Method and device for visible region allocation in communication system having XL-MIMO antennas

Abstract

This method of a base station for allocating a visible region (VR) in a communication system having a plurality of antennas may comprise the steps of: acquiring location information of a second UE making an initial access; selecting, from among UEs communicating with the base station, a first UE, which is closest to the second UE; transmitting a first RS to the second UE through a first VR allocated to the first UE from among XL-MIMO antennas; receiving, from the second UE, a first report message including a measurement value for the first RS measured by the second UE; and allocating the first VR to the second UE if it is determined, on the basis of the first report message, that the second UE can use the first VR, and the first UE and the second UE can share the first VR through a multiplexing method.

Description

Method and device for allocating a visible area in a communication system having an XL-MIMO antenna

[0001] The present disclosure relates to improved communication technologies, and more particularly to extra-large scale massive MIMO (XL-MIMO) technologies.

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

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

[0004] Meanwhile, 5G communication systems utilize massive multiple input multiple output (MIMO) systems to simultaneously service multiple terminals and achieve higher data transmission rates. Future 6G communication systems are considering deploying even more antennas on the walls of large buildings to secure the spatial dimension that current massive MIMO systems cannot provide. Antenna systems that deploy even more antennas on a wide surface than a massive MIMO system are defined as extra-large scale massive MIMO (XL-MIMO) systems.

[0005] In these XL-MIMO systems, a procedure is required to allocate optimal antenna areas to terminals.

[0006] The purpose of the present disclosure to solve the above problems is to provide a method and device for allocating an optimal antenna area to a terminal in an XL-MIMO system.

[0007] According to one embodiment of the present disclosure for achieving the above object, a method of a base station may include: obtaining location information of a second user equipment (UE) that makes an initial connection; selecting a first UE that is closest to the second UE among UEs communicating with the base station; transmitting a first reference signal (RS) to the second UE through a first visibility region (VR) allocated to the first UE among a plurality of antennas; receiving a first report message including a measurement value for the first RS measured by the second UE from the second UE; and, if it is determined based on the first report message that the second UE can use the first VR and the first UE and the second UE can share the first VR through a multiplexing method, allocating the first VR to the second UE.

[0008] The above multiplexing method may be any one of time division multiplexing, frequency division multiplexing, or code division multiplexing.

[0009] If the reference signal received power (RSRP) value of the first RS measured by the second UE is equal to or greater than a preset threshold value, it may be determined that the second UE can use the first VR.

[0010] The method may further include the steps of: dividing the first VR into a 1-1 VR and a 1-2 VR based on a first quality of service (QoS) requirement of the first UE and a second QoS requirement of the second UE when the first UE and the second UE cannot share the first VR through the multiplexing method; allocating the 1-1 VR to the first UE; and allocating the 1-2 VR to the second UE.

[0011] Each of the first QoS requirement and the second QoS requirement may include at least one of a priority level, a packet delay budget, a packet error rate, a maximum data burst volume, or a data rate requirement.

[0012] The base station can obtain the first QoS requirement and the second QoS requirement from the core network.

[0013] The base station can obtain the first QoS requirement from the first UE and the second QoS requirement from the second UE.

[0014] The method may further include: transmitting a second RS to the first UE through the first-1 VR; receiving a second report message including a measurement value for the second RS measured by the first UE from the first UE; confirming whether the first-1 VR satisfies the first QoS requirement of the first UE based on the second report message; and determining the first-1 VR as the VR of the first UE if the first-1 VR satisfies the first QoS requirement of the first UE.

[0015] The method may further include: requesting information about a VR candidate of the first UE when the first-1 VR does not satisfy the first QoS requirement of the first UE; selecting a second VR to be added to the first-1 VR based on the VR candidate of the first UE; transmitting a third RS to the first UE through the first-1 VR and the second VR; receiving a third report message including a measurement value for the third RS measured by the first UE from the first UE; and determining the first-1 VR and the second VR as VRs of the first UE when the measurement value for the third RS included in the third report message satisfies the first QoS requirement of the first UE.

[0016] The method may further include: transmitting a fourth RS to the second UE through the first-second VR; receiving a fourth report message including a measurement value for the fourth RS measured by the second UE from the second UE; confirming whether the first-second VR satisfies the second QoS requirement of the second UE based on the measurement value for the fourth RS included in the fourth report message; and determining the first-second VR as the VR of the second UE if the first-second VR satisfies the second QoS requirement of the second UE.

[0017] The method may further include: determining a first antenna area that is not assigned to any UE among adjacent antennas of the 1-2 VR when the 1-2 VR does not satisfy the second QoS requirement of the 2 UE; selecting a first antenna group including a preset number of antennas among antennas in the first antenna area; transmitting a fifth RS to the 2 UE through antennas belonging to the 1-2 VR and antennas of the first antenna group; receiving a fifth report message including a measurement value of the fifth RS measured by the 2 UE from the 2 UE; and determining the 1-2 VR and the first antenna group as a VR of the 2 UE when the measurement value of the 5 RS included in the 5 report message satisfies the second QoS requirement of the 2 UE.

[0018] According to one embodiment of the present disclosure for achieving the above purpose, a base station includes at least one processor, wherein the at least one processor is configured to:

[0019] The method may include: obtaining location information of a second user equipment (UE) that initially connects; selecting a first UE that is closest to the second UE among UEs communicating with the base station; transmitting a first reference signal (RS) to the second UE through a first visibility region (VR) allocated to the first UE among a plurality of antennas; receiving a first report message including a measurement value for the first RS measured by the second UE from the second UE; and allocating the first VR to the second UE when it is determined that the second UE can use the first VR based on the first report message and the first UE and the second UE can share the first VR through a multiplexing method.

[0020] The above multiplexing method may be any one of time division multiplexing, frequency division multiplexing, or code division multiplexing.

[0021] If the reference signal received power (RSRP) value of the first RS measured by the second UE is equal to or greater than a preset threshold value, it may be determined that the second UE can use the first VR.

[0022] The at least one processor of the base station:

[0023] In the case where the first UE and the second UE cannot share the first VR through the multiplexing method, the method may include: dividing the first VR into a 1-1 VR and a 1-2 VR based on a first quality of service (QoS) requirement of the first UE and a second QoS requirement of the second UE; allocating the 1-1 VR to the first UE; and allocating the 1-2 VR to the second UE.

[0024] According to one embodiment of the present disclosure for achieving the above object, a method of a second user equipment (UE) may include: transmitting location related information of the second UE to a base station upon initial connection with the base station; receiving a measurement report control message including configuration information and report configuration information of a first reference signal (RS); receiving the first RS from the base station through a first visibility region (VR) allocated to the first UE; measuring a first reference signal received power (RSRP) for the first RS; transmitting a first report message including the measured first RSRP to the base station; and transmitting / receiving a signal with the base station based on first VR allocation information when first VR allocation information is received from the base station.

[0025] When the VR allocation information indicates the first VR, the VR allocation information may include information indicating a multiplexing method for sharing the first VR between the first UE and the second UE.

[0026] The above multiplexing method may be any one of time division multiplexing, frequency division multiplexing, or code division multiplexing.

[0027] The method may further include: receiving a second RS from the base station through the first-second VR when the VR allocation information indicates a first-second VR that is different from the first VR information; measuring a second RSRP for the second RS; transmitting a second report message including the measured second RSRP to the base station; and receiving second VR allocation information from the base station.

[0028] The method may further include: receiving a third RS received from the base station when the second VR allocation information indicates allocation of an additional antenna to the first-second VR; measuring a third RSRP for the third RS; transmitting a third report message including the measured third RSRP to the base station; and receiving third VR allocation information from the base station.

[0029] According to the present disclosure, there is an advantage in that a base station using an XL_MIMO antenna can quickly allocate an appropriate VR by allowing a initially connected UE to share a VR region allocated to a UE currently performing existing communication. If the VR region allocated to a UE currently performing existing communication cannot be shared with the initially connected UE, the VR region of the existing communicating UE can be divided and allocated, thereby reducing the VR allocation time. In addition, if the communication performance of either the initially connected UE or the communicating UE deteriorates due to VR division, an additional antenna can be effectively added to the divided VR. This has the advantage of preventing a degradation in communication performance.

[0030] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0031] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0032] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0033] Figure 4a is a block diagram illustrating a first embodiment of a transmission path.

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

[0035] Figure 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0036] Figure 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0037] Figure 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0038] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0039] Figure 9 is a conceptual diagram for explaining a case where a new subscriber UE occurs and a UE communicates with a base station having an XL-MIMO antenna system.

[0040] Figure 10a is a flowchart for reporting location information to a base station during an initial connection procedure of a new UE to a base station having an XL-MIMO antenna system.

[0041] FIG. 10b is a flowchart illustrating a case where a new UE transmits a reference signal during a random access procedure to a base station having an XL-MIMO antenna system.

[0042] FIG. 10c is a flowchart illustrating a case where a new UE provides location information of the UE to a base station after establishing an RRC connection with the base station having an XL-MIMO antenna system.

[0043] Figure 11 is a flowchart illustrating a procedure for a base station having an XL-MIMO antenna system to search for a VR based on the capabilities of a new UE.

[0044] Figure 12 is a conceptual diagram illustrating a case where a base station having an XL-MIMO antenna system divides VR between a communicating UE and a new UE.

[0045] Figure 13 is a flowchart illustrating the operation of a base station having an XL-MIMO antenna system by receiving QoS requirements from UEs.

[0046] Figure 14 is a flowchart illustrating an operation for a base station having an XL-MIMO antenna system to divide VR #3 to UEs.

[0047] Figure 15 is a conceptual diagram illustrating a case where a base station having an XL-MIMO antenna system expands the VR of a communicating UE.

[0048] Figure 16 is a conceptual diagram illustrating a case where a base station having an XL-MIMO antenna system expands the VR of a new UE.

[0049] FIG. 17a is a flowchart illustrating an operation of a base station having an XL-MIMO antenna system to additionally allocate VR to UE #3.

[0050] Figure 17b is a flowchart illustrating an operation of a base station having an XL-MIMO antenna system to additionally allocate VR to UE #k.

[0051] FIG. 18 is a flowchart illustrating the selection, division and / or additional allocation operations of VRs to base stations and UEs having an XL-MIMO antenna system.

[0052] 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.

[0053] 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.

[0054] 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.”

[0055] 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.”

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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)).

[0063] 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.”

[0064] The communication network to which the embodiment is applied is not limited to what is described below, and the embodiment may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the communication network may be used in the same sense as the communication system.

[0065] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0066] 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.

[0067] 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.

[0068] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0069] 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.

[0070] 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).

[0071] 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).

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0079] 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).

[0080] 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.

[0081] 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).

[0082] 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).

[0083] 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).

[0084] 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).

[0085] 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).

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] Figure 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0095] 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.

[0096] 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."

[0097] Figure 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0098] 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.

[0099] Figure 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0100] 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.

[0101] 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.

[0102] Subcarrier spacing 15 kHz 30 kHz 60 kHz 120 kHz 240 kHz 480 kHz OFDM symbol length [μs] 66.733.316.78.34.22.1 CP length [μs] 4.762.381.190.600.300.151 Number of OFDM symbols in ms 142856112224448

[0103] 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.

[0104] 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.

[0105] 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."

[0106] 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.

[0107] 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.

[0108] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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).

[0114] 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.

[0115] 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).

[0116] Meanwhile, future 6G communication systems are considering deploying more antennas on the walls of large buildings to secure the spatial dimension that current massive MIMO systems cannot provide. Antenna systems that deploy even more antennas across a wide surface than a massive MIMO system are defined as extra-large scale massive MIMO (XL-MIMO) systems.

[0117] XL-MIMO systems can have antenna structures that deploy a larger number of antennas on the walls of wide buildings, such as airports, shopping malls, and stadiums, than massive MIMO systems. XL-MIMO systems not only offer the high data transmission rate, low interference between user equipment (UE), and high energy efficiency that conventional massive MIMO systems can achieve, but also achieve spatial dimensions that massive MIMO systems cannot achieve by deploying antennas widely on the walls of wide buildings, such as airports, shopping malls, and stadiums.

[0118] Unlike large-scale MIMO systems where antennas are clustered in a small space, XL-MIMO systems have antennas distributed widely as described above, which leads to different physical channel characteristics between XL-MIMO antennas and UEs. In other words, the channel with the UE changes depending on the location of the XL-MIMO antenna. This phenomenon of the channel with the UE changing depending on the location of the XL-MIMO antenna is defined as a channel non-stationary characteristic.

[0119] Due to the non-fixed channel characteristics of the XL-MIMO system, a phenomenon occurs in which a meaningful signal is observed only in a specific antenna area among the entire antenna array of the XL-MIMO system for a specific UE. Here, a meaningful signal may mean a signal in which the reference signal received power (RSRP) exceeds a threshold value. For example, when a UE transmits an uplink (UL) signal to the XL-MIMO system, a meaningful UL signal may be received only in a specific antenna array among the entire antenna array of the XL-MIMO system, and when the XL-MIMO system transmits a downlink (DL) signal to the UE, only a DL signal transmitted from a specific antenna array among the entire antenna array of the XL-MIMO system may be a meaningful signal to the UE.

[0120] Due to the non-stationary nature of the channel, the antenna region where a significant signal is observed for a specific UE in an XL-MIMO system is defined as the visibility region (VR).

[0121] In an XL-MIMO system, the communication performance of a specific UE is defined by a specific antenna array, VR, among the entire antenna array of the XL-MIMO system. Therefore, the XL-MIMO system must estimate the VR for each UE and share the estimated VR between the XL-MIMO system and the UE. Furthermore, the XL-MIMO system and the UE must communicate via the estimated VR to maximize communication resource efficiency.

[0122] If the VR of each UE is not known, the XL-MIMO system must transmit DL signals through all antennas and receive UL signals through all antennas. In other words, the XL-MIMO system that does not know the VR must perform channel estimation and beam management processes even for antennas with low transmission and reception performance. This not only wastes communication resources such as time, frequency, and antennas, but also increases the computational burden on the base station. Therefore, when a UE initially accesses the XL-MIMO system, it is very important for the XL-MIMO system to identify the VR of the UE.

[0123] In the current 5G communication system, when a base station and a UE communicate, signals are transmitted and received using the entire antenna array of the base station. However, in order to communicate using only some of the antennas of the base station or the antennas of the UE in the future, the current standard proposes the concept of dividing the antenna array into small subarray structures with predetermined sizes using the concept of a panel. Among the 3GPP standard documents, TS 38.214 specifies the precoding matrix indicator (PMI). According to the PMI specification of TS 38.214, the configuration of the antenna array according to the number of CSI-RS antenna ports is defined in a single-panel / multi-panel environment. The configuration of the antenna array according to the number of CSI-RS antenna ports specifies the number of horizontal antennas, the number of vertical antennas, and the number of beams.

[0124] Additionally, the same standard document defines different PMIs in a table, distinguishing them according to the type of antenna array, number of layers, antenna ports, codebook mode, etc. Here, the type of antenna array can be either single panel or multi-panel.

[0125] In a multi-panel MIMO system based on the 5G NR standard, each panel may be comprised of multiple radio frequency integrated circuits (RFICs). For the downlink (DL), multiple panels may be utilized to cooperate with each other to transmit signals to a single UE. For the uplink (UL), multiple panels installed in a UE may be utilized to cooperate with each other to transmit signals to a base station.

[0126] In general, as the number of antennas assigned to a single panel increases, hardware implementation complexity increases. Therefore, multi-panel MIMO systems offer advantages in terms of hardware design cost and power consumption. Additionally, multiplexing gains can be achieved by ensuring sufficient spacing between antenna panels.

[0127] In this way, the current 3GPP standard defines and utilizes multiple panels to reduce computational complexity and power consumption in environments utilizing a very large number of antennas, and to selectively utilize more appropriate panels based on the channel environment between UEs. In particular, future 6G communication systems such as XL-MIMO may require a procedure to select an appropriate antenna region for each UE from a wide range of antennas and assign it as a VR. In this case, the VR assigned to each UE should be flexibly selected in a form that maximizes communication performance, rather than having a specific form.

[0128] However, the panels defined in the current 3GPP standard are limited to a rectangular structure, and the number of antennas included in each panel is also determined in advance in a table. For this reason, the method according to the current 3GPP standard is not suitable for randomly selecting antenna areas appropriate for each UE's situation, such as VR used in XL-MIMO systems. Therefore, to allocate VR in an XL-MIMO system, a process is required to identify the current UE's environment and requirements and determine an appropriate antenna area.

[0129] In addition, when serving multiple UEs in an XL-MIMO system, it must be able to efficiently find a combination of VRs that can provide sufficient communication performance to each UE. Unlike the current standard that serves the UE using all antennas that the base station has, the XL-MIMO system must select antennas corresponding to VRs by considering various conditions such as the location of the UE to be served, the surrounding environment, and scatterers between the base station and the UE. Therefore, additional overhead may occur when allocating VRs that was not present in the existing 5G NR standard process. In addition, the antenna area allocated to a VR can be significantly affected by the location and surrounding environment of each UE. Therefore, if a VR is allocated to a specific UE without considering the presence of other UEs, the XL-MIMO system may allocate the same VR to two or more UEs, or some of the VRs allocated to different UEs may be shared.

[0130] If there are UEs sharing a VR, the communication performance of the UEs sharing the VR may degrade. Therefore, in XL-MIMO systems that communicate with multiple UEs, VR combinations that minimize interference between UEs must be considered during the VR allocation process.

[0131] Based on the above, the present disclosure describes a method and device for efficiently allocating VRs to each UE in an XL-MIMO system, taking into account the UE's location, surrounding environment, and even interference with other UEs. Furthermore, the present disclosure defines an initial access procedure and related parameters that take VR allocation into account.

[0132] First, this disclosure assumes a situation where a base station configured as an XL-MIMO system allocates a VR to each UE in order to provide services to multiple UEs simultaneously.

[0133] Assuming that VRs are allocated to all UEs without considering the presence of other UEs, the base station can allocate an optimal VR to each UE based on its characteristics. The UE characteristics may include at least one of the following: the electromagnetic spectrum in which the UE is located, latency requirements, target data rates, or mobility. In other words, the base station can allocate an optimal VR to each UE based on information about one or more of the UE characteristics.

[0134] However, if the optimal VR is allocated to each UE by considering only the characteristics of each UE as described above, significant resources may be consumed to select the antenna region corresponding to the optimal VR. This resource consumption may increase in proportion to the number of UEs. In addition, as described above, at least some of the VRs allocated to different UEs may overlap. In this way, if a base station simultaneously communicates with UEs that have at least some overlapping VRs, the communication performance for the UEs may deteriorate. The reason why at least some of the VRs allocated to different UEs overlap as described above is because the base station allocates VRs to each UE without considering the existence of other UEs.

[0135] In general, when UEs are close to each other, the locations and / or number of scatterers may be identical. In other words, the surrounding environments of adjacent UEs may be identical or similar. Therefore, if a base station assigns VRs to multiple UEs without considering other UEs, a significant portion of the assigned VRs may overlap.

[0136] Therefore, in order to avoid interference between UEs, this disclosure describes a method in which a base station assigns VRs to UEs in adjacent or similar locations so that VRs overlap as little as possible. To allocate an appropriate VR combination that minimizes interference between UEs in an XL-MIMO system supporting multiple UEs, this disclosure can perform three main operations.

[0137] First, the base station can allocate the optimal VR to support each UE based on its location, surrounding environment, and the location and number of scatterers. As previously described, this process can be performed by selectively considering at least one of the following: the electromagnetic range of each UE, delay requirements, target data rate, or mobility of the UE. If the VRs assigned to each UE do not overlap through the above process, the XL-MIMO system can achieve optimal communication performance.

[0138] Second, when all or part of the VRs assigned to UEs through the preceding procedure overlap, the base station can reallocate the overlapping VR areas based on the UE's requirements. By reallocating the overlapping antenna areas of VRs to UEs based on the UE's requirements, the base station can minimize interference between UEs. However, if the overlapping antenna areas between UEs are large or the number of UEs sharing an antenna area is too large, the requirements of some or all UEs may not be met after reallocation.

[0139] Third, a base station with an XL-MIMO system can extend the VR of each UE to the antenna area around the already allocated VR to address the communication performance degradation caused by the reallocation of VRs in the second step. If there are additional allocatable antenna areas around the split VR, the base station can additionally allocate the additional allocatable antenna areas to the VRs allocated in the second step. Since the additionally allocated antenna areas are likely to share similar channel conditions to the antenna areas allocated to the VRs in the first step, improved communication performance between the base station and the UE can be expected by additionally allocating antenna areas adjacent to the modified VRs in the second step.

[0140] To achieve the above-described operation, the base station must be able to dynamically select an antenna array and assign an optimal VR to each UE. Therefore, the present disclosure, described below, will illustrate the three-step procedure described above as follows. Furthermore, to facilitate understanding of the procedures described herein, the present disclosure will be based on the 5G NR standard, which is currently undergoing standardization and concurrently undergoing some commercialization. However, the present disclosure can be applied not only to 5G NR but also to all technologies utilizing 6G or XL-MIMO antennas that will be proposed in the future.

[0141] First, a method for allocating VRs for initial access UEs in a base station using an XL-MIMO system is described. Second, a method for segmenting VRs in a base station using an XL-MIMO system is described. Third, a method for expanding segmented VRs in a base station using an XL-MIMO system is described.

[0142] (1) VR allocation method for initial access UE in a base station using an XL-MIMO system

[0143] The present disclosure described below is an embodiment for a case where a base station includes an XL-MIMO system. Therefore, even if not specifically mentioned, it is assumed that the base station includes an XL-MIMO system. Therefore, the XL-MIMO system may be understood as a base station. In addition, a UE may have one or more UE panels. In other words, the base station and the UE may be capable of transmitting and receiving signals (or data) through beamforming. Therefore, the base station can transmit a signal to the UE by applying transmit beamforming to the signal to be transmitted to the UE using XL-MIMO antennas, and the UE can receive a signal transmitted from the base station by applying receive beamforming. In addition, the present disclosure described below assumes the following situations.

[0144] First, assume that the base station is already communicating with multiple UEs.

[0145] Second, assume a situation where a new UE that was not communicating with the base station wants to communicate with the base station.

[0146] Third, we assume that VR determination is unnecessary for UE antennas. The reason for this third assumption is that base stations with XL-MIMO systems have a very large number of antennas, but UEs have a very small number of antennas compared to the number of antennas included in the XL-MIMO system. Therefore, VR estimation for UE antennas may not be necessary.

[0147] Fourth, it is assumed that the base station knows the locations of the UEs communicating with the base station. There are various methods that the base station can use to determine the location of the UE. For the simplest example, the UE can report its own location to the base station based on GPS or a location detection signal transmitted by the base station. As another example, the base station can estimate (or obtain) the location information of the UE through various methods, such as linking with other base stations. In another example, if the base station is composed of a central unit (CU), a distributed unit (DU), and multiple radio units (RUs), the multiple RUs can be used to estimate the location information of the UE.

[0148] Fifth, it is assumed that the base station stores and / or manages information about VRs allocated to UEs communicating with the base station and information about antenna areas not allocated to VRs as VR candidates.

[0149] Figure 9 is a conceptual diagram for explaining a case where a new subscriber UE occurs and a UE communicates with a base station having an XL-MIMO antenna system.

[0150] Referring to FIG. 9, an XL-MIMO antenna (910) included in a base station (not shown in FIG. 9) is illustrated. A first UE (921) may be communicating with the base station. A scatterer (930) may exist between the first UE (921) and the XL-MIMO antenna (910). The scatterer (930) may not be a component necessarily required for communication between the first UE (921) and the XL-MIMO antenna (910). As described above, the base station may allocate only a specific portion of the antennas (911) of the XL-MIMO antenna (910) to the first UE (921) in order to communicate with the first UE (921). Here, the specific portion of the antennas (911) may correspond to the VR described above. In the following description, the VR allocated to the first UE (921) is referred to as the first VR (911). The first VR (921) assigned to the first UE (921) may vary depending on the presence or absence of a scatterer (930).

[0151] When performing downlink communication, the base station can transmit a signal to be transmitted to the first UE (921) through the first VR (911) of the XL-MIMO antenna (910) by applying beamforming. The first VR (911) may be an antenna area allocated to the first UE (921) using any one of the methods according to the present disclosure described below and / or a search method using the entire panel of the XL-MIMO antenna (910). A signal transmitted from the base station can be transmitted to the first UE (921) through the scatterer (930). Accordingly, the first UE (921) can receive the signal transmitted from the base station. When performing uplink (UL) communication, a signal transmitted by the first UE (921) by applying beamforming can be transmitted to the first VR (911) of the XL-MIMO antenna (910) through the scatterer (930). Therefore, the base station can receive the signal transmitted by the first UE (921) through the first VR (911) of the XL-MIMO antenna (910).

[0152] A new second UE (922) may wish to communicate with the base station. Here, the second UE (922) may be an initial connection UE. In other words, it may not be an RRC idle mode or RRC inactive mode UE. It may be very inefficient for the base station to search for a VR using the entire area of ​​the XL-MIMO antenna (910) for the second UE (922) that must perform the initial connection. Therefore, the following describes a method for the base station to efficiently allocate a VR to the second UE (922) when there are UE(s) that are already performing communication.

[0153] The present disclosure described below describes a method for allocating a VR using the location information of a second UE (922). In addition, a base station according to the present disclosure may know the location information of the UE(s) in communication in advance. Typically, two adjacent UEs in a communication system may have identical or similar VRs. If the UE closest to the second UE (922) is the first UE (921), the second UE (922) may have the same VR or a similar VR as the first UE (911). Therefore, when the second UE (922) initially connects to the base station, the base station must be able to obtain the location information of the second UE (922). Various methods may be used by the base station to obtain the location information of the UE. An embodiment thereof will be described below with reference to the drawings.

[0154] When the base station obtains the location information of the second UE (922), the base station can calculate the distance to the UE(s) with which it is communicating. The base station can select the UE that is closest to the second UE (922). The base station can transmit a reference signal (RS) using the VR assigned to the UE that is closest to the second UE (922). The second UE (922) can receive the RS from the base station and measure the power of the received RS (e.g., reference signal received power (RSRP)). The second UE (922) can transmit a report message to the base station based on the received RSRP. The base station can receive the report message from the second UE (922) and, based on the received report message, determine whether the VR assigned to the UE that is closest to the second UE (922) is suitable for communicating with the second UE (922).

[0155] Specific embodiments based on the above description are described with reference to the attached drawings.

[0156] Figure 10a is a flowchart for reporting location information to a base station during an initial connection procedure of a new UE to a base station having an XL-MIMO antenna system.

[0157] In step S1000, the base station can periodically broadcast a synchronization signal / physical broadcast channel (PBCH) block (or synchronization signal block (SSB)) so that all UEs within its cell can receive it. For example, in the case of a 5G NR system, SS / PBCH can be transmitted in 20ms units. Therefore, a UE wishing to access the base station can receive SSB / PBCH from the base station.

[0158] In step S1002, a UE that receives an SS / PBCH block from a base station can obtain downlink synchronization based on a synchronization signal. In addition, the UE can obtain a portion of system information from a master information block (MIB) included in the PBCH. The MIB may include essential information related to a cell and information for receiving SIB1 among system information blocks (SIBs) during the initial cell selection procedure. In the 5G NR system, various types of SIBs exist, and the information included in each SIB can be distinguished by a number assigned to the SIB, such as SIB1, SIB2, SIB3, etc.

[0159] Step S1010 may be a procedure for the UE to obtain a SIB from the base station. For 5G NR, MIB and SIB1 may be referred to as minimum system information (SI). SIB1 may also be referred to as remaining minimum system information (RMSI). The UE may receive SIB1 based on the MIB transmitted by the base station.

[0160] According to one embodiment of the present disclosure, a base station may transmit a SIB and a positioning reference signal (PRS) together to quickly obtain location information of a UE. Various cases in which the SIB and PRS are transmitted together are described below.

[0161] In step S1011, the base station can transmit the PRS together with SIB1. If SIB1 and PRS are transmitted together, the frequency offset and time offset values ​​of the PRS can be transmitted at a location that is predefined (pre-defined, pre-configured, or preset) by the standard. Therefore, if the PRS is transmitted together with SIB1 in step S1011, the UE can receive the PRS while simultaneously acquiring SIB1. The UE can identify the transmission method of other SIBs based on the received SIB1. For example, SIB1 can include information indicating SIBs that are periodically transmitted and SIBs that are transmitted upon request among SIBs other than SIB1. Therefore, the UE can identify SIBs that are periodically transmitted and SIBs that are transmitted upon request by acquiring SIB1. In addition, the UE can estimate the location of the UE using the PRS received from the base station. When the UE estimates the location of the UE using the PRS, the location can be estimated based on the reception timing of the PRS. Additionally, when estimating the UE's position using the PRS, the UE may further utilize at least one of the time difference of arrival (TDOA), angle of arrival (AOA), and / or angle of departure (AoD).

[0162] In Figure 10a, the case where SIB1 and PRS are transmitted together is exemplified as Case #1. Therefore, when SIB1 and PRS are transmitted together, PRS may not be transmitted in Cases #2 and #3, which will be described below. Conversely, when SIB and PRS are transmitted in Cases #2 and #3, SIB1 may not be transmitted together with PRS. As another example, Cases #1, #2, and #3 may all be used.

[0163] In step S1012, the base station can transmit all of the periodically transmitted SIBs or at least one of the periodically transmitted SIBs along with the PRS. If at least one SIB and the PRS are transmitted together, the frequency offset and time offset values ​​of the PRS can be transmitted at a location predefined by the standard. Therefore, the UE can receive the PRS along with all of the SIBs transmitted by the base station in step S1012 or receive the SIB and the PRS along with at least one of the periodically transmitted SIBs. The UE can obtain the system information transmitted by the base station from the received SIB. In addition, the UE can estimate the location of the UE using the PRS received from the base station. The method for calculating the location of the UE based on the PRS can be the same method as described in Case #1 above.

[0164] As described above, if Case #1 is used, where SIB1 and PRS are transmitted together, at least one of the periodic SIBs exemplified by Case #2 may not be transmitted together with the PRS. Conversely, if at least one of the periodically transmitted SIBs is transmitted together with the PRS, the SIB and PRS may not be transmitted together in Cases #1 and #3. As another example, Cases #1, #2, and #3 may all be performed, as described above.

[0165] In step S1013, if the UE needs to request specific system information (e.g., SIBx) from the base station, the UE may transmit an SIBx request message to the base station. When the UE transmits the SIBx request message to the base station, it may be because SIBx is required. Therefore, the base station may receive the SIBx request message from the UE in step S1013. In response to receiving the SIBx request message, the base station may transmit the requested SIBx to the UE in step S1014. At this time, the base station may transmit a PRS to the UE together with the SIBx. Therefore, the UE may receive the PRS together with the SIBx from the base station in step S1013. The UE may obtain system information based on the received SIBx, and may also calculate the location of the UE based on the PRS received from the base station. The method for calculating the location of the UE based on the PRS may be the same method as described above in Case #1.

[0166] The PRS described above is explained as an example of a case where it is transmitted together with at least one SIB among the SIBs. In other words, in Case #1, the base station may transmit SIB1 together with the PRS, in Case #2, the base station may transmit at least one SIB among the periodic SIBs together with the PRS, and in Case #3, the base station may transmit the SIB transmitted in response to the UE's request together with the PRS.

[0167] Accordingly, the UE can receive the PRS through at least one of the methods described above, Case #1 to Case #3. In step S1015, the UE can calculate the location of the UE based on the received PRS. Then, in step S1016, the UE location information can be transmitted to the base station. Accordingly, the base station can receive the UE location information from the UE in step S1016.

[0168] The method for transmitting UE location information will be described with reference to the drawings described below. Furthermore, FIG. 10a illustrates an example of a method for a UE to report its location to a base station. In other words, FIG. 10a corresponds to a procedure in which a UE, upon receiving a PRS from a base station during a downlink synchronization process, calculates its location and reports it to the base station. Alternatively, the UE may transmit a specific reference signal to the base station, and the base station may estimate the UE's location. In other words, the UE may transmit a specific uplink signal, allowing the base station to estimate the UE's location. Below, a method for a base station to estimate the UE's location is described.

[0169] FIG. 10b is a flowchart illustrating a case where a new UE transmits a reference signal during a random access procedure to a base station having an XL-MIMO antenna system.

[0170] Before referring to FIG. 10b, it should be noted that random access procedures, as is well known, include two-step and four-step random access methods. Furthermore, random access procedures can be categorized into contention-based random access (CBRA) and contention-free random access (CFRA). Since the present disclosure assumes a UE initial access procedure, the example of FIG. 10b may be based on a four-step CBRA method. However, based on the description in FIG. 10b, the two-step method can also be applied to the CFRA method.

[0171] Additionally, the procedure of FIG. 10b may be performed if the UE's location was not acquired in the procedure of FIG. 10a or if the procedure of FIG. 10a does not utilize PRS. For example, if the base station acquires the UE's location information through the method using PRS described in FIG. 10a, the operation described for the base station to acquire the UE's location information in the procedure described in FIG. 10b may not be performed. As another example, the procedure of FIG. 10a and the procedure of FIG. 10b described below may be performed together.

[0172] Step S1020 may be a RACH procedure based on the four-step CBRA method as described above.

[0173] In step S1021, the UE may transmit a first message (Msg1) and a sounding reference signal (SRS) to the base station. The first message may be composed of a specific sequence selected based on information included in SIB1 described above in FIG. 10A for a 5G NR system. Msg1 may be referred to as a random access (RA) preamble and may be transmitted in a preset RACH occasion (RO). The RO information may be obtained based on system information, such as SIB1. The RO information may be information on resources (e.g., time and frequency) on which the RACH preamble is transmitted.

[0174] The present disclosure can provide a method for a base station to quickly acquire the location of a UE during the initial access procedure of the UE. Accordingly, in FIG. 10b, the case where SRS is transmitted together with Msg1 of the RACH procedure is exemplified as Case #1. In Case #2, which will be described below, Msg1 and SRS may not be transmitted together. In other words, in Case #2, the UE may transmit only Msg1 in step S1021. Conversely, in Case #1, the UE may not apply Case #2. As another example, the UE may apply both Case #1 and Case #2.

[0175] In step S1021, the base station can receive Msg1 and SRS from the UE. The base station can confirm the presence of a new UE by receiving Msg1, and can calculate a Timing Advance (TA) value using Msg1. In addition, the base station can estimate the location of the UE using the SRS received together with Msg1. When the base station estimates the location of the UE using the SRS, the location can be estimated (or calculated) based on the reception timing of the SRS. In addition, when the base station estimates the location of the UE using the SRS, the base station can further use at least one of the time difference of arrival (TDoA), the angle of arrival (AoA), and / or the angle of departure (AoD).

[0176] In step S1022, the base station may transmit a second message (message 2, Msg2) to the UE in response to Msg1. The second message may be referred to as an RA response (RAR) and may include time information based on the distance between the UE and the base station, such as a TA value and uplink grant information. Accordingly, in step S1022, the UE may receive Msg2 within a window set for receiving Msg2, and may obtain various information, such as TA information and uplink grant information, from the received Msg2.

[0177] In step S1023, the UE may transmit a third message (message 3, Msg3) and an SRS. Msg3 may be transmitted via resources based on the uplink grant information previously included in Msg2. Additionally, in the case of an initial access procedure, Msg3 may include an RRC setup request. Therefore, the base station may receive Msg3 in step S1023, and may also receive an SRS transmitted together with Msg3. If the base station receives an SRS together with Msg3 in step S1023, the base station may estimate (or calculate) the location of the UE using the SRS, as described previously in step S1021.

[0178] Additionally, the case where Msg3 and SRS are transmitted may correspond to Case #2, where the base station estimates the UE's location via uplink, as described above. Therefore, if Case #1 is performed, Case #2 may not be performed. Conversely, if Case #2 is performed, Case #1 may not be performed. As another example, both Case #1 and Case #2 may be performed.

[0179] In step S1024, the base station may transmit a fourth message (message 4, Msg4) to the UE. Msg4 may be a message for contention resolution. Msg4 may be transmitted including a UE identifier for contention resolution. The UE may receive Msg4 from the base station in step S1024. Accordingly, the UE may receive Msg4 in step S1024 and obtain a UE identifier from the received Msg4.

[0180] In step S1030, the base station can determine the location of the UE based on the SRS received from the UE in the procedures of Case #1 and / or Case #2. This location determination can be performed by determining the estimated value as the location of the UE in the manner described above when only Case #1 or Case #2 is used. If Case #1 and Case #2 are used together or the location information of the UE is received from the UE based on the method described above in FIG. 10a, the base station can also determine the location of the UE by comparing the estimated value via the SRS with the location information received from the UE.

[0181] FIG. 10c is a flowchart illustrating a case where a new UE provides location information of the UE to a base station after establishing an RRC connection with the base station having an XL-MIMO antenna system.

[0182] This may be an operation following the RACH procedure as described above in FIG. 10b. If the UE's location information was not acquired in FIG. 10a and / or FIG. 10b or the procedure for acquiring the UE's location information was not performed, the base station can acquire the UE's location information through the procedure in FIG. 10c.

[0183] In step S1040, a new UE may perform an RRC connection establishment procedure with a base station having an XL-MIMO antenna. The RRC connection establishment procedure may be performed based on a method according to 5G NR. In the case of a UE that connects initially, the UE may initiate the RRC connection establishment procedure by transmitting an RRC setup request message to the base station, as described above in FIG. 10b. The base station may provide RRC configuration information to the UE through the RRC connection establishment procedure of step S1040. Accordingly, the UE may receive RRC configuration information from the base station through the RRC connection establishment procedure of step S1040.

[0184] In step S1050, the base station may perform a procedure for acquiring UE location information. The procedure for acquiring UE location information may be performed using the current 5G NR standard, by modifying some of the 5G NR standards, or by defining a new message.

[0185] In step S1051, the base station may transmit a UE location information request message to the UE. In one embodiment, the UE location information request message may use the UE information request message defined in the 5G NR standard. According to the 5G NR standard, the UE information request message may include a coarse UE location request field. Accordingly, the base station may request information about the coarse location of the UE by transmitting the UE information request message to the UE. The UE information request message may also include various other information. Since the present disclosure describes a procedure for the base station to obtain location information of the UE, a description of information unrelated to the present disclosure is omitted.

[0186] Accordingly, the UE may receive a UE information request message in step S1051. The UE may generate a UE information response message in response to receiving the UE capability request message. The UE may transmit a UE information response message to the base station in step S1052. At this time, the UE information response message may include information about the approximate location of the UE. If the UE can obtain its own location using a global navigation satellite system (GNSS), the information about the UE location may be information mapped based on location information corresponding to the latitude and longitude obtained by the UE using the GNSS at a preset resolution.

[0187] In step S1052, the base station can receive a UE information response message from the UE and obtain approximate UE location information included in the UE information response message.

[0188] The above description is based on the current 5G NR standard. If the standard is configured to include more detailed UE location information, the base station can obtain the exact location of the UE by transmitting and receiving the UE capability request message and the UE capability information message. For example, instead of performing steps S1051 and S1052, a new message can be defined to obtain the UE location information.

[0189] The base station may transmit a UE location information request message to the UE. The UE location information request message may be a newly defined message. Alternatively, the UE location information request message may be a message configured to report the UE location by assigning additional fields to another message.

[0190] When a UE receives a UE location information request message from a base station, the UE may transmit a response message containing UE location information to the base station in response. At this time, the UE location information may be the UE's location acquired using GNSS, or may be the UE's location information estimated based on signals received from the base station(s).

[0191] In addition to the methods described above, the base station can also obtain the location information of the UE in another way. For example, the base station can periodically transmit SSB beams as described above in FIG. 10a. At this time, the SSB beams can be beamformed and transmitted in each direction. The UE can select the beam with the highest RSRP value through a beam search procedure in which the SSB is transmitted. Thereafter, the UE can perform the RACH procedure. When transmitting an RA preamble, the UE can transmit the RA preamble by beamforming in the direction in which the highest SSB among the received beams was transmitted.

[0192] The base station can receive the RA preamble from the UE from a specific direction, that is, from the direction corresponding to a specific SSB. Therefore, the base station can know the direction from which the RA preamble was received. In other words, the base station can check the TDoA information. In addition, the base station can calculate (or confirm) the distance between the UE and the base station based on the RA preamble. The distance between the UE and the base station can be determined based on the TA value. In this way, the base station can also estimate the location of the UE based on the beam direction between the base station and the UE and the distance between the base station and the UE.

[0193] The base station can acquire the location of a new UE using at least one of the methods described in FIGS. 10A through 10C. The base station then needs to determine whether the new UE supports VR. If so, the base station can assign an appropriate VR to the new UE. The following describes the procedures for determining whether a UE supports VR and the procedures for searching for an appropriate VR.

[0194] Figure 11 is a flowchart illustrating a procedure for a base station having an XL-MIMO antenna system to search for a VR based on the capabilities of a new UE.

[0195] In step S1100, the base station may transmit a UE capability enquiry message to the UE. The UE capability enquiry message may include a field requesting information on whether the UE is a UE capable of communicating using an XL-MIMO antenna. Accordingly, the UE may receive a UE capability enquiry message from the base station in step S1100. The UE that receives the UE capability enquiry message may generate a UE capability information message. At this time, if there is a request from the base station for information on whether the UE is capable of communicating using an XL-MIMO antenna, the UE may generate the UE capability information message by including information indicating whether the UE is capable of communicating using an XL-MIMO antenna in the UE capability information message. For example, similar to the UE power classes defined in the current 5G NR standard, whether the UE supports VR may be defined in the standard by dividing it into different classes depending on the hardware performance of the UE. Accordingly, the UE may generate the UE capability information by indicating whether it supports VR or including a VR support class value.

[0196] In step S1102, the UE can transmit the generated UE capability information message to the base station. Accordingly, the base station can receive the UE capability information message from the UE in step S1102.

[0197] In step S1104, the base station can check whether the UE supports XL-MIMO based on the UE capability information message. If the UE capability information message does not include information on whether the UE supports XL-MIMO or indicates that the UE cannot support XL-MIMO, the base station may not perform the following procedures. On the other hand, if the UE includes information on whether the UE supports XL-MIMO and indicates that the UE can support XL-MIMO, the following procedures for allocating VR to the new UE may be performed.

[0198] In step S1106, the base station may select one UE among the communicating UEs that is closest to the new UE, or two or more UEs within a preset threshold distance among the adjacent UEs. In step S1104, the base station may first calculate the distance between the new UE and the communicating UE to select the UE that is closest to the new UE among the communicating UEs. An example of the result of calculating the distance between the new UE and the adjacent UE is shown in Table 2 below. In Table 2 below, the UEs may be communicating UEs, and it is assumed that all five communicating UEs communicate using VR. However, this is only an example for convenience of explanation, and the number of UEs actually communicating may be more or less than the number shown in Table 2.

[0199] UE Index VR Index Distance from new UE ()UE #1VR #135UE #2VR #2143UE #3VR #38UE #4VR #456UE #5VR #517

[0200] As previously described, the base station may already know the location information of the UEs in communication. Furthermore, the location of the new UE may be calculated using at least one of the methods described in the procedures of FIGS. 10A through 10C. Therefore, the base station can select a UE communicating with the new UE and calculate the distance between the two UEs.

[0201] For example, if the base station only has approximate angle and distance information of the UE, the base station may calculate the distance between the communicating UEs and the new UE using only the approximate angle and distance information.

[0202] Alternatively, if the base station can obtain precise positioning information from all UEs communicating with the new UE using GNSS, the base station can calculate the distance by calculating the difference in the positions of the two UEs.

[0203] As illustrated in Table 2 above, the base station can calculate the distance between the new UE and the communicating UE and select the communicating UE with the smallest distance value as the closest UE. Therefore, according to the example in Table 2, UE #3 can be the closest UE to the new UE.

[0204] Additionally, if the location information of the new UE and / or the communicating UEs is inaccurate, the base station may select two or more communicating UEs as candidates for VR determination for the new UE. As another example, if the base station only knows the approximate location of the new UE and the exact locations of the communicating UEs, the base station may select communicating UEs located within a certain range (distance) based on the approximate location of the new UE as candidates for VR determination for the new UE.

[0205] According to the above description and the example in Table 2, if only one UE is selected among the communicating UEs, UE #3 may be set as a candidate for VR determination for the new UE. As another example, if the preset range among the communicating UEs is 20 m, UE #3 and UE #5 may be set as candidates for VR determination for the new UE.

[0206] If UE #3 and UE #5 are included in the candidate set for VR determination for the new UE, the base station must first select one of UE #3 and UE #5. The base station can select one of the UEs included in the candidate set for VR determination for the new UE based on the calculated distance as illustrated in Table 2. For example, the base station can select UE #3, which is located at a close distance from the new UE among the communicating UEs that satisfy the condition (e.g., within 20 m).

[0207] Afterwards, the base station can perform a procedure to check whether the VR assigned to the communicating UE is a suitable VR for the new UE.

[0208] In step S1110, the base station may transmit a measurement report control message to the UE. The measurement report control message may be a newly defined message according to the present disclosure. The measurement report control message may be configured as an RRC reconfiguration message including information described below, configured as a medium access control (MAC)-control element (CE) (MAC-CE), or configured as downlink control information (DCI).

[0209] The measurement report control message may include RS configuration information and / or RS report configuration information transmitted to the new UE. If information related to VR configuration is transmitted to the new UE in the RRC configuration information during the procedure of FIG. 10c described above, step S1110 may be omitted. The measurement report control message or RRC configuration information of step S1110 may include information on a threshold for VR selection (VR selection RSRP threshold). The threshold for VR selection may be set to a lower value than the RSRP threshold used in the beam management process. However, if the threshold for VR selection is set to too low a value, the channel may deteriorate during communication. Therefore, the thresholds for VR selection may be preset to two or more values. If two or more thresholds are set, the base station may instruct the UE which threshold to use in step S1110.

[0210] The RS configuration information included in the measurement report control message or RRC configuration information may include resource information (e.g., time, frequency, and / or transmission count information) on which the RS is transmitted. The RS configuration information may also include information on the type of RS being transmitted. In the present disclosure, for convenience of explanation, it is assumed that the RS transmitted for VR selection is a CSI-RS. However, the RS transmitted for VR selection is not limited to a CSI-RS. For example, the RS transmitted for VR selection may be a new RS or an RS other than a CSI-RS among the RSs currently used in 5G NR.

[0211] The reporting configuration information of an RS included in a measurement report control message or RRC configuration information may be information on how the UE that measured the RS transmitted for VR selection reports. The reporting configuration information of the RS may be configured to be reported as a single bit. In the following description, a single bit indicator that reports whether the RSRP value of the received RS is greater than or equal to the threshold for VR selection is referred to as a VR selection indicator (VRselectionindicator).

[0212] According to one embodiment of the present disclosure, the RS reporting configuration information may be configured so that the UE reports only the VR selection indicator. As another example, the RS reporting configuration information may be configured so that the UE reports both the VR selection indicator and the RSRP value of the received RS. Here, the VR selection indicator may be a single bit of information.

[0213] The reporting configuration information of the RS may further include information on how to configure the VR selection indicator. For example, the reporting configuration information of the RS may further include information configured to report the VR selection indicator as "1" when the RSRP value of the received RS is equal to or greater than the threshold for VR selection, and to report the VR selection indicator as "zero (0)" when the RSRP value of the received RS is less than the threshold for VR selection. As another example of how to configure the VR selection indicator, the reporting configuration information of the RS may further include information configured to report the VR selection indicator as "+1" when the RSRP value of the received RS is equal to or greater than the threshold for VR selection, and to report the VR selection indicator as "-1" when the RSRP value of the received RS is less than the threshold for VR selection.

[0214] The reason why the VR selection indicator is configured as one bit is because the base station already knows the optimal beamforming vector to be used for transmission via VR #3 for UE #3. Therefore, even if the new UE does not report other beamforming information to the base station, the base station can determine a beamforming vector to support the new UE that is the same or similar to that of UE #3.

[0215] In step S1112, the base station can transmit the CSI-RS to be transmitted to the new UE through VR #3 assigned to UE #3. Accordingly, the UE can receive the CSI-RS from the base station through VR #3 in step S1112.

[0216] In step S1114, the UE can determine whether the RSRP measurement value of the received CSI-RS is greater than or equal to a threshold for VR selection based on the RSRP measurement result of the received CSI-RS and step S1110 and / or RRC configuration information. The RSRP value of the CSI-RS measured by the UE and the threshold for VR selection can be exemplified as shown in Table 3 below.

[0217] VR Index RSRP value for CSI-RS measured from new UE Threshold for VR selection VR #3 RSRP_72 RSRP_60

[0218] As shown in Table 3, if the RSRP value for the CSI-RS transmitted through VR #3 allocated to UE #3 from a new UE is greater than or equal to the threshold for VR selection, the UE may generate a report message to report measurement result information. The report message may include VR selection indicator information as described above. If only one UE is selected in Table 2, the format may be as shown in Table 3.

[0219] In step S1116, the UE may report a VR selection indicator to the base station. At this time, the VR selection indicator may be included in a CSI-RS measurement report message used in 5G NR. However, the CSI-RS measurement report message according to the present disclosure may not include an RSRP value. In other words, the CSI-RS measurement report message may include only VR selection indicator information, or only an RSRP value for the received CSI-RS, or an RSRP value for the received CSI-RS and VR selection indicator information.

[0220] The base station can receive the CSI-RS measurement report message transmitted by the UE in step S1116, and can determine whether VR #3 is a VR suitable for the new UE based on the information included in the CSI-RS measurement report message. If VR #3 is a VR suitable for the new UE, the procedures below step S1120 may not be performed. On the other hand, if VR #3 is not a VR suitable for the new UE, the base station can perform step S1120 or a procedure for setting a VR for the new UE.

[0221] Meanwhile, if VR #3 is a VR suitable for a new UE and an additional beamforming vector needs to be determined for the new UE, the base station can determine the beamforming vector using the method below.

[0222] The base station may transmit additional CSI-RS to a new UE using a first beam used by a UE communicating using VR #3 and a second beam and / or a third beam adjacent to the first beam. The UE may measure an RSRP value for each of the CSI-RS received via the first beam, the CSI-RS received via the second beam, and the CSI-RS received via the third beam. The UE may compare the first RSRP value measured for the CSI-RS received via the first beam, the second RSRP value measured for the CSI-RS received via the second beam, and the third RSRP value measured for the CSI-RS received via the third beam, respectively, with a threshold for VR selection. The UE may transmit a CSI-RS measurement report message for each of the first RSRP value, the second RSRP value, and the third RSRP value. In this case, the CSI-RS measurement report message may include the measured RSRP value or may include only a VR selection indicator. The reason for reporting the measured RSRP value in the CSI-RS measurement report message is to enable the base station to select the beam when two or more of the first beam, second beam, and third beam exceed the threshold for VR selection.

[0223] In the process of determining the additional beamforming vector described above, a method of transmitting CSI-RS to a new UE using multiple beams or a case where the base station transmits CSI-RS using only one beam supporting an existing UE can be optionally implemented.

[0224] On the other hand, if VR #3 is unsuitable for the new UE, the base station can select a candidate UE that has not undergone the above verification process from the candidate pool for VR determination. In the example above, the base station has verified that VR #3, assigned to UE #3, is a suitable VR for the new UE. Therefore, UE #5 may be included in the candidate pool for VR determination. If UE #5 is included in the candidate pool, the following procedure may be performed.

[0225] In step S1120, the base station can transmit CSI-RS to the new UE through VR #5 corresponding to UE #5, which is set as a candidate for VR determination. The procedure of step S1120 may be the same as step S1116. In step S1120, the UE can receive CSI-RS, and in step S1122, the UE can generate a VR selection indicator based on the RSRP measurement result of the CSI-RS. Step S1122 may be the same procedure as step S1114 described above. In step S1124, the UE can transmit a CSI-RS measurement report message to the base station. Accordingly, the base station can receive a CSI-RS measurement report message for VR #5 from the UE. Step S1124 may be the same procedure as step S1116 described above.

[0226] The procedures using VR #3 and VR #5 described above can only be performed for a certain number of VRs. Performing steps S1112 through S1116 for too many VRs may degrade the accuracy of VR measurement and may also be undesirable, as it requires a significant amount of time. Therefore, the base station can identify a suitable VR for a new UE by utilizing the VRs assigned to an appropriate number of communicating UEs.

[0227] If a suitable VR for the new UE is determined, the base station may transmit a VR assignment message to the new UE. If a suitable VR for the new UE is not determined, the VR assignment message may include new VR information as described in section (2). Additionally, if a suitable VR for the new UE is not determined, the base station may transmit a measurement report control message to the new UE and the communicating UE together with the VR assignment message or after transmitting the VR assignment message.

[0228] The procedure described above can determine a suitable VR for a new UE. Once a suitable VR for a new UE is determined, the base station can verify whether the communicating UE and the new UE can share the VR. For example, assume that VR #3, which was being used by UE #3, is determined to be a suitable VR for the new UE.

[0229] The base station can determine whether UE #3 and the new UE can share VR #3 using any one of time division multiplexing, frequency division multiplexing, or code division multiplexing. If UE #3 and the new UE can share VR #3 using any one or more of the above multiplexing methods, the base station can allocate VR #3 to the new UE. On the other hand, if UE #3 and the new UE cannot share VR #3 using any of the above-described multiplexing methods, the base station may need to reallocate VR to the new UE. The VR area reallocation procedure is described in section (2) below.

[0230] Meanwhile, if the candidate group for determining the VR of a new UE includes only one communicating UE and the VR area of ​​the UE is not suitable for the VR of the new UE, or if the candidate group for determining the VR of the new UE includes two or more communicating UEs and all VRs corresponding to two or more UEs included in the candidate group are not suitable for the VR of the new UE, the base station may perform a VR search procedure to support the new UE.

[0231] There are two possible approaches to VR discovery to support new UEs. First, the base station can assume it doesn't know the UE's location and use all XL-MIMO antennas to find a suitable VR for the new UE.

[0232] Second, since the location information of the UE is known as described above in FIGS. 10a to 10c, the VR search time of the new UE can be reduced by forming a beam to an area corresponding to the location.

[0233] For the second method, since the direction of the UE and the distance between the UE and the base station are known, the step of finding the optimal VR can be reduced by beamforming to adjacent directions in that direction.

[0234] (2) VR division method in a base station using an XL-MIMO system

[0235] Section (2) described below can be performed when the VR of the communicating UE is identical to the optimal VR of the new UE, and the two UEs cannot share and use the VR. In other words, based on the description in Section (1), it may be determined that the VR of the communicating UE is identical to the optimal VR of the new UE. Furthermore, it may be the case that the VR of the communicating UE cannot be shared with the new UE, regardless of any multiplexing method. In such cases, a method for appropriately dividing and using the VR between the communicating UE and the new UE is described below.

[0236] This disclosure describes a method for partitioning a VR based on the quality of service (OoS) requirements of a UE communicating with a new UE. However, this is merely an example, and other factors besides QoS may be considered independently or together. If a UE communicating with a base station equipped with an XL-MIMO antenna and a new UE are partitioned into VRs based on this disclosure, the result may be as shown in FIG. 12.

[0237] Figure 12 is a conceptual diagram illustrating a case where a base station having an XL-MIMO antenna system divides VR between a communicating UE and a new UE.

[0238] Referring to FIG. 12, an XL-MIMO antenna (1210) included in a base station (not shown in FIG. 12) is illustrated. A first UE (1221) may be a UE communicating with the base station as described above in FIG. 9. A scatterer (1230) may exist between the first UE (1221) and the XL-MIMO antenna (1210). The scatterer (1230) may not be a component necessarily required for communication between the first UE (1221) and the XL-MIMO antenna (1210). Comparing FIG. 9 and FIG. 12, the following is provided.

[0239] In FIG. 9, the base station may have divided and allocated the VR (911) allocated to the first UE (921) to the first UE (1221) and the second UE (1222) based on the QoS requirements in FIG. 12. Accordingly, the VR (911) allocated to the first UE (921) in FIG. 9 may be configured as the first VR (1211) allocated to the first UE (1221) and the second VR (1212) allocated to the second UE (1222) in FIG. 12. The first UE (1221) and the second UE (1222) have exemplified a case where a channel is formed with the XL-MIMO antenna through the same scatterer (1230).

[0240] A channel can be formed between the first VR (1211) of the XL-MIMO antenna (1210) and the first UE (1221) via the scatterer (1230). In Fig. 12, a channel (1221b) between the first VR (1211) and the scatterer (1230) and a channel (1221a) between the scatterer (1230) and the first UE (1221) are illustrated as solid lines, and a channel (1222b) between the second VR (1212) and the scatterer (1230) and a channel (1222a) between the scatterer (1230) and the second UE (1222) are illustrated as dotted lines.

[0241] Below, a method of allocating VR to a first UE (1221) and a second UE (1222) as shown in FIG. 12 is described.

[0242] Figure 13 is a flowchart illustrating the operation of a base station having an XL-MIMO antenna system by receiving QoS requirements from UEs.

[0243] Before explaining Figure 13, based on the explanation in Section (1), we assume that VR #3, assigned to UE #3 for a new UE, is the optimal VR. Therefore, the explanation will assume that the communicating UE is UE #3. Furthermore, we will assume that the new UE that initially connects is UE #k.

[0244] In step S1300, the base station may transmit a UE information request message to UE #3. In the present disclosure, the UE information request message may include a field requesting service quality information. Accordingly, UE #3 may receive a UE information request message including a field requesting service quality information for a flow communicating with the base station in step S1300.

[0245] In step S1302, UE #3 may generate a UE information message in response to a UE information request message received from the base station, and may transmit the generated UE information message to the base station. The UE information message may include QoS information, for example, a 5G QoS identifier (5QI). The 5QI may be information mapped to one or more of a resource type, a priority level, a packet delay budget, a packet error rate, a maximum data burst volume, and a data rate requirement. Here, the packet delay budget may mean a latency requirement, and the resource type may be divided into a guaranteed bit rate (GBR) method and a non-guaranteed bit rate (non-GBR).

[0246] In step S1302, the base station may receive a UE information message from UE #3. In addition, in step S1304, the base station may store the UE information received from UE #3.

[0247] Steps S1300, S1302, and S1304 described above may be procedures acquired in advance when UE #3 initiates communication. Accordingly, procedures such as allocating a VR to UE #3 may be performed thereafter.

[0248] In addition, when a new UE, UE #k, makes an initial connection, the VR used by UE #3 may be the optimal VR for UE #k through the procedure (1) above. In this case, the base station must verify the QoS requirements of UE #k. Therefore, the base station can transmit a UE information request message to UE #k in step S1310, and as described above, the UE information request message may include a field requesting service quality information. Therefore, UE #k can receive the UE information request message in step S1310.

[0249] In step S1312, UE #k may generate a UE information message in response to the UE information request message received from the base station and transmit the generated UE information message to the base station. The UE information message may include QoS information, such as 5QI, as described above.

[0250] In step S1312, the base station may receive a UE information message from UE #k. Furthermore, in step S1314, the base station may store the UE information received from UE #k. Through the above procedure, the QoS received from UE #3 and the QoS received from UE #k can be exemplified as shown in Table 4 below.

[0251] Priority Level Data Rate Requirements (Guaranteed Bit Rate, Kbps) Delay Requirements (Packet Delay Budget, ms) UE #320500150 UE #k40300200

[0252] The example in Table 4 illustrates a case where only priority levels, data requirements, and delay requirements are included among the 5QIs. However, as explained above, the 5QIs can be mapped based on more information. Therefore, it is also possible to comprehensively consider service quality information received from each UE, such as packet error loss rate (PELR) and maximum data burst volume. However, for convenience of explanation, the present disclosure describes a case where only the QoS information illustrated in Table 4 is used. In addition, the priority levels of each UE can be additionally used when the QoS requirements of a specific UE cannot be satisfied. Therefore, the base station can continuously maintain QoS requirements as long as the UE maintains communication.

[0253] In step S1316, the base station can split VR #3 based on the 5QI of UE #3 and the 5QI of UE #k based on information as shown in Table 4. The number of antennas before VR #3 is split and an example of VR #3 being allocated to UE #3 and UE #k can be exemplified as shown in Table 5 below.

[0254] Antennas belonging to VR Number of antennas VR index Antennas of VR #3 before partitioning A #1, A #2, …, A #256256 VR #3 Antennas assigned to UE #3 after partitioning A #1, A #2, …, A #160160 VR #3 Antennas assigned to UE #k after partitioning A #161, A #162, …, A #25696 VR #k

[0255] Table 5 illustrates a case where the base station simply partitions VR #3 based on the number of antennas based on the QoS requirements received from the UEs as described in Table 4 above. The method for determining the number of antennas to be allocated to UE #3 and UE #k can be determined based on the QoS requirements as follows. As illustrated in Table 5 above, VR #3 allocated to UE #3 may have a total of 256 antennas allocated. In addition, the data rate requirement may be 500 Kbps for UE #3 and 300 Kbps for UE #k as illustrated in Table 4. Therefore, when partitioning the antennas of VR #3 to UE #3 and UE #k, the number of antennas to be allocated to UE #3 may be determined based on the data rate requirement required by UE #3 as in Equation 1 below, and the number of antennas to be allocated to UE #k may be determined based on the data rate requirement required by UE #k as in Equation 2 below.

[0256]

[0257]

[0258] In mathematical expressions 1 and 2, r1 may represent a data rate requirement of UE #3, r2 may represent a data rate requirement of UE #k, and n may represent the total number of antennas allocated to VR #3.

[0259] Based on the mathematical expression 1 exemplified above, it can be seen that the number of antennas to be allocated to UE #3 can be 160, and based on the mathematical expression 2, the number of antennas to be allocated to UE #k can be 96.

[0260] In the above mathematical equations 1 and 2, only information about the number of antennas can be confirmed. Therefore, the base station must determine the antenna area to be reassigned to UE #3, and may also determine the antenna area to be reassigned to UE #k.

[0261] The method for determining the number of antennas described above only uses data rate requirements, such as GBR. However, the number of antennas to be allocated to UE #3 and UE #k in VR #3 can be determined by comprehensively considering additional QoS requirements, such as delay requirements or priorities, other than GBR.

[0262] Furthermore, the present disclosure has been described assuming a case where the number of antennas is divided. However, other methods may be used. For example, the base station may divide VR #3 into a predetermined number of groups. The base station may then select a representative antenna for each group and divide the number of selected representative antennas into groups based on the data rate requirements required by UE #3 and UE #k. In this case, antennas belonging to the same group as the representative antenna may be assigned to the same UE as the representative antenna. When the base station configures and uses the representative antenna, the number of antenna groups and the location of the representative antenna are implementation examples, and therefore, a detailed description of the method is omitted in the present disclosure.

[0263] Meanwhile, the example of FIG. 12 described above illustrates a case where a VR is divided into two sub-VRs, resulting in a continuous antenna area. However, the antenna areas within each sub-VR may be discontinuously divided. Since such discontinuous division is also an implementation issue for the base station, a detailed description of the method is omitted in this disclosure.

[0264] Even when VR #3 is partitioned and uses the antennas assigned to UE #3 and UE #k, it is necessary to check whether the data rate is satisfied. In other words, although the number of antennas is appropriately partitioned, the base station may need to perform additional procedures to determine which antennas in which area should be selected. The additional procedures for partitioning VR #3 are further described below.

[0265] Meanwhile, the above description assumes that QoS requirements are transmitted using a UE information request message. However, they may be transmitted in other ways besides the UE information request message. For example, a UE wishing to communicate may transmit its QoS requirement information to the base station using uplink control information (UCI). As another example, a UE wishing to communicate may transmit its QoS requirement information together with the RACH procedure. As yet another example, a UE wishing to communicate may transmit its QoS requirement information to the base station using a UE assistance information message or a newly defined RRC message that allows the UE to transmit QoS information to the base station.

[0266] Figure 14 is a flowchart illustrating an operation for a base station having an XL-MIMO antenna system to divide VR #3 to UEs.

[0267] It may be the case that the number of antennas to be allocated to UE #3 and UE #k is determined according to the procedure of FIG. 13 before the operation described in FIG. 14. For example, as described above, it may be the case that UE #3 is allocated 160 antennas in VR #3, and UE #k is allocated 96 antennas in VR #3. In addition, the base station may pre-configure a candidate set of deployment areas of the 160 antennas allocated to UE #3, and may pre-configure a candidate set of deployment areas of the 96 antennas allocated to UE #k.

[0268] In step S1400, the base station may transmit a VR change indication message to UE #3. The VR change indication message may indicate that the number of antennas currently assigned to UE #3 is to be changed. The VR change indication message may include information on a candidate set of antenna deployment areas or an order index of the antenna deployment areas as described above. VR #3 may have 256 antennas as described above, the number of antennas to be assigned to UE #3 may be 160, and it is assumed that the number of antennas to be assigned to UE #k is 96. Therefore, when the 160 antennas to be assigned to UE #3 are determined, the antennas to be assigned to UE #k may be automatically determined. The antenna indices to be assigned to UE #3 are assumed to be VR #3-11, VR #3-21, VR #3-31, … hereinafter. And the antenna indices to be assigned to UE #k are assumed to be VR #3-12, VR #3-22, VR #3-32, … hereinafter.

[0269] Additionally, the VR change indication message may indicate a reporting request for CSI-RS transmitted through the changed VR region, and may indicate a reporting method for the CSI-RS. The reporting method for the CSI-RS may indicate whether to report the RSRP value for the measured CSI-RS, only the VR division indicator (VRdivisionIndicator), or both the RSRP value and the VR division indicator for the measured CSI-RS.

[0270] Additionally, the VR change indication message may indicate which RSRP threshold to use when multiple RSRP thresholds are configured for UE #3. The VR change indication message may use a newly defined RRC reconfiguration message, MAC-CE, or DCI.

[0271] In step S1401, the base station may transmit a VR information message to UE #k. The VR information message may contain substantially the same information as the VR change indication message. However, since UE #k does not have a previously allocated VR, information indicating a change in the number or range of allocated antennas may be excluded. As another example, UE #k may be configured with a VR different from the VR previously allocated during the initial access phase, or may be instructed to change the number or range of antennas of the VR previously allocated during the initial access phase.

[0272] Steps S1400 and S1401 may be performed simultaneously, or step S1401 may be performed first and step S1400 may be performed later.

[0273] In step S1402, the base station can transmit CSI-RS to UE #3 using VR #3-11. In step S1402, UE #3 can receive the CSI-RS transmitted by the base station and measure the received CSI-RS. In this case, the CSI-RS may be transmitted via VR #3-11.

[0274] In step S1406, UE #3 may transmit report information including the result of measuring CSI-RS to the base station based on the reporting method indicated in step S1400. The example of FIG. 14 may be an example in which the report information includes a VR split indicator. The VR split indicator may be configured with one bit. For example, if the result of measuring the received CSI-RS is suitable for communication, UE #3 may set the VR split indicator value to "1", and if the result of measuring the received CSI-RS is not suitable for communication, UE #3 may set the VR split indicator value to "0". The reason why the VR split indicator may be set to one bit is because, as explained above, the optimal beamforming vector for VR #3 is already known through UE #3.

[0275] Since this disclosure is a procedure for verifying whether the data rate requirement is satisfied, UE #3 can verify the data rate conversion value based on the RSRP value measured by the received CSI-RS and the conversion table between the RSRP value and the data rate. For example, UE #3 can have the data rate requirement as shown in Table 6 and the data rate measured by the CSI-RS.

[0276] Data rate requirements (Kbps) Data rate converted from UE #3 (Kbps) 300 270

[0277] As shown in Table 6, although the data rate requirement is 300, this is an example where the RSRP value measured by UE #3 for the CSI-RS received via VR #3-11 is converted to a data rate of 270. Therefore, UE #3 may not satisfy the data rate requirement when using VR #3-11. Therefore, in this case, UE #3 may transmit report information to the base station including information indicating that VR #3-11 is inappropriate. In other words, UE #3 may transmit report information to the base station by setting the VR split indicator value to "0". Meanwhile, the base station may transmit CSI-RS to UE #k using VR #3-12 in step S1404. In step S1404, UE #k may receive the CSI-RS transmitted by the base station and measure the received CSI-RS. At this time, the CSI-RS may be transmitted via VR #3-12.

[0278] In step S1408, UE #k may transmit report information including the result of measuring CSI-RS based on the reporting method indicated in step S1401 to the base station. If the result of measuring the received CSI-RS is suitable for communication, UE #k may set the VR segmentation indicator value to "1", and if the result of measuring the received CSI-RS is not suitable for communication, UE #k may set the VR segmentation indicator value to "0". In addition, the report information may include data rate information of UE #3.

[0279] As described above, since the present disclosure is a procedure for verifying whether the data rate requirement is satisfied, UE #k can verify the data rate conversion value based on the RSRP value measured by the received CSI-RS and the conversion table between the RSRP value and the data rate. UE #k has the data rate requirement as shown in Table 7 and can have the data rate measured by the CSI-RS.

[0280] Data rate requirements (Kbps) Data rate converted from UE #3 (Kbps) 200220

[0281] As shown in Table 7, although the data rate requirement is 200, this is an example where the RSRP value measured by UE #k for the CSI-RS received through VR #3-12 is converted to a data rate of 220. Therefore, UE #k may satisfy the data rate requirement when using VR #3-12. Therefore, UE #k may transmit report information to the base station including information indicating that VR #3-12 is appropriate. In other words, UE #k may transmit report information to the base station by setting the VR split indicator value to "1". The base station may receive report information from UE #3 and UE #k, respectively, in steps S1406 and S1408. And, based on the received report information, it may be determined whether additional VR review is required.

[0282] If both VR segmentation indicators received from UE #3 and UE #k are set to "1", the base station may not perform steps S1410 to S1416. On the other hand, if both VR segmentation indicators received from UE #3 and UE #k are set to "0", steps S1410 to S1416 may be performed.

[0283] Meanwhile, if the VR segmentation indicator is set to “0” only from one of UEs, UE #3 or UE #k, the VR area expansion method may be used according to the operation of section (3) described below.

[0284] In addition, only one CSI-RS is transmitted in step S1402 or S1404. However, if necessary, more than two CSI-RSs may be transmitted. In addition, for UE #3, the CSI-RS may be transmitted using only one beam, and for UE #k, the CSI-RS may be transmitted using multiple beams. In addition, as described above, when the VR area is divided using representative antennas for each group, the CSI-RS may be transmitted using only the representative antenna.

[0285] Steps S1410 to S1416 may be the same iterative procedure as steps S1402 to S1408 described above. However, in steps S1402 to S1408, VR #3-11 may be assigned to UE #3 and VR #3-12 may be assigned to UE #k, while in steps S1410 to S1416, VR #3-21 may be assigned to UE #3 and VR #-22 may be assigned to UE #k.

[0286] This procedure can be repeated as many times as there are allocation candidates for the preset VR area, and if at least one UE satisfies the allocated VR area, the procedure of section (3) can be performed. On the other hand, if all UEs are not suitable for communication by being allocated VR #3, a procedure for allocating a new VR for UE #k can be performed.

[0287] If at least one UE satisfies the assigned VR area, the base station may perform a beam management procedure for the UEs that satisfy the QoS in step S1420. In the beam management procedure, the base station may transmit a message for allocating a VR to the UEs that satisfy the assigned VR area. In addition, in the beam management procedure, the base station may further transmit VR allocation information for allocating an additional VR, as described in section (3), to the UEs that do not satisfy the assigned VR area. In addition, after transmitting the VR allocation message, the base station may transmit a measurement report control message to the UEs that satisfy the assigned VR area.

[0288] In step S1422, the base station can transmit VR #3-1 information to UE #3. Therefore, UE #3 can receive VR #3-1 information from the base station in step S1422. At this time, VR #3-1 may be a VR that satisfies the QoS required by UE #3, or it may be a VR that does not satisfy it. If VR #3-1 does not satisfy the QoS required by UE #3, an additional antenna can be allocated through the procedure in section (3).

[0289] In step S1424, the base station can transmit VR #k information to UE #k. Therefore, UE #k can receive VR #k information from the base station in step S1424. At this time, VR #k may be a VR that satisfies the QoS required by UE #3, or may be a VR that does not satisfy it. If VR #k does not satisfy the QoS required by UE #k, an additional antenna can be allocated through the procedure in section (3).

[0290] However, at least one of VR #3-1 or VR #k transmitted in step S1422 or step S1424 may satisfy the QoS required by the corresponding UE.

[0291] (3) VR expansion method in a base station using an XL-MIMO system

[0292] In the previously described section (1), a procedure for selecting the closest UE among communicating UEs based on the location of the new UE is described. Based on section (1), the new UE can share the VR of the selected UE. If the new UE and the communicating UE cannot share the same VR, a method for splitting the VR is described in section (2). In section (2), a method for splitting the VR based on the QoS requirements of the new UE and the requirements of the communicating UE is described as one embodiment. When the VR of the communicating UE is split and allocated to the new UE, the QoS requirements of at least one of the new UE and the communicating UE may not be met. A method for extending the VR for a UE whose QoS requirements are not met is described below.

[0293] In the present disclosure described below, a base station having an XL-MIMO system can additionally allocate a VR candidate or an antenna region around the VR to a UE that does not satisfy the QoS requirements after dividing the VR of a UE communicating with a new UE. The base station can update the VR so that the UE that does not satisfy the QoS requirements satisfies the QoS requirements by additionally allocating a VR candidate or an antenna region around the VR to the UE.

[0294] When performing a VR expansion procedure, the base station may perform a different VR expansion method for a UE that does not meet QoS requirements than for a new UE that is communicating with the base station. Here, the VR expansion method may refer to an antenna region search procedure.

[0295] First, if the communicating UE does not meet the QoS requirements of the communicating UE after VR segmentation, the base station can additionally allocate a VR to the communicating UE using VR candidate information when allocating a VR to the communicating UE. At this time, the VR candidate information may be stored in advance by the base station or may be stored by the communicating UE. If the VR candidate information is stored by the communicating UE, the base station can obtain the VR candidate information by requesting it from the communicating UE and receiving it from the communicating UE.

[0296] When allocating a VR to a communicating UE, if there are two or more VR regions in the VR candidate information, the base station can determine which VR candidate to additionally allocate. A VR candidate may be an antenna region with a high RSRP measured, even though it was not selected as the VR for the communicating UE. Therefore, when extending a VR for a communicating UE, the base station can expand the VR based on the VR candidate information. In other words, the base station can expand the VR by additionally allocating VR candidate antennas to satisfy the QoS requirements of the communicating UE.

[0297] Figure 15 is a conceptual diagram illustrating a case where a base station having an XL-MIMO antenna system expands the VR of a communicating UE.

[0298] Referring to FIG. 15, an XL-MIMO antenna (1510) included in a base station (not shown in FIG. 15) is illustrated. A first UE (1521) may be a UE communicating with the base station as described above in FIG. 12. A scatterer (1530) may exist between the first UE (1521) and the XL-MIMO antenna (1510). Also in FIG. 15, a first VR (1511) is assigned to the first UE (1521) based on QoS requirements, and a second VR (1512) is assigned to the second UE (1522). In the example of FIG. 15, the first UE (1521) has an extended first VR that further includes an additionally assigned antenna (1513) in addition to the first VR (1511). Therefore, the first UE (1521) has an extended first VR.

[0299] On the other hand, the second VR (1512) allocated to the second UE (1522) may be able to satisfy the QoS requirements required by the second UE (1522). Therefore, the second UE (1522) does not have an additional allocated antenna.

[0300] Accordingly, the extended first VR (1511, 1513) of the XL-MIMO antenna (1510) can form a channel with the first UE (1521) through the scatterer (1530). In FIG. 15, the channel (1521b) between the extended first VR (1511, 1513) and the scatterer (1530) and the channel (1521a) between the scatterer (1530) and the first UE (1521) are illustrated as solid lines, and when compared with FIG. 12, it can be visually confirmed that it has been extended by the additionally allocated antenna (1513). The channel (1522b) between the second VR (1512) and the scatterer (1530) and the channel (1522a) between the scatterer (1530) and the second UE (1522) are illustrated as dotted lines.

[0301] The above only describes VR expansion for a communicating UE. However, the VR of a new UE can also be expanded. As explained in Section (2), this may occur if the QoS requirements of either the communicating UE or the new UE are not met. Therefore, the VR assigned to the new UE may not meet the QoS requirements of the new UE. In such cases, antennas adjacent to the antennas assigned to the VR of the new UE can be additionally allocated. This allows the VR of the new UE to be expanded.

[0302] Figure 16 is a conceptual diagram illustrating a case where a base station having an XL-MIMO antenna system expands the VR of a new UE.

[0303] Referring to FIG. 16, an XL-MIMO antenna (1610) included in a base station (not shown in FIG. 16) is illustrated. A first UE (1621) may be a UE communicating with the base station as described above in FIG. 15. A scatterer (1630) may exist between the first UE (1621) and the XL-MIMO antenna (1610). Also in FIG. 16, a first VR (1611) is assigned to the first UE (1621) based on QoS requirements, and a second VR (1612) is assigned to the second UE (1622). In the example of FIG. 16, the second UE (1622) has an extended second VR that further includes an additionally assigned antenna (1613) in addition to the second VR (1512). Therefore, the second UE (1621) has an extended second VR.

[0304] On the other hand, the first VR (1611) allocated to the first UE (1621) may be able to satisfy the QoS requirements required by the first UE (1621). Therefore, the first UE (1621) does not have an additional allocated antenna.

[0305] Accordingly, the extended second VR (1612, 1613) of the XL-MIMO antenna (1610) can form a channel with the second UE (1622) through the scatterer (1630). In FIG. 16, the channel (1622b) between the extended second VR (1612, 1613) and the scatterer (1630) and the channel (1622a) between the scatterer (1630) and the second UE (1622) are illustrated with dotted lines. The channel (1621b) between the first VR (1611) and the scatterer (1630) and the channel (1621a) between the scatterer (1630) and the first UE (1621) are illustrated with solid lines.

[0306] FIG. 17a is a flowchart illustrating an operation of a base station having an XL-MIMO antenna system to additionally allocate VR to UE #3.

[0307] Figure 17a primarily describes the procedure for additionally allocating antennas to the VR of a communicating UE when the communicating UE's QoS requirements are not met. Furthermore, in describing Figure 17a, it is assumed that the communicating UE is UE #3, as described in Section (2), and the new UE is UE #k.

[0308] At step S1700, the base station may transmit a VR candidate information request message to UE #3, the communicating UE. The VR candidate information request message may be a newly defined message according to the present disclosure. In the case of 5G NR, the VR candidate information request message may also be used as a UE information request message. Therefore, UE #3, the communicating UE, may receive a VR candidate information request message from the base station at step S1700.

[0309] In step S1702, UE #3 may generate a VR candidate information message in response to the VR candidate information request message. UE #3 may then transmit the VR candidate information message to the base station. If the VR candidate information request message is a UE information request message, the VR candidate information message may be a UE information response message. At this time, the VR candidate information may include one or more VR candidates. If the VR candidate information includes two or more VR candidates, UE #3 may list the VR candidates in order of priority.

[0310] The base station may receive a VR candidate information message from UE #3 in step S1702. If the VR candidate information message includes three VR candidates, the base station may receive information as shown in Table 8 below.

[0311] VR Candidate Antennas in VR Number of antennas in VR VR Candidate #1A #257, …, A #384128VR Candidate #2A #385, …, A #512128VR Candidate #3A #513, …, A #640128

[0312] If the base station stores and manages VR candidates of communicating UEs, steps S1700 and S1702 may not be performed. The embodiment of the present disclosure may be an embodiment that assumes a case where the UE stores and manages VR candidates. The procedure for UE #3 to store VR candidate information in the embodiment of the present disclosure may be one of two cases. First, if UE #3 is allocated a VR to support itself using a VR allocation technique that considers the electromagnetic wave region in the XL-MIMO system, UE #3 may store several top antenna areas with high measured received signals among the antennas that are not set as VRs as VR candidates.

[0313] Second, when a VR for UE #3 is allocated based on a VR of another terminal as described in the present disclosure, UE #3 can store and manage the remaining area of ​​the VR that was used as a reference when its own VR was allocated as VR candidate information.

[0314] In step S1710, if the base station obtains VR candidate information as shown in Table 8, it can determine which VR candidate to select first based on the VR candidate information. As described above, the VR candidates in Table 8 may be listed in order of priority. In other words, VR candidate #1 may have the highest priority, VR candidate #2 may have the next highest priority, and VR candidate #3 may have the lowest priority. Therefore, the base station may determine the order of antenna regions to be additionally allocated in the order of VR candidate #1, VR candidate #2, and VR candidate #3 with the highest priority. In addition, the base station may also check whether VR candidate #1, VR candidate #2, and VR candidate #3 are assignable to UE #3. For example, the base station can check whether the antenna of VR candidate #1 is assignable to UE #3 by checking whether the antenna region is assigned to another UE. If VR candidate #1 is assigned to an antenna region assigned to another UE, the base station can check whether VR candidate #2 is assignable to UE #3. For convenience of explanation, in this disclosure, it is assumed that all VR candidates are assignable to UE #3.

[0315] In step S1712, the base station may transmit the CSI-RS to UE #3 using an extended VR that adds VR candidate #1 to the divided VR #3 as described in section (2). At this time, the CSI-RS may be transmitted using all antennas of the divided VR #3 and VR candidate #1. Alternatively, the CSI-RS may be transmitted only through representative antennas among the antennas of the divided VR #3 and VR candidate #1. The present disclosure is not limited to either of the two methods.

[0316] In addition, the number of beams transmitting the CSI-RS may be one or multiple beams. In other words, the base station may transmit the CSI-RS to UE #3 through only one beam. As another example, the base station may transmit the CSI-RS to UE #3 using multiple beams. In the present disclosure, since the location of UE #3 is known, UE #3 can measure the CSI-RS even if only one beam is transmitted. Therefore, a method using one beam can be used. However, in case of seeking a more precise beam based on VR division, the CSI-RS may be transmitted through multiple beams. Therefore, UE #3 can receive the CSI-RS from the base station through the extended VR in step S1712.

[0317] In step S1714, UE #3 can measure the RSRP of the CSI-RS received via the extended VR. Based on the measurement result of the RSRP of the CSI-RS received via the extended VR, UE #3 can determine whether the data rate requirement is satisfied. In step S1714, UE #3 can transmit a report message including the verification result information to the base station.

[0318] In this disclosure, a method for allocating VRs based on the data rate among the QoS provided to a UE has been described. Accordingly, even when adding VRs, whether to add VRs to a UE can be determined based on the data rate among the QoS. Accordingly, as described above, UE #3 can have a table mapping the RSRP value and data rate of a CSI-RS. Using the RSRP value and data rate mapping table of the CSI-RS, UE #3 can determine whether the measured RSRP value of the CSI-RS satisfies the data rate of the QoS. The data rate according to the QoS of UE #3 can be 300 Kbps, as exemplified in Table 6 above.

[0319] The table below shows an example of the RSRP value of CSI-RS received through extended VR and the data rate obtained through the data rate mapping table as 410 Kbps compared to the value before VR candidate #1 is allocated, as shown in Table 9.

[0320] Antenna Index Number of Antennas Data Rate (Kbps) Before Additional Antenna Allocation A #1, A #2, …, A #160160270 After Additional Antenna Allocation A #1, A #2, …, A #160,A #257, …, A #384288410

[0321] As shown in Table 9, the data rate of UE #3 before the additional antenna allocation was 270 Kbps, but after the additional antenna allocation, the data rate of UE #3 may increase to 410 Kbps. Therefore, the report message transmitted by UE #3 in step S1714 may include data rate information or may be a 1-bit conformity report. In the present disclosure, the 1-bit conformity report information may be VR extension indicator information. Information about the VR extension indicator may be set during RRC configuration or RRC re-establishment of UE #3, or through a VR candidate information request message. If the QoS required by UE #3 is satisfied, the VR extension indicator can be set to "1", and if the QoS required by UE #3 is not satisfied, the VR extension indicator can be set to "0". The reason why UE #3 can transmit to the base station only the VR extension indicator consisting of one bit as a measurement report for CSI-RS is that VR #3 before splitting is the VR that UE #3 was using for communication, so the same beamforming vector may be used for adjacent antenna regions. If the same beamforming vector cannot be used, UE #3 may need to additionally transmit separate information for beamforming. The additional information may be included in the report message. The additional information may further include, for example, at least one of a precoding matrix indicator (PMI), a rank indicator (RI), or a channel quality indicator (CQI).

[0322] In step S1714, the base station may receive a report message from UE #3. In addition, the base station may determine whether the QoS of UE #3 is satisfied based on the report message received in step S1716. In the embodiment described above, if VR candidate #1 is additionally allocated to the divided VR of UE #3, the QoS required by UE #3 may be satisfied. In this case, if the QoS required by UE #3 is satisfied, steps S1722 and S1724 may not be performed.

[0323] On the other hand, if the QoS required by UE #3 is not satisfied, the base station may perform steps S1722 and S1724. Step S1722 may be the same procedure as step S1712. However, the only difference is that in step S1712, VR candidate #1 is additionally allocated to the divided VR of UE #3, whereas in step S1722, VR candidate #2 is additionally allocated to the divided VR of UE #3. In addition, step S1724 may be the same procedure as step S1714 described above. Therefore, redundant description of the same content is omitted.

[0324] Meanwhile, even if there are two or more VR candidates for UE #3, the procedure described above may be performed only for one VR candidate or only for two VR candidates depending on the latency requirement. In order to satisfy the latency requirement, a procedure for checking VR candidates may be performed by setting a separate timer according to the latency requirement. In other words, the base station may start a timer according to the latency requirement when checking VR candidates that can be used for VR expansion among the VR candidates. In addition, the base station may perform a procedure to check whether QoS is satisfied by additionally allocating a VR candidate to UE #3 while the timer according to the latency requirement is running. If the latency requirement timer expires during the procedure for additionally allocating a VR candidate, the VR additional allocation procedure may be terminated.

[0325] When the VR additional allocation procedure ends without additional VR allocation for UE #3 in communication, the base station can have UE #3 communicate using the existing VR without performing VR splitting. In addition, for the new UE, UE #k, the base station can perform a procedure for selecting a VR based on the entire XL-MIMO antenna or the location of UE #k. As another example, if the priority of the new UE, UE #k, is much higher than that of UE #3, the base station can instruct UE #3 to perform a handover and allocate the split VR for UE #k or the VR allocated to UE #3 to perform communication.

[0326] Furthermore, if the QoS requirements of UE #3 are met through VR extension through the above procedure, all procedures according to the present disclosure can be completed. In other words, the base station can communicate with UE #3, which is currently communicating, using the VR determined through VR extension, and can communicate with UE #k, which is a new UE, using the VR determined through VR segmentation.

[0327] Figure 17b is a flowchart illustrating an operation of a base station having an XL-MIMO antenna system to additionally allocate VR to UE #k.

[0328] Figure 17b primarily describes the procedure for additionally allocating antennas to the VR of a new UE when the new UE's QoS requirements are not met. Furthermore, in describing Figure 17b, it is assumed that the communicating UE is UE #3, as described in Section (2), and the new UE is UE #k.

[0329] In step S1730, the base station may determine an antenna region adjacent to the VR allocated to the new UE, UE #k, that is not allocated to another UE. Step S1730 may be performed when, as previously described, the VR allocated to UE #k does not meet the QoS requirements required by UE #k. While the present disclosure uses data rate as one of the QoS parameters, other QoS parameters may be used alone, or data rate and other QoS parameters may be considered together.

[0330] In step S1732, the base station can group antenna areas based on a predetermined method. Various methods can be used for the predetermined method, but for the sake of ease of understanding and explanation, the present disclosure assumes a case of adjacent antenna numbers. Accordingly, the base station can group UE #k in a predetermined number of antenna areas adjacent to the VR allocated to UE #k among the VRs of UE #3, and not used by other UEs.

[0331] In step S1734, the base station can determine the order of additionally allocated antenna groups from the determined groups. For example, if candidate groups exist such as candidate group #1, candidate group #2, candidate group #3, etc., the order of sequentially allocating additional antennas from each candidate group can be determined.

[0332] In step S1742, the base station can transmit the CSI-RS to UE #k using the extended VR by adding candidate group #1 to the VR #k divided into UE #k as described in section (2) above. At this time, the CSI-RS can be transmitted using all antennas of the divided VR #k and candidate group #1. As another example, the CSI-RS can be transmitted only through representative antennas among the antennas of the divided VR #k and candidate group #1. The present disclosure is not limited to either of the two methods.

[0333] In addition, the number of beams transmitting the CSI-RS may be one or multiple beams. In other words, the base station may transmit the CSI-RS to UE #k through only one beam. As another example, the base station may transmit the CSI-RS to UE #k using multiple beams. In the present disclosure, since the approximate or exact location of UE #k is known, UE #k can measure the CSI-RS even if only one beam is transmitted. Therefore, a method using one beam can be used. However, in case of seeking a more precise beam, the CSI-RS may be transmitted through multiple beams. Therefore, UE #k can receive the CSI-RS from the base station through the extended VR in step S1742.

[0334] In step S1744, UE #k may measure the RSRP of the CSI-RS received via the extended VR. Based on the measurement result of the RSRP of the CSI-RS received via the extended VR, UE #k may determine whether the data rate requirement is satisfied. In step S1744, UE #k may transmit a report message including the verification result information to the base station.

[0335] In this disclosure, a method for allocating VRs based on a data rate among QoS provided to a UE has been described. Accordingly, even when adding a VR, whether to add a VR to a UE can be determined based on the data rate among QoS. Accordingly, as described above, UE #k can have a table in which the RSRP value of a CSI-RS and the data rate are mapped. UE #k can use the table mapping the RSRP value of the CSI-RS and the data rate to determine whether the measured RSRP value of the CSI-RS satisfies the data rate of the QoS. The data rate according to the QoS of UE #k can be 200 Kbps, as exemplified in Table 7 above. In addition, unlike described in Table 7, when communicating using VR #k allocated to UE #k through VR partitioning, it is assumed that the data rate is 180 Kbps.

[0336] The RSRP value of CSI-RS received through extended VR and the data rate obtained through the data rate mapping table are 260 Kbps. The table below shows the values ​​compared to before candidate group #1 is assigned.

[0337] Antenna Index Number of Antennas Data Rate (Kbps) Before Additional Antenna Allocation A #161, A #162, …, A #25696180 After Additional Antenna Allocation A #161, A #162, …, A #256, A #641, …, A #704160260

[0338] In the example of Table 10, it is assumed that after the antenna region including the antennas indicated by A #641, 쪋, and A #704 is additionally allocated to VR #k, the data rate of the new UE, UE #k, is greater than the data rate required by QoS. In other words, as illustrated in Table 10, the data rate of UE #k before the additional antenna allocation was 180 Kbps, but after the additional antenna allocation, the data rate of UE #k may increase to 260 Kbps. Therefore, the report message transmitted by UE #k in step S1744 may include data rate information or may be a 1-bit conformity report. In the present disclosure, the 1-bit conformity report information may be VR extension indicator information. Information about the VR extension indicator may be included in an RRC message during the RRC setup procedure of UE #k and transmitted to UE #k. If the QoS required by UE #k is satisfied, the VR extension indicator can be set to "1", and if the QoS required by UE #k is not satisfied, the VR extension indicator can be set to "0".

[0339] The reason why UE #k can transmit to the base station only a VR extension indicator consisting of one bit as a measurement report for CSI-RS is because VR #k is a part of the VR that UE #3 was using for communication, and the base station knows the beamforming vector for VR #k in advance. In addition, it is assumed that the same beamforming vector can be used for adjacent antennas. Therefore, if the same beamforming vector cannot be used when using adjacent antennas, UE #k can transmit additional information for beamforming to the base station. At this time, the additional information can be transmitted by being included in the report message. The additional information can further include at least one of PMI, RI, and CQI, for example.

[0340] In step S1744, the base station may receive a report message from UE #k. In addition, the base station may determine whether the QoS of UE #k is satisfied based on the report message received in step S1746. In the embodiment described above, if candidate group #1 is additionally assigned to VR #k of UE #k, the QoS required by UE #k may be satisfied. In this case, if the QoS required by UE #k is satisfied, steps S1752 and S1754 may not be performed.

[0341] On the other hand, if the QoS required by UE #k is not satisfied, the base station can perform steps S1752 and S1754. Step S1752 may be the same procedure as step S1742. However, the only difference is that in step S1742, candidate group #1 is additionally allocated to VR #k of UE #k, whereas in step S1752, candidate group #2 is additionally allocated to VR #k. In addition, step S1754 may be the same procedure as step S1744 described above. Therefore, redundant description of the same content is omitted.

[0342] Meanwhile, even if there are two or more candidate groups in UE #k, the procedure described above may be performed for only one candidate group, or for only two candidate groups, depending on latency requirements. To satisfy the latency requirements, a procedure for checking candidate groups may be performed by setting a separate timer according to the latency requirements. Since the description of this procedure may be the same as the procedure described above in FIG. 17a, a duplicate description will be omitted.

[0343] The operations described above in FIGS. 1 to 17b may or may not be performed selectively. Furthermore, the operations described above may be simply combined, partially combined, or applied in an expanded manner.

[0344] FIG. 18 is a flowchart illustrating the selection, division and / or additional allocation operations of VRs to base stations and UEs having an XL-MIMO antenna system.

[0345] Referring to Fig. 18, it can be largely composed of four steps, such as step S1810, step S1820, step S1830, and step S1840.

[0346] Step S1810 may be a procedure for selecting a UE communicating closest to a new UE to find a VR to assign to the new UE in an XL-MIMO antenna system. More specifically, steps S1811 and S1812 may be performed.

[0347] In step S1811, the base station has VR information of the communicating UE and can obtain location information of the communicating UE.

[0348] The location information of a communicating UE may be provided when the UE first connects, or from a moving UE during communication. Alternatively, the location information of the UE may be obtained from the UE by the base station querying the communicating UE based on a specific period or event. Alternatively, the base station may perform a separate procedure to obtain the location of the communicating UE. For example, the location of the communicating UE may be obtained using a PRS or an SRS transmitted by the UE.

[0349] The VR assigned to a UE may change depending on the UE's location. Therefore, the base station can store VR information that changes depending on the UE's location.

[0350] Step S1812 may be a procedure between the base station and the new UE. When a new UE connects, the base station can obtain the UE's location information using at least one of the methods described above. The base station can then search for the UE closest to the new UE among the UEs in communication. The base station can transmit an RS to the new UE using the VR assigned to the UE closest to the new UE. The new UE can report an RSRP value measured from the received RS to the base station. Through the above procedure, the base station can determine whether the VR of the UE in communication closest to the new UE is suitable for communication with the new UE.

[0351] Although not illustrated in FIG. 18, the base station may determine whether the same VR can be assigned to the UE communicating closest to the new UE. For example, if the same VR can be assigned to the UE communicating closest to the new UE through any of time division multiplexing, frequency division multiplexing, or code division multiplexing, the base station may assign the same VR to the new UE and the communicating UE and terminate the procedure.

[0352] On the other hand, if the same VR cannot be allocated to the UE communicating closest to the new UE, the base station may perform step S1820.

[0353] Step S1820 may be a procedure performed when, in an XL-MIMO antenna system, the VR assigned to the UE closest to the new UE is a suitable VR for the new UE, and when the UE communicating with the new UE cannot share the VR. Step S1820 may be a procedure for dividing and allocating the VR used by the communicating UE to each UE communicating with the new UE. More specifically, steps S1821, S1822, and S1823 may be performed.

[0354] In step S1821, the base station can check the QoS requirements of each UE communicating with the new UE. At this time, the communicating UE may be the UE closest to the new UE selected in step S1810 or a UE to which a common VR with the new UE must be assigned. If the base station has previously stored the QoS requirements of each UE communicating with the new UE, no special procedure may be required. If the QoS requirements of each UE communicating with the new UE must be received from the core network, the base station can inquire about the QoS requirements of each new UE and the communicating UE from the core network and obtain them. If the QoS requirements of each UE communicating with the new UE must be inquired about to each UE, the base station can request and obtain the QoS requirements from each UE communicating with the new UE. If the base station needs to inquire about the QoS of each UE by inquiring about it, the QoS of the communicating UE may be stored in advance by the base station.

[0355] In step S1822, the base station can partition the VR based on QoS requirements. At this time, the VR may be assigned to the UE closest to the new UE, or a VR of a UE that must be assigned a common VR with the new UE. The VR partitioning method using data rates can partition the VR based on the previously described mathematical equations 1 and 2.

[0356] In step S1823, the base station can measure the QoS of each UE for the divided VR. The QoS can have various parameters, and at least the QoS parameters used in step S1822 can be used as parameters. However, if the delay requirement is not a QoS parameter used in step S1822, the delay requirement can be additionally considered. If the inspection result in step S1823 shows that both the new UE and the communicating UE satisfy the QoS requirement even if they use the divided VR, the base station can perform communication using the VR divided and allocated to the new UE, and the base station can perform communication through the VR divided and allocated to the communicating UE. On the other hand, if at least one UE communicates through the divided VR, there may be a case where the QoS requirement is not satisfied. In this case, the base station can perform step S1830.

[0357] Step S1830 may be a procedure performed when, in an XL-MIMO antenna system, the VR used by the communicating UE is divided and allocated to each UE communicating with the new UE, but the communicating UE does not satisfy the QoS requirements with the divided VR alone. Specifically, step S1830 may be performed as steps S1831 and S1832.

[0358] Step S1831 may be a case where an additional VR for a communicating UE needs to be allocated. In step S1831, the base station may request VR candidate information from the communicating UE. Upon receiving the VR candidate information request from the base station, the UE may report VR candidate information stored by the communicating UE to the base station. The VR candidate information may be a VR candidate acquired by the communicating UE during the initial access procedure. If the base station stores and manages VR candidate information for the communicating UE, step S1831 may not be performed.

[0359] Step S1832 may be a procedure performed after step S1832. In step S1832, the base station may additionally allocate antennas based on the VR candidates. At this time, the base station may additionally allocate antennas in order of priority, starting with the highest priority VR candidate and moving on to the lowest priority VR candidate, to find a VR candidate that satisfies the QoS requirements. Furthermore, the base station may add VR candidates that satisfy the QoS requirements and determine the VR to allocate to the communicating UE.

[0360] Step S1840 may be a procedure performed when, in an XL-MIMO antenna system, the VR used by the communicating UE is divided and allocated to each UE communicating with the new UE, but the new UE cannot satisfy the QoS requirements with only the divided VR.

[0361] In step S1841, the base station may add antennas to the new UE through VR expansion. At this time, among the antennas adjacent to the VR allocated to the new UE for VR expansion, antennas that are not assigned to other UEs may be selected first. The selected antennas may be organized into multiple candidate groups based on a predetermined method, and the order in which the candidate groups are examined may be determined to find antennas to be added to the VR. The decision on which antennas to add to the VR may be based on the QoS requirements of the new UE.

[0362] 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.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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. In the method of the base station, A step of obtaining location information of a second user equipment (UE) that initially connects; A step of selecting a first UE that is closest to the second UE among the UEs communicating with the base station; A step of transmitting a first reference signal (RS) to the second UE through a first visibility region (VR) assigned to the first UE among a plurality of antennas; A step of receiving a first report message including a measurement value for the first RS measured by the second UE from the second UE; and A step of allocating the first VR to the second UE, if it is determined that the second UE can use the first VR based on the first report message and the first UE and the second UE can share the first VR through a multiplexing method, Method of base station.

2. In claim 1, The above multiplexing method is one of time division multiplexing, frequency division multiplexing, or code division multiplexing. Method of base station.

3. In claim 1, If the reference signal received power (RSRP) value of the first RS measured by the second UE is greater than or equal to a preset threshold value, it is determined that the second UE can use the first VR. Method of base station.

4. In claim 1, If the first UE and the second UE cannot share the first VR through the above multiplexing method, A step of dividing the first VR into a 1-1 VR and a 1-2 VR based on a first quality of service (QoS) requirement of the first UE and a second QoS requirement of the second UE; a step of allocating the above 1-1 VR to the above 1 UE; and Further comprising the step of allocating the above 1-2 VR to the above 2 UE. Method of base station.

5. In claim 4, Each of the first QoS requirement and the second QoS requirement includes at least one of a priority level, a packet delay budget, a packet error rate, a maximum data burst volume, or a data rate requirement. Method of base station.

6. In claim 4, The above base station obtains the first QoS requirement and the second QoS requirement from the core network. Method of base station.

7. In claim 4, The base station obtains the first QoS requirement from the first UE and obtains the second QoS requirement from the second UE. Method of base station.

8. In claim 4, A step of transmitting a second RS to the first UE through the first-1 VR; A step of receiving a second report message including a measurement value for the second RS measured by the first UE from the first UE; A step of checking whether the first-1 VR satisfies the first QoS requirement of the first UE based on the second report message; and Further comprising a step of determining the 1-1 VR as the VR of the 1 UE if the 1-1 VR satisfies the 1 QoS requirement of the 1 UE. Method of base station.

9. In claim 8, If the above 1-1 VR does not satisfy the above 1 QoS requirement of the above 1 UE, A step of requesting information on a VR candidate of the first UE; A step of selecting a second VR to be added to the first-1 VR based on the VR candidates of the first UE; A step of transmitting a third RS to the first UE through the first-1 VR and the second VR; A step of receiving a third report message including a measurement value for the third RS measured by the first UE from the first UE; and Further comprising a step of determining the 1-1 VR and the 2 VR as VRs of the 1 UE if the measurement value for the 3rd RS included in the 3rd report message satisfies the 1st QoS requirement of the 1st UE. Method of base station.

10. In claim 4, A step of transmitting the 4th RS to the 2nd UE through the 1st-2nd VR; A step of receiving a fourth report message including a measurement value for a fourth RS measured by the second UE from the second UE; A step of verifying whether the first-second VR satisfies the second QoS requirement of the second UE based on the measurement value for the fourth RS included in the fourth report message; and Further comprising a step of determining the 1-2 VR as the VR of the 2nd UE if the 1-2 VR satisfies the 2nd QoS requirement of the 2nd UE. Method of base station.

11. In claim 10, If the above 1-2 VR does not satisfy the above 2nd QoS requirement of the above 2nd UE, A step of determining a first antenna area that is not assigned to any UE among the adjacent antennas of the above 1-2 VRs; A step of selecting a first antenna group including a preset number of antennas among the antennas within the first antenna area: A step of transmitting the fifth RS to the second UE through the antennas belonging to the first-second VR and the antennas of the first antenna group; A step of receiving a fifth report message including a measurement value of the fifth RS measured by the second UE from the second UE; and If the measurement value of the fifth RS included in the fifth report message satisfies the second QoS requirement of the second UE, further comprising a step of determining the first-second VR and the first antenna group as the VR of the second UE. Method of base station.

12. At the base station, At least one processor, wherein the at least one processor comprises: A step of obtaining location information of a second user equipment (UE) that initially connects; A step of selecting a first UE that is closest to the second UE among the UEs communicating with the base station; A step of transmitting a first reference signal (RS) to the second UE through a first visibility region (VR) assigned to the first UE among a plurality of antennas; A step of receiving a first report message including a measurement value for the first RS measured by the second UE from the second UE; and Based on the first report message, it is determined that the second UE can use the first VR, and if the first UE and the second UE can share the first VR through a multiplexing method, a step of allocating the first VR to the second UE is performed. Base station.

13. In claim 12, The above multiplexing method is one of time division multiplexing, frequency division multiplexing, or code division multiplexing. Base station.

14. In claim 12, If the reference signal received power (RSRP) value of the first RS measured by the second UE is greater than or equal to a preset threshold value, it is determined that the second UE can use the first VR. Base station.

15. In claim 12, At least one processor of the base station: If the first UE and the second UE cannot share the first VR through the above multiplexing method, A step of dividing the first VR into a 1-1 VR and a 1-2 VR based on a first quality of service (QoS) requirement of the first UE and a second QoS requirement of the second UE; a step of allocating the above 1-1 VR to the above 1 UE; and To perform the step of allocating the above 1-2 VR to the above 2 UE, Base station.

16. In a method of a second user equipment (UE), A step of transmitting location related information of the second UE to the base station upon initial connection with the base station; A step of receiving a measurement report control message including configuration information and report configuration information of a first reference signal (RS); A step of receiving the first RS through a first visibility region (VR) allocated to the first UE from the base station; A step of measuring a first reference signal received power (RSRP) for the first RS; A step of transmitting a first report message including the measured first RSRP to the base station; and Including a step of transmitting / receiving a signal with the base station based on the first VR allocation information when the first VR allocation information is received from the base station. Method of the second UE.

17. In claim 16, If the VR allocation information indicates the first VR, the VR allocation information includes information indicating a multiplexing method for sharing the first VR between the first UE and the second UE. Method of the second UE.

18. In claim 17, The above multiplexing method is one of time division multiplexing, frequency division multiplexing, or code division multiplexing. Method of the second UE.

19. In claim 16, A step of receiving a second RS from the base station through the first-second VR when the VR allocation information indicates a first-second VR that is different from the first VR information; A step of measuring a second RSRP for the second RS; A step of transmitting a second report message including the measured second RSRP to the base station; and Further comprising the step of receiving second VR allocation information from the base station, Method of the second UE.

20. In claim 19, A step of receiving a third RS received from the base station when the second VR allocation information indicates allocation of an additional antenna to the first-second VR; A step of measuring a third RSRP for the third RS; A step of transmitting a third report message including the measured third RSRP to the base station; and Further comprising the step of receiving third VR allocation information from the base station; Method of the second UE.

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