequency Resource #1, Beam #H can be used in Time Resource #3 and Frequency Resource #2, and Beam #I can be used in Time Resource #3 and Frequency Resource #3.

[0165] Each of time resources #1, #2, and #3 may include one or more symbols or one or more slots. Each of frequency resources #1, #2, and #3 may include one or more REs or one or more RBs. Communication between the base station and the terminal in each time-frequency resource may be performed using different beams. When a full 2D beam sweeping procedure is performed, the repetition factor-frequency parameter and the repetition factor-time parameter may be set as shown in Table 11 below. In other words, the repetition factor-frequency parameter may be set to off, and the repetition factor-time parameter may be set to off.

[0166]

[0167] To perform a full 2D beam sweeping procedure, the base station may set the repetition factor-frequency parameter to off and the repetition factor-time parameter to off, and transmit the repetition factor-frequency parameter and the repetition factor-time parameter set to off to the terminal through signaling. The terminal may receive the repetition factor-frequency parameter and the repetition factor-time parameter through the base station's signaling. When the repetition factor-frequency parameter is set to off and the repetition factor-time parameter is set to off, the terminal may determine that a full 2D beam sweeping procedure is being performed and may perform communication with the base station based on the full 2D beam sweeping procedure.

[0168] To support a full 2D beam sweeping procedure, the base station may additionally transmit to the terminal via signaling parameters defined in Table 8 (e.g., timeDomainEqualPattern parameter) and / or parameters defined in Table 9 (e.g., StartingRB-RB group n parameter, nrofRBs-RB group n parameter, peridicityAndOffset-RB group n parameter, firstOFDMSymbolInTimeDomain-RB group n parameter). The base station may transmit the parameters defined in Table 9 to the terminal after transmitting the timeDomainEqualPattern parameter, which is set to off, to the terminal. In this case, among the parameters defined in Table 9, only the peridicityAndOffset-RB group n-parameter and the firstOFDMSymbolInTimeDomain-RB group n-parameter may be transmitted to the terminal, and the StartingRB-RB group n-parameter and the nrofRBs-RB group n-parameter may be transmitted to the terminal regardless of the value of the timeDomainEqualPattern parameter. Alternatively, all parameters defined in Table 9 may be transmitted to the terminal. Alternatively, the base station may transmit the parameters defined in Table 9 to the terminal without transmitting the timeDomainEqualPattern parameter. In other words, the parameters defined in Table 9 may be set regardless of the value of the timeDomainEqualPattern parameter.

[0169] The terminal can receive parameters defined in Table 8 and / or Table 9 through the signaling of the base station, and can determine the starting RB, number of RBs, transmission period, starting offset, and / or starting symbol for each frequency resource (e.g., RB group) based on the value of each of the received parameters. A full 2D beam sweeping procedure between the base station and the terminal can be performed based on the parameters defined in Table 9. In the time domain, each RB group can be associated with multiple beams. For example, in the embodiment of FIG. 12, the RB group belonging to frequency resource #1 can be associated with beams #A, #D, and #G, the RB group belonging to frequency resource #2 can be associated with beams #B, #E, and #H, and the RB group belonging to frequency resource #3 can be associated with beams #C, #F, and #I.

[0170] [Parameter indicating whether beam sweeping procedure is supported]

[0171] Even when a base station performs a frequency beam sweeping procedure using frequency-dependent beams, the terminal may not be able to support the frequency beam sweeping procedure. In other words, the terminal (e.g., a legacy terminal) may not be able to support the frequency beam sweeping procedure depending on its capabilities. Since the terminal must receive and process signals / channels through multiple beams within the same time resource during the frequency beam sweeping procedure, a high amount of computation may be required from the terminal. Therefore, the frequency beam sweeping function may be limited depending on the terminal's capabilities. A frequencyBandSweeping parameter may be defined to indicate whether the terminal supports the frequency beam sweeping procedure. The frequencyBandSweeping parameter may be set as shown in Table 12 below.

[0172]

[0173] A frequencyBandSweeping parameter set to a first value (e.g., 0) may indicate that the terminal does not support a frequency beam sweeping procedure (e.g., an RB-level beam sweeping procedure). A frequencyBandSweeping parameter set to a second value (e.g., 1) may indicate that the terminal supports a frequency beam sweeping procedure (e.g., an RB-level beam sweeping procedure). The terminal may transmit the frequencyBandSweeping parameter to a base station via signaling. The frequencyBandSweeping parameter may be included in UE capability information (or a new RRC message) transmitted by the terminal to the base station. The base station may receive the frequencyBandSweeping parameter from the terminal and determine whether the terminal supports a frequency beam sweeping procedure based on the value of the frequencyBandSweeping parameter. If the terminal supports a frequency beam sweeping procedure, the base station may transmit a signal / channel (e.g., CSI-RS) based on a time-fixed-frequency beam sweeping procedure or a full 2D beam sweeping procedure. If the terminal does not support a frequency beam sweeping procedure, the base station may transmit a signal / channel (e.g., CSI-RS) based on a beam-fixed transmission procedure or a frequency-fixed-time beam sweeping procedure.

[0174] Transmission of signals / channels (e.g., CSI-RS) may be performed in units of RB (e.g., RB group) or RE (e.g., RE group). A terminal that does not support the RB-level beam sweeping procedure may not support the RE-level beam sweeping procedure. A terminal that supports the RB-level beam sweeping procedure may support the RE-level beam sweeping procedure. In other words, the terminal must first support the RB-level beam sweeping procedure in order to support the RE-level beam sweeping procedure. In a situation where the terminal transmits a frequencyBandSweeping parameter set to a second value (e.g., 1) to the base station, the terminal may transmit a parameter to the base station indicating whether it supports the RE-level beam sweeping procedure.

[0175] When the frequency beam sweeping procedure is performed in RE units, different beams may be used for each RE. For the RE-level beam sweeping procedure, a higher amount of computation may be required at the terminal. Whether the terminal supports the RE-level beam sweeping procedure can be indicated by the subcarrierSweeping parameter. The subcarrierSweeping parameter can be set as shown in Table 13 below.

[0176]

[0177] A subcarrierSweeping parameter set to a first value (e.g., 0) may indicate that the terminal does not support RE-level beam sweeping procedures. In other words, a subcarrierSweeping parameter set to a first value (e.g., 0) may indicate that the terminal supports only RB-level beam sweeping procedures. A subcarrierSweeping parameter set to a second value (e.g., 1) may indicate that the terminal supports RE-level beam sweeping procedures. In other words, a subcarrierSweeping parameter set to a second value (e.g., 1) may indicate that the terminal supports both RB-level beam sweeping procedures and RE-level beam sweeping procedures. The terminal may transmit the subcarrierSweeping parameter to a base station via signaling. The subcarrierSweeping parameter may be included in UE capability information (or a new RRC message) that the terminal transmits to the base station. The base station can receive a subcarrierSweeping parameter from a terminal and determine whether the terminal supports an RE-level beam sweeping procedure based on the value of the subcarrierSweeping parameter.

[0178] If the terminal supports the RE-level beam sweeping procedure, the base station may transmit the signal / channel (e.g., CSI-RS) by performing the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure in RE units (or RE group units). If the terminal does not support the RE-level beam sweeping procedure, the base station may transmit the signal / channel (e.g., CSI-RS) by performing the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure in RB units (or RB group units).

[0179] Next-generation communication systems can support ultra-high frequency broadbands, including the terahertz band. In next-generation communication systems, subcarrier spacing (SCS) may be set high to address high phase noise and large Doppler effects. Since the phase noise of oscillators for the terahertz band is high, interference between carriers (or subcarriers) may increase if the SCS is set low. Large Doppler effects occur in high-frequency bands, and setting the SCS high may be necessary to reduce these effects. In broadband communication, if the SCS is small, the size of the Fast Fourier Transform (FFT) increases, which can drastically increase implementation complexity.

[0180] Based on the reasons described above, a large SCS may be applied in a communication system supporting ultra-high frequency broadband, and the frequency difference between adjacent REs may increase. In the aforementioned situation, if beam sequencing phenomena and / or frequency-dependent beams are used, the beam characteristics between adjacent REs may differ significantly, so the RE-level beam sweeping procedure can be easily performed. In the present disclosure, whether a terminal supports the RE-level beam sweeping procedure may be indicated by the subcarrierSweeping parameter, and the base station may determine the beam sweeping method according to the capabilities of the terminal. The base station may determine whether to apply the RE-level beam sweeping procedure based on the value of the subcarrierSweeping parameter received from the terminal. The base station may determine an appropriate beam sweeping method by considering the balance between the computational load on the terminal and the performance of the communication system.

[0181] Figure 13 is a flowchart illustrating a communication method based on a beam sweeping procedure.

[0182] Referring to FIG. 13, the terminal can generate UE capability information and transmit the UE capability information to a base station (S1301). The UE capability information may include parameters indicating whether the terminal supports a beam sweeping procedure in the frequency domain. For example, the UE capability information may include at least one of a frequencyBandSweeping parameter or a subcarrierSweeping parameter. The frequencyBandSweeping parameter may indicate whether the terminal supports an RB-level beam sweeping procedure. The subcarrierSweeping parameter may indicate whether the terminal supports an RE-level beam sweeping procedure. Based on its capability, the terminal can set parameters indicating whether it supports a beam sweeping procedure in the frequency domain (e.g., an RB-level beam sweeping procedure, an RE-level beam sweeping procedure) and transmit the UE capability information including said parameters to a base station (S1301).

[0183] A base station may receive UE capability information from a terminal (S1301). Based on the parameter(s) included in the UE capability information, the base station may determine whether the terminal supports a beam sweeping procedure in the frequency domain. The base station may determine a beam sweeping procedure for communication between the base station and the terminal by considering the beam sweeping procedure supported by the terminal (S1302). Alternatively, the base station may determine a beam sweeping procedure for communication between the base station and the terminal without considering the beam sweeping procedure supported by the terminal (S1302). In other words, the terminal provides the base station with a parameter indicating whether it supports a beam sweeping procedure, but the base station may determine the beam sweeping procedure without considering the terminal's capability (S1302).

[0184] In S1302, the base station may select (e.g., determine) one of the following procedures: a beam-fixed transmission procedure, a time-fixed-frequency beam sweeping procedure, a frequency-fixed-time beam sweeping procedure, or a full 2D beam sweeping procedure. If the terminal does not support a beam sweeping procedure in the frequency domain, the base station may select a beam-fixed transmission procedure or a frequency-fixed-time beam sweeping procedure. If the terminal supports a beam sweeping procedure in the frequency domain, the base station may select a time-fixed-frequency beam sweeping procedure or a full 2D beam sweeping procedure. Alternatively, if the terminal supports a beam sweeping procedure in the frequency domain, the base station may select one of the following procedures: a beam-fixed transmission procedure, a time-fixed-frequency beam sweeping procedure, a frequency-fixed-time beam sweeping procedure, or a full 2D beam sweeping procedure.

[0185] The base station can generate configuration information for a selected beam sweeping procedure and transmit said configuration information to a terminal via signaling (S1302). The configuration information for the beam sweeping procedure may include parameters indicating the type of beam sweeping procedure. The parameters indicating the type of beam sweeping procedure may be a repetition factor-frequency parameter and a repetition factor-time parameter. If both the repetition factor-frequency parameter and the repetition factor-time parameter are set to ON, this may indicate that a beam fixed transmission procedure is performed. If the repetition factor-frequency parameter is set to OFF and the repetition factor-time parameter is set to ON, this may indicate that a time fixed-frequency beam sweeping procedure is performed. If the repetition factor-frequency parameter is set to ON and the repetition factor-time parameter is set to OFF, this may indicate that a frequency fixed-time beam sweeping procedure is performed. If both the repetition factor-frequency parameter and the repetition factor-time parameter are set to off, this may indicate that a full 2D beam sweeping procedure is performed.

[0186] When a time-fixed-frequency beam sweeping procedure is performed, the configuration information of the beam sweeping procedure may further include the timeDomainEqualPattern parameter. The timeDomainEqualPattern parameter may indicate whether the same transmission period and / or the same start offset is applied in the time domain for the frequency resources to which the beam sweeping procedure is applied. If the timeDomainEqualPattern parameter is set to off, the configuration information of the beam sweeping procedure may further include at least one of the StartingRB-RB group n parameter, nrofRBs-RB group n parameter, periodicityAndOffset-RB group n parameter, or firstOFDMSymbolInTimeDomain-RB group n parameter. The StartingRB-RB group n parameter may indicate the starting RB of RB group #n. The nrofRBs-RB group n parameter may indicate the number of RBs belonging to RB group #n. The periodicityAndOffset-RB group n parameter RB The firstOFDMSymbolInTimeDomain-RB group n parameter may indicate the transmission period and / or start offset of the signal / channel in the time domain for group #n. The firstOFDMSymbolInTimeDomain-RB group n parameter may indicate the first symbol (e.g., the first symbol within a slot) of the signal / channel being transmitted in the time domain for RB group #n.

[0187] When a full 2D beam sweeping procedure is performed, the configuration information of the beam sweeping procedure may further include the timeDomainEqualPattern parameter. The timeDomainEqualPattern parameter may indicate whether the same transmission period and / or the same start offset is applied in the time domain for the frequency resources to which the beam sweeping procedure is applied. If the timeDomainEqualPattern parameter is set to off, the configuration information of the beam sweeping procedure may further include at least one of the StartingRB-RB group n parameter, nrofRBs-RB group n parameter, periodicityAndOffset-RB group n parameter, or firstOFDMSymbolInTimeDomain-RB group n parameter. The StartingRB-RB group n parameter may indicate the starting RB of RB group #n. The nrofRBs-RB group n parameter may indicate the number of RBs belonging to RB group #n. The periodicityAndOffset-RB group n parameter is an RB group The firstOFDMSymbolInTimeDomain-RB group n parameter may indicate the transmission period and / or start offset of the signal / channel in the time domain for #n. The firstOFDMSymbolInTimeDomain-RB group n parameter may indicate the first symbol (e.g., the first symbol within the slot) of the signal / channel transmitted in the time domain for RB group #n.

[0188] The terminal can receive configuration information for a beam sweeping procedure through the signaling of the base station (S1303). The terminal can check the parameters included in the configuration information for the beam sweeping procedure. Based on the repetition factor-frequency parameter and the repetition factor-time parameter, the terminal can check the type of beam sweeping procedure applied in the communication between the terminal and the base station. The terminal can check the parameters for the identified beam sweeping procedure (e.g., timeDomainEqualPattern parameter, StartingRB-RB group n parameter, nrofRBs-RB group n parameter, periodicityAndOffset-RB group n parameter, firstOFDMSymbolInTimeDomain-RB group n parameter).

[0189] In S1304, the base station can transmit a signal / channel to the terminal by performing a beam sweeping procedure according to the type indicated by the configuration information. In S1304, the terminal can determine the type of beam sweeping procedure based on the configuration information and can receive a signal / channel from the base station through the beam sweeping procedure according to the determined type.

[0190] Meanwhile, in next-generation communication systems, many antennas may be used, and as high precision is required in the position estimation process, the beam width may be reduced and the complexity of the beam sweeping procedure may increase. In the present disclosure, a beam sweeping procedure in the frequency domain and parameters required for said beam sweeping procedure may be proposed, and existing beam sweeping procedures in the time domain may be extended to the frequency domain. Based on the proposal of the present disclosure, the high complexity and overhead of the beam sweeping procedure required in next-generation communication systems may be reduced. In existing beam sweeping procedures, a method of transmitting the beam in a fixed single direction and a method of sweeping the beam in the time domain have been considered, but in the present disclosure, four scenarios for beam sweeping (e.g., a beam fixed transmission procedure, a time fixed-frequency beam sweeping procedure, a frequency fixed-time beam sweeping procedure, and a full 2D beam sweeping procedure) may be proposed.

[0191] When a beam sweeping procedure is performed in the frequency domain, the transmission period and / or start offset of a signal / channel in the time domain for each frequency resource to which the beam sweeping procedure is applied can be set independently. In the time domain, the transmission period and / or start offset of a signal / channel can be set differently for each frequency resource. According to the present disclosure, the overhead and computational burden caused by the beam sweeping procedure can be reduced. Different beams can be applied to each frequency resource (e.g., RB, RE), and the beam sweeping procedure can be performed efficiently in a communication system that considers frequency-dependent beams. According to the beam sweeping procedure proposed in the present disclosure, the complexity problem of existing beam sweeping procedures can be resolved. The beam sweeping procedure proposed in the present disclosure can be applied to communication that considers beam sequent phenomena and / or JPTA.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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 UE (user equipment), A step of receiving configuration information for a beam sweeping procedure from a base station; A step of determining the type of beam sweeping procedure based on the above setting information; and A step comprising receiving a signal from the base station through a beam sweeping procedure according to a determined type, UE's method.

2. In Claim 1, The types of the above beam sweeping procedures are classified into beam-fixed transmission procedures, time-fixed-frequency beam sweeping procedures, frequency-fixed-time beam sweeping procedures, and full 2D beam sweeping procedures, and The above beam-fixed transmission procedure is a procedure without beam sweeping, and in the above time-fixed-frequency beam sweeping procedure, beam sweeping is performed in units of frequency resources, in the above frequency-fixed-time beam sweeping procedure, beam sweeping is performed in units of time resources, and in the above full 2D beam sweeping procedure, beam sweeping is performed in units of frequency resources and time resources, UE's method.

3. In Claim 2, The above frequency resource unit is a resource block (RB) group or resource element (RE) group, the RB group includes one or more RBs, the RE group includes one or more REs, the above time resource unit is a slot group or symbol group, the slot group includes one or more slots, and the symbol group includes one or more symbols, UE's method.

4. In Claim 2, Based on whether the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, the setting information includes a parameter indicating whether to maintain the transmission period and start offset of the signal in the time domain. UE's method.

5. In Claim 2, Based on the fact that the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, and that the transmission period and start offset of the signal are not maintained in the time domain, the configuration information includes a parameter indicating the transmission period and start offset of the signal in each of the frequency resources to which the beam sweeping is applied, and a parameter indicating the first symbol in which the signal is transmitted within the slot. UE's method.

6. In Claim 2, Based on whether the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, the configuration information includes start RB information and RB count information for each of the frequency resources to which the beam sweeping is applied. UE's method.

7. In Claim 1, The above configuration information includes a repetition factor-frequency parameter indicating whether to perform repeated transmission in the frequency domain and a repetition factor-time parameter indicating whether to perform repeated transmission in the time domain, wherein the repetition factor-frequency parameter and the repetition factor-time parameter are used to indicate the type of beam sweeping procedure. UE's method.

8. In Claim 7, The repetition factor-frequency parameter set to ON and the repetition factor-time parameter set to ON indicate that the type of beam sweeping procedure is a beam fixed transmission procedure without beam sweeping, and The repetition factor-frequency parameter set to off and the repetition factor-time parameter set to on indicate that the type of beam sweeping procedure is a time-fixed-frequency beam sweeping procedure in which beam sweeping of frequency resource units is performed, and The repetition factor-frequency parameter set to ON and the repetition factor-time parameter set to OFF indicate that the type of beam sweeping procedure is a frequency-fixed-time beam sweeping procedure in which beam sweeping in time resource units is performed, and The repetition factor-frequency parameter set to off and the repetition factor-time parameter set to off indicate that the type of beam sweeping procedure is a full 2D beam sweeping procedure in which beam sweeping is performed in frequency resource units and time resource units, UE's method.

9. In Claim 1, The method further includes the step of transmitting information to the base station indicating whether the UE supports the beam sweeping procedure in the frequency domain, The above setting information is determined based on whether the UE supports the beam sweeping procedure in the frequency domain, UE's method.

10. In Claim 9, In the above frequency domain, the beam sweeping procedure is an RB-level beam sweeping procedure or an RE-level beam sweeping procedure, wherein the RB-level beam sweeping procedure is performed on the unit of an RB group, and the RE-level beam sweeping procedure is performed on the unit of an RE group, UE's method.

11. As a method of base station, A step of generating configuration information for a beam sweeping procedure; A step of transmitting the setting information for the above beam sweeping procedure to the UE (user equipment); and A step comprising transmitting a signal to the UE by performing a beam sweeping procedure according to the type indicated by the above setting information, Base station method.

12. In Claim 11, The types of the above beam sweeping procedures are classified into beam-fixed transmission procedures, time-fixed-frequency beam sweeping procedures, frequency-fixed-time beam sweeping procedures, and full 2D beam sweeping procedures, and The above beam-fixed transmission procedure is a procedure without beam sweeping, and in the above time-fixed-frequency beam sweeping procedure, beam sweeping is performed in units of frequency resources, in the above frequency-fixed-time beam sweeping procedure, beam sweeping is performed in units of time resources, and in the above full 2D beam sweeping procedure, beam sweeping is performed in units of frequency resources and time resources, Base station method.

13. In Claim 12, The above frequency resource unit is a resource block (RB) group or resource element (RE) group, the RB group includes one or more RBs, the RE group includes one or more REs, the above time resource unit is a slot group or symbol group, the slot group includes one or more slots, and the symbol group includes one or more symbols, Base station method.

14. In Claim 12, Based on whether the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, the setting information includes a parameter indicating whether to maintain the transmission period and start offset of the signal in the time domain. Base station method.

15. In Claim 12, Based on the fact that the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, and that the transmission period and start offset of the signal are not maintained in the time domain, the configuration information includes a parameter indicating the transmission period and start offset of the signal in each of the frequency resources to which the beam sweeping is applied, and a parameter indicating the first symbol in which the signal is transmitted within the slot. Base station method.

16. In Claim 12, Based on whether the type of the beam sweeping procedure is the time-fixed-frequency beam sweeping procedure or the full 2D beam sweeping procedure, the configuration information includes start RB information and RB count information for each of the frequency resources to which the beam sweeping is applied. Base station method.

17. In Claim 12, The above configuration information includes a repetition factor-frequency parameter indicating whether to perform repeated transmission in the frequency domain and a repetition factor-time parameter indicating whether to perform repeated transmission in the time domain, wherein the repetition factor-frequency parameter and the repetition factor-time parameter are used to indicate the type of beam sweeping procedure. Base station method.

18. In Claim 17, The repetition factor-frequency parameter set to ON and the repetition factor-time parameter set to ON indicate that the type of beam sweeping procedure is a beam fixed transmission procedure without beam sweeping, and The repetition factor-frequency parameter set to off and the repetition factor-time parameter set to on indicate that the type of beam sweeping procedure is a time-fixed-frequency beam sweeping procedure in which beam sweeping of frequency resource units is performed, and The repetition factor-frequency parameter set to ON and the repetition factor-time parameter set to OFF indicate that the type of beam sweeping procedure is a frequency-fixed-time beam sweeping procedure in which beam sweeping in time resource units is performed, and The repetition factor-frequency parameter set to off and the repetition factor-time parameter set to off indicate that the type of beam sweeping procedure is a full 2D beam sweeping procedure in which beam sweeping is performed in frequency resource units and time resource units, Base station method.

19. In Claim 11, The method further includes the step of receiving information from the UE indicating whether the UE supports the beam sweeping procedure in the frequency domain, The above setting information is determined based on whether the UE supports the beam sweeping procedure in the frequency domain, Base station method.

20. In Claim 19, In the above frequency domain, the beam sweeping procedure is an RB-level beam sweeping procedure or an RE-level beam sweeping procedure, wherein the RB-level beam sweeping procedure is performed on the unit of an RB group, and the RE-level beam sweeping procedure is performed on the unit of an RE group, Base station method.

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