Method and apparatus for multi-user spatial multiplexing in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate than a 4G communication system, such as LTE. A method for a user equipment (UE) in a wireless communication system according to an embodiment of the present disclosure may comprise: an operation of receiving a first message requesting information on a beam of the UE from a base station; an operation of transmitting, to the base station, a second message including information on the beam of the UE; an operation of receiving, from the base station, first control information instructing the UE to transmit a sounding reference signal (SRS) by using at least one beam among a plurality of beams; an operation of transmitting at least one SRS to the base station by using the at least one beam on the basis of the first control information; and an operation of receiving, from the base station, information on at least one beam to be used when the UE receives a data signal according to channel information acquired on the basis of the at least one SRS.

Description

Method and device for multi-user spatial multiplexing in a wireless communication system

[0001] The present disclosure relates to a method for multi-user spatial multiplexing transmission in a wireless communication system.

[0002] Looking back at the evolution of wireless communication over successive generations, technologies have primarily been developed for human-facing services such as voice, multimedia, and data. With the commercialization of 5G (5th-generation) communication systems, an explosive increase in connected devices is expected to be connected to communication networks. Examples of networked objects include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction equipment, and factory equipment. Mobile devices are expected to evolve into diverse form factors, including augmented reality glasses, virtual reality headsets, and holographic devices. In the 6th-generation (6G) era, efforts are being made to develop improved 6G communication systems to connect hundreds of billions of devices and objects and provide diverse services. For this reason, 6G communication systems are often referred to as "beyond 5G."

[0003] The 6G communication system, expected to be realized around 2030, will have a maximum transmission speed of terabytes per second (i.e., 1,000 gigabits per second) and a wireless latency of 100 microseconds (μsec). In other words, compared to 5G, the transmission speed in a 6G communication system will be 50 times faster, while the wireless latency will be reduced to one-tenth.

[0004] To achieve these high data rates and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz band (e.g., from 95 gigahertz (GHz) to 3 terahertz (THz)). Compared to the millimeter wave (mmWave) band introduced in 5G, the terahertz band is expected to experience more severe path loss and atmospheric absorption, making it more crucial to ensure signal reach, or coverage, in this band. Key technologies to ensure coverage include radio frequency (RF) components, antennas, new waveforms that offer better coverage than OFDM (orthogonal frequency division multiplexing), beamforming, and multiple antenna transmission technologies such as massive multiple-input and multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas. In addition, new technologies such as metamaterial-based lenses and antennas, high-dimensional spatial multiplexing using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RIS) are being discussed to improve the coverage of terahertz band signals.

[0005] In addition, in order to improve frequency efficiency and system network, 6G communication systems are developing full duplex technology that utilizes the same frequency resources for uplink and downlink at the same time; network technology that integrates satellites and high-altitude platform stations (HAPS); network structure innovation technology that supports mobile base stations and enables optimization and automation of network operation; dynamic spectrum sharing technology through collision avoidance based on spectrum usage prediction; AI-based communication technology that utilizes artificial intelligence (AI) from the design stage and internalizes end-to-end AI support functions to realize system optimization; and next-generation distributed computing technology that realizes services with complexity that exceeds the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources (mobile edge computing (MEC), cloud, etc.). In addition, efforts are being made to further strengthen connectivity between devices, further optimize networks, promote softwareization of network entities, and increase the openness of wireless communications through the design of new protocols to be used in 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for the safe use of data, and the development of technologies for maintaining privacy.

[0006] Research and development of these 6G communication systems are expected to enable a new level of hyper-connected experience (the next hyper-connected experience) through the hyper-connectivity of 6G communication systems, which encompass not only connections between things but also connections between people and things. Specifically, 6G communication systems are expected to enable services such as truly immersive extended reality (Truly Immersive XR), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which are provided through 6G communication systems through enhanced security and reliability, will find application in diverse fields such as industry, medicine, automobiles, and home appliances.

[0007] Meanwhile, the need for an SRS transmission and reception method for multi-user spatial multiplexing transmission in a hybrid beamforming system is emerging.

[0008] The present disclosure proposes a method for enabling a base station to obtain channel state information that varies depending on a beam of a terminal in a hybrid beamforming system.

[0009] According to one embodiment, a method of a user equipment (UE) in a wireless communication system may include: receiving a first message requesting information about a beam of the UE from a base station; transmitting a second message including information about the beam of the UE to the base station; receiving first control information from the base station instructing the UE to transmit a sounding reference signal (SRS) using at least one beam among a plurality of beams; transmitting at least one SRS to the base station using the at least one beam based on the first control information; and receiving, from the base station, information about at least one beam to be used by the UE when receiving a data signal based on channel information acquired based on the at least one SRS.

[0010] According to one embodiment, a method of a base station in a wireless communication system may include: transmitting a first message requesting information about a beam of a user equipment (UE) to the UE; receiving a second message from the UE including information about the beam of the UE; transmitting first control information to the UE indicating that the UE transmits a sounding reference signal (SRS) using at least one beam among a plurality of beams; receiving at least one SRS based on the at least one beam from the UE; and transmitting to the UE information about at least one beam to be used by the UE when receiving a data signal according to channel information acquired based on the at least one SRS.

[0011] According to one embodiment, in a wireless communication system, a user equipment (UE) includes a transceiver; and a control unit. The control unit receives a first message requesting information about a beam of the UE from a base station, controls transmission of a second message including information about the beam of the UE to the base station, receives first control information from the base station instructing the UE to transmit a sounding reference signal (SRS) using at least one beam among a plurality of beams, controls transmission of at least one SRS to the base station using the at least one beam based on the first control information, and receives information about at least one beam to be used by the UE when receiving a data signal from the base station based on channel information acquired based on the at least one SRS.

[0012] According to one embodiment, in a wireless communication system, a base station includes a transceiver; and a control unit. The control unit may control a first message requesting information about a beam of a user equipment (UE) to be transmitted to the UE, a second message including information about the beam of the UE to be received from the UE, first control information instructing the UE to transmit a sounding reference signal (SRS) using at least one beam among a plurality of beams to the UE, receive at least one SRS based on the at least one beam from the UE, and control the UE to transmit information about at least one beam to be used when the UE receives a data signal according to channel information acquired based on the at least one SRS to the UE.

[0013] A method and device according to an embodiment of the present disclosure can increase MU-MIMIO (multi-user multiple-input multiple-output) transmission efficiency by considering CSI (channel state) that varies depending on the beam of terminals in a hybrid beamforming system.

[0014] FIG. 1 is a diagram illustrating the basic structure of the time-frequency domain in a wireless communication system according to an embodiment of the present invention.

[0015] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to an embodiment of the present invention.

[0016] FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to an embodiment of the present invention.

[0017] FIG. 4 illustrates an example of a hybrid beamforming system according to one embodiment of the present disclosure.

[0018] FIG. 5A illustrates an example of CSI according to an analog beam of a UE according to one embodiment of the present disclosure.

[0019] FIG. 5b is a diagram for explaining an effective channel according to an analog beam of a UE according to one embodiment of the present disclosure.

[0020] FIGS. 6A and 6B illustrate examples of correlations of CSI according to an analog beam of a UE according to one embodiment of the present disclosure.

[0021] FIG. 7 illustrates an example of full beam SRS transmission according to one embodiment of the present disclosure.

[0022] FIG. 8 illustrates an example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0023] FIG. 9 is a diagram for explaining the operation of a UE and a base station for full beam SRS transmission according to one embodiment of the present disclosure.

[0024] FIG. 10 illustrates an example of full beam SRS transmission according to one embodiment of the present disclosure.

[0025] FIG. 11 illustrates another example of full beam SRS transmission according to one embodiment of the present disclosure.

[0026] FIG. 12 is a diagram for explaining the operation of a UE and a base station for partial beam SRS transmission according to one embodiment of the present disclosure.

[0027] FIG. 13 illustrates an example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0028] FIG. 14 illustrates an example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0029] FIG. 15 illustrates another example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0030] FIG. 16 illustrates another example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0031] FIG. 17 illustrates another example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0032] FIG. 18 is a block diagram illustrating a UE according to embodiments of the present disclosure.

[0033] FIG. 19 is a block diagram illustrating a base station according to embodiments of the present disclosure.

[0034] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings. It should be noted that, where possible, identical components are represented by identical reference numerals throughout the attached drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the gist of the present disclosure will be omitted.

[0035] In describing the embodiments in this specification, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0036] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0037] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

[0038] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0039] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0040] Here, the term '~ unit' used in the present embodiment means software or hardware components such as FPGA (field programmable gate array) or ASIC (application specific integrated circuit), and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Accordingly, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, components and '~parts' may be implemented to regenerate one or more CPUs within a device or secure multimedia card.

[0041] In embodiments of the present disclosure, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, an eNB, a Node B, a BS, a radio access unit, a base station controller, or a node on a network. In addition, the base station may be a network entity including at least one of an IAB-donor (Integrated Access and Backhaul - donor), which is a gNB that provides network access to terminal(s) through a network of backhaul and access links in an NR system, and an IAB-node, which is a radio access network (RAN) node that supports NR access link(s) to the terminal(s) and supports NR backhaul links to the IAB-donor or another IAB-node. A terminal may be wirelessly connected through an IAB-node and may transmit and receive data with an IAB-donor connected to at least one IAB-node through a backhaul link.

[0042] In addition, the terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer, or various devices capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, the fifth generation mobile communication technology (5G, new radio, NR) or 6G developed after LTE-A may be included here, and the 5G or 6G below may also be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a scope that does not significantly deviate from the scope of the present disclosure at the discretion of a person having skilled technical knowledge.

[0043] Terms used in the following description to refer to signals, channels, control information, network entities, and device components are provided for convenience of explanation. Furthermore, terms used in the following description to identify nodes, messages, interfaces between network entities, and various pieces of information are provided for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0044] Additionally, while this disclosure describes various embodiments using terminology used in certain communication standards (e.g., 3rd Generation Partnership Project (3GPP)), these are merely illustrative examples. The various embodiments of this disclosure can be easily modified and applied to other communication systems.

[0045] FIG. 1 is a diagram illustrating the basic structure of a time-frequency domain, which is a wireless resource domain in which data or control channels are transmitted, in a wireless communication system according to one embodiment of the present disclosure.

[0046] The horizontal axis of Figure 1 represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as 1 OFDM symbol (102) on the time axis and 1 subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can constitute one resource block (RB, 104). One subframe (110) on the time axis can include multiple OFDM symbols (102). For example, the length of one subframe can be 1 ms.

[0047] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0048] Figure 2 illustrates an example of a structure of a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202). One frame (200) can be defined as 10ms. One subframe (201) can be defined as 1ms, and therefore one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( =14). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per 1 subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In an example of FIG. 2, cases where the subcarrier spacing setting value μ = 0 (204) and μ = 1 (205) are illustrated. When μ = 0 (204), 1 subframe (201) may be composed of one slot (202), and when μ = 1 (205), 1 subframe (201) may be composed of two slots (203). That is, the number of slots per 1 subframe ( ) may vary, and accordingly the number of slots per frame ( ) may vary.

[0049] FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to one embodiment of the present disclosure.

[0050] FIG. 3 shows an example in which the UE bandwidth (300) is set to two bandwidth portions, namely, bandwidth portion #1 (BWP#1) (301) and bandwidth portion #2 (BWP#2) (302). The base station can set one or more bandwidth portions to the UE, and can set the information in [Table 1] below for each bandwidth portion.

[0051] BWP ::= SEQUENCE {bwp-Id BWP-Id,(bandwidth part identifier)locationAndBandwidth INTEGER (1..65536),(bandwidth part location)subcarrierSpacing ENUMERATED {n0, n1, n2, n3, n4, n5},(subcarrier spacing)cyclicPrefix ENUMERATED { extended}(cyclic prefix)}

[0052] Of course, the above example is not limited, and in addition to the above configuration information, various parameters related to the bandwidth portion can be configured for the terminal. The above information can be transmitted from the base station to the terminal via upper layer signaling, for example, RRC (Radio Resource Control) signaling. At least one bandwidth portion among the configured one or more bandwidth portions can be activated. Whether or not the configured bandwidth portion is activated can be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via DCI.

[0053] Meanwhile, to meet the rapidly increasing traffic demand in 5G or 6G communications, the use of centimeter wave frequencies (cmWave) spectrum (e.g., upper-mid band (UMB); 7-15 GHz) is being considered. Devices using UMB can install more antenna elements (AEs) while maintaining a similar aperture size to C-band due to the shorter wavelength.

[0054] Devices using UMB may introduce a hybrid antenna structure with a larger number of digital ports (e.g., 256TR at BS, xT8R at UE) and phase shifters implemented in each subarray compared to C-band to improve system performance, including MU-MIMO (multiple user-multiple input multiple output) transmission.

[0055] FIG. 4 illustrates an example of a hybrid beamforming system according to one embodiment of the present disclosure.

[0056] Referring to FIG. 4, a hybrid beamforming system may include a UE (400) and a base station (BS) (440) having a hybrid antenna structure. The UE (400) and the BS (440) may include a hybrid antenna structure capable of performing hybrid beamforming transmission in the form of a combination of an analog beam and a digital beam.

[0057] The UE (400) may include a digital precoding unit (410), a plurality of digital port units (411, 412), a plurality of analog beamforming units (420, 425), and a plurality of sub-array units (430, 435). The plurality of digital port units (411, 412) may include a first digital port (411) to an M-th (wherein, M is a natural number greater than 2) digital port (412). The plurality of analog beamforming units (420, 425) may include a first analog beamforming unit (420) to an M-th analog beamforming unit (425) connected to the first digital port (411) to the M-th digital port (412), respectively. The first analog beamforming unit (420) may include a plurality of phase shifters (421, 422), and the M analog beamforming unit (425) may include a plurality of phase shifters (426, 427).

[0058] The plurality of sub-array units (430, 435) may include the first sub-array unit (430) to the M-th sub-array unit (435) connected to the first analog beamforming unit (420) to the M-th analog beamforming unit (425), respectively. The first sub-array unit (430) may include a plurality of AEs (antenna elements), and each of the plurality of AEs may be connected to each of the plurality of phase shifters (421, 422). The M-th sub-array unit (435) may include a plurality of AEs, and each of the plurality of AEs may be connected to each of the plurality of phase shifters (426, 427).

[0059] The BS (440) may include a digital precoding unit (450), a plurality of digital port units (451, 452), a plurality of analog beamforming units (460, 465), and a plurality of sub-array units (470, 475). The plurality of digital port units (451, 452) may include a first digital port (451) to an M-th digital port (452). The plurality of analog beamforming units (460, 465) may include a first analog beamforming unit (460) to an M-th analog beamforming unit (465) connected to the first digital port (451) to the M-th digital port (452), respectively. The first analog beamforming unit (460) may include a plurality of phase shifters (461, 462), and the M analog beamforming unit (465) may include a plurality of phase shifters (466, 467).

[0060] The plurality of sub-array units (470, 475) may include the first sub-array unit (470) to the M-th sub-array unit (475) connected to the first analog beamforming unit (460) to the M-th analog beamforming unit (465), respectively. The first sub-array unit (470) may include a plurality of AEs, and each of the plurality of AEs may be connected to each of the plurality of phase shifters (461, 462). The M-th sub-array unit (475) may include a plurality of AEs, and each of the plurality of AEs may be connected to each of the plurality of phase shifters (466, 467).

[0061] In the present disclosure, the digital ports (411, 412, 451, 452) may also be referred to as transceiver units (TRX) or RF chains. Each digital port (411, 412, 451, 452) may be implemented as a subarray structure in which a plurality of AEs are connected.

[0062] FIG. 5A illustrates an example of CSI according to an analog beam of a UE according to one embodiment of the present disclosure.

[0063] Referring to FIG. 5A, a UE (500) may include a digital port (510), an analog beamformer (520), and a plurality of AEs (530). In a hybrid beamforming-based MIMO system, channel state information (CSI) may vary depending on the analog beam (or beams) of the BS (640) or the UE (500).

[0064] The UE (500) may include M digital ports, and the BS (540) may include N digital ports. In Fig. 5a, for convenience of explanation, M=1 is assumed, but the present invention can also be applied when M>1.

[0065] The subarray of UE(500) has M a The dog's AE is installed, represents the analog beam (or beam) of the UE (500). Here, , where F represents the beam book of the UE (500) and B represents the number of beams of the UE.

[0066] According to one embodiment, the BS (540) can receive a sounding reference signal (SRS) transmitted from the UE (500) in a specific beam. Here, the specific beam of the BS (540) can be implemented in at least one of various forms including a wide beam, a narrow beam, a common beam, and an adaptive beam. According to one embodiment, the specific beam of the BS (540) can be determined based on the SRS of the UE (500) or the CSI report of the UE (500). According to one embodiment, the specific beam of the BS (540) can change over time.

[0067] Before the UE (500) applies the analog beam, the CSI between the AE of the UE (500) and the digital port of the BS (540) is can be expressed as a specific beam. When SRS is transmitted by applying , the CSI estimated by BS (540) is It can be expressed as an effective channel matrix. According to the above formula, the beam of the UE (500) CSI estimated by BS (540) according to can be different. Multiple different CSIs can be generated depending on the beam of the UE (500).

[0068] Multi-CSI set according to the beam of UE(500) can be expressed as . Since MU (multi-user) transmission affects transmission performance not only by channel strength but also by the relative relationship between UE channels (e.g., spatial correlation), MU transmission performance may vary depending on various CSI combinations according to the beam applied by each UE. For example, when BS (540) uses ZF (zero-forcing) precoding that nulls interference, the lower the correlation between UE channels, the better the spatial separation and the higher the SINR (signal to interference noise ratio) of each UE.

[0069] In a hybrid antenna structure, the CSI estimated based on the SRS varies depending on the beam of the UE (500), and the BS (540) can estimate multi-CSI depending on the various beams of the UE (500). Since the MU performance may vary depending on which beam each UE applies to transmit the SRS, the BS (540) must know the multi-CSI set applied to all beams of each UE for optimal MU transmission.

[0070] FIG. 5b is a diagram for explaining an effective channel according to an analog beam of a UE according to one embodiment of the present disclosure.

[0071] Referring to Figures 5a and 5b, UE (500) beam f (0) When transmitting SRS to CSI H (0) , UE(500) beam f (1) When SRS is transmitted to CSI H (1) , and UE(500) beam f (B-1) When transmitting SRS to CSI H (B-1) The size and direction of the effective channel for each can be implemented differently.

[0072] FIGS. 6A and 6B illustrate examples of correlations of CSI according to an analog beam of a UE according to one embodiment of the present disclosure.

[0073] Referring to Figure 6a, the first UE beams CSI obtained when transmitting SRS Wow, the second UE beams CSI obtained when transmitting SRS It shows the correlation between CSI Wow CSI can be highly correlated.

[0074] Referring to Figure 6b, the first UE beams CSI obtained when transmitting SRS And the second UE beams CSI obtained when transmitting SRS It shows the correlation between CSI Wow CSI can be an almost orthogonal relationship.

[0075] CSI of Fig. 6b Wow CSI is the CSI of Fig. 6a Wow CSI It may be a better CSI combination for MU transmission. For example, class When generating a ZF precoder and transmitting DL MU, class Generating a ZF precoder can improve performance when transmitting DL MUs.

[0076] FIG. 7 illustrates an example of full beam SRS transmission according to one embodiment of the present disclosure.

[0077] Referring to FIG. 7, the base station can transmit first control information (Full beam SRS configuration) regarding full beam SRS transmission to the UE so that the UE can sequentially apply all beams to transmit SRS.

[0078] The base station can receive a full beam SRS transmitted by the UE by sequentially applying all beams. Based on the received full beam SRS, the base station can select one beam to apply for signal transmission and transmit second control information including selected beam information to the UE.

[0079] Afterwards, if necessary, the UE can transmit SRS by sequentially applying all beams.

[0080] FIG. 8 illustrates an example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0081] Referring to FIG. 8, in order to reduce SRS overhead or to transmit SRS using only some beams among all beams of the UE, the base station may transmit first control information (Partial beam SRS configuration) regarding partial beam SRS transmission to the UE.

[0082] The base station can receive a full beam SRS transmitted by the UE by sequentially applying all beams. Based on the received full beam SRS, the base station can select one beam to apply for signal transmission and transmit second control information including selected beam information to the UE.

[0083] The base station may transmit activation information (Partial beam SRS activation) to the UE, which enables SRS to be transmitted using only some of the UE's beams. In one embodiment, the UE may repeatedly transmit SRS using some of the beams based on the activation information (Partial beam SRS activation). In one embodiment, the UE may reduce SRS overhead by transmitting SRS using some of the beams based on the activation information (Partial beam SRS activation).

[0084] FIG. 9 is a diagram for explaining the operation of a UE and a base station for full beam SRS transmission according to one embodiment of the present disclosure.

[0085] Referring to FIG. 9, in operation 901, the base station (920) may transmit a UE beam information request requesting UE beam information to the UE (910). In operation 903, the UE (910) may transmit a beam information report including UE beam information to the base station (920).

[0086] According to one embodiment, the beam information report includes information about whether the UE (910) supports analog beams, the analog beam type (e.g., {wide, narrow}), and the number of beams (the number of wide beams B). w , number of narrow beams B n , total number of beams B total (including at least one of the following) analog beam switching delay It may include at least one of the following:

[0087] In operation 905, the base station (920) may set a full beam SRS configuration based on the UE beam information report and transmit it to the UE. According to one embodiment, the full beam SRS configuration may be transmitted via RRC signaling.

[0088] According to one embodiment, the full beam SRS configuration may include information on the number of SRS resources to be used for full beam SRS and full beam set. According to one embodiment, the base station (920) may determine at least one of the number of SRS resources to be used for full beam SRS and the full beam set based on the information included in the beam information report.

[0089] In one embodiment, B total ≤B max (B max = maximum number of SRS resources that can be allocated to UE (910), the number of beams B to be used for full beam SRS transmission is B=B total can be set to . According to one embodiment, B total >B max , B n max If , B=B n can be set to .

[0090] In one embodiment, B total >B max , B n >B max , B w ≤B max If , B=B w Set to or B=B max After setting, the base station (920) selects B among all beams max ​An indicator may be transmitted (or enabled) to the UE (910) to instruct it to randomly select a dog.

[0091] In one embodiment, B total >B max , B n >B max , B w >B max If , B=B max After setting, the base station (920) selects B among all beams max An indicator can be transmitted (or enabled) to the UE (910) to instruct it to randomly select a dog.

[0092] According to one embodiment, the beam switching delay τ of the UE (910) s Based on this, the base station (920) can determine (or set) SRS resource settings.

[0093] In one embodiment, τ s <τ th In this case, the base station (920) may allocate continuous SRS resources to the UE (910) as full beam SRS resources. According to one embodiment, τ s ≥τ th In this case, the base station can allocate discontinuous SRS resources to the UE (910) as full beam SRS resources.

[0094] According to one embodiment, the full beam SRS configuration may include full beam SRS resource information. According to one embodiment, the full beam SRS resource information may include SRS resource information (S) on which full beam SRS transmission is to be performed. f ) can be expressed as above.

[0095] In one embodiment, the full beam SRS configuration may include a full beam SRS indicator. The full beam SRS indicator may instruct to transmit SRS by sequentially applying the configured full beam.

[0096] According to one embodiment, the full beam SRS configuration may include a transmission period and a slot offset value related to the full beam SRS transmission. According to one embodiment, the full beam SRS configuration may include a reception configuration indicator (RCI) state set for PDSCH reception. According to one embodiment, the base station (920) may map each SRS resource to be allocated to the UE (910) and the RCI state 1:1, and transmit (or set) the mapping information to the UE (910).

[0097] According to one embodiment, the RCI may be set as shown in Table 2. Referring to Table 2, RCI state ID 1 may be mapped to a transmission beam applied by the UE (910) when transmitting an SRS in SRS resource 5. Referring to Table 2, RCI state ID 3 may be mapped to a transmission beam applied by the UE (910) when transmitting an SRS in SRS resource 7. The RCI information may indicate an RCI index when the base station (920) schedules a PDSCH. In order to instruct the UE (910) to use the UE beam applied when transmitting an SRS in the SRS resource mapped to the RCI index as a reception beam when receiving a PDSCH, the base station (920) may transmit the RCI information to the UE (910).

[0098] [Table 2]

[0099]

[0100] In operation 907, operation 909, and operation 911, the UE (910) may perform full beam SRS transmission based on full beam SRS configuration information. The UE (910) may transmit B beams (e.g., F(1), F(2),…, F(B)) set based on the full beam SRS configuration. f SRS can be transmitted by sequentially applying it to SRS resources belonging to .

[0101] In operation 913, the base station (920) can obtain K multi-CSI sets to which the full beam of each UE is applied for K UEs, and based on this, determine a beam of each UE suitable for MU transmission (Beam selection for PDSCH transmission).

[0102] Various methods can be considered in determining the beam of each UE suitable for MU transmission. According to one embodiment, the UE beam can be determined based on the sum rate. The base station (910) can calculate a sum rate set considering all possible beam combinations of UEs. For example, when K=2 and B=3, the possible sum rate set is This can be. Here is UE 1 beam CSI and UE 2 beam when applied It represents the sum rate calculated based on the CSI when ZF precoding is applied. For example, when the base station (910) applies ZF precoding, can be calculated as . Here is the noise power, Pk represents the transmission power allocated to UE k. In the sum rate set, a beam pair of UEs that maximizes the sum rate can be determined. For example, The beam pairs of UEs can be determined as follows.

[0103] According to one embodiment, the beam of each UE suitable for MU transmission can be determined based on the condition number of the MU channel matrix. Since the smaller the condition number of the MIMO channel matrix, the better the spatial separation tends to be, so the best beam combination that minimizes the condition number can be selected. For example, when K=2 and B=3, the MU-MIMO channel composed of the beam combination of each UE It can be expressed as follows. At this time, MU-MIMO channel matrix The condition number is can be expressed as . Here, are each It represents the maximum and minimum singular value. The base station (920) can determine the UE beam pair that minimizes the condition number χ(i1,i2).

[0104] According to one embodiment, the beam of each UE suitable for MU transmission can be determined based on the correlation between UE channels. The lower the correlation between UE channels, the better the spatial separation and the higher the MU-MIMO transmission performance. For example, when K=3 and B=3, UE 1 transmits beam Channel when transmitting SRS with applied Correlations between channels of other UEs It can be expressed as follows. Here, is the beam of UE k channel applied and UE m's beam channel applied It represents the correlation between the beams. Similarly, UE 1 Channel when transmitting SRS with applied Correlations between channels of other UEs can be expressed as follows. Similarly, UE 1 beam Channel when transmitting SRS with applied Correlations between channels of other UEs It can be expressed as follows. UE 1 is beam channel when applied and the average correlation between other UE channels. can be calculated as follows: Here, can be calculated. Based on the above correlation values, the beam for UE 1 can be selected as the beam that minimizes the average correlation. Similarly, each UE beam can be determined for the remaining UEs 2 and UE 3.

[0105] In operation 915, the base station (920) may transmit information about the selected beam to the UE (910). After determining each UE beam, the base station (920) may transmit control information to the UE (910) instructing that the UE Tx beam used for SRS transmission suitable for MU-MIMO transmission be applied as the Rx beam when receiving a PDSCH. For example, if the RCI state ID is indicated by DCI, the UE (910) may assume that the UE Tx beam applied in the SRS resource mapped to the RCI state ID is applied as the Rx beam when receiving the PDSCH scheduled by the DCI. For example, if the base station (920) transmits the selected beam information including RCI state ID = 1, the UE (910) may apply the Tx beam applied by the UE (910) when transmitting the SRS in SRS resource 5 as the Rx beam when receiving the PDSCH scheduled by the DCI based on the RCI state ID.

[0106] In operation 917, the base station (920) generates a precoder and transmits a PDSCH signal under the assumption that UEs receive PDSCH with a beam mapped to the RCI state ID, and the UE (910) can receive the PDSCH by applying the beam mapped to the RCI state ID.

[0107] FIG. 10 illustrates an example of full beam SRS transmission according to one embodiment of the present disclosure.

[0108] Fig. 10 shows an embodiment of full beam SRS transmission, where the number of UEs is 4 (K=4), the number of beams of each UE is 2 (B=2), and the transmissionComb K of SRS TC Assume =4.

[0109] Referring to FIG. 10, the base station can set the following for each of UE 1 to UE4 based on the Full beam SRS configuration.

[0110] UE 1: S f ={0, 1}, transmission comb offset =0

[0111] UE 2: S f ={2, 3}, transmission comb offset =1

[0112] UE 3: S f ={4, 5}, transmission comb offset =2

[0113] UE 4: S f ={6, 7}, transmission comb offset =3

[0114] In one embodiment, UE 1 to UE4 may transmit Full beam SRS every Periodicity of full beam SRS (T0).

[0115] FIG. 11 illustrates another example of full beam SRS transmission according to one embodiment of the present disclosure.

[0116] Fig. 11 shows an embodiment of full beam SRS transmission, assuming that the number of UEs is 4 (K=4), the number of beams of each UE is 4 (B=4), and the transmissionComb of SRS is K_TC=4.

[0117] Referring to FIG. 11, the base station can set the following for each of UE 1 to UE4 based on the Full beam SRS configuration.

[0118] UE 1: S f ={0, 1, 2, 3}, transmission comb offset =0

[0119] UE 2: S f ={4, 5, 6, 7}, transmission comb offset =1

[0120] UE 3: S f ={8, 9, 10, 11}, transmission comb offset =2

[0121] UE 4: S f ={12, 13, 14, 15}, transmission comb offset =3

[0122] In one embodiment, UE 1 to UE4 may transmit Full beam SRS every Periodicity of full beam SRS (T0).

[0123] FIG. 12 is a diagram for explaining the operation of a UE and a base station for partial beam SRS transmission according to one embodiment of the present disclosure.

[0124] Referring to FIG. 12, in operation 1201, the base station (1220) may transmit a UE beam information request requesting UE beam information to the UE (1210). In operation 1203, the UE (1210) may transmit a beam information report including UE beam information to the base station (1220).

[0125] In operation 1205, the base station (1220) may transmit (or set) a beam SRS configuration for partial beam SRS transmission to the UE (1210) based on the UE beam information. According to one embodiment, the beam SRS configuration may be transmitted via RRC signaling.

[0126] According to one embodiment, the beam SRS configuration may include full beam SRS resource information. According to one embodiment, the full beam SRS resource information may include SRS resource information (S) on which full beam SRS transmission is to be performed. f ) may be included.

[0127] According to one embodiment, the beam SRS configuration may include partial beam SRS resource information. According to one embodiment, the partial beam SRS resource information may include SRS resource information (S) on which partial beam SRS transmission is to be performed. p ) may be included.

[0128] In one embodiment, the partial beam SRS resource may be a subset of the full beam SRS resource (i.e., S p ⊂S f ). According to one embodiment, the partial beam SRS resource information may be expressed as a combination for the full beam SRS resource according to the number of beams (Q) selected.

[0129] In one embodiment, B=4, S f When ={4,5,6,7}, each of Tables 3 to 5 can be configured according to the Q value. According to one embodiment, the base station (1220) transmits a Full beam SRS cycle (T f ) and partial beam SRS period (T P ) can be informed of each. According to one embodiment, (N=number of partial beam SRS transmissions) may be used. According to one embodiment, the base station (1220) may inform the UE (1210) of the full beam SRS slot offset and the partial beam SRS slot offset, respectively.

[0130] [Table 3] When Q=1

[0131]

[0132] [Table 4] When Q=2

[0133]

[0134] [Table 5] When Q=3

[0135]

[0136] In operations 1207, 1209, and 1211, the UE (1210) can perform full beam SRS transmission based on beam SRS configuration information. The UE (1210) can sequentially apply B beams (e.g., F(1), F(2), ..., F(B)) configured based on the beam SRS configuration to SRS resources belonging to transmit full beam SRS.

[0137] In operation 1213, the base station (1220) can determine a partial beam set to be used for partial beam SRS transmission based on the full beam SRS. The base station (1220) can obtain K multi-CSI sets to which the full beam of each UE is applied for K UEs, and determine a beam set P of each UE suitable for MU transmission based on the MU multi-CSI set. The base station (1220) can determine a partial beam set including Q (≤ B) beams among the B beams used for full beam SRS based on the full beam SRS of the UEs. According to an embodiment, various methods can be considered in determining the partial beam set.

[0138] According to one embodiment, to determine the partial beam set, at least one of a method of selecting Q beam combinations of each UE that maximize a sum rate, a method of selecting Q beam combinations of each UE that minimize a condition number, a method of selecting Q beam combinations of each UE that minimize a correlation between UE channels, a method of selecting Q beams with the largest SRS reception strength of each UE, and a method of randomly determining Q beams may be considered.

[0139] In operation 1215, the base station (1220) may transmit a partial beam SRS activation to the UE (1210) so that the UE (1210) initiates partial beam SRS transmission based on the determined partial beam set. According to one embodiment, the base station (1220) may transmit a partial full SRS activation control signal to the UE (1210) including at least one of a selected partial beam set (P), a number of beams (Q), a partial full SRS resource, and repetition information for the selected beams.

[0140] In one embodiment, partial beam SRS activation may be transmitted as a downlink control indicator (DCI) or a MAC control element (MAC-CE). In one embodiment, repetition of the selected beams may be indicated by a repetition factor. For example, when the repetition factor is 2, the UE (1210) may repeatedly transmit each beam included in the partial beam set (P) twice within the same partial beam SRS period.

[0141] In one embodiment, the base station (1220) may inform the UE (1210) of the selected beams through the SRS resource ID transmitted in the full beam SRS. For example, B=4, Q=2, S f={4,5,6,7}, it can be indicated by defining the partial beam set field = Partial beam resource index 2. Referring to Table 4, the UE (1210) can know that the beams used in the full beam SRS resource {4,7} are selected through the partial beam set field = resource pool index 2. The partial beam set field can be determined based on full beam SRS resource information. The full beam SRS resource information can be information included in the beam SRS configuration.

[0142] According to one embodiment, the base station (1220) may inform the UE (1210) of the SRS resources on which the selected beams are transmitted through the SRS resource ID transmitted in the full beam SRS. For example, B=4, Q=2, S f ={4,5,6,7}, it can be indicated by defining the partial beam SRS resource field = Partial beam resource index 5. Referring to Table 4, the UE (1210) can recognize that the selected beams should be transmitted on the {6,7} resource through the partial beam SRS resource field = resource pool index 5. The partial beam SRS resource field can be determined based on full beam SRS resource information. The full beam SRS resource information can be information included in the beam SRS configuration.

[0143] In operations 1217, 1219, and 1221, the UE (1210) may perform partial beam SRS transmission by applying Q beams selected based on partial beam SRS activation information to partial SRS resources. For example, B=4, Q=2, S f When ={4,5,6,7}, partial beam set field = Resource pool index 2, partial beam SRS resource field = Partial beam resource index 5, the UE can transmit SRS by applying the two beams used in {4,7} among the full beam SRS resources to SRS {6,7} resources, respectively.

[0144] In operation 1223, when transmitting a PDSCH signal, the base station (1220) may inform the UE (1210) of Rx beam information to be applied when receiving a scheduled PDSCH based on the Resource pool indexes corresponding to Q=1 of the partial beam SRS resource pool, through DCI. For example, when instructed to receive a PDSCH signal through Resource pool index 3, the UE (1210) may receive the Tx beam used when transmitting the SRS in SRS resource {7} as the Rx beam when receiving the scheduled PDSCH signal. Alternatively, similar to the full beam SRS, the base station (1220) may instruct the UE (1210) of the PDSCH Rx beam through the RCI state.

[0145] FIG. 13 illustrates an example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0146] In Fig. 13, a partial beam SRS transmission method may be used to perform SRS transmission using only some of the beams applied to full beam SRS in order to reduce the overhead of full beam SRS or for repetition transmission to strengthen SRS signal strength.

[0147] Referring to FIG. 13, a UE can transmit a full beam SRS to a base station using all B beams for SRS transmission. The base station can receive the full beam SRS, select a partial beam set based on the full beam SRS, and transmit a partial beam SRS control signal (Partial beam SRS activation) including the partial beam set information to the UE.

[0148] The UE can perform partial beam SRS transmission for Q (≤B) beams based on information included in the partial beam SRS control signal (Partial beam SRS activation).

[0149] The UE has a periodicity (T) of full beam SRS f =NT p , N>1) can perform full beam SRS transmission. The UE can transmit partial beam SRS with Periodicity (T p ) can perform partial beam SRS transmission.

[0150] FIG. 14 illustrates an example of partial beam SRS transmission according to an embodiment of the present disclosure, and FIG. 15 illustrates another example of partial beam SRS transmission according to an embodiment of the present disclosure.

[0151] In Fig. 14 and Fig. 15, the parameters for partial beam SRS transmission are K=4, B=4, Q=2, TransmissinoComb K TC = can be set to 4.

[0152] In FIG. 14 and FIG. 15, parameters for UE 1 to UE 4 for partial beam SRS transmission can be set as follows.

[0153] UE 1: S f ={0, 1, 2, 3}, transmission comb offset =0

[0154] UE 2: S f ={4, 5, 6, 7}, transmission comb offset =1

[0155] UE 3: S f ={8, 9, 10, 11}, transmission comb offset =2

[0156] UE 4: S f ={12, 13, 14, 15}, transmission comb offset =3

[0157] Fig. 14 illustrates an example of repetition for repeatedly transmitting selected beams through partial beam SRS transmission. Referring to Fig. 14, through repetition factor = 2, each UE can repeatedly transmit two selected beams twice each within the same partial beam SRS period. For example, partial beam SRS activation signal information for UE 2 may include Q=2, Partial beam set field = 2 (meaning beam 0 and beam 3 applied to Full beam SRS resource {4,7}), Partial beam SRS resource field = 1, Repetition factor = 2 (repeatedly transmitting the two selected beams 1 and beam 2 in SRS resource {4,6}, respectively).

[0158] Fig. 15 shows an example of reducing SRS overhead compared to full beam SRS through partial beam SRS transmission. Referring to Fig. 15, through repetition factor = 1, each UE can transmit two selected beams once each within the same partial beam SRS period. For example, partial beam SRS activation signal information for UE 2 can include Q = 2, Partial beam set field = 2 (meaning beam 0 and beam 3 applied to full beam SRS resource {4,7}), Partial beam SRS resource field = 5, Repetition factor = 1 (transmit the two selected beams 1 and beam 2 on SRS resource {6,7}, respectively).

[0159] In one embodiment, when K1 UEs newly connected to the network need to transmit full beam SRS while K0 UEs connected to the network are transmitting partial beam SRS, the base station should schedule the UEs only when the number K1 of UEs to be newly scheduled is greater than or equal to a certain value (i.e., K1 > K). th ), aperiodic full beam SRS transmission can be requested to K0 UEs connected to the network, and scheduling and precoder generation can be performed based on the full beam SRS of all K0+K1 UEs. According to one embodiment, the base station can perform scheduling and precoder generation only when the number K1 of UEs to be newly scheduled is greater than or equal to a certain number (i.e., K1>K th ), aperiodic partial beam SRS transmission can be requested to K0 UEs connected to the network, and partial beam SRS transmission can be instructed for beams that were not used in the existing partial beam SRS transmission (i.e., unselected beams). If K1≤K th In this case, the base station can perform scheduling and precoder generation based on the CSI acquired with the full beam SRS of K1 newly connected to the network and the CSI acquired with the partial beam SRS of K1 UEs connected to the network.

[0160] FIG. 16 illustrates another example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0161] Referring to Figure 16, the base station schedules UEs when the number of UEs to be newly scheduled is greater than a certain number (i.e., K1>K). th ), aperiodic full beam SRS transmission can be requested to K0 UEs connected to the network.

[0162] In Fig. 16, K0=2, K1=2, K th =1, B=4, TransmissinoComb K TC =4. Referring to Fig. 16, UE 1 and UE 2 represent UEs that have previously connected to the network, and UE 3 and UE 4 represent UEs that have newly connected to the network. K1>K th Therefore, the base station can transmit an aperiodic full beam SRS trigger control signal to UE 1 and UE 2. According to an embodiment, the aperiodic full beam SRS trigger control signal can be transmitted via DCI or MACE-CE signaling. According to an embodiment, the aperiodic full beam SRS trigger control signal can include at least one of an aperiodic full beam SRS trigger indicator, aperiodic full beam SRS resource information, and an aperiodic full beam SRS slot offset.

[0163] FIG. 17 illustrates another example of partial beam SRS transmission according to one embodiment of the present disclosure.

[0164] Figure 17 shows that when the number of UEs that the base station must newly schedule, K1, is greater than a certain number (i.e., K1>K th ), shows an example of requesting aperiodic partial beam SRS transmission to K0 UEs connected to the network.

[0165] In Fig. 17, K0=2, K1=2, K th =1, B=4, TransmissinoComb K TC=4. Referring to Fig. 17, UE 1 and UE 2 represent previously connected UEs, and UE 3 and UE 4 represent newly connected UEs to the network. K1>K th Therefore, the base station may transmit an aperiodic partial beam SRS trigger control signal to UE 1 and UE 2. According to an embodiment, the aperiodic partial beam SRS trigger control signal may be transmitted as DCI or MACE-CE signaling. According to an embodiment, the aperiodic partial beam SRS trigger control signal may include at least one of an aperiodic partial beam SRS trigger indicator, aperiodic partial beam SRS resource information, and an aperiodic partial beam SRS slot offset.

[0166] The base station can instruct each UE that is not connected to the network to use beams that were not selected for the existing partial beam SRS transmission for aperiodic partial beam SRS transmission. For example, if UE 1 was transmitting the existing partial beam SRS on beam {1, 2}, the base station can instruct UE 1 to perform SRS transmission using beam {0, 4}, which was not selected for the aperiodic partial beam SRS. For example, if UE 2 was transmitting the existing partial beam SRS on beam {0, 3}, the base station can instruct UE 2 to perform SRS transmission using beam {1, 2}, which was not selected for the aperiodic partial beam SRS.

[0167] FIG. 18 is a block diagram illustrating a UE according to embodiments of the present disclosure.

[0168] The UE of FIG. 18 may be implemented as a UE or terminal illustrated in FIGS. 1 to 17. Referring to FIG. 18, the UE may include a transceiver unit (1810), a memory (1820), and a control unit (1830).

[0169] The transceiver (1810) can transmit and receive signals with a base station, network device, or other terminal. The transceiver (1810) may also be referred to as a transceiver. The transceiver (1810) may include a transmitter and a receiver.

[0170] The memory (1820) can store at least one of information transmitted and received through the transceiver (1810) and information generated through the control unit (1830).

[0171] The control unit (1830) may be defined as a circuit or application-specific integrated circuit, or at least one processor. The control unit (1830) may control the overall operation of the UE or terminal according to the embodiments proposed in the present disclosure. For example, the control unit (1830) may control the signal flow between each block to perform operations according to the flowchart described above. Specifically, the control unit (1830) may control the operations of the UE or terminal, for example, as illustrated in FIGS. 1 to 17 .

[0172] According to one embodiment, the control unit (1830) may receive a first message from the base station requesting information about a beam of the UE. According to one embodiment, the control unit (1830) may transmit a second message including information about the beam of the UE to the base station. According to one embodiment, the control unit (1830) may receive first control information from the base station instructing the UE to transmit a sounding reference signal (SRS) using at least one beam among a plurality of beams. According to one embodiment, the control unit (1830) may transmit at least one SRS to the base station using the at least one beam based on the first control information. According to one embodiment, the control unit (1830) may receive from the base station information about at least one beam to be used by the UE when receiving a data signal based on channel information acquired based on the at least one SRS.

[0173] According to one embodiment, the information about the beam of the UE may include at least one of whether the UE supports an analog beam, an analog beam type, the number of analog beams of each analog beam type, the total number of analog beams, and an analog beam switching delay.

[0174] According to one embodiment, the first control information may include at least one of information related to a full beam SRS that sequentially applies a plurality of analog beams of the UE determined by the base station based on information about the beam of the UE to perform SRS transmission, and information related to a partial beam SRS that sequentially applies some analog beams of the UE to perform SRS transmission.

[0175] According to one embodiment, the information related to the full beam SRS may include at least one of SRS resource information for performing SRS transmission by sequentially applying a plurality of analog beams of the UE, an indicator for instructing to sequentially apply a plurality of analog beams of the UE to the SRS resource, mapping information that corresponds each SRS resource to an independent index, a transmission period of the full beam SRS, and slot offset information of the full beam SRS.

[0176] According to one embodiment, the information related to the partial beam SRS may include at least one of SRS resource information for performing SRS transmission by sequentially applying some analog beams of the UE, information about some analog beams to be used for the partial beam SRS transmission, an indicator for instructing to sequentially apply some analog beams of the UE to the SRS resources, a transmission period of the partial beam SRS, slot offset information of the partial beam SRS, and information for instructing repeated transmission within the transmission period of the some analog beams.

[0177] According to one embodiment, the SRS resource information for performing SRS transmission by sequentially applying some analog beams of the UE may be configured as a part of the entire beam SRS resources.

[0178] According to one embodiment, the control unit (1830) may receive scheduling information including index information mapped to each SRS resource from the base station. According to one embodiment, the control unit (1830) may receive the data signal from the base station using a transmission analog beam used in the SRS resource mapped to the scheduling information and the index information.

[0179] FIG. 19 is a block diagram illustrating a base station according to embodiments of the present disclosure.

[0180] The base station of FIG. 19 may be implemented with the base stations, BS eNBs, and gNBs illustrated in FIGS. 1 to 17. Referring to FIG. 19, the base station may include a transceiver unit (1910), a memory (1920), and a control unit (1930).

[0181] The transceiver (1910) can transmit and receive signals with a terminal, another base station, or a network device. The transceiver (1910) may also be referred to as a transceiver. The transceiver (1910) may include a transmitter and a receiver.

[0182] The memory (1920) can store at least one of information transmitted and received through the transceiver (1910) and information generated through the control unit (1930).

[0183] The control unit (1930) may be defined as a circuit, an application-specific integrated circuit, or at least one processor. The control unit (1930) may control the overall operation of the base station according to the embodiment proposed in the present disclosure. For example, the control unit (1930) may control the signal flow between each block to perform operations according to the flowchart described above. Specifically, the control unit (1930) may control the operation of the base station, BS eNB, and gNB, for example, as illustrated in FIGS. 1 to 17 .

[0184] According to one embodiment, the control unit (1930) may transmit a first message requesting information about a beam of a user equipment (UE) to the UE. According to one embodiment, the control unit (1930) may receive a second message including information about the beam of the UE from the UE. According to one embodiment, the control unit (1930) may transmit first control information to the UE, which instructs the UE to transmit a sounding reference signal (SRS) using at least one beam among a plurality of beams. According to one embodiment, the control unit (1930) may receive at least one SRS based on the at least one beam from the UE. According to one embodiment, the control unit (1930) may transmit to the UE information about at least one beam to be used by the UE when receiving a data signal, based on channel information acquired based on the at least one SRS.

[0185] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software. If implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute the methods according to the embodiments described in the claims or specification of the present disclosure.

[0186] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0187] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0188] In the specific embodiments of the present disclosure described above, components included in the invention are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0189] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method of UE (user equipment) in a wireless communication system, An operation of receiving a first message from a base station requesting information about a beam of the UE; An operation of transmitting a second message including information about a beam of the UE to the base station; An operation of receiving first control information from the base station, the first control information instructing the UE to transmit a sounding reference signal (SRS) using at least one beam among a plurality of beams; An operation of transmitting at least one SRS to the base station using at least one beam based on the first control information; and A method characterized by comprising an operation of receiving, from the base station, information about at least one beam to be used when the UE receives a data signal based on channel information acquired based on at least one SRS.

2. In the first paragraph, information about the beam of the UE is: A method characterized by including at least one of whether the UE supports analog beams, an analog beam type, the number of analog beams of each analog beam type, the total number of analog beams, and an analog beam switching delay.

3. In the first paragraph, the first control information is: A method characterized in that it includes at least one of information related to a full beam SRS that sequentially applies a plurality of analog beams of the UE determined by the base station based on information about the beam of the UE to perform SRS transmission, and information related to a partial beam SRS that sequentially applies some analog beams of the UE to perform SRS transmission.

4. In the third paragraph, the information related to the entire beam SRS is: A method characterized in that it includes at least one of the number of multiple analog beams of the UE determined by the base station based on information about the beam of the UE, SRS resource information for performing SRS transmission by sequentially applying the multiple analog beams of the UE, an indicator for instructing to sequentially apply the multiple analog beams of the UE to the SRS resource, mapping information that corresponds each SRS resource to an independent index, a transmission period of the entire beam SRS, and slot offset information of the entire beam SRS.

5. In the third paragraph, information related to the partial beam SRS is: A method characterized in that it includes at least one of SRS resource information for performing SRS transmission by sequentially applying some analog beams of the UE, information on some analog beams to be used for the partial beam SRS transmission, an indicator for instructing to sequentially apply some analog beams of the UE to the SRS resources, a transmission period of the partial beam SRS, slot offset information of the partial beam SRS, and information for instructing repeated transmission within the transmission period of the partial analog beam.

6. In paragraph 5, A method characterized in that the SRS resource information for performing SRS transmission by sequentially applying some analog beams of the UE is configured as a part of the entire beam SRS resources.

7. In paragraph 1, An operation of receiving scheduling information including index information mapped to each SRS resource from the base station; and A method characterized by further comprising an operation of using a transmission analog beam used in an SRS resource mapped to the scheduling information and the index information as a reception analog beam when receiving the data signal from the base station.

8. In a method of a base station in a wireless communication system, An action of transmitting a first message requesting information about a beam of a UE (user equipment) to the UE; An operation of receiving a second message from the UE, the second message including information about a beam of the UE; An operation of transmitting first control information to the UE, the first control information instructing the UE to transmit a sounding reference signal (SRS) using at least one beam among a plurality of beams; An operation of receiving at least one SRS based on at least one beam from the UE; A method characterized by comprising an operation of transmitting to the UE information about at least one beam to be used when the UE receives a data signal based on channel information acquired based on at least one SRS.

9. In paragraph 8, information about the beam of the UE is: A method characterized by including at least one of whether the UE supports analog beams, an analog beam type, the number of analog beams of each analog beam type, the total number of analog beams, and an analog beam switching delay.

10. In paragraph 8, the first control information is: A method characterized in that it includes at least one of information related to a full beam SRS that sequentially applies a plurality of analog beams of the UE determined by the base station based on information about the beam of the UE to perform SRS transmission, and information related to a partial beam SRS that sequentially applies some analog beams of the UE to perform SRS transmission.

11. In paragraph 10, information related to the entire beam SRS is: A method characterized in that it includes at least one of the number of multiple analog beams of the UE determined by the base station based on information about the beam of the UE, SRS resource information for performing SRS transmission by sequentially applying the multiple analog beams of the UE, an indicator for instructing that the multiple analog beams of the UE be sequentially applied to the SRS resource, mapping information that corresponds each SRS resource to an independent index, a transmission period of the entire beam SRS, and slot offset information of the entire beam SRS.

12. In paragraph 10, information related to the partial beam SRS is: A method characterized in that it includes at least one of SRS resource information for performing SRS transmission by sequentially applying some analog beams of the UE, information on some analog beams to be used for the partial beam SRS transmission, an indicator for instructing to sequentially apply some analog beams of the UE to the SRS resources, a transmission period of the partial beam SRS, slot offset information of the partial beam SRS, and information for instructing repeated transmission within the transmission period of the partial analog beam.

13. In paragraph 12, A method characterized in that the SRS resource information for performing SRS transmission by sequentially applying some analog beams of the UE is configured as a part of the entire beam SRS resources.

14. In a wireless communication system, in UE (user equipment), Transmitter and receiver; and comprising a control unit, wherein the control unit is: Receive a first message requesting information about a beam of the UE from the base station, Control to transmit a second message including information about the beam of the UE to the base station, The UE receives first control information from the base station, which instructs the UE to transmit an SRS (sounding reference signal) using at least one beam among a plurality of beams, Controlling to transmit at least one SRS to the base station using at least one beam based on the first control information, A UE characterized in that it receives from the base station information about at least one beam to be used when the UE receives a data signal based on channel information acquired based on at least one SRS.

15. In a base station in a wireless communication system, Transmitter and receiver; and comprising a control unit, wherein the control unit is: Control to transmit a first message requesting information about a beam of the UE (user equipment) to the UE, Receive a second message from the UE that includes information about the beam of the UE, Controlling the UE to transmit first control information instructing the UE to transmit an SRS (sounding reference signal) using at least one beam among a plurality of beams, Receive at least one SRS based on at least one beam from the UE, A base station characterized in that it controls to transmit to the UE information about at least one beam to be used when the UE receives a data signal based on channel information acquired based on at least one SRS.

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