Sensing method and apparatus for terminals

Abstract

This method of a base station comprises the steps of: configuring angle regions in which sensing for terminals is performed; establishing a correspondence between each of the angle regions and one or more beams, such that each of the angle regions is identifiable; and transmitting, to the terminals by using the one or more beams, a sensing initiation request indicating a subcarrier frequency set including subcarrier frequencies associated with each of the one or more beams, wherein each subcarrier frequency corresponds to a resource element index indicating one resource element on a resource grid.

Description

Sensing method and device for terminals

[0001] The present disclosure relates to a sensing technology for terminals, and more specifically, to a technology for performing sensing for terminals based on beam squint and beam split phenomena.

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

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

[0004] NR communication networks can use frequency ranges (FR) 1 and FR 2 as frequency bands. When NR communication networks use FR 2, high path attenuation may occur due to the high frequency band. NR communication networks can use massive multiple-input multiple-output (MIMO) and beamforming to compensate for the high path attenuation and increase the information transmission rate.

[0005] A terminal and a base station can determine the optimal beam for communication between the terminal and the base station through beam sweeping. The base station can determine the location of the terminal (e.g., the angular region where the terminal is located) by forming beams associated with different synchronization signal blocks (SSBs) in different directions. The base station can sequentially form a single beam within a single time resource. The terminal can measure the performance of a single beam within a single time resource. The time required for beam sweeping may be proportional to the number of candidate beams. Therefore, a method for estimating the location of the terminal through formation of multiple beams (multi-beams) within a single time resource may be required.

[0006] The purpose of the present disclosure to solve the above problems is to provide a sensing method and device for terminals.

[0007] According to a first embodiment of the present disclosure for achieving the above object, a method of a base station includes the steps of setting angular regions in which sensing is performed for terminals, setting a correspondence between each of the angular regions and one or more beam(s) so that each of the angular regions is identified, and transmitting a sensing initiation request using the one or more beam(s) to the terminals, the sensing request indicating a set of sub-carrier frequencies including a sub-carrier frequency associated with each of the one or more beam(s), wherein the sub-carrier frequency corresponds to a resource element index indicating one resource element on a resource grid.

[0008] The method of the base station may further include, before setting the angular regions, a step of determining at least one of the number of terminals or the density of the terminals based on identifiers of the terminals in a connected state with the base station.

[0009] The method of the base station may further include a step of determining at least one of the number of beams used for the sensing, the frequency band used for the sensing, the number of sub-arrays included in an antenna array belonging to the base station, the number of the angular regions, or the size of each of the angular regions based on at least one of the number of the terminals or the density of the terminals.

[0010] The above sensing initiation request may further include at least one of information on the maximum number of resource element indices corresponding to each of the above angular regions or information on the RSRP (reference signal received power) threshold.

[0011] The method of the base station may include the steps of receiving reports from first terminals among the terminals in response to the sensing initiation request, and determining an angular region to which each of the first terminals belongs based on a set of resource element indices indicated by the reports.

[0012] The method of the base station may further include a step of identifying one or more second terminal(s) among the terminals that have not transmitted report(s) in response to the sensing initiation request, or one or more third terminal(s) among the terminals that have transmitted report(s) indicating a set of resource element indices that do not match the correspondence between each of the angular regions and the one or more beam(s) in response to the sensing initiation request.

[0013] The method of the base station may further include a step of determining angular region(s) corresponding to one or more resource element index sets(s) including at least one of the resource element index(es) belonging to each of the resource element index sets(s) indicated by the report(s) transmitted by the one or more third terminal(s).

[0014] The method of the base station may further include a step of determining whether to perform additional sensing for the one or more second terminal(s) and the one or more third terminal(s), and whether to perform the additional sensing may be determined based on delay requests set for the one or more second terminal(s) and the one or more third terminal(s).

[0015] In order to achieve the above object, a method of a terminal according to a first embodiment of the present disclosure includes the steps of receiving a sensing initiation request from a base station, monitoring a frequency band including sub-carrier frequencies indicated by the sensing initiation request to identify beams, measuring RSRP (reference signal received power) values ​​of the beams, and determining first beams among the beams based on a comparison result between the RSRP values ​​and an RSRP threshold indicated by the sensing initiation request.

[0016] The method of the terminal may further include a step of determining one or more second beam(s) among the first beams based on RSRP values ​​of the first beams, and a step of transmitting a report to the base station indicating a set of resource element indices including resource element indices corresponding to each of the sub-carrier frequencies associated with the one or more second beam(s).

[0017] The number of elements of the resource element index set may not exceed the maximum number of resource element indices indicated by the sensing initiation request, and the RSRP values ​​of the one or more second beam(s) may be greater than the RSRP value(s) of one or more beam(s) among the first beams that are not the one or more second beam(s).

[0018] The method of the terminal may further include the step of transmitting a report to the base station indicating a set of resource element indices including resource element indices corresponding to each of the sub-carrier frequencies associated with the first beams.

[0019] The number of elements of the resource element index set may not exceed the maximum number of resource element indices indicated by the sensing initiation request, and the report may include RSRP values ​​of the first beams.

[0020] The method of the terminal may further include a step of receiving a sensing initiation request from the base station based on a decision of the base station as to whether to perform additional sensing for the terminal in response to the report.

[0021] According to a first embodiment of the present disclosure for achieving the above object, a base station comprises at least one processor, wherein the at least one processor causes the base station to set angular regions in which sensing is performed for terminals, set a correspondence between each of the angular regions and one or more beam(s) so that each of the angular regions is identified, and transmit a sensing initiation request using the one or more beam(s) to the terminals, the sensing request indicating a set of sub-carrier frequencies including a sub-carrier frequency associated with each of the one or more beam(s), wherein the sub-carrier frequency corresponds to a resource element index indicating one resource element on a resource grid.

[0022] The at least one processor may further cause the base station to determine at least one of the number of terminals or the density of the terminals based on identifiers of the terminals in a connected state with the base station before setting the angular regions.

[0023] The above sensing initiation request may further include at least one of information on the maximum number of resource element indices corresponding to each of the above angular regions or information on the RSRP (reference signal received power) threshold.

[0024] The at least one processor is configured to cause the base station to receive reports from first terminals among the terminals in response to the sensing initiation request, and

[0025] It may further be caused to determine the angular region to which each of the first terminals belongs based on the set of resource element indices indicated by the above reports.

[0026] The at least one processor may further cause the base station to identify one or more second terminal(s) among the terminals that have not transmitted report(s) in response to the sensing initiation request, or one or more third terminal(s) among the terminals that have transmitted report(s) in response to the sensing initiation request indicating a set of resource element indices that do not match the correspondence between each of the angular regions and the one or more beam(s).

[0027] The at least one processor may further cause the base station to determine an angular region(s) corresponding to one or more resource element index set(s) including at least one of the resource element index(es) belonging to each of the resource element index set(s) indicated by the report(s) transmitted by the one or more third terminal(s).

[0028] The at least one processor may further cause the base station to determine whether to perform additional sensing for the one or more second terminal(s) and the one or more third terminal(s), wherein whether to perform the additional sensing may be determined based on delay requests set for the one or more second terminal(s) and the one or more third terminal(s).

[0029] According to the present disclosure, a base station can set angular regions in which sensing is performed and determine a frequency band used for sensing. The base station can set a subcarrier set including a subcarrier frequency corresponding to each beam, and map each subcarrier to a resource element on a resource grid. The resource element can be indicated by a resource element index. The base station can transmit a sensing initiation request including information on a maximum number of resource element indices that can correspond to a subcarrier set and one angular region using beams to terminals. Terminals receiving the sensing initiation request can measure RSRP (reference signal received power) values ​​of the received beams. The terminals can determine a number of beams corresponding to the maximum number of resource element indices from among the received beams in order of highest RSRP value. The terminals can report one or more resource element indices corresponding to the determined beams to the base station. The base station can determine a location of each terminal (e.g., an angular region to which each terminal belongs) based on the reported one or more resource element indices.

[0030] Through the above-described procedure, the base station can form multiple beams pointing in different directions from a single time resource and determine the locations of terminals receiving the multiple beams described above. By forming multiple beams from a single time resource, the base station can determine the locations of terminals using fewer time resources.

[0031] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0032] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0033] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0034] Figure 4a is a block diagram illustrating a first embodiment of a transmission path.

[0035] Figure 4b is a block diagram illustrating a first embodiment of a receiving path.

[0036] Figure 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0037] Figure 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0038] Figure 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0039] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0040] FIG. 9 is a conceptual diagram illustrating a first embodiment of a correspondence relationship between an angular region and one or more beams.

[0041] FIG. 10 is a conceptual diagram illustrating a second embodiment of a correspondence relationship between an angular region and one or more beams.

[0042] FIG. 11 is a conceptual diagram illustrating a third embodiment of a correspondence relationship between an angular region and one or more beams.

[0043] FIG. 12a is a flowchart illustrating a first embodiment of a sensing method for terminals using multiple beams.

[0044] FIG. 12b is a flowchart illustrating a first embodiment of a sensing method for terminals using multiple beams.

[0045] FIG. 13a is a flowchart illustrating a second embodiment of a sensing method for terminals using multiple beams.

[0046] FIG. 13b is a flowchart illustrating a second embodiment of a sensing method for terminals using multiple beams.

[0047] This disclosure may be subject to various modifications and various embodiments. Specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the disclosure.

[0048] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component." The term "and / or" may refer to a combination of multiple related items described herein or to any of multiple related items described herein.

[0049] In the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Additionally, in the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.”

[0050] 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.”

[0051] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0052] The terminology used in this disclosure is only used to describe specific embodiments and is not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0053] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0054] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding in describing the present disclosure, the same reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted. In addition to the embodiments explicitly described in the present disclosure, operations may be performed according to combinations of embodiments, extensions of embodiments, and / or modifications of embodiments. The performance of some operations may be omitted, and the order of operation may be changed.

[0055] In an embodiment, even if a method (e.g., transmitting or receiving a signal) performed by a first communication node among communication nodes is described, a corresponding second communication node can perform a method (e.g., receiving or transmitting a signal) corresponding to the method performed by the first communication node. That is, if an operation of a UE (user equipment) is described, a corresponding base station can perform an operation corresponding to the operation of the UE. Conversely, if an operation of a base station is described, a corresponding UE can perform an operation corresponding to the operation of the base station.

[0056] A base station may be referred to as a NodeB, an evolved NodeB, a gNodeB (next generation node B), a gNB, a device, an apparatus, a node, a communication node, a BTS (base transceiver station), a RRH (radio remote head), a TRP (transmission reception point), a RU (radio unit), an RSU (road side unit), a radio transceiver, an access point, an access node, etc. A UE may be referred to as a terminal, a device, an apparatus, a node, a communication node, an end node, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, an OBU (on-broad unit), etc.

[0057] In the present disclosure, signaling may be at least one of upper layer signaling, MAC signaling, or PHY (physical) signaling. A message used for upper layer signaling may be referred to as an "upper layer message" or an "upper layer signaling message." A message used for MAC signaling may be referred to as a "MAC message" or a "MAC signaling message." A message used for PHY signaling may be referred to as a "PHY message" or a "PHY signaling message." Upper layer signaling may refer to a transmission and reception operation of system information (e.g., a master information block (MIB), a system information block (SIB)) and / or an RRC message. MAC signaling may refer to a transmission and reception operation of a MAC control element (CE). PHY signaling may refer to a transmission and reception operation of control information (e.g., downlink control information (DCI), uplink control information (UCI), sidelink control information (SCI)).

[0058] In the present disclosure, “an operation (e.g., a transmission operation) is set” may mean that “setting information for the operation (e.g., an information element, a parameter)” and / or “information instructing the performance of the operation” is signaled. “An information element (e.g., a parameter) is set” may mean that the information element is signaled. In the present disclosure, “a signal and / or a channel” may mean a signal, a channel, or “a signal and a channel,” and a signal may be used to mean “a signal and / or a channel.”

[0059] The communication networks to which the embodiments are applied are not limited to those described below, and the embodiments may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the term "communication network" may be used interchangeably with the term "communication system."

[0060] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0061] Referring to FIG. 1, the communication system (100) may include a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). In addition, the communication system (100) may further include a core network (e.g., a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), a mobility management entity (MME)). If the communication system (100) is a 5G communication system (e.g., a new radio (NR) system), the core network may include an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc.

[0062] A plurality of communication nodes (110 to 130) can support a communication protocol (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) specified in the 3GPP (3rd generation partnership project) standard. The plurality of communication nodes (110 to 130) may support CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (non-orthogonal multiple access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (space division multiple access) technology, etc. Each of the plurality of communication nodes may have the following structure.

[0063] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0064] Referring to FIG. 2, a communication node (200) may include at least one processor (210), a memory (220), and a transmission / reception device (230) that is connected to a network and performs communication. In addition, the communication node (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the communication node (200) may be connected by a bus (270) and communicate with each other.

[0065] The processor (210) can execute program commands stored in at least one of the memory (220) and the storage device (260). The processor (210) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which the methods according to embodiments of the present disclosure are performed. Each of the memory (220) and the storage device (260) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0066] Referring again to FIG. 1, the communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) may form a macro cell. Each of the fourth base station (120-1) and the fifth base station (120-2) may form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) may be within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) may be within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be within the cell coverage of the third base station (110-3). The first terminal (130-1) may be within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be within the cell coverage of the fifth base station (120-2).

[0067] Here, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as a NodeB (NB), an evolved NodeB (eNB), a gNB, an advanced base station (ABS), a high reliability-base station (HR-BS), a base transceiver station (BTS), a radio base station, a radio transceiver, an access point, an access node, a radio access station (RAS), a mobile multihop relay-base station (MMR-BS), a relay station (RS), an advanced relay station (ARS), a high reliability-relay station (HR-RS), a home NodeB (HNB), a home eNodeB (HeNB), a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), etc.

[0068] Each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), high reliability-mobile station (HR-MS), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, on board unit (OBU), etc.

[0069] Meanwhile, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in a different frequency band or may operate in the same frequency band. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to each other via an ideal backhaul link or a non-ideal backhaul link, and may exchange information with each other via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to the core network via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0070] Additionally, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may support MIMO transmission (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, sidelink communication (e.g., device to device communication (D2D), proximity services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can perform an operation corresponding to the base station (110-1, 110-2, 110-3, 120-1, 120-2) and an operation supported by the base station (110-1, 110-2, 110-3, 120-1, 120-2). For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO scheme, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) by the SU-MIMO scheme. Alternatively, the second base station (110-2) can transmit signals to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO method, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive signals from the second base station (110-2) based on the MU-MIMO method.

[0071] Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can transmit a signal to the fourth terminal (130-4) based on the CoMP scheme, and the fourth terminal (130-4) can receive a signal from the first base station (110-1), the second base station (110-2), and the third base station (110-3) based on the CoMP scheme. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive a signal with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its cell coverage based on the CA scheme. Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can control sidelink communication between the fourth terminal (130-4) and the fifth terminal (130-5), and each of the fourth terminal (130-4) and the fifth terminal (130-5) can perform sidelink communication under the control of the second base station (110-2) and the third base station (110-3), respectively.

[0072] Meanwhile, communication nodes performing communication in a communication network may be configured as follows. The communication node illustrated in Fig. 3 may be a specific embodiment of the communication node illustrated in Fig. 2.

[0073] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0074] Referring to FIG. 3, each of the first communication node (300a) and the second communication node (300b) may be a base station or a UE. The first communication node (300a) may transmit a signal to the second communication node (300b). The transmission processor (311) included in the first communication node (300a) may receive data (e.g., a data unit) from a data source (310). The transmission processor (311) may receive control information from the controller (316). The control information may include at least one of system information, RRC configuration information (e.g., information configured by RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0075] The transmitting processor (311) may perform a processing operation on data (e.g., an encoding operation, a symbol mapping operation, etc.) to generate data symbol(s). The transmitting processor (311) may perform a processing operation on control information (e.g., an encoding operation, a symbol mapping operation, etc.) to generate control symbol(s). In addition, the transmitting processor (311) may generate synchronization / reference symbol(s) for a synchronization signal and / or a reference signal.

[0076] The Tx MIMO processor (312) may perform a spatial processing operation (e.g., a precoding operation) on data symbol(s), control symbol(s), and / or synchronization / reference symbol(s). The output (e.g., a symbol stream) of the Tx MIMO processor (312) may be provided to modulators (MODs) included in the transceivers (313a to 313t). The modulators (MODs) may perform a processing operation on the symbol stream to generate modulation symbols, and may perform an additional processing operation (e.g., an analog conversion operation, an amplification operation, a filtering operation, an upconversion operation) on the modulation symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (313a to 313t) may be transmitted via the antennas (314a to 314t).

[0077] Signals transmitted by the first communication node (300a) may be received by antennas (364a to 364r) of the second communication node (300b). Signals received by the antennas (364a to 364r) may be provided to demodulators (DEMODs) included in transceivers (363a to 363r). The demodulator (DEMOD) may perform a processing operation (e.g., a filtering operation, an amplification operation, a downconversion operation, a digital conversion operation) on the signal to obtain samples. The demodulator (DEMOD) may perform an additional processing operation on the samples to obtain symbols. The MIMO detector (362) may perform a MIMO detection operation on the symbols. The receiving processor (361) may perform a processing operation (e.g., a deinterleaving operation, a decoding operation) on the symbols. The output of the receiving processor (361) may be provided to a data sink (360) and a controller (366). For example, data may be provided to the data sink (360), and control information may be provided to the controller (366).

[0078] Meanwhile, the second communication node (300b) can transmit a signal to the first communication node (300a). The transmitting processor (368) included in the second communication node (300b) can receive data (e.g., data units) from a data source (367) and perform a processing operation on the data to generate data symbol(s). The transmitting processor (368) can receive control information from the controller (366) and perform a processing operation on the control information to generate control symbol(s). In addition, the transmitting processor (368) can perform a processing operation on a reference signal to generate reference symbol(s).

[0079] The Tx MIMO processor (369) may perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or reference symbol(s). The output (e.g., symbol stream) of the Tx MIMO processor (369) may be provided to modulators (MODs) included in the transceivers (363a to 363t). The modulators (MODs) may perform processing operations on the symbol streams to generate modulation symbols, and may perform additional processing operations (e.g., analog conversion operations, amplification operations, filtering operations, upconversion operations) on the modulation symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (363a to 363t) may be transmitted via the antennas (364a to 364t).

[0080] Signals transmitted by the second communication node (300b) may be received by the antennas (314a to 314r) of the first communication node (300a). The signals received by the antennas (314a to 314r) may be provided to demodulators (DEMODs) included in the transceivers (313a to 313r). The demodulator (DEMOD) may perform a processing operation (e.g., a filtering operation, an amplification operation, a downconversion operation, a digital conversion operation) on the signal to obtain samples. The demodulator (DEMOD) may perform an additional processing operation on the samples to obtain symbols. The MIMO detector (320) may perform a MIMO detection operation on the symbols. The receiving processor (319) may perform a processing operation (e.g., a deinterleaving operation, a decoding operation) on the symbols. The output of the receiving processor (319) may be provided to a data sink (318) and a controller (316). For example, data may be provided to the data sink (318) and control information may be provided to the controller (316).

[0081] Memories (315 and 365) can store data, control information, and / or program code. Scheduler (317) can perform scheduling operations for communication. The processors (311, 312, 319, 361, 368, 369) and controllers (316, 366) illustrated in FIG. 3 may be the processor (210) illustrated in FIG. 2 and may be used to perform the methods described in the present disclosure.

[0082] FIG. 4a is a block diagram illustrating a first embodiment of a transmission path, and FIG. 4b is a block diagram illustrating a first embodiment of a reception path.

[0083] Referring to FIGS. 4A and 4B, a transmission path (410) may be implemented in a communication node that transmits a signal, and a reception path (420) may be implemented in a communication node that receives a signal. The transmission path (410) may include a channel coding and modulation block (411), an S-to-P (serial-to-parallel) block (512), an N IFFT (Inverse Fast Fourier Transform) block (413), a P-to-S (parallel-to-serial) block (414), a CP (cyclic prefix) addition block (415), and an UC (up-converter) (UC) (416). The receiving path (420) may include a DC (down-converter) (421), a CP removal block (422), an S-to-P block (423), an N FFT block (424), a P-to-S block (425), and a channel decoding and demodulation block (426). Here, N may be a natural number.

[0084] In the transmission path (410), information bits may be input to a channel coding and modulation block (411). The channel coding and modulation block (411) may perform a coding operation (e.g., a low-density parity check (LDPC) coding operation, a polar coding operation, etc.) and a modulation operation (e.g., a quadrature phase shift keying (QPSK), a quadrature amplitude modulation (QAM), etc.) on the information bits. The output of the channel coding and modulation block (411) may be a sequence of modulation symbols.

[0085] The S-to-P block (412) can convert modulation symbols in the frequency domain into parallel symbol streams to generate N parallel symbol streams. N can be an IFFT size or an FFT size. The N IFFT block (413) can perform an IFFT operation on the N parallel symbol streams to generate signals in the time domain. The P-to-S block (414) can convert the output (e.g., parallel signals) of the N IFFT block (413) into a serial signal to generate a serial signal.

[0086] The CP addition block (415) can insert a CP into a signal. The UC (416) can up-convert the frequency of the output of the CP addition block (415) to an RF (radio frequency) frequency. Additionally, the output of the CP addition block (415) can be filtered at the baseband before up-conversion.

[0087] A signal transmitted from a transmission path (410) may be input to a reception path (420). An operation in the reception path (420) may be the reverse operation of the operation in the transmission path (410). A DC (421) may down-convert the frequency of the received signal to a baseband frequency. A CP removal block (422) may remove a CP from a signal. The output of the CP removal block (422) may be a serial signal. An S-to-P block (423) may convert the serial signal into parallel signals. An N FFT block (424) may perform an FFT algorithm to generate N parallel signals. A P-to-S block (425) may convert the parallel signals into a sequence of modulation symbols. A channel decoding and demodulation block (426) may perform a demodulation operation on the modulation symbols and perform a decoding operation on the result of the demodulation operation to restore data.

[0088] In FIGS. 4A and 4B , Discrete Fourier Transform (DFT) and Inverse DFT (IDFT) may be used instead of FFT and IFFT. Each of the blocks (e.g., components) in FIGS. 4A and 4B may be implemented by at least one of hardware, software, or firmware. For example, some of the blocks in FIGS. 4A and 4B may be implemented by software, and the remaining blocks may be implemented by hardware or a “combination of hardware and software.” In FIGS. 4A and 4B , a block may be subdivided into multiple blocks, multiple blocks may be integrated into a single block, some blocks may be omitted, and blocks supporting other functions may be added.

[0089] Figure 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0090] Referring to FIG. 5, time resources in a communication system can be divided into frame units. For example, system frames can be set consecutively in the time domain of the communication system. The length of a system frame can be 10 ms (milliseconds). The system frame number (SFN) can be set from #0 to #1023. In this case, 1024 system frames can be repeated in the time domain of the communication system. For example, the SFN of the system frame after system frame #1023 can be #0.

[0091] A system frame may include two half frames. A half frame may be 5 ms long. A half frame located at the beginning of the system frame may be referred to as "half frame #0," and a half frame located at the end of the system frame may be referred to as "half frame #1." A system frame may include 10 subframes. A subframe may be 1 ms long. The 10 subframes within a system frame may be referred to as "subframes #0-9."

[0092] Figure 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0093] Referring to FIG. 6, one subframe may include n slots, where n may be a natural number. Accordingly, one subframe may be composed of one or more slots.

[0094] Figure 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0095] Referring to Figure 7, a single slot may include one or more symbols. A single slot illustrated in Figure 7 may include 14 symbols. The length of a slot may vary depending on the number and length of symbols contained in the slot. Alternatively, the length of a slot may vary depending on the numerology.

[0096] In a communication system, the numerology applied to physical signals and channels may be variable. The numerology may be variable to meet various technical requirements of the communication system. In a communication system applying CP (cyclic prefix)-based OFDM waveform technology, the numerology may include subcarrier spacing and CP length (or CP type). Table 1 may be a first embodiment of a method for configuring a numerology for a CP-OFDM-based communication system. At least some of the numerologies in Table 1 may be supported depending on the frequency band in which the communication system operates. In addition, the communication system may additionally support numerologies not listed in Table 1.

[0097]

[0098] When the subcarrier spacing is 15 kHz (e.g., μ=0), the slot length can be 1 ms. In this case, one system frame can contain 10 slots. When the subcarrier spacing is 30 kHz (e.g., μ=1), the slot length can be 0.5 ms. In this case, one system frame can contain 20 slots.

[0099] When the subcarrier spacing is 60 kHz (e.g., μ=2), the slot length can be 0.25 ms. In this case, one system frame can contain 40 slots. When the subcarrier spacing is 120 kHz (e.g., μ=3), the slot length can be 0.125 ms. In this case, one system frame can contain 80 slots. When the subcarrier spacing is 240 kHz (e.g., μ=4), the slot length can be 0.0625 ms. In this case, one system frame can contain 160 slots.

[0100] A symbol may be configured as a downlink (DL) symbol, a flexible (FL) symbol, or an uplink (UL) symbol. A slot consisting solely of DL symbols may be referred to as a "DL slot," a slot consisting solely of FL symbols may be referred to as an "FL slot," and a slot consisting solely of UL symbols may be referred to as a "UL slot."

[0101] The slot format can be semi-statically configured by higher layer signaling (e.g., RRC signaling). Information indicating the semi-static slot format can be included in the system information, and the semi-static slot format can be configured cell-specifically. In addition, the semi-static slot format can be additionally configured for each terminal through terminal-specific higher layer signaling (e.g., RRC signaling). The flexible symbol of the cell-specifically configured slot format can be overridden to a downlink symbol or an uplink symbol by terminal-specific higher layer signaling. In addition, the slot format can be dynamically indicated by physical layer signaling (e.g., a slot format indicator (SFI) included in DCI). The semi-statically configured slot format can be overridden by a dynamically indicated slot format. For example, the semi-statically configured flexible symbol can be overridden to a downlink symbol or an uplink symbol by the SFI.

[0102] The reference signal may be a channel state information-reference signal (CSI-RS), a sounding reference signal (SRS), a demodulation-reference signal (DM-RS), a phase tracking-reference signal (PT-RS), etc. The channel may be a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), etc. In the present disclosure, a control channel may mean a PDCCH, a PUCCH, or a PSCCH, and a data channel may mean a PDSCH, a PUSCH, or a PSSCH.

[0103] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0104] Referring to FIG. 8, a resource consisting of one symbol (e.g., an OFDM symbol) in the time domain and one subcarrier in the frequency domain may be defined as a "RE (resource element)". Resources consisting of one OFDM symbol in the time domain and K subcarriers in the frequency domain may be defined as a "REG (resource element group)". A REG may include K REs. A REG may be used as a basic unit for resource allocation in the frequency domain. K may be a natural number. For example, K may be 12. N may be a natural number. In the slot illustrated in FIG. 7, N may be 14. N OFDM symbols may be used as a basic unit for resource allocation in the time domain.

[0105] In the present disclosure, RB may mean CRB (common RB). Alternatively, RB may mean PRB or VRB (virtual RB). In a communication system, CRB may mean RB that constitutes a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). Carriers and / or bandwidth portions may be arranged on the common RB grid. That is, the carrier and / or bandwidth portions may be composed of CRB(s). RBs or CRBs that constitute the bandwidth portions may be referred to as PRBs, and within the bandwidth portions, the CRB index may be appropriately converted to the PRB index.

[0106] Downlink data can be transmitted via the PDSCH. The base station can transmit PDSCH configuration information (e.g., scheduling information) to the terminal via the PDCCH. The terminal can obtain the PDSCH configuration information by receiving the PDCCH (e.g., downlink control information (DCI)). For example, the PDSCH configuration information can include the MCS (modulation coding scheme) used for transmitting and receiving the PDSCH, time resource information of the PDSCH, frequency resource information of the PDSCH, feedback resource information for the PDSCH, etc. The PDSCH can refer to a radio resource through which downlink data is transmitted and received. Alternatively, the PDSCH can refer to the downlink data itself. The PDCCH can refer to a radio resource through which downlink control information (e.g., DCI) is transmitted and received. Alternatively, the PDCCH can refer to the downlink control information itself.

[0107] A terminal can perform a monitoring operation on the PDCCH to receive a PDSCH transmitted from a base station. The base station can inform the terminal of the configuration information for the PDCCH monitoring operation using a higher layer message (e.g., an RRC (radio resource control) message). The configuration information for the PDCCH monitoring operation can include CORESET (control resource set) information and search space information.

[0108] CORESET information may include PDCCH DMRS (demodulation reference signal) information, PDCCH precoding information, PDCCH occasion information, etc. The PDCCH DMRS may be a DMRS used to demodulate the PDCCH. The PDCCH occasion may be a region where the PDCCH can exist. That is, the PDCCH occasion may be a region where DCI can be transmitted. The PDCCH occasion may be referred to as a PDCCH candidate. The PDCCH occasion information may include time resource information and frequency resource information of the PDCCH occasion. In the time domain, the length of the PDCCH occasion may be indicated in symbol units. In the frequency domain, the size of the PDCCH occasion may be indicated in RB units (e.g., in PRB (physical resource block) units or CRB (common resource block) units).

[0109] The search space information may include a coreset identifier (ID) associated with the search space, a period of PDCCH monitoring, and / or an offset. The period and offset of PDCCH monitoring may each be indicated on a slot-by-slot basis. In addition, the search space information may further include an index of the symbol at which the PDCCH monitoring operation begins.

[0110] A base station can configure a bandwidth part (BWP) for downlink communication. The BWP can be configured differently for each terminal. The base station can inform the terminal of the BWP configuration information using higher layer signaling. The higher layer signaling can mean "transmission operation of system information" and / or "transmission operation of RRC (radio resource control) message." The number of BWPs configured for one terminal can be one or more. The terminal can receive BWP configuration information from the base station and check the BWP(s) configured by the base station based on the BWP configuration information. When multiple BWPs are configured for downlink communication, the base station can activate one or more BWPs among the multiple BWPs. The base station can transmit the configuration information of the activated BWP(s) to the terminal using at least one of higher layer signaling, a medium access control (MAC) control element (CE), or DCI. The base station can perform downlink communication using the activated BWP(s). The terminal can identify the activated BWP(s) by receiving configuration information of the activated BWP(s) from the base station, and perform a downlink reception operation in the activated BWP(s).

[0111]

[0112] In an NR communication network, the initial access procedure may include cell search and cell selection procedures. The cell search and cell selection procedures may be performed in the following manner. A base station may sequentially transmit synchronization signal block (SSB) beams directed in multiple directions through beam sweeping. A terminal may measure the reference signal received power (RSRP) values ​​of the received SSB beams. The terminal may select the SSB beam with the highest measured RSRP value among the SSB beams. The terminal and the base station may complete downlink synchronization using the SSB beam with the highest measured RSRP value.

[0113] In an NR communication network, beam management procedures may include an initial beam establishment procedure, a beam adjustment procedure, and a beam failure recovery procedure. The initial beam establishment procedure and the beam adjustment procedure may select a pair with the highest RSRP value among transmit beam-receive beam pairs through beam sweeping.

[0114] Beam sweeping used in the initial access procedure or beam management procedure can be performed through the following operations. The base station can sequentially form beams in the time domain that are directed to a specific angular domain through beam steering. The terminal can sequentially detect the beams formed by the base station. The terminal can measure the RSRP values ​​of the detected beams. The terminal can transmit a report to the base station about the SSB of the beam for which the highest RSRP value is measured among the received RSRP values. The base station can determine the optimal transmit beam-receive beam pair based on the report transmitted from the terminal.

[0115] 6G communication networks may use higher terahertz (THz) frequencies than those used in NR communication networks to avoid high path loss. Beams used in 6G communication networks may have stronger directivity than those used in NR communication networks. More beams may be required to cover the same angular range as those used in NR communication networks. Considering the beam sweeping characteristic of forming a single beam within the same time resource, 6G communication networks may consume more time resources than NR communication networks to perform initial access procedures or beam management procedures.

[0116] The size of the antenna array used in a 6G communication network may be larger than the size of the antenna array used in a NR communication network. The antenna array used in a 6G communication network may be composed of sub-arrays. The sub-arrays may use the same center frequency. Beams associated with the same frequency (e.g., center frequency) may be formed by each sub-array. The above-described phenomenon may be referred to as beam splitting.

[0117] 6G communication networks may have wider and higher bandwidths than existing NR communication networks, such as the terahertz band used in NR communication networks. When an antenna array operates in the terahertz band, the following phenomenon may occur. When the antenna array forms a beam at a center frequency, beams oriented in different directions may be formed for each subcarrier frequency. The further the beam associated with a subcarrier frequency is from the center frequency, the more likely it is to be steered in a direction different from the direction of the beam associated with the center frequency. This phenomenon may be referred to as beam squint. If beam squint is not prevented, even if the antenna array forms a beam in one direction, the beams formed depending on the subcarrier frequency may be steered in multiple directions. A true time delay (TTD) network may be used to compensate for the directions of beams steered in different directions due to beam squint.

[0118] The beam splitting and / or beam squinting described above can pose a problem in steering the beam in the intended direction. However, by applying the beam splitting or beam squinting phenomenon, beams can be formed simultaneously in a single time resource.

[0119] In the present disclosure, a situation may be assumed in which a base station estimates or determines the positions (e.g., angular regions) of terminals. Hereinafter, the operation of estimating or determining the positions of terminals may be referred to as "sensing." The positions of each terminal may correspond to one angular region. To reduce the time resources consumed in estimating the angular region to which each terminal belongs, beam squint and / or beam splitting phenomena may be utilized. The base station may simultaneously form beams including angular regions in one time resource to determine the angular region to which each terminal belongs.

[0120] When a base station includes a large antenna array with a large number of antenna elements, the base station can divide the antenna array into sub-arrays. The base station can form beams that are steered in different directions through the sub-arrays. The formed beams can be associated with the same frequency (e.g., center frequency). The operation of the base station described above may be based on the beam splitting phenomenon. The base station can form beams by selecting specific sub-carriers among sub-carriers belonging to the frequency band in which the antenna array operates (e.g., terahertz band). The base station can steer the beams in the direction intended by the base station by selecting the specific sub-carriers. The operation of the base station described above may be based on the beam squint phenomenon.

[0121] A base station can form multiple beams within a single time resource by utilizing beam splitting and / or beam squinting phenomena. However, when a base station forms multiple beams by utilizing beam splitting and / or beam squinting phenomena, the following problems may occur. A base station that forms multiple beams by utilizing beam splitting and / or beam squinting phenomena cannot determine the angular region to which a terminal belongs based on the terminal's report. The above-mentioned problems will be explained below.

[0122] When beam sweeping is performed in an NR communication network, beams associated with different indices (e.g., SSB indices) can be sequentially formed over different time resources. These formed beams can be steered in different directions. Therefore, the base station can determine the angular region to which a terminal belongs based on the indices reported by the terminal.

[0123] When a base station forms multiple beams using beam splitting and / or beam squint phenomenon, beams steered in different directions due to beam squint may be associated with different sub-carrier frequencies. The base station may receive reports transmitted from terminals that have received beams associated with different sub-carrier frequencies. Through the reports, the base station may identify resource element indices corresponding to the sub-carrier frequencies associated with the beams. The resource element index may indicate one resource element on a resource grid. The base station may determine the angular regions to which the terminals belong based on the resource element indices. Therefore, the base station may identify the angular regions through beams steered in different directions due to the beam squint phenomenon.

[0124] However, beams steered in different directions due to beam splitting can be associated with the same frequency. The base station can receive reports from terminals that have received beams steered in different directions due to beam splitting. The base station can only identify a single resource element index based on these reports. Since the base station only identifies a single resource element index from terminals belonging to different angular regions, it cannot identify the angular regions to which the terminals belong.

[0125] A means for solving the above-described problem may be as follows. The base station may steer beams associated with different sub-carrier frequencies into a single angular region. The method for steering beams associated with different sub-carrier frequencies into a single angular region may be as follows. The beam squint phenomenon and the beam split phenomenon may occur simultaneously. Therefore, the base station may select first sub-carrier frequencies among the sub-carrier frequencies included in the frequency band in which the antenna array belonging to the base station operates so that the beams associated with different sub-carrier frequencies are steered into a single angular region due to the beam squint. If the first sub-carrier frequencies do not exist, the base station may adjust the direction of the beams emitted from the antenna array through a time delay network (TDN) so that the beams associated with different sub-carrier frequencies are steered into a single angular region. When the base station forms beams in a single time resource in the above-described manner, each of the angular regions may be distinguished by one or more beams associated with different sub-carrier frequencies. Therefore, the base station may determine the angular region to which the terminal transmitting the report belongs based on the resource element indices indicated by the report transmitted from the terminal.

[0126] Hereinafter, the timing at which sensing is performed on terminals in the overall call processing procedure will be described. The base station can perform sensing on terminals that are in a connected state with the base station (e.g., in an RRC (radio resource control) connection state). When performing sensing on terminals that are in an RRC connection state with the base station, the base station can perform the sensing within the beam management procedure. Alternatively, the base station can perform sensing on terminals that are not in a connected state with the base station (e.g., terminals that must complete an initial access procedure for communication with the base station). When the base station performs sensing on terminals that are not in a connected state with the base station, the base station can perform the sensing during the initial access procedure.

[0127] Below, performance indicators used when performing sensing on terminals will be described. In the present disclosure, terminals can measure the RSRP values ​​of received beams to evaluate their performance. Based on the measured RSRP values, terminals can report the resource element index corresponding to the received beams to the base station. However, when terminals evaluate the performance of beams, not only RSRP but also RSRQ (reference signal received quality) and CQI (channel quality indicator) can be used.

[0128] FIG. 9 is a conceptual diagram illustrating a first embodiment of a correspondence relationship between an angular region and one or more beams.

[0129] Referring to FIG. 9, a base station (910) may include an antenna array composed of two sub-arrays. Each sub-array may include M antenna elements. The base station (910) may identify five angular regions through multiple beams. Terminals (920-1, 920-2, 920-3, 920-4, 920-5) may be in an RRC connection state with the base station (910). Each of the terminals (920-1, 920-2, 920-3, 920-4, 920-5) may belong to one angular region. Hereinafter, a procedure for the base station (910) to perform sensing on the terminals (920-1, 920-2, 920-3, 920-4, 920-5) in an RRC connection state with the base station (910) will be described.

[0130]

[0131] The base station can obtain identifiers of each terminal from the terminals through communication with the terminals in an RRC connection state. The identifiers may be identifiers obtained from the terminals in a previous beam management procedure of the base station. The identifiers may include at least one of an international mobile subscriber identity (IMSI), a temporary mobile subscriber identity (TMSI), or a 5G globally unique temporary identifier (5G-GUTI). Based on the identifiers, the base station can obtain at least one of information on the number of terminals or information on the density of terminals. Referring to Table 2, it can be confirmed that the number of terminals based on the information on the number of terminals obtained by the base station is 3.

[0132] As disclosed in Table 2, the base station can determine at least one of the number of beams used for sensing the terminals, the frequency band used for sensing the terminals, the number of sub-arrays included in the antenna array belonging to the base station, the angular range in which sensing is performed, the number of angular regions belonging to the angular range, or the size of each of the angular regions based on at least one of the information on the number of terminals or the information on the density of the terminals. For example, when the number of terminals is large or the density of terminals is high, the base station can set the parameters for forming multiple beams as follows. The base station can increase the number of beams formed. The base station can reduce the number of sub-arrays. When the number of sub-arrays is reduced, the beams can be formed thinner. The base station can divide the angular range in which sensing is performed into more angular regions. The number of angular regions can be determined after the angular range is determined.

[0133] Referring to FIG. 9, a base station can establish a correspondence between each of angular regions and one or more beams steered in one direction by the base station. One or more beams steered in one direction by the base station may be included in one angular region. Alternatively, one angular region may include one or more beams steered in one direction by the base station. The base station can map each of the sub-carrier frequencies included in the frequency band determined by the base station to each of the beams steered in multiple directions by the beam squint. The base station can establish a sub-carrier frequency set, which is a set including the sub-carrier frequencies as elements. The sub-carrier frequency set can be defined by a parameter called 'SubcarrierFrequencySet'. The base station can establish two or more sub-carrier frequency sets. Each of the established sub-carrier frequency sets can correspond to a different angular range. The base station can use one or more sub-carrier frequency sets for forming multiple beams. The base station can determine the number of sub-arrays for causing beam splitting and then determine the maximum number of resource element indices that a terminal can report. The maximum number of resource element indices can be defined with a parameter called 'ResourceElementIndexCount'.

[0134] When a base station performs sensing for terminals that are in an RRC connection state with the base station as well as terminals that are not in a connection state with the base station (e.g., terminals that must perform an initial access procedure for communication with the base station), the base station may acquire or set the information or parameters disclosed in Table 2 excluding the number of terminals without information on the number of terminals or density information on the terminals. When the base station performs sensing for terminals that are in an RRC connection state, the base station may not perform a control signaling procedure with the terminals.

[0135] Sensing of terminals in an RRC connection state with a base station can be triggered when the base station transmits a sensing initiation request to the terminals. The base station can periodically perform sensing on each terminal in an RRC connection state with the base station. Through sensing, the base station can sequentially acquire information on the angular region belonging to each terminal in an RRC connection state with the base station. The parameters for multi-beam formation disclosed in Table 2 or basic information for sensing can be acquired or set before the base station transmits a sensing initiation request to the terminals.

[0136]

[0137] Referring to Table 3, it can be confirmed that one angular range is divided into five angular regions by the base station. The base station can establish a correspondence between each angular region and one or more beams. Each of the one or more beams can be associated with one sub-carrier frequency. The base station can map each of the sub-carrier frequencies to one resource element index. One resource element index can indicate one resource element on the resource grid. One angular region can correspond to a resource element index set including one or more RE indices. Therefore, the base station can determine the angular region to which a terminal that has transmitted a report indicating a resource element index set belongs.

[0138] For example, angular region #1 is the subcarrier frequency can correspond to a beam associated with the subcarrier frequency can correspond to resource element index #1 (hereinafter referred to as 'RE #1'). RE #1 can indicate one resource element on the resource grid. Angular region #2 is the sub-carrier frequency , can correspond to beams associated with the subcarrier frequency , Each of them can correspond to RE #1 and RE #2, respectively. RE #1 and RE #2 can indicate different resource elements on the resource grid. When the base station receives a report from the terminal indicating a resource element index set including RE #1 and RE #2 as elements, the base station can determine the angular area to which the terminal belongs as angular area #2.

[0139] The base station can map the resource element index to the sub-carrier frequency in a different way than disclosed in Table 3. The base station can generate a first array by sorting the sub-carrier frequencies included in the sub-carrier frequency set in order of increasing frequency. The base station can generate a second array by sorting the resource element indexes included in one resource block in order of increasing sub-carrier frequency of the resource element indicated by the resource element index. The base station can map the resource element index to each of the sub-carrier frequencies by mapping the n-th element of the first array to the n-th element of the second array. Alternatively, the base station can map the resource element indexes indicating the resource elements included in one resource block to one sub-carrier frequency. In the above mapping method, the mapping between the sub-carrier frequency and the resource element index can be a 1:N mapping (N is a natural number greater than or equal to 2).

[0140]

[0141] Referring to Table 4, a sensing initiation request that triggers sensing for terminals performed by a base station can be identified. The base station can transmit sensing initiation requests to terminals to perform sensing for the terminals. The base station can transmit the sensing initiation requests to the terminals using one or more beams corresponding to each of the angular regions. Alternatively, the base station can transmit the sensing initiation requests to the terminals independently of the beam management procedure. The base station can transmit the sensing initiation request and the parameters disclosed in Table 4 through at least one of DCI belonging to DCI format 1 or DCI format 2, system information, MAC-CE, or other RRC signaling.

[0142] A sensing initiation request may cause terminals receiving the sensing initiation request to measure the RSRP of the received beams and transmit a report indicating a set of resource element indices to the base station. The sensing initiation request may include at least one of a subcarrier frequency set, a maximum number of resource element indices, or an RSRP threshold for sensing. The RSRP threshold for sensing may be defined by the base station with a parameter called 'sensingRSRPthreshold'. Alternatively, at least one of the subcarrier frequency set, the maximum number of resource element indices, or the RSRP threshold for sensing may be transmitted to the terminals in a message separate from the sensing initiation request. The base station may not include information on the maximum number of resource element indices and / or information on the RSRP threshold for sensing in the sensing initiation request.

[0143] A terminal that receives a sensing initiation request from a base station can perform a monitoring operation on a frequency band to which sub-carrier frequencies included in a sub-carrier frequency set belong. Based on the monitoring operation, the terminal can detect beams transmitted from the base station. The terminal can measure the RSRP values ​​of the detected beams.

[0144] The terminal may determine first beams associated with RSRP values ​​higher than or equal to an RSRP threshold for sensing (sensingRSRPthreshold) among the detected beams based on the RSRP values ​​of the detected beams. The terminal may list the first beams in the order in which high RSRP values ​​are measured. The terminal may select one or more second beam(s) with high measured RSRPs among the listed first beams, up to the maximum number of resource element indexes. In other words, the terminal may configure a beam set including one or more second beam(s) among the first beams. The size of the configured beam set may not exceed the maximum number of resource element indexes. The RSRP value(s) of the one or more second beam(s) may be greater than the RSRP value(s) of one or more beam(s) that are not one or more of the second beam(s) among the first beams. Alternatively, the terminal may list the received beams in the order in which high RSRP values ​​are measured. The terminal may select one or more beams with high measured RSRPs among the listed beams, up to the maximum number of resource element indexes. In other words, the terminal may configure a set including the first beams among the received beams. The size of the configured set may not exceed the maximum number of resource element indices. The RSRP values ​​of the first beams may be greater than the RSRP values ​​of the beams that are not the first beams among the received beams.

[0145] The terminal may generate a resource element index set including resource element indices corresponding to sub-carrier frequencies associated with the first beams. The terminal may transmit a report indicating the generated resource element index set to the base station. If the base station does not include information on the maximum number of resource element indexes and / or information on an RSRP threshold for sensing in the sensing initiation request, the terminal may transmit a report including a resource element index set including resource element indices corresponding to sub-carrier frequencies associated with the received beams and / or RSRP values ​​of the received beams to the base station.

[0146] The terminal can transmit a report indicating a resource element index set and / or RSRP values ​​of received beams to the base station through a channel state information (CSI) reporting procedure or uplink control information (UCI). Alternatively, the terminal can map each resource element index included in the resource element index set to a transmission configuration indication (TCI) state and then transmit the TCI state to the base station. The procedure for the terminal to report the RSRP values ​​of received beams may be as follows. The base station can transmit a UEInformationRequest message to the terminal through RRC signaling. The terminal can transmit a UEInformationResponse message to the base station in response to the UEInformationRequest message. Alternatively, the terminal can receive system information including an indication of performance reporting of beams from the base station. The terminal can transmit a MeasurementReport message or a UEAssistanceInformation message to the base station in response to the indication of performance reporting of beams.

[0147]

[0148] Referring to Table 4, the indexes of terminals on which the base station performs sensing and the resource element index sets reported by the terminals to the base station can be confirmed. After receiving a sensing initiation request, terminal #1 can report a resource element index set called {RE #1, RE #2} to the base station. Terminal #2 may not report a resource element index set to the base station. Terminal #3 can report a resource element index set called {RE #4} to the base station after receiving a sensing initiation request.

[0149] Terminal #2 may not transmit a report to the base station for the following reasons: Terminal #2 may not receive a sensing initiation request from the base station. Terminal #2 may decide not to participate in sensing after receiving a sensing initiation request from the base station due to factors such as the amount of traffic it handles. The RSRP values ​​of the beams received by Terminal #2 may not all exceed the RSRP threshold for sensing.

[0150]

[0151] Referring to Table 6, the base station can determine the angular region to which the terminal transmitting the report belongs based on one or more resource element indices included in the resource element index set indicated by the report received from the terminal. The base station can terminate sensing without determining the terminal for which the angular region has been determined as an additional sensing candidate terminal. The base station can identify a terminal that has not transmitted a report indicating a resource element index set, and determine the identified terminal as an additional sensing candidate terminal. The order in which the angular region determination operation and the operation for determining whether the terminal is an additional sensing candidate terminal are performed can be changed.

[0152] For example, as disclosed in Table 5, the base station may receive a report indicating a resource element index set {RE #1, RE #2} from terminal #1. The base station may determine angular region #2 corresponding to {RE #1, RE #2} as the angular region to which terminal #1 belongs, as disclosed in Table 3. As disclosed in Table 5, the base station may receive a report indicating a resource element index set {RE #4} from terminal #3. The base station may determine angular region #5 corresponding to {RE #4} as the angular region to which terminal #3 belongs, as disclosed in Table 3. The base station may not receive a report indicating a resource element index set from terminal #2, as disclosed in Table 5. Therefore, the base station may determine terminal #2 as an additional sensing candidate terminal.

[0153] FIG. 10 is a conceptual diagram illustrating a second embodiment of a correspondence relationship between an angular region and one or more beams.

[0154] Referring to FIG. 10, a terminal may be located at the boundary between angular regions #2 and #3. Sensing for terminals located at the boundary between angular regions will be described below.

[0155]

[0156] A terminal may transmit a report indicating a resource element index set to a base station. The base station may determine whether an angular region corresponding to the received resource element index set exists based on a correspondence relationship between the resource element index set and the angular region set in advance by the base station. The base station may determine that an angular region corresponding to the received resource element index set does not exist. In other words, the base station may receive a resource element index set that does not match the correspondence relationship between the resource element index set and the angular region set in advance. The base station may identify a terminal that has transmitted a report indicating a resource element index set that does not match the correspondence relationship between the resource element index set and the angular region set in advance, and determine the identified terminal as an additional sensing candidate terminal. The base station may estimate angular regions corresponding to a resource element index set including at least one resource element index among the elements of the received resource element index set as angular regions to which the terminal belongs. The above-described operations will be described below with reference to Table 4. The order in which the angular region estimation operation and the additional sensing candidate terminal determination operation are performed may be changed.

[0157] Terminal #4 may be located at the boundary between angular region #2 and angular region #3. Terminal #4 may transmit a report indicating a resource element index set {RE #1, RE #3} to the base station. The base station may determine whether an angular region corresponding to {RE #1, RE #3} exists. The base station may determine that an angular region corresponding to {RE #1, RE #3} does not exist based on a correspondence between a preset resource element index set and an angular region. The base station may estimate that angular region #2 corresponding to {RE #1, RE #2}, a resource element set including RE #1 as an element, and angular region #3 corresponding to {RE #2, RE #3}, a resource element set including RE #3 as an element, are angular regions to which terminal #4 belongs. The base station may determine terminal #4 as an additional sensing candidate terminal.

[0158]

[0159] The method by which the base station obtains information on the latency requirements of additional sensing candidate terminals may be as follows. The base station may obtain information on the latency requirements of additional sensing candidate terminals through a previous beam management procedure. The base station may request information on the latency requirements by sending a UEInformationRequest message to the additional sensing candidate terminals. The additional sensing candidate terminals may send a UEInformationResponse message containing information on the latency requirements to the base station in response to the UEInformationRequest message.

[0160] The base station may determine whether to perform additional sensing on terminals identified as additional sensing candidates based on the delay requirements set for the terminals. The base station may not transmit a sensing initiation request to additional sensing candidate terminals whose delay requirements are less than or equal to a predefined delay requirement. The base station may transmit a sensing initiation request to additional sensing candidate terminals whose delay requirements are greater than the predefined delay requirement.

[0161] Referring to Table 8, since terminal #2 did not transmit a report to the base station, the base station can determine terminal #2 as an additional sensing candidate terminal. The base station can determine the delay requirement set for terminal #2. and can be compared with a predefined delay requirement T. The base station It can be confirmed that this is smaller than T. Based on the above comparison result, the base station may not transmit a sensing initiation request to terminal #2 and may terminate sensing for terminal #2. Since the angular region to which terminal #4 belongs has not been determined as one, the base station may determine terminal #4 as an additional sensing candidate terminal. The base station may determine the delay request set for terminal #4. and can be compared with a predefined delay requirement T. The base station It can be confirmed that this is greater than T. Based on the above comparison result, the base station can transmit a sensing initiation request to terminal #4.

[0162] FIG. 11 is a conceptual diagram illustrating a third embodiment of a correspondence relationship between an angular region and one or more beams.

[0163] Referring to FIG. 11, a base station (1110) may include an antenna array composed of two sub-arrays. Each sub-array may include M antenna elements. The base station (1110) may identify five angular regions through multi-beams. Terminals (1120-1, 1120-2, 1120-3) may not be in an RRC connection state with the base station (1110). Therefore, the terminals (1120-1, 1120-2, 1120-3) may perform an initial connection procedure with the base station (1110) to communicate with the base station (1110). Each of the terminals (1120-1, 1120-2, 1120-3) may belong to one angular region. Terminal (1120-1) may belong to angular region #2, and terminal (1120-3) may belong to angular region #5. The terminal (1120-2) may be located at the boundary between angular areas #2 and #3.

[0164] The base station can perform sensing on terminals that are not in an RRC connection state during the initial connection procedure with the terminals. Below, the procedure for the base station (1110) to perform sensing on terminals (1120-1, 1120-2, 1120-3) that are not in an RRC connection state with the base station (1110) will be described.

[0165]

[0166] Referring to Table 9, in sensing terminals that are not in an RRC connection state with the base station, the base station cannot obtain at least one of the number of terminals or the density of terminals in advance. The base station may transmit SSB beams to the terminals for downlink synchronization for the initial access procedure. The base station may determine the area in which the SSB beams are transmitted as the angular range in which sensing is performed. The base station may determine the frequency band used to form the SSB beams as the frequency band used for sensing.

[0167] Referring to FIG. 11, a base station can establish a correspondence between each of angular regions and one or more beams steered in one direction by the base station. One or more beams steered in one direction by the base station may be included in one angular region. Alternatively, one angular region may include one or more beams steered in one direction by the base station. The base station can map each of the sub-carrier frequencies included in the frequency band determined by the base station to each of the beams steered in multiple directions by the beam squint. The base station can establish a sub-carrier frequency set, which is a set including the sub-carrier frequencies as elements. The sub-carrier frequency set can be defined by a parameter called 'SubcarrierFrequencySet'. The base station can establish two or more sub-carrier frequency sets. Each of the established sub-carrier frequency sets can correspond to a different angular range. The base station can use one or more sub-carrier frequency sets for forming multiple beams. The base station can determine the number of sub-arrays for causing beam splitting and then determine the maximum number of resource element indices that a terminal can report. The maximum number of resource element indices can be defined with a parameter called 'ResourceElementIndexCount'.

[0168] Sensing of terminals that are not in an RRC connection state with the base station can be triggered when the base station transmits an SSB beam to the terminal. The base station can periodically perform sensing on each terminal that is not in an RRC connection state with the base station. Through sensing, the base station can sequentially acquire information on the angular region belonging to each terminal that is not in an RRC connection state with the base station. The parameters for multi-beam formation disclosed in Table 9 or basic information for sensing can be acquired or set before the base station transmits an SSB beam to the terminals.

[0169]

[0170] Referring to Table 10, it can be confirmed that one angular range is divided into five angular regions by the base station. The base station can establish a correspondence between each angular region and one or more beams. Each of the one or more beams can be associated with one sub-carrier frequency. The base station can map each of the sub-carrier frequencies to one resource element index. One resource element index can indicate one resource element on the resource grid. One angular region can correspond to a resource element index set including one or more RE indices. Therefore, the base station can determine the angular region to which a terminal that has transmitted a report indicating a resource element index set belongs.

[0171] For example, angular region #1 is the subcarrier frequency can correspond to a beam associated with the subcarrier frequency can correspond to resource element index #1 (hereinafter referred to as 'RE #1'). RE #1 can indicate one resource element on the resource grid. Angular region #2 is the sub-carrier frequency , can correspond to beams associated with the subcarrier frequency , Each of them can correspond to RE #1 and RE #2, respectively. RE #1 and RE #2 can indicate different resource elements on the resource grid. When the base station receives a report from the terminal indicating a resource element index set including RE #1 and RE #2 as elements, the base station can determine the angular area to which the terminal belongs as angular area #2.

[0172] The base station can map the resource element index to the sub-carrier frequency in a different way than disclosed in Table 10. The base station can generate a first array by sorting the sub-carrier frequencies included in the sub-carrier frequency set in order of increasing frequency. The base station can generate a second array by sorting the resource element indexes included in one resource block in order of increasing sub-carrier frequency of the resource element indicated by the resource element index. The base station can map the resource element index to each of the sub-carrier frequencies by mapping the n-th element of the first array to the n-th element of the second array. Alternatively, the base station can map the resource element indexes indicating the resource elements included in one resource block to one sub-carrier frequency. In the above mapping method, the mapping between the sub-carrier frequency and the resource element index can be a 1:N mapping (N is a natural number greater than or equal to 2).

[0173]

[0174] Referring to Table 11, the SSBs that trigger sensing of terminals performed by the base station can be identified. The base station can transmit SSBs to terminals to perform sensing of the terminals. The base station can transmit SSBs to the terminals using one or more beams corresponding to each angular region.

[0175] The SSBs may cause terminals receiving the SSBs to measure the RSRP of the received beams and transmit a report indicating a set of resource element indices to the base station. The SSB may include at least one of a subcarrier frequency set, a maximum number of resource element indices, or an RSRP threshold for sensing. The RSRP threshold for sensing may be defined by the base station with a parameter called 'sensingRSRPthreshold'. Alternatively, at least one of the subcarrier frequency set, the maximum number of resource element indices, or the RSRP threshold for sensing may be transmitted to the terminals via a signal separate from the SSB. The base station may not include information on the maximum number of resource element indices and / or information on the RSRP threshold for sensing in the SSB.

[0176] A terminal receiving an SSB from a base station can perform a monitoring operation for a frequency band to which sub-carrier frequencies included in a sub-carrier frequency set belong. The terminal can detect beams transmitted from the base station based on the monitoring operation. The terminal can measure RSRP values ​​of the detected beams. The terminal can list the received beams in the order in which the highest RSRP values ​​are measured. The terminal can select one or more beams with a high measured RSRP among the listed beams up to the maximum number of resource element indexes. In other words, the terminal can set a set including the first beams among the received beams. The size of the set set may not exceed the maximum number of resource element indexes. The RSRP values ​​of the first beams may be greater than the RSRP values ​​of beams other than the first beams among the received beams.

[0177] The terminal may generate a resource element index set including resource element indices corresponding to sub-carrier frequencies associated with the first beams. The terminal may transmit a report indicating the generated resource element index set to the base station. If the base station does not include information on the maximum number of resource element indexes and / or information on an RSRP threshold for sensing in the sensing initiation request, the terminal may transmit a report including a resource element index set including resource element indices corresponding to sub-carrier frequencies associated with the received beams and / or RSRP values ​​of the received beams to the base station.

[0178] The terminal may transmit a report indicating the RSRP values ​​of the received beams and / or a set of resource element indices to the base station via a physical random access channel (PRACH) configured for uplink synchronization. Alternatively, the terminal may transmit a report indicating the resource element indices and / or the RSRP values ​​of the received beams to the base station via a physical uplink shared channel (PUSCH) after the initial access procedure is completed.

[0179]

[0180] Referring to Table 12, the indexes of terminals on which the base station performs sensing and the resource element index sets reported by the terminals to the base station can be confirmed. After receiving the SSB, terminal #1 can report the resource element index set {RE #1, RE #2} to the base station. After receiving the SSB, terminal #2 can report the resource element index set {RE #1, RE #3} to the base station. After receiving the SSB, terminal #3 can report the resource element index set {RE #4} to the base station.

[0181] Unlike what is disclosed in Table 12, terminal #2 may not report the resource element index set to the base station. The reasons why terminal #2 does not transmit the report to the base station may be as follows: terminal #2 may not be able to receive SSB from the base station. terminal #2 may decide not to participate in sensing after receiving SSB from the base station due to the amount of traffic that terminal #2 handles. RSRP values ​​of the beams received by terminal #2 may not all exceed the RSRP threshold for sensing.

[0182]

[0183] Referring to Table 13, the base station may determine the angular region to which the terminal transmitting the report belongs based on one or more resource element indices included in the resource element index set indicated by the report received from the terminal. The base station may terminate sensing without determining the terminal for which the angular region has been determined as an additional sensing candidate terminal.

[0184] For example, as disclosed in Table 12, the base station may receive a report indicating a resource element index set {RE #1, RE #2} from terminal #1. The base station may determine angular region #2 corresponding to {RE #1, RE #2} as the angular region to which terminal #1 belongs, as disclosed in Table 10. As disclosed in Table 12, the base station may receive a report indicating a resource element index set {RE #4} from terminal #3. The base station may determine angular region #5 corresponding to {RE #4} as the angular region to which terminal #3 belongs, as disclosed in Table 3. The base station may receive a report indicating a resource element index set {RE #1, RE #3} from terminal #2, as disclosed in Table 12. Therefore, the base station may not determine an angular region to which terminal #2 belongs as one. The base station can determine angular region #2 and angular region #3, which are angular regions corresponding to a resource element index set (e.g., {RE #1, RE #2}, {RE #2, RE #3}) that includes at least one of RE #1 or RE #3, which are elements of {RE #1, RE #3}, as the angular region to which terminal #2 belongs.

[0185] The base station may terminate sensing during the initial connection procedure. Therefore, the base station may not select terminal #2 as a candidate for additional sensing and may not perform additional sensing for terminal #2. The information about the angular regions of terminals #1, #2, and #3 acquired by the base station may be used in the beam management procedure performed by the base station after the initial connection procedure.

[0186] FIG. 12a is a flowchart illustrating a first embodiment of a sensing method for terminals using multiple beams.

[0187] The operations of the base stations or terminals derived from Tables 2 to 8 can also be performed in the same manner as the procedures disclosed in the descriptions of FIGS. 12a and 12b. The operations disclosed in the description of FIG. 12b can be performed after the operations disclosed in the description of FIG. 12a are performed.

[0188] Referring to FIG. 12A, terminals (1210, 1220, 1230) may be in an RRC connection state with a base station. As disclosed in Table 2, the base station may set basic information for sensing (e.g., angular range and frequency band) and / or parameters for multi-beam formation (e.g., number of angular regions, number of sub-arrays, sub-carrier frequency sets, and maximum number of resource element indices) based on the number and / or density of terminals (S1210).

[0189] The base station can establish a correspondence between each of the angular regions and one or more beams steered in one direction by the base station (S1220). The one or more beams steered in one direction by the base station can be included in one angular region. The base station can map each of the sub-carrier frequencies included in the frequency band determined by the base station to each of the beams steered in multiple directions by the beam squint. The base station can establish a sub-carrier frequency set which is a set including the sub-carrier frequencies as elements. The base station can determine the number of sub-arrays for causing beam splitting and then determine the maximum number of resource element indices that each of the terminals (1210, 1220, 1230) can report.

[0190] The base station may transmit a sensing initiation request to terminals (1210, 1220, 1230) using one or more beams corresponding to each of the angular regions (S1230). The sensing initiation request may include at least one of a subcarrier frequency set, a maximum number of resource element indices, or an RSRP threshold for sensing.

[0191] The terminals (1210, 1220, 1230) that have received a sensing initiation request from the base station can perform a monitoring operation for a frequency band to which the sub-carrier frequencies included in the sub-carrier frequency set belong. The terminals (1210, 1220, 1230) can detect beams transmitted from the base station based on the monitoring operation. The terminals (1210, 1220, 1230) can measure RSRP values ​​of the detected beams (S1240). The terminals (1210, 1220, 1230) can set a set including the first beams among the received beams. The size of the set set may not exceed the maximum number of resource element indices. The RSRP values ​​of the first beams may be greater than the RSRP values ​​of the beams other than the first beams among the received beams.

[0192] Terminals (1210, 1230) may generate a resource element index set including resource element indices corresponding to sub-carrier frequencies associated with the first beams. Terminals (1210, 1230) may transmit a report indicating the generated resource element index set to the base station (S1250).

[0193] FIG. 12b is a flowchart illustrating a first embodiment of a sensing method for terminals using multiple beams.

[0194] Referring to FIG. 12B, the base station can determine the angular region to which the terminals (1210) that transmitted the report belong based on one or more resource element indexes included in the resource element index set indicated by the report received from the terminals (1210) (S1260). The base station can identify terminals (1220) for which the angular region cannot be determined because the report indicating the resource element index set is not transmitted (S1270), and can determine the identified terminals (1220) as additional sensing candidate terminals. The base station can identify terminals (1230) for which the angular region cannot be determined as one because the angular region corresponding to the received resource element index set does not exist (S1270), and can determine the identified terminals (1230) as additional sensing candidate terminals. The order of the angular region determination operation for the terminals (1210) and the confirmation operation for the terminals (1220, 1230) may be interchanged.

[0195] The base station may determine whether to perform additional sensing for terminals (1220, 1230) determined as additional sensing candidate terminals based on delay requests set for the terminals (1220, 1230) (S1280). The base station may not transmit a sensing initiation request to additional sensing candidate terminals (1230) whose delay request is less than or equal to a predefined delay request and may terminate sensing for the additional sensing candidate terminals (1220). The base station may transmit a sensing initiation request to additional sensing candidate terminals (1220) whose delay request is greater than a predefined delay request (S1290).

[0196] FIG. 13a is a flowchart illustrating a second embodiment of a sensing method for terminals using multiple beams.

[0197] The operations of the base stations or terminals derived from Tables 9 to 13 can also be performed in the same manner as the procedures disclosed in the descriptions of FIGS. 13a and 13b. The operations disclosed in the description of FIG. 13b can be performed after the operations disclosed in the description of FIG. 13a are performed.

[0198] In sensing terminals (1310, 1320, 1330) that are not in an RRC connection state with the base station, the base station cannot obtain in advance at least one of information on the number of terminals (1310, 1320, 1330) or information on the density of terminals (1310, 1320, 1330). The base station can transmit SSB beams to the terminals (1310, 1320, 1330) for downlink synchronization for an initial access procedure. The base station can determine the area in which the SSB beams are transmitted as the angular range in which sensing is performed. The base station can determine the frequency band used to form the SSB beams as the frequency band used for sensing. Therefore, the base station can set basic information for sensing and / or parameters for forming multiple beams without information on the number and density of terminals (1310, 1320, 1330) (S1310).

[0199] The base station can establish a correspondence between each of the angular regions and one or more beams steered in one direction by the base station (S1320). One or more beams steered in one direction by the base station may be included in one angular region. Alternatively, one angular region may include one or more beams steered in one direction by the base station. The base station can map each of the sub-carrier frequencies included in the frequency band determined by the base station to each of the beams steered in multiple directions by the beam squint. The base station can establish a sub-carrier frequency set, which is a set including the sub-carrier frequencies as elements. The base station can establish two or more sub-carrier frequency sets. Each of the established sub-carrier frequency sets may correspond to a different angular range. The base station can use one or more sub-carrier frequency sets for forming a multi-beam. The base station can determine the number of sub-arrays for causing beam splitting and then determine the maximum number of resource element indices that can be reported by the terminals (1310, 1320, 1330).

[0200] A base station may transmit SSBs to terminals (1310, 1320, 1330) to perform sensing on the terminals (1310, 1320, 1330) (S1330). The base station may transmit the SSBs to the terminals (1310, 1320, 1330) using one or more beams corresponding to each angular region. The SSBs may cause the terminals (1310, 1320, 1330) receiving the SSBs to measure the RSRP of the received beams and transmit a report indicating a set of resource element indices to the base station. The SSB may include at least one of a subcarrier frequency set, a maximum number of resource element indices, or an RSRP threshold for sensing.

[0201] Terminals (1310, 1320, 1330) that receive SSB from a base station can perform a monitoring operation on a frequency band to which sub-carrier frequencies included in a sub-carrier frequency set belong. Terminals (1310, 1320, 1330) can detect beams transmitted from the base station based on the monitoring operation. Terminals (1310, 1320, 1330) can measure RSRP values ​​of the detected beams (S1340). Terminals (1310, 1320, 1330) can set a set including the first beams among the received beams. The size of the set set may not exceed the maximum number of resource element indices. The RSRP values ​​of the first beams may be greater than the RSRP values ​​of beams other than the first beams among the received beams. Terminals (1310, 1320, 1330) can generate a resource element index set including resource element indices corresponding to sub-carrier frequencies associated with the first beams. The terminals can transmit a report indicating the generated resource element index set to the base station (S1350).

[0202] FIG. 13b is a flowchart illustrating a second embodiment of a sensing method for terminals using multiple beams.

[0203] Referring to FIG. 13B, the base station may determine the angular regions to which the terminals (1310, 1320, 1330) that transmitted the reports belong based on one or more resource element indexes included in the resource element index set indicated by the reports received from the terminals (1310, 1320, 1330) (S1360). The base station may terminate the initial access procedure for the terminals (1310, 1330) for which one angular region has been determined. The base station may identify the terminals (1320) that reported a resource element index set that does not match the correspondence between the preset resource element index set and the angular region (S1370). The base station may determine the angular regions to which the terminals (1320) belong, the resource element index sets that include at least one of the resource element indexes belonging to the resource element index set that does not match the preset correspondence. Once the angular areas are determined, the base station can terminate the initial connection procedure with the terminals (1320) (S1380).

[0204]

[0205] The operations of the method according to the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores information readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0206] Additionally, the computer-readable recording medium may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. The program instructions may include not only machine language codes produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0207] While some aspects of the present disclosure have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one or more of the most significant method steps may be performed by such a device.

[0208] A programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described in the present disclosure. The field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described in the present disclosure. In general, the methods are preferably performed by some hardware device.

[0209] Although the present disclosure has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the claims below.

Claims

1. As a method of base station, A step of setting angular regions in which sensing is performed on terminals; A step of establishing a correspondence between each of the angular regions and one or more beam(s) so that each of the angular regions is identified; and comprising the step of transmitting a sensing initiation request using said one or more beam(s) to said terminals, wherein said sensing initiation request indicates a set of sub-carrier frequencies including a sub-carrier frequency associated with each of said one or more beam(s); The above sub-carrier frequency corresponds to a resource element index indicating one resource element on the resource grid. Base station method.

2. In claim 1, Before setting the above angular areas, the method further comprises a step of determining at least one of the number of terminals or the density of the terminals based on the identifiers of the terminals in a connected state with the base station. Base station method.

3. In claim 2, Further comprising a step of determining at least one of the number of beams used for the sensing, the frequency band used for the sensing, the number of sub-arrays included in the antenna array belonging to the base station, the number of the angular regions, or the size of each of the angular regions based on at least one of the number of the terminals or the density of the terminals. Base station method.

4. In claim 1, The sensing initiation request further includes at least one of information on the maximum number of resource element indices corresponding to each of the angular regions or information on the RSRP (reference signal received power) threshold. Base station method.

5. In claim 1, A step of receiving reports from first terminals among the terminals in response to the sensing initiation request; and Further comprising a step of determining an angular region to which each of the first terminals belongs based on a set of resource element indices indicated by the above reports. Base station method.

6. In claim 1, Further comprising a step of identifying one or more second terminal(s) among the terminals that do not transmit report(s) in response to the sensing initiation request, or one or more third terminal(s) among the terminals that transmit report(s) indicating a set of resource element indices that do not match the correspondence between each of the angular regions and the one or more beam(s) in response to the sensing initiation request. Base station method.

7. In claim 6, Further comprising a step of determining an angular region(s) corresponding to one or more resource element index sets(s) including at least one of the resource element index(es) belonging to each of the resource element index sets(s) indicated by the report(s) transmitted by the one or more third terminal(s), Base station method.

8. In claim 6, Further comprising a step of determining whether to perform additional sensing for the one or more second terminal(s) and the one or more third terminal(s), Whether or not to perform the above additional sensing is determined based on the delay requirements set for the one or more second terminal(s) and the one or more third terminal(s). Base station method.

9. As a terminal method, A step of receiving a sensing initiation request from a base station; A step of monitoring a frequency band including sub-carrier frequencies indicated by the sensing initiation request to identify beams; a step of measuring RSRP (reference signal received power) values ​​of the above beams; and A step of determining first beams among the beams based on a comparison result between the RSRP values ​​and the RSRP threshold indicated by the sensing initiation request, Terminal method.

10. In claim 9, A step of determining one or more second beam(s) among the first beams based on the RSRP values ​​of the first beams; and Further comprising the step of transmitting to the base station a report indicating a set of resource element indices including a resource element index corresponding to each of the sub-carrier frequency(s) associated with the one or more second beam(s), Terminal method.

11. In claim 10, The number of elements of the resource element index set does not exceed the maximum number of resource element indices indicated by the sensing initiation request, and the RSRP value(s) of the one or more second beam(s) is(are) greater than the RSRP value(s) of one or more beam(s) among the first beams that are not the one or more second beam(s). Terminal method.

12. In claim 9, Further comprising the step of transmitting to the base station a report indicating a set of resource element indices including a resource element index corresponding to each of the sub-carrier frequencies associated with the first beams, Terminal method.

13. In claim 12, The number of elements of the resource element index set does not exceed the maximum number of resource element indexes indicated by the sensing initiation request, and the report includes RSRP values ​​of the first beams. Terminal method.

14. In claim 10, Further comprising the step of receiving a sensing initiation request from the base station based on the base station's decision as to whether to perform additional sensing for the terminal in response to the report. Terminal method.

15. As a base station, Contains at least one processor, At least one processor of the base station, Set the angular regions where sensing is performed on the terminals; Establishing a correspondence between each of the angular regions and one or more beam(s) so that each of the angular regions is identified; and Causing said terminals to transmit a sensing initiation request using said one or more beam(s) indicating a set of sub-carrier frequencies including sub-carrier frequencies associated with each of said one or more beam(s); The above sub-carrier frequency corresponds to a resource element index indicating one resource element on the resource grid. Base station.

16. In claim 15, The at least one processor further causes the base station to determine at least one of the number of terminals or the density of the terminals based on the identifiers of the terminals in a connected state with the base station before setting the angular regions. Base station.

17. In claim 15, The sensing initiation request further includes at least one of information on the maximum number of resource element indices corresponding to each of the angular regions or information on the RSRP (reference signal received power) threshold. Base station.

18. In claim 15, At least one processor of the base station, Receiving reports from first terminals among the terminals in response to the sensing initiation request; and Further causing the angular region to be determined to which each of the first terminals belongs based on the set of resource element indices indicated by the above reports. Base station.

19. In claim 15, At least one processor of the base station, Further causing one or more second terminal(s) among said terminals to not transmit report(s) in response to said sensing initiation request, or one or more third terminal(s) among said terminals to transmit report(s) indicating a set of resource element indices that do not match said correspondence between each of said angular regions and said one or more beam(s) in response to said sensing initiation request, Base station.

20. In claim 19, At least one processor of the base station, Further causing the angular region(s) to be determined corresponding to one or more resource element index sets(s) including at least one of the resource element index(es) belonging to each of the resource element index sets(s) indicated by the report(s) transmitted by the one or more third terminal(s), Base station.

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